Merge remote-tracking branch 'upstream/master' into fc_1dstream

101 files changed, 4888 insertions, 4058 deletions

diff --git a/src/compiler/csharp_generator.cc b/src/compiler/csharp_generator.cc
index 591e5ae3d4..48157033db 100644
--- a/src/compiler/csharp_generator.cc
+++ b/src/compiler/csharp_generator.cc
@@ -495,6 +495,9 @@ void GenerateClientStub(Printer *out, const ServiceDescriptor *service) {
 
   // override NewInstance method
   out->Print(
+      "/// <summary>Creates a new instance of client from given "
+      "<c>ClientBaseConfiguration</c>.</summary>\n");
+  out->Print(
       "protected override $name$ NewInstance(ClientBaseConfiguration "
       "configuration)\n",
       "name", GetClientClassName(service));
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_config/client_channel.c
index a6056c3e8d..cbf79afa17 100644
--- a/src/core/ext/client_config/client_channel.c
+++ b/src/core/ext/client_config/client_channel.c
@@ -513,10 +513,14 @@ static void retry_waiting_locked(grpc_exec_ctx *exec_ctx, call_data *calld) {
 
 static void subchannel_ready(grpc_exec_ctx *exec_ctx, void *arg,
                              grpc_error *error) {
-  call_data *calld = arg;
+  grpc_call_element *elem = arg;
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
   gpr_mu_lock(&calld->mu);
   GPR_ASSERT(calld->creation_phase ==
              GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL);
+  grpc_polling_entity_del_from_pollset_set(exec_ctx, calld->pollent,
+                                           chand->interested_parties);
   calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
   if (calld->connected_subchannel == NULL) {
     gpr_atm_no_barrier_store(&calld->subchannel_call, 1);
@@ -564,6 +568,9 @@ typedef struct {
   grpc_closure closure;
 } continue_picking_args;
 
+/** Return true if subchannel is available immediately (in which case on_ready
+    should not be called), or false otherwise (in which case on_ready should be
+    called when the subchannel is available). */
 static bool pick_subchannel(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                             grpc_metadata_batch *initial_metadata,
                             uint32_t initial_metadata_flags,
@@ -629,8 +636,8 @@ static bool pick_subchannel(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
     gpr_mu_unlock(&chand->mu);
     // TODO(dgq): make this deadline configurable somehow.
     const grpc_lb_policy_pick_args inputs = {
-        calld->pollent, initial_metadata, initial_metadata_flags,
-        &calld->lb_token_mdelem, gpr_inf_future(GPR_CLOCK_MONOTONIC)};
+        initial_metadata, initial_metadata_flags, &calld->lb_token_mdelem,
+        gpr_inf_future(GPR_CLOCK_MONOTONIC)};
     r = grpc_lb_policy_pick(exec_ctx, lb_policy, &inputs, connected_subchannel,
                             NULL, on_ready);
     GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "pick_subchannel");
@@ -672,6 +679,7 @@ static void cc_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
                                          grpc_call_element *elem,
                                          grpc_transport_stream_op *op) {
   call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
   grpc_deadline_state_client_start_transport_stream_op(exec_ctx, elem, op);
   /* try to (atomically) get the call */
@@ -739,14 +747,20 @@ retry:
       calld->connected_subchannel == NULL &&
       op->send_initial_metadata != NULL) {
     calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL;
-    grpc_closure_init(&calld->next_step, subchannel_ready, calld);
+    grpc_closure_init(&calld->next_step, subchannel_ready, elem);
     GRPC_CALL_STACK_REF(calld->owning_call, "pick_subchannel");
+    /* If a subchannel is not available immediately, the polling entity from
+       call_data should be provided to channel_data's interested_parties, so
+       that IO of the lb_policy and resolver could be done under it. */
     if (pick_subchannel(exec_ctx, elem, op->send_initial_metadata,
                         op->send_initial_metadata_flags,
                         &calld->connected_subchannel, &calld->next_step,
                         GRPC_ERROR_NONE)) {
       calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
       GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_subchannel");
+    } else {
+      grpc_polling_entity_add_to_pollset_set(exec_ctx, calld->pollent,
+                                             chand->interested_parties);
     }
   }
   /* if we've got a subchannel, then let's ask it to create a call */
diff --git a/src/core/ext/client_config/lb_policy.h b/src/core/ext/client_config/lb_policy.h
index 110d08fcac..de424cd105 100644
--- a/src/core/ext/client_config/lb_policy.h
+++ b/src/core/ext/client_config/lb_policy.h
@@ -35,7 +35,6 @@
 #define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
 
 #include "src/core/ext/client_config/subchannel.h"
-#include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /** A load balancing policy: specified by a vtable and a struct (which
@@ -55,8 +54,6 @@ struct grpc_lb_policy {
 
 /** Extra arguments for an LB pick */
 typedef struct grpc_lb_policy_pick_args {
-  /** Parties interested in the pick's progress */
-  grpc_polling_entity *pollent;
   /** Initial metadata associated with the picking call. */
   grpc_metadata_batch *initial_metadata;
   /** Bitmask used for selective cancelling. See \a
@@ -153,7 +150,8 @@ void grpc_lb_policy_init(grpc_lb_policy *policy,
     once the pick is complete with its error argument set to indicate
     success or failure.
 
-    Any I/O should be done under \a pick_args->pollent. */
+    Any IO should be done under the \a interested_parties \a grpc_pollset_set
+    in the \a grpc_lb_policy struct. */
 int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                         const grpc_lb_policy_pick_args *pick_args,
                         grpc_connected_subchannel **target, void **user_data,
diff --git a/src/core/ext/client_config/subchannel.c b/src/core/ext/client_config/subchannel.c
index 0bbaa3e382..4cece2d908 100644
--- a/src/core/ext/client_config/subchannel.c
+++ b/src/core/ext/client_config/subchannel.c
@@ -220,8 +220,8 @@ static gpr_atm ref_mutate(grpc_subchannel *c, gpr_atm delta,
                             : gpr_atm_no_barrier_fetch_add(&c->ref_pair, delta);
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
-          "SUBCHANNEL: %p %12s 0x%08d -> 0x%08d [%s]", c, purpose, (int)old_val,
-          (int)(old_val + delta), reason);
+          "SUBCHANNEL: %p %s 0x%08" PRIxPTR " -> 0x%08" PRIxPTR " [%s]", c,
+          purpose, old_val, old_val + delta, reason);
 #endif
   return old_val;
 }
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index 626f285b90..9af92b787d 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -69,8 +69,8 @@
  * possible scenarios:
  *
  * 1. This is the first server list received. There was no previous instance of
- *    the Round Robin policy. \a rr_handover() will instantiate the RR policy
- *    and perform all the pending operations over it.
+ *    the Round Robin policy. \a rr_handover_locked() will instantiate the RR
+ *    policy and perform all the pending operations over it.
  * 2. There's already a RR policy instance active. We need to introduce the new
  *    one build from the new serverlist, but taking care not to disrupt the
  *    operations in progress over the old RR instance. This is done by
@@ -78,7 +78,7 @@
  *    references are held on the old RR policy, it'll be destroyed and \a
  *    glb_rr_connectivity_changed notified with a \a GRPC_CHANNEL_SHUTDOWN
  *    state. At this point we can transition to a new RR instance safely, which
- *    is done once again via \a rr_handover().
+ *    is done once again via \a rr_handover_locked().
  *
  *
  * Once a RR policy instance is in place (and getting updated as described),
@@ -86,8 +86,8 @@
  * forwarding them to the RR instance. Any time there's no RR policy available
  * (ie, right after the creation of the gRPCLB policy, if an empty serverlist
  * is received, etc), pick/ping requests are added to a list of pending
- * picks/pings to be flushed and serviced as part of \a rr_handover() the moment
- * the RR policy instance becomes available.
+ * picks/pings to be flushed and serviced as part of \a rr_handover_locked() the
+ * moment the RR policy instance becomes available.
  *
  * \see https://github.com/grpc/grpc/blob/master/doc/load-balancing.md for the
  * high level design and details. */
@@ -134,6 +134,9 @@ static void initial_metadata_add_lb_token(
 }
 
 typedef struct wrapped_rr_closure_arg {
+  /* the closure instance using this struct as argument */
+  grpc_closure wrapper_closure;
+
   /* the original closure. Usually a on_complete/notify cb for pick() and ping()
    * calls against the internal RR instance, respectively. */
   grpc_closure *wrapped_closure;
@@ -155,9 +158,8 @@ typedef struct wrapped_rr_closure_arg {
   /* The RR instance related to the closure */
   grpc_lb_policy *rr_policy;
 
-  /* when not NULL, represents a pending_{pick,ping} node to be freed upon
-   * closure execution */
-  void *owning_pending_node; /* to be freed if not NULL */
+  /* heap memory to be freed upon closure execution. */
+  void *free_when_done;
 } wrapped_rr_closure_arg;
 
 /* The \a on_complete closure passed as part of the pick requires keeping a
@@ -183,10 +185,10 @@ static void wrapped_rr_closure(grpc_exec_ctx *exec_ctx, void *arg,
     }
   }
   GPR_ASSERT(wc_arg->wrapped_closure != NULL);
-
   grpc_exec_ctx_sched(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_REF(error),
                       NULL);
-  gpr_free(wc_arg->owning_pending_node);
+  GPR_ASSERT(wc_arg->free_when_done != NULL);
+  gpr_free(wc_arg->free_when_done);
 }
 
 /* Linked list of pending pick requests. It stores all information needed to
@@ -207,10 +209,6 @@ typedef struct pending_pick {
    * upon error. */
   grpc_connected_subchannel **target;
 
-  /* a closure wrapping the original on_complete one to be invoked once the
-   * pick() has completed (regardless of success) */
-  grpc_closure wrapped_on_complete;
-
   /* args for wrapped_on_complete */
   wrapped_rr_closure_arg wrapped_on_complete_arg;
 } pending_pick;
@@ -230,8 +228,9 @@ static void add_pending_pick(pending_pick **root,
   pp->wrapped_on_complete_arg.initial_metadata = pick_args->initial_metadata;
   pp->wrapped_on_complete_arg.lb_token_mdelem_storage =
       pick_args->lb_token_mdelem_storage;
-  grpc_closure_init(&pp->wrapped_on_complete, wrapped_rr_closure,
-                    &pp->wrapped_on_complete_arg);
+  pp->wrapped_on_complete_arg.free_when_done = pp;
+  grpc_closure_init(&pp->wrapped_on_complete_arg.wrapper_closure,
+                    wrapped_rr_closure, &pp->wrapped_on_complete_arg);
   *root = pp;
 }
 
@@ -239,10 +238,6 @@ static void add_pending_pick(pending_pick **root,
 typedef struct pending_ping {
   struct pending_ping *next;
 
-  /* a closure wrapping the original on_complete one to be invoked once the
-   * ping() has completed (regardless of success) */
-  grpc_closure wrapped_notify;
-
   /* args for wrapped_notify */
   wrapped_rr_closure_arg wrapped_notify_arg;
 } pending_ping;
@@ -251,10 +246,11 @@ static void add_pending_ping(pending_ping **root, grpc_closure *notify) {
   pending_ping *pping = gpr_malloc(sizeof(*pping));
   memset(pping, 0, sizeof(pending_ping));
   memset(&pping->wrapped_notify_arg, 0, sizeof(wrapped_rr_closure_arg));
-  pping->next = *root;
-  grpc_closure_init(&pping->wrapped_notify, wrapped_rr_closure,
-                    &pping->wrapped_notify_arg);
   pping->wrapped_notify_arg.wrapped_closure = notify;
+  pping->wrapped_notify_arg.free_when_done = pping;
+  pping->next = *root;
+  grpc_closure_init(&pping->wrapped_notify_arg.wrapper_closure,
+                    wrapped_rr_closure, &pping->wrapped_notify_arg);
   *root = pping;
 }
 
@@ -307,13 +303,6 @@ typedef struct glb_lb_policy {
 
   /** for tracking of the RR connectivity */
   rr_connectivity_data *rr_connectivity;
-
-  /* a wrapped (see \a wrapped_rr_closure) on-complete closure for readily
-   * available RR picks */
-  grpc_closure wrapped_on_complete;
-
-  /* arguments for the wrapped_on_complete closure */
-  wrapped_rr_closure_arg wc_arg;
 } glb_lb_policy;
 
 /* Keeps track and reacts to changes in connectivity of the RR instance */
@@ -399,14 +388,14 @@ static grpc_lb_addresses *process_serverlist(
           GPR_ARRAY_SIZE(server->load_balance_token) - 1;
       grpc_mdstr *lb_token_mdstr = grpc_mdstr_from_buffer(
           (uint8_t *)server->load_balance_token, lb_token_size);
-      user_data = grpc_mdelem_from_metadata_strings(
-          GRPC_MDSTR_LOAD_REPORTING_INITIAL, lb_token_mdstr);
+      user_data = grpc_mdelem_from_metadata_strings(GRPC_MDSTR_LB_TOKEN,
+                                                    lb_token_mdstr);
     } else {
       gpr_log(GPR_ERROR,
               "Missing LB token for backend address '%s'. The empty token will "
               "be used instead",
               grpc_sockaddr_to_uri((struct sockaddr *)&addr.addr));
-      user_data = GRPC_MDELEM_LOAD_REPORTING_INITIAL_EMPTY;
+      user_data = GRPC_MDELEM_LB_TOKEN_EMPTY;
     }
 
     grpc_lb_addresses_set_address(lb_addresses, addr_idx, &addr.addr, addr.len,
@@ -424,9 +413,43 @@ static void lb_token_destroy(void *token) {
   if (token != NULL) GRPC_MDELEM_UNREF(token);
 }
 
-static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
-                                 const grpc_grpclb_serverlist *serverlist,
-                                 glb_lb_policy *glb_policy) {
+/* perform a pick over \a rr_policy. Given that a pick can return immediately
+ * (ignoring its completion callback) we need to perform the cleanups this
+ * callback would be otherwise resposible for */
+static bool pick_from_internal_rr_locked(
+    grpc_exec_ctx *exec_ctx, grpc_lb_policy *rr_policy,
+    const grpc_lb_policy_pick_args *pick_args,
+    grpc_connected_subchannel **target, wrapped_rr_closure_arg *wc_arg) {
+  GPR_ASSERT(rr_policy != NULL);
+  const bool pick_done =
+      grpc_lb_policy_pick(exec_ctx, rr_policy, pick_args, target,
+                          (void **)&wc_arg->lb_token, &wc_arg->wrapper_closure);
+  if (pick_done) {
+    /* synchronous grpc_lb_policy_pick call. Unref the RR policy. */
+    if (grpc_lb_glb_trace) {
+      gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")",
+              (intptr_t)wc_arg->rr_policy);
+    }
+    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick");
+
+    /* add the load reporting initial metadata */
+    initial_metadata_add_lb_token(pick_args->initial_metadata,
+                                  pick_args->lb_token_mdelem_storage,
+                                  GRPC_MDELEM_REF(wc_arg->lb_token));
+
+    gpr_free(wc_arg);
+  }
+  /* else, the pending pick will be registered and taken care of by the
+   * pending pick list inside the RR policy (glb_policy->rr_policy).
+   * Eventually, wrapped_on_complete will be called, which will -among other
+   * things- add the LB token to the call's initial metadata */
+
+  return pick_done;
+}
+
+static grpc_lb_policy *create_rr_locked(
+    grpc_exec_ctx *exec_ctx, const grpc_grpclb_serverlist *serverlist,
+    glb_lb_policy *glb_policy) {
   GPR_ASSERT(serverlist != NULL && serverlist->num_servers > 0);
 
   grpc_lb_policy_args args;
@@ -446,18 +469,21 @@ static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
   return rr;
 }
 
-static void rr_handover(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
-                        grpc_error *error) {
+static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
+                               glb_lb_policy *glb_policy, grpc_error *error) {
   GPR_ASSERT(glb_policy->serverlist != NULL &&
              glb_policy->serverlist->num_servers > 0);
   glb_policy->rr_policy =
-      create_rr(exec_ctx, glb_policy->serverlist, glb_policy);
+      create_rr_locked(exec_ctx, glb_policy->serverlist, glb_policy);
 
   if (grpc_lb_glb_trace) {
     gpr_log(GPR_INFO, "Created RR policy (0x%" PRIxPTR ")",
             (intptr_t)glb_policy->rr_policy);
   }
   GPR_ASSERT(glb_policy->rr_policy != NULL);
+  grpc_pollset_set_add_pollset_set(exec_ctx,
+                                   glb_policy->rr_policy->interested_parties,
+                                   glb_policy->base.interested_parties);
   glb_policy->rr_connectivity->state = grpc_lb_policy_check_connectivity(
       exec_ctx, glb_policy->rr_policy, &error);
   grpc_lb_policy_notify_on_state_change(
@@ -478,11 +504,9 @@ static void rr_handover(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
       gpr_log(GPR_INFO, "Pending pick about to PICK from 0x%" PRIxPTR "",
               (intptr_t)glb_policy->rr_policy);
     }
-    grpc_lb_policy_pick(exec_ctx, glb_policy->rr_policy, &pp->pick_args,
-                        pp->target,
-                        (void **)&pp->wrapped_on_complete_arg.lb_token,
-                        &pp->wrapped_on_complete);
-    pp->wrapped_on_complete_arg.owning_pending_node = pp;
+    pick_from_internal_rr_locked(exec_ctx, glb_policy->rr_policy,
+                                 &pp->pick_args, pp->target,
+                                 &pp->wrapped_on_complete_arg);
   }
 
   pending_ping *pping;
@@ -495,8 +519,7 @@ static void rr_handover(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
               (intptr_t)glb_policy->rr_policy);
     }
     grpc_lb_policy_ping_one(exec_ctx, glb_policy->rr_policy,
-                            &pping->wrapped_notify);
-    pping->wrapped_notify_arg.owning_pending_node = pping;
+                            &pping->wrapped_notify_arg.wrapper_closure);
   }
 }
 
@@ -509,13 +532,16 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
     if (glb_policy->serverlist != NULL) {
       /* a RR policy is shutting down but there's a serverlist available ->
        * perform a handover */
-      rr_handover(exec_ctx, glb_policy, error);
+      gpr_mu_lock(&glb_policy->mu);
+      rr_handover_locked(exec_ctx, glb_policy, error);
+      gpr_mu_unlock(&glb_policy->mu);
     } else {
       /* shutting down and no new serverlist available. Bail out. */
       gpr_free(rr_conn_data);
     }
   } else {
     if (error == GRPC_ERROR_NONE) {
+      gpr_mu_lock(&glb_policy->mu);
       /* RR not shutting down. Mimic the RR's policy state */
       grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker,
                                   rr_conn_data->state, GRPC_ERROR_REF(error),
@@ -524,6 +550,7 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
       grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy,
                                             &rr_conn_data->state,
                                             &rr_conn_data->on_change);
+      gpr_mu_unlock(&glb_policy->mu);
     } else { /* error */
       gpr_free(rr_conn_data);
     }
@@ -648,15 +675,15 @@ static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
-    grpc_exec_ctx_sched(exec_ctx, &pp->wrapped_on_complete, GRPC_ERROR_NONE,
-                        NULL);
+    grpc_exec_ctx_sched(exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
+                        GRPC_ERROR_NONE, NULL);
     pp = next;
   }
 
   while (pping != NULL) {
     pending_ping *next = pping->next;
-    grpc_exec_ctx_sched(exec_ctx, &pping->wrapped_notify, GRPC_ERROR_NONE,
-                        NULL);
+    grpc_exec_ctx_sched(exec_ctx, &pping->wrapped_notify_arg.wrapper_closure,
+                        GRPC_ERROR_NONE, NULL);
     pping = next;
   }
 
@@ -686,11 +713,9 @@ static void glb_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_polling_entity_del_from_pollset_set(
-          exec_ctx, pp->pick_args.pollent, glb_policy->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_sched(
-          exec_ctx, &pp->wrapped_on_complete,
+          exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
           GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1), NULL);
     } else {
       pp->next = glb_policy->pending_picks;
@@ -719,10 +744,8 @@ static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->pick_args.initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_polling_entity_del_from_pollset_set(
-          exec_ctx, pp->pick_args.pollent, glb_policy->base.interested_parties);
       grpc_exec_ctx_sched(
-          exec_ctx, &pp->wrapped_on_complete,
+          exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure,
           GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1), NULL);
     } else {
       pp->next = glb_policy->pending_picks;
@@ -775,39 +798,20 @@ static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
               (intptr_t)glb_policy->rr_policy);
     }
     GRPC_LB_POLICY_REF(glb_policy->rr_policy, "glb_pick");
-    memset(&glb_policy->wc_arg, 0, sizeof(wrapped_rr_closure_arg));
-    glb_policy->wc_arg.rr_policy = glb_policy->rr_policy;
-    glb_policy->wc_arg.target = target;
-    glb_policy->wc_arg.wrapped_closure = on_complete;
-    glb_policy->wc_arg.lb_token_mdelem_storage =
-        pick_args->lb_token_mdelem_storage;
-    glb_policy->wc_arg.initial_metadata = pick_args->initial_metadata;
-    glb_policy->wc_arg.owning_pending_node = NULL;
-    grpc_closure_init(&glb_policy->wrapped_on_complete, wrapped_rr_closure,
-                      &glb_policy->wc_arg);
-
-    pick_done =
-        grpc_lb_policy_pick(exec_ctx, glb_policy->rr_policy, pick_args, target,
-                            (void **)&glb_policy->wc_arg.lb_token,
-                            &glb_policy->wrapped_on_complete);
-    if (pick_done) {
-      /* synchronous grpc_lb_policy_pick call. Unref the RR policy. */
-      if (grpc_lb_glb_trace) {
-        gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")",
-                (intptr_t)glb_policy->wc_arg.rr_policy);
-      }
-      GRPC_LB_POLICY_UNREF(exec_ctx, glb_policy->wc_arg.rr_policy, "glb_pick");
 
-      /* add the load reporting initial metadata */
-      initial_metadata_add_lb_token(
-          pick_args->initial_metadata, pick_args->lb_token_mdelem_storage,
-          GRPC_MDELEM_REF(glb_policy->wc_arg.lb_token));
-    }
+    wrapped_rr_closure_arg *wc_arg = gpr_malloc(sizeof(wrapped_rr_closure_arg));
+    memset(wc_arg, 0, sizeof(wrapped_rr_closure_arg));
+
+    grpc_closure_init(&wc_arg->wrapper_closure, wrapped_rr_closure, wc_arg);
+    wc_arg->rr_policy = glb_policy->rr_policy;
+    wc_arg->target = target;
+    wc_arg->wrapped_closure = on_complete;
+    wc_arg->lb_token_mdelem_storage = pick_args->lb_token_mdelem_storage;
+    wc_arg->initial_metadata = pick_args->initial_metadata;
+    wc_arg->free_when_done = wc_arg;
+    pick_done = pick_from_internal_rr_locked(exec_ctx, glb_policy->rr_policy,
+                                             pick_args, target, wc_arg);
   } else {
-    /* else, the pending pick will be registered and taken care of by the
-     * pending pick list inside the RR policy (glb_policy->rr_policy) */
-    grpc_polling_entity_add_to_pollset_set(exec_ctx, pick_args->pollent,
-                                           glb_policy->base.interested_parties);
     add_pending_pick(&glb_policy->pending_picks, pick_args, target,
                      on_complete);
 
@@ -931,7 +935,7 @@ static lb_client_data *lb_client_data_create(glb_lb_policy *glb_policy) {
 
   /* Note the following LB call progresses every time there's activity in \a
    * glb_policy->base.interested_parties, which is comprised of the polling
-   * entities passed to glb_pick(). */
+   * entities from \a client_channel. */
   lb_client->lb_call = grpc_channel_create_pollset_set_call(
       glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
       glb_policy->base.interested_parties,
@@ -1076,6 +1080,7 @@ static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
 
       /* update serverlist */
       if (serverlist->num_servers > 0) {
+        gpr_mu_lock(&lb_client->glb_policy->mu);
         if (grpc_grpclb_serverlist_equals(lb_client->glb_policy->serverlist,
                                           serverlist)) {
           if (grpc_lb_glb_trace) {
@@ -1093,7 +1098,7 @@ static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
         if (lb_client->glb_policy->rr_policy == NULL) {
           /* initial "handover", in this case from a null RR policy, meaning
            * it'll just create the first RR policy instance */
-          rr_handover(exec_ctx, lb_client->glb_policy, error);
+          rr_handover_locked(exec_ctx, lb_client->glb_policy, error);
         } else {
           /* unref the RR policy, eventually leading to its substitution with a
            * new one constructed from the received serverlist (see
@@ -1101,6 +1106,7 @@ static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
           GRPC_LB_POLICY_UNREF(exec_ctx, lb_client->glb_policy->rr_policy,
                                "serverlist_received");
         }
+        gpr_mu_unlock(&lb_client->glb_policy->mu);
       } else {
         if (grpc_lb_glb_trace) {
           gpr_log(GPR_INFO,
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 961a0c9b19..6533327343 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -39,7 +39,6 @@
 
 typedef struct pending_pick {
   struct pending_pick *next;
-  grpc_polling_entity *pollent;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -119,8 +118,6 @@ static void pf_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
-    grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                             p->base.interested_parties);
     grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
     gpr_free(pp);
     pp = next;
@@ -138,8 +135,6 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_sched(
           exec_ctx, pp->on_complete,
@@ -168,8 +163,6 @@ static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                               p->base.interested_parties);
       grpc_exec_ctx_sched(
           exec_ctx, pp->on_complete,
           GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1), NULL);
@@ -229,11 +222,8 @@ static int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_polling_entity_add_to_pollset_set(exec_ctx, pick_args->pollent,
-                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollent = pick_args->pollent;
     pp->target = target;
     pp->initial_metadata_flags = pick_args->initial_metadata_flags;
     pp->on_complete = on_complete;
@@ -319,8 +309,6 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
           *pp->target = selected;
-          grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                                   p->base.interested_parties);
           grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
           gpr_free(pp);
         }
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index 930fa86aca..9bd3f9da24 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -78,9 +78,6 @@ int grpc_lb_round_robin_trace = 0;
 typedef struct pending_pick {
   struct pending_pick *next;
 
-  /* polling entity for the pick()'s async notification */
-  grpc_polling_entity *pollent;
-
   /* output argument where to store the pick()ed user_data. It'll be NULL if no
    * such data is present or there's an error (the definite test for errors is
    * \a target being NULL). */
@@ -318,8 +315,6 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                               p->base.interested_parties);
       *target = NULL;
       grpc_exec_ctx_sched(
           exec_ctx, pp->on_complete,
@@ -348,8 +343,6 @@ static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                               p->base.interested_parties);
       *pp->target = NULL;
       grpc_exec_ctx_sched(
           exec_ctx, pp->on_complete,
@@ -403,7 +396,6 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_lock(&p->mu);
   if ((selected = peek_next_connected_locked(p))) {
     /* readily available, report right away */
-    gpr_mu_unlock(&p->mu);
     *target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
 
     if (user_data != NULL) {
@@ -416,17 +408,15 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     }
     /* only advance the last picked pointer if the selection was used */
     advance_last_picked_locked(p);
+    gpr_mu_unlock(&p->mu);
     return 1;
   } else {
     /* no pick currently available. Save for later in list of pending picks */
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_polling_entity_add_to_pollset_set(exec_ctx, pick_args->pollent,
-                                           p->base.interested_parties);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollent = pick_args->pollent;
     pp->target = target;
     pp->on_complete = on_complete;
     pp->initial_metadata_flags = pick_args->initial_metadata_flags;
@@ -482,8 +472,6 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                     "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
                     (void *)selected->subchannel, (void *)selected);
           }
-          grpc_polling_entity_del_from_pollset_set(exec_ctx, pp->pollent,
-                                                   p->base.interested_parties);
           grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
           gpr_free(pp);
         }
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/load_reporting/load_reporting.h
index e37817d8c2..e13097654d 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/load_reporting/load_reporting.h
@@ -37,13 +37,21 @@
 #include <grpc/impl/codegen/grpc_types.h>
 #include "src/core/lib/channel/channel_stack.h"
 
-/** Metadata key for initial metadata coming from clients */
-/* TODO(dgq): change to the final value TBD */
-#define GRPC_LOAD_REPORTING_INITIAL_MD_KEY "load-reporting-initial"
+/** Metadata key for the gRPC LB load balancer token.
+ *
+ * The value corresponding to this key is an opaque token that is given to the
+ * frontend as part of each pick; the frontend sends this token to the backend
+ * in each request it sends when using that pick. The token is used by the
+ * backend to verify the request and to allow the backend to report load to the
+ * gRPC LB system. */
+#define GRPC_LB_TOKEN_MD_KEY "lb-token"
 
-/** Metadata key for trailing metadata from servers */
-/* TODO(dgq): change to the final value TBD */
-#define GRPC_LOAD_REPORTING_TRAILING_MD_KEY "load-reporting-trailing"
+/** Metadata key for gRPC LB cost reporting.
+ *
+ * The value corresponding to this key is an opaque binary blob reported by the
+ * backend as part of its trailing metadata containing cost information for the
+ * call. */
+#define GRPC_LB_COST_MD_KEY "lb-cost"
 
 /** Identifiers for the invocation point of the users LR callback */
 typedef enum grpc_load_reporting_source {
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 394f0cb832..22bf36367f 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -75,7 +75,7 @@ static grpc_mdelem *recv_md_filter(void *user_data, grpc_mdelem *md) {
 
   if (md->key == GRPC_MDSTR_PATH) {
     calld->service_method = grpc_mdstr_as_c_string(md->value);
-  } else if (md->key == GRPC_MDSTR_LOAD_REPORTING_INITIAL) {
+  } else if (md->key == GRPC_MDSTR_LB_TOKEN) {
     calld->initial_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
     return NULL;
   }
@@ -193,7 +193,7 @@ static grpc_mdelem *lr_trailing_md_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
 
-  if (md->key == GRPC_MDSTR_LOAD_REPORTING_TRAILING) {
+  if (md->key == GRPC_MDSTR_LB_COST) {
     calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
     return NULL;
   }
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
index 7d5279b9da..bd87253ed3 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
@@ -36,14 +36,11 @@
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/metadata.h"
 
-extern int grpc_http_write_state_trace;
-
 void grpc_chttp2_plugin_init(void) {
   grpc_chttp2_base64_encode_and_huffman_compress =
       grpc_chttp2_base64_encode_and_huffman_compress_impl;
   grpc_register_tracer("http", &grpc_http_trace);
   grpc_register_tracer("flowctl", &grpc_flowctl_trace);
-  grpc_register_tracer("http_write_state", &grpc_http_write_state_trace);
 }
 
 void grpc_chttp2_plugin_shutdown(void) {}
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 1dd7fef76f..97780d90f2 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -65,91 +65,59 @@
 #define MAX_CLIENT_STREAM_ID 0x7fffffffu
 int grpc_http_trace = 0;
 int grpc_flowctl_trace = 0;
-int grpc_http_write_state_trace = 0;
-
-#define TRANSPORT_FROM_WRITING(tw)                                        \
-  ((grpc_chttp2_transport *)((char *)(tw)-offsetof(grpc_chttp2_transport, \
-                                                   writing)))
-
-#define TRANSPORT_FROM_PARSING(tp)                                        \
-  ((grpc_chttp2_transport *)((char *)(tp)-offsetof(grpc_chttp2_transport, \
-                                                   parsing)))
-
-#define TRANSPORT_FROM_GLOBAL(tg)                                         \
-  ((grpc_chttp2_transport *)((char *)(tg)-offsetof(grpc_chttp2_transport, \
-                                                   global)))
-
-#define STREAM_FROM_GLOBAL(sg) \
-  ((grpc_chttp2_stream *)((char *)(sg)-offsetof(grpc_chttp2_stream, global)))
-
-#define STREAM_FROM_PARSING(sg) \
-  ((grpc_chttp2_stream *)((char *)(sg)-offsetof(grpc_chttp2_stream, parsing)))
 
 static const grpc_transport_vtable vtable;
 
 /* forward declarations of various callbacks that we'll build closures around */
-static void writing_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
-static void reading_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
-static void parsing_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
-static void reading_action_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                  grpc_error *error);
-static void post_parse_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error);
-static void initiate_writing_locked(grpc_exec_ctx *exec_ctx, void *t,
+static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *t,
+                                      grpc_error *error);
+static void write_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
+static void write_action_end(grpc_exec_ctx *exec_ctx, void *t,
+                             grpc_error *error);
+static void write_action_end_locked(grpc_exec_ctx *exec_ctx, void *t,
                                     grpc_error *error);
-static void initiate_read_flush_locked(grpc_exec_ctx *exec_ctx, void *t,
-                                       grpc_error *error);
-static void terminate_writing_with_lock(grpc_exec_ctx *exec_ctx, void *t,
-                                        grpc_error *error);
 
-static void start_writing(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t);
-static void end_waiting_for_write(grpc_exec_ctx *exec_ctx,
-                                  grpc_chttp2_transport *t, grpc_error *error);
+static void read_action_begin(grpc_exec_ctx *exec_ctx, void *t,
+                              grpc_error *error);
+static void read_action_locked(grpc_exec_ctx *exec_ctx, void *t,
+                               grpc_error *error);
 
+static void complete_fetch_locked(grpc_exec_ctx *exec_ctx, void *gs,
+                                  grpc_error *error);
+static void complete_fetch(grpc_exec_ctx *exec_ctx, void *gs,
+                           grpc_error *error);
 /** Set a transport level setting, and push it to our peer */
 static void push_setting(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_chttp2_setting_id id, uint32_t value);
 
-/** Start disconnection chain */
-static void drop_connection(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                            grpc_error *error);
-
-/** Cancel a stream: coming from the transport API */
-static void cancel_from_api(grpc_exec_ctx *exec_ctx,
-                            grpc_chttp2_transport_global *transport_global,
-                            grpc_chttp2_stream_global *stream_global,
-                            grpc_error *error);
-
-static void close_from_api(grpc_exec_ctx *exec_ctx,
-                           grpc_chttp2_transport_global *transport_global,
-                           grpc_chttp2_stream_global *stream_global,
-                           grpc_error *error);
+static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                           grpc_chttp2_stream *s, grpc_error *error);
 
 /** Start new streams that have been created if we can */
-static void maybe_start_some_streams(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global);
-
-static void connectivity_state_set(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_connectivity_state state, grpc_error *error, const char *reason);
+static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t);
 
-static void check_read_ops(grpc_exec_ctx *exec_ctx,
-                           grpc_chttp2_transport_global *transport_global);
-
-static void incoming_byte_stream_update_flow_control(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, size_t max_size_hint,
-    size_t have_already);
+static void connectivity_state_set(grpc_exec_ctx *exec_ctx,
+                                   grpc_chttp2_transport *t,
+                                   grpc_connectivity_state state,
+                                   grpc_error *error, const char *reason);
+
+static void incoming_byte_stream_update_flow_control(grpc_exec_ctx *exec_ctx,
+                                                     grpc_chttp2_transport *t,
+                                                     grpc_chttp2_stream *s,
+                                                     size_t max_size_hint,
+                                                     size_t have_already);
 static void incoming_byte_stream_destroy_locked(grpc_exec_ctx *exec_ctx,
                                                 void *byte_stream,
                                                 grpc_error *error_ignored);
 static void fail_pending_writes(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport_global *transport_global,
-                                grpc_chttp2_stream_global *stream_global,
+                                grpc_chttp2_transport *t, grpc_chttp2_stream *s,
                                 grpc_error *error);
 
-static void set_write_state(grpc_chttp2_transport *t,
-                            grpc_chttp2_write_state state, const char *reason);
+static void close_transport_locked(grpc_exec_ctx *exec_ctx,
+                                   grpc_chttp2_transport *t, grpc_error *error);
+static void end_all_the_calls(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                              grpc_error *error);
 
 /*******************************************************************************
  * CONSTRUCTION/DESTRUCTION/REFCOUNTING
@@ -161,34 +129,31 @@ static void destruct_transport(grpc_exec_ctx *exec_ctx,
 
   grpc_endpoint_destroy(exec_ctx, t->ep);
 
-  gpr_slice_buffer_destroy(&t->global.qbuf);
+  gpr_slice_buffer_destroy(&t->qbuf);
 
-  gpr_slice_buffer_destroy(&t->writing.outbuf);
-  grpc_chttp2_hpack_compressor_destroy(&t->writing.hpack_compressor);
+  gpr_slice_buffer_destroy(&t->outbuf);
+  grpc_chttp2_hpack_compressor_destroy(&t->hpack_compressor);
 
-  gpr_slice_buffer_destroy(&t->parsing.qbuf);
   gpr_slice_buffer_destroy(&t->read_buffer);
-  grpc_chttp2_hpack_parser_destroy(&t->parsing.hpack_parser);
-  grpc_chttp2_goaway_parser_destroy(&t->parsing.goaway_parser);
+  grpc_chttp2_hpack_parser_destroy(&t->hpack_parser);
+  grpc_chttp2_goaway_parser_destroy(&t->goaway_parser);
 
   for (i = 0; i < STREAM_LIST_COUNT; i++) {
     GPR_ASSERT(t->lists[i].head == NULL);
     GPR_ASSERT(t->lists[i].tail == NULL);
   }
 
-  GPR_ASSERT(grpc_chttp2_stream_map_size(&t->parsing_stream_map) == 0);
-  GPR_ASSERT(grpc_chttp2_stream_map_size(&t->new_stream_map) == 0);
+  GPR_ASSERT(grpc_chttp2_stream_map_size(&t->stream_map) == 0);
 
-  grpc_chttp2_stream_map_destroy(&t->parsing_stream_map);
-  grpc_chttp2_stream_map_destroy(&t->new_stream_map);
+  grpc_chttp2_stream_map_destroy(&t->stream_map);
   grpc_connectivity_state_destroy(exec_ctx, &t->channel_callback.state_tracker);
 
-  grpc_combiner_destroy(exec_ctx, t->executor.combiner);
+  grpc_combiner_destroy(exec_ctx, t->combiner);
 
   /* callback remaining pings: they're not allowed to call into the transpot,
      and maybe they hold resources that need to be freed */
-  while (t->global.pings.next != &t->global.pings) {
-    grpc_chttp2_outstanding_ping *ping = t->global.pings.next;
+  while (t->pings.next != &t->pings) {
+    grpc_chttp2_outstanding_ping *ping = t->pings.next;
     grpc_exec_ctx_sched(exec_ctx, ping->on_recv,
                         GRPC_ERROR_CREATE("Transport closed"), NULL);
     ping->next->prev = ping->prev;
@@ -196,37 +161,40 @@ static void destruct_transport(grpc_exec_ctx *exec_ctx,
     gpr_free(ping);
   }
 
+  while (t->write_cb_pool) {
+    grpc_chttp2_write_cb *next = t->write_cb_pool->next;
+    gpr_free(t->write_cb_pool);
+    t->write_cb_pool = next;
+  }
+
   gpr_free(t->peer_string);
   gpr_free(t);
 }
 
-/*#define REFCOUNTING_DEBUG 1*/
-#ifdef REFCOUNTING_DEBUG
-#define REF_TRANSPORT(t, r) ref_transport(t, r, __FILE__, __LINE__)
-#define UNREF_TRANSPORT(cl, t, r) unref_transport(cl, t, r, __FILE__, __LINE__)
-static void unref_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                            const char *reason, const char *file, int line) {
-  gpr_log(GPR_DEBUG, "chttp2:unref:%p %d->%d %s [%s:%d]", t, t->refs.count,
-          t->refs.count - 1, reason, file, line);
+#ifdef GRPC_CHTTP2_REFCOUNTING_DEBUG
+void grpc_chttp2_unref_transport(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t, const char *reason,
+                                 const char *file, int line) {
+  gpr_log(GPR_DEBUG, "chttp2:unref:%p %" PRIdPTR "->%" PRIdPTR " %s [%s:%d]", t,
+          t->refs.count, t->refs.count - 1, reason, file, line);
   if (!gpr_unref(&t->refs)) return;
   destruct_transport(exec_ctx, t);
 }
 
-static void ref_transport(grpc_chttp2_transport *t, const char *reason,
-                          const char *file, int line) {
-  gpr_log(GPR_DEBUG, "chttp2:  ref:%p %d->%d %s [%s:%d]", t, t->refs.count,
-          t->refs.count + 1, reason, file, line);
+void grpc_chttp2_ref_transport(grpc_chttp2_transport *t, const char *reason,
+                               const char *file, int line) {
+  gpr_log(GPR_DEBUG, "chttp2:  ref:%p %" PRIdPTR "->%" PRIdPTR " %s [%s:%d]", t,
+          t->refs.count, t->refs.count + 1, reason, file, line);
   gpr_ref(&t->refs);
 }
 #else
-#define REF_TRANSPORT(t, r) ref_transport(t)
-#define UNREF_TRANSPORT(cl, t, r) unref_transport(cl, t)
-static void unref_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) {
+void grpc_chttp2_unref_transport(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t) {
   if (!gpr_unref(&t->refs)) return;
   destruct_transport(exec_ctx, t);
 }
 
-static void ref_transport(grpc_chttp2_transport *t) { gpr_ref(&t->refs); }
+void grpc_chttp2_ref_transport(grpc_chttp2_transport *t) { gpr_ref(&t->refs); }
 #endif
 
 static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
@@ -241,51 +209,41 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   memset(t, 0, sizeof(*t));
 
   t->base.vtable = &vtable;
-  t->executor.write_state = GRPC_CHTTP2_WRITES_CORKED;
   t->ep = ep;
   /* one ref is for destroy */
   gpr_ref_init(&t->refs, 1);
-  /* ref is dropped at transport close() */
-  gpr_ref_init(&t->shutdown_ep_refs, 1);
-  t->executor.combiner = grpc_combiner_create(grpc_endpoint_get_workqueue(ep));
+  t->combiner = grpc_combiner_create(grpc_endpoint_get_workqueue(ep));
   t->peer_string = grpc_endpoint_get_peer(ep);
   t->endpoint_reading = 1;
-  t->global.next_stream_id = is_client ? 1 : 2;
-  t->global.is_client = is_client;
-  t->writing.outgoing_window = DEFAULT_WINDOW;
-  t->parsing.incoming_window = DEFAULT_WINDOW;
-  t->global.stream_lookahead = DEFAULT_WINDOW;
-  t->global.connection_window_target = DEFAULT_CONNECTION_WINDOW_TARGET;
-  t->global.ping_counter = 1;
-  t->global.pings.next = t->global.pings.prev = &t->global.pings;
-  t->parsing.is_client = is_client;
-  t->parsing.deframe_state =
-      is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0;
-  t->parsing.is_first_frame = true;
-  t->writing.is_client = is_client;
+  t->next_stream_id = is_client ? 1 : 2;
+  t->is_client = is_client;
+  t->outgoing_window = DEFAULT_WINDOW;
+  t->incoming_window = DEFAULT_WINDOW;
+  t->stream_lookahead = DEFAULT_WINDOW;
+  t->connection_window_target = DEFAULT_CONNECTION_WINDOW_TARGET;
+  t->ping_counter = 1;
+  t->pings.next = t->pings.prev = &t->pings;
+  t->deframe_state = is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0;
+  t->is_first_frame = true;
   grpc_connectivity_state_init(
       &t->channel_callback.state_tracker, GRPC_CHANNEL_READY,
       is_client ? "client_transport" : "server_transport");
 
-  gpr_slice_buffer_init(&t->global.qbuf);
-
-  gpr_slice_buffer_init(&t->writing.outbuf);
-  grpc_chttp2_hpack_compressor_init(&t->writing.hpack_compressor);
-  grpc_closure_init(&t->writing_action, writing_action, t);
-  grpc_closure_init(&t->reading_action, reading_action, t);
-  grpc_closure_init(&t->reading_action_locked, reading_action_locked, t);
-  grpc_closure_init(&t->parsing_action, parsing_action, t);
-  grpc_closure_init(&t->post_parse_locked, post_parse_locked, t);
-  grpc_closure_init(&t->initiate_writing, initiate_writing_locked, t);
-  grpc_closure_init(&t->terminate_writing, terminate_writing_with_lock, t);
-  grpc_closure_init(&t->initiate_read_flush_locked, initiate_read_flush_locked,
+  gpr_slice_buffer_init(&t->qbuf);
+
+  gpr_slice_buffer_init(&t->outbuf);
+  grpc_chttp2_hpack_compressor_init(&t->hpack_compressor);
+
+  grpc_closure_init(&t->write_action_begin_locked, write_action_begin_locked,
                     t);
-  grpc_closure_init(&t->writing.done_cb, grpc_chttp2_terminate_writing,
-                    &t->writing);
+  grpc_closure_init(&t->write_action, write_action, t);
+  grpc_closure_init(&t->write_action_end, write_action_end, t);
+  grpc_closure_init(&t->write_action_end_locked, write_action_end_locked, t);
+  grpc_closure_init(&t->read_action_begin, read_action_begin, t);
+  grpc_closure_init(&t->read_action_locked, read_action_locked, t);
 
-  gpr_slice_buffer_init(&t->parsing.qbuf);
-  grpc_chttp2_goaway_parser_init(&t->parsing.goaway_parser);
-  grpc_chttp2_hpack_parser_init(&t->parsing.hpack_parser);
+  grpc_chttp2_goaway_parser_init(&t->goaway_parser);
+  grpc_chttp2_hpack_parser_init(&t->hpack_parser);
 
   gpr_slice_buffer_init(&t->read_buffer);
 
@@ -294,28 +252,24 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
      large enough that the exponential growth should happen nicely when it's
      needed.
      TODO(ctiller): tune this */
-  grpc_chttp2_stream_map_init(&t->parsing_stream_map, 8);
-  grpc_chttp2_stream_map_init(&t->new_stream_map, 8);
+  grpc_chttp2_stream_map_init(&t->stream_map, 8);
 
   /* copy in initial settings to all setting sets */
   for (i = 0; i < GRPC_CHTTP2_NUM_SETTINGS; i++) {
-    t->parsing.settings[i] = grpc_chttp2_settings_parameters[i].default_value;
     for (j = 0; j < GRPC_NUM_SETTING_SETS; j++) {
-      t->global.settings[j][i] =
-          grpc_chttp2_settings_parameters[i].default_value;
+      t->settings[j][i] = grpc_chttp2_settings_parameters[i].default_value;
     }
   }
-  t->global.dirtied_local_settings = 1;
+  t->dirtied_local_settings = 1;
   /* Hack: it's common for implementations to assume 65536 bytes initial send
      window -- this should by rights be 0 */
-  t->global.force_send_settings = 1 << GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE;
-  t->global.sent_local_settings = 0;
+  t->force_send_settings = 1 << GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE;
+  t->sent_local_settings = 0;
 
   if (is_client) {
-    gpr_slice_buffer_add(
-        &t->writing.outbuf,
-        gpr_slice_from_copied_string(GRPC_CHTTP2_CLIENT_CONNECT_STRING));
-    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "initial_write");
+    gpr_slice_buffer_add(&t->outbuf, gpr_slice_from_copied_string(
+                                         GRPC_CHTTP2_CLIENT_CONNECT_STRING));
+    grpc_chttp2_initiate_write(exec_ctx, t, false, "initial_write");
   }
 
   /* configure http2 the way we like it */
@@ -330,34 +284,18 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 
   if (channel_args) {
     for (i = 0; i < channel_args->num_args; i++) {
-      if (0 ==
-          strcmp(channel_args->args[i].key, GRPC_ARG_MAX_CONCURRENT_STREAMS)) {
-        if (is_client) {
-          gpr_log(GPR_ERROR, "%s: is ignored on the client",
-                  GRPC_ARG_MAX_CONCURRENT_STREAMS);
-        } else {
-          const grpc_integer_options options = {-1, 0, INT_MAX};
-          const int value =
-              grpc_channel_arg_get_integer(&channel_args->args[i], options);
-          if (value >= 0) {
-            push_setting(exec_ctx, t,
-                         GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
-                         (uint32_t)value);
-          }
-        }
-      } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER)) {
+      if (0 == strcmp(channel_args->args[i].key,
+                      GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER)) {
         const grpc_integer_options options = {-1, 0, INT_MAX};
         const int value =
             grpc_channel_arg_get_integer(&channel_args->args[i], options);
         if (value >= 0) {
-          if ((t->global.next_stream_id & 1) != (value & 1)) {
+          if ((t->next_stream_id & 1) != (value & 1)) {
             gpr_log(GPR_ERROR, "%s: low bit must be %d on %s",
                     GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER,
-                    t->global.next_stream_id & 1,
-                    is_client ? "client" : "server");
+                    t->next_stream_id & 1, is_client ? "client" : "server");
           } else {
-            t->global.next_stream_id = (uint32_t)value;
+            t->next_stream_id = (uint32_t)value;
           }
         }
       } else if (0 == strcmp(channel_args->args[i].key,
@@ -366,16 +304,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
         const int value =
             grpc_channel_arg_get_integer(&channel_args->args[i], options);
         if (value >= 0) {
-          t->global.stream_lookahead = (uint32_t)value;
-        }
-      } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER)) {
-        const grpc_integer_options options = {-1, 0, INT_MAX};
-        const int value =
-            grpc_channel_arg_get_integer(&channel_args->args[i], options);
-        if (value >= 0) {
-          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE,
-                       (uint32_t)value);
+          t->stream_lookahead = (uint32_t)value;
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER)) {
@@ -383,118 +312,125 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
         const int value =
             grpc_channel_arg_get_integer(&channel_args->args[i], options);
         if (value >= 0) {
-          grpc_chttp2_hpack_compressor_set_max_usable_size(
-              &t->writing.hpack_compressor, (uint32_t)value);
-        }
-      } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_MAX_METADATA_SIZE)) {
-        const grpc_integer_options options = {-1, 0, INT_MAX};
-        const int value =
-            grpc_channel_arg_get_integer(&channel_args->args[i], options);
-        if (value >= 0) {
-          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
-                       (uint32_t)value);
+          grpc_chttp2_hpack_compressor_set_max_usable_size(&t->hpack_compressor,
+                                                           (uint32_t)value);
         }
-      } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_HTTP2_MAX_FRAME_SIZE)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
-        } else if (channel_args->args[i].value.integer < 16384 ||
-                   channel_args->args[i].value.integer > 16777215) {
-          gpr_log(GPR_ERROR, "%s: must be between 16384 and 16777215",
-                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
-        } else {
-          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE,
-                       (uint32_t)channel_args->args[i].value.integer);
+      } else {
+        static const struct {
+          const char *channel_arg_name;
+          grpc_chttp2_setting_id setting_id;
+          grpc_integer_options integer_options;
+          bool availability[2] /* server, client */;
+        } settings_map[] = {
+            {GRPC_ARG_MAX_CONCURRENT_STREAMS,
+             GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
+             {-1, 0, INT_MAX},
+             {true, false}},
+            {GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER,
+             GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE,
+             {-1, 0, INT_MAX},
+             {true, true}},
+            {GRPC_ARG_MAX_METADATA_SIZE,
+             GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
+             {-1, 0, INT_MAX},
+             {true, true}},
+            {GRPC_ARG_HTTP2_MAX_FRAME_SIZE,
+             GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE,
+             {-1, 16384, 16777215},
+             {true, true}},
+        };
+        for (j = 0; j < (int)GPR_ARRAY_SIZE(settings_map); j++) {
+          if (0 == strcmp(channel_args->args[i].key,
+                          settings_map[j].channel_arg_name)) {
+            if (!settings_map[j].availability[is_client]) {
+              gpr_log(GPR_DEBUG, "%s is not available on %s",
+                      settings_map[j].channel_arg_name,
+                      is_client ? "clients" : "servers");
+            } else {
+              int value = grpc_channel_arg_get_integer(
+                  &channel_args->args[i], settings_map[j].integer_options);
+              if (value >= 0) {
+                push_setting(exec_ctx, t, settings_map[j].setting_id,
+                             (uint32_t)value);
+              }
+            }
+            break;
+          }
         }
       }
     }
   }
 
-  set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE, "uncork");
-  grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "init");
+  grpc_chttp2_initiate_write(exec_ctx, t, false, "init");
 }
 
 static void destroy_transport_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                      grpc_error *error) {
   grpc_chttp2_transport *t = tp;
   t->destroying = 1;
-  drop_connection(exec_ctx, t, GRPC_ERROR_CREATE("Transport destroyed"));
-  UNREF_TRANSPORT(exec_ctx, t, "destroy");
+  close_transport_locked(
+      exec_ctx, t,
+      grpc_error_set_int(GRPC_ERROR_CREATE("Transport destroyed"),
+                         GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state));
+  GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "destroy");
 }
 
 static void destroy_transport(grpc_exec_ctx *exec_ctx, grpc_transport *gt) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)gt;
-  grpc_combiner_execute(exec_ctx, t->executor.combiner,
+  grpc_combiner_execute(exec_ctx, t->combiner,
                         grpc_closure_create(destroy_transport_locked, t),
-                        GRPC_ERROR_NONE);
-}
-
-/** block grpc_endpoint_shutdown being called until a paired
-    allow_endpoint_shutdown is made */
-static void prevent_endpoint_shutdown(grpc_chttp2_transport *t) {
-  gpr_ref(&t->shutdown_ep_refs);
-}
-
-static void allow_endpoint_shutdown_locked(grpc_exec_ctx *exec_ctx,
-                                           grpc_chttp2_transport *t) {
-  if (gpr_unref(&t->shutdown_ep_refs)) {
-    grpc_endpoint_shutdown(exec_ctx, t->ep);
-  }
+                        GRPC_ERROR_NONE, false);
 }
 
 static void close_transport_locked(grpc_exec_ctx *exec_ctx,
                                    grpc_chttp2_transport *t,
                                    grpc_error *error) {
   if (!t->closed) {
-    if (grpc_http_write_state_trace) {
-      gpr_log(GPR_DEBUG, "W:%p close transport", t);
+    if (t->write_state != GRPC_CHTTP2_WRITE_STATE_IDLE) {
+      if (t->close_transport_on_writes_finished == NULL) {
+        t->close_transport_on_writes_finished =
+            GRPC_ERROR_CREATE("Delayed close due to in-progress write");
+      }
+      t->close_transport_on_writes_finished =
+          grpc_error_add_child(t->close_transport_on_writes_finished, error);
+      return;
+    }
+    if (!grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, NULL)) {
+      error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS,
+                                 GRPC_STATUS_UNAVAILABLE);
     }
     t->closed = 1;
-    connectivity_state_set(exec_ctx, &t->global, GRPC_CHANNEL_SHUTDOWN,
+    connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_SHUTDOWN,
                            GRPC_ERROR_REF(error), "close_transport");
-    allow_endpoint_shutdown_locked(exec_ctx, t);
+    grpc_endpoint_shutdown(exec_ctx, t->ep);
 
     /* flush writable stream list to avoid dangling references */
-    grpc_chttp2_stream_global *stream_global;
-    grpc_chttp2_stream_writing *stream_writing;
-    while (grpc_chttp2_list_pop_writable_stream(
-        &t->global, &t->writing, &stream_global, &stream_writing)) {
-      GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2_writing");
+    grpc_chttp2_stream *s;
+    while (grpc_chttp2_list_pop_writable_stream(t, &s)) {
+      GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:close");
     }
+    end_all_the_calls(exec_ctx, t, GRPC_ERROR_REF(error));
   }
   GRPC_ERROR_UNREF(error);
 }
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
-void grpc_chttp2_stream_ref(grpc_chttp2_stream_global *stream_global,
-                            const char *reason) {
-  grpc_stream_ref(STREAM_FROM_GLOBAL(stream_global)->refcount, reason);
+void grpc_chttp2_stream_ref(grpc_chttp2_stream *s, const char *reason) {
+  grpc_stream_ref(s->refcount, reason);
 }
-void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx,
-                              grpc_chttp2_stream_global *stream_global,
+void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx, grpc_chttp2_stream *s,
                               const char *reason) {
-  grpc_stream_unref(exec_ctx, STREAM_FROM_GLOBAL(stream_global)->refcount,
-                    reason);
+  grpc_stream_unref(exec_ctx, s->refcount, reason);
 }
 #else
-void grpc_chttp2_stream_ref(grpc_chttp2_stream_global *stream_global) {
-  grpc_stream_ref(STREAM_FROM_GLOBAL(stream_global)->refcount);
+void grpc_chttp2_stream_ref(grpc_chttp2_stream *s) {
+  grpc_stream_ref(s->refcount);
 }
-void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx,
-                              grpc_chttp2_stream_global *stream_global) {
-  grpc_stream_unref(exec_ctx, STREAM_FROM_GLOBAL(stream_global)->refcount);
+void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx, grpc_chttp2_stream *s) {
+  grpc_stream_unref(exec_ctx, s->refcount);
 }
 #endif
 
-static void finish_init_stream_locked(grpc_exec_ctx *exec_ctx, void *sp,
-                                      grpc_error *error) {
-  grpc_chttp2_stream *s = sp;
-  grpc_chttp2_register_stream(s->t, s);
-  GRPC_CHTTP2_STREAM_UNREF(exec_ctx, &s->global, "init");
-}
-
 static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                        grpc_stream *gs, grpc_stream_refcount *refcount,
                        const void *server_data) {
@@ -509,41 +445,30 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   /* We reserve one 'active stream' that's dropped when the stream is
      read-closed. The others are for incoming_byte_streams that are actively
      reading */
-  gpr_ref_init(&s->global.active_streams, 1);
-  GRPC_CHTTP2_STREAM_REF(&s->global, "chttp2");
+  gpr_ref_init(&s->active_streams, 1);
+  GRPC_CHTTP2_STREAM_REF(s, "chttp2");
 
-  grpc_chttp2_incoming_metadata_buffer_init(&s->parsing.metadata_buffer[0]);
-  grpc_chttp2_incoming_metadata_buffer_init(&s->parsing.metadata_buffer[1]);
-  grpc_chttp2_incoming_metadata_buffer_init(
-      &s->global.received_initial_metadata);
-  grpc_chttp2_incoming_metadata_buffer_init(
-      &s->global.received_trailing_metadata);
-  grpc_chttp2_data_parser_init(&s->parsing.data_parser);
-  gpr_slice_buffer_init(&s->writing.flow_controlled_buffer);
-  s->global.deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  grpc_chttp2_incoming_metadata_buffer_init(&s->metadata_buffer[0]);
+  grpc_chttp2_incoming_metadata_buffer_init(&s->metadata_buffer[1]);
+  grpc_chttp2_data_parser_init(&s->data_parser);
+  gpr_slice_buffer_init(&s->flow_controlled_buffer);
+  s->deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  grpc_closure_init(&s->complete_fetch, complete_fetch, s);
+  grpc_closure_init(&s->complete_fetch_locked, complete_fetch_locked, s);
 
-  REF_TRANSPORT(t, "stream");
+  GRPC_CHTTP2_REF_TRANSPORT(t, "stream");
 
   if (server_data) {
-    GPR_ASSERT(t->executor.parsing_active);
-    s->global.id = (uint32_t)(uintptr_t)server_data;
-    s->parsing.id = s->global.id;
-    s->global.outgoing_window =
-        t->global.settings[GRPC_PEER_SETTINGS]
-                          [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
-    s->parsing.incoming_window = s->global.max_recv_bytes =
-        t->global.settings[GRPC_SENT_SETTINGS]
-                          [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
+    s->id = (uint32_t)(uintptr_t)server_data;
+    s->outgoing_window = t->settings[GRPC_PEER_SETTINGS]
+                                    [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
+    s->incoming_window = s->max_recv_bytes =
+        t->settings[GRPC_SENT_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
     *t->accepting_stream = s;
-    grpc_chttp2_stream_map_add(&t->parsing_stream_map, s->global.id, s);
-    s->global.in_stream_map = true;
+    grpc_chttp2_stream_map_add(&t->stream_map, s->id, s);
   }
 
-  grpc_closure_init(&s->init_stream, finish_init_stream_locked, s);
-  GRPC_CHTTP2_STREAM_REF(&s->global, "init");
-  grpc_combiner_execute(exec_ctx, t->executor.combiner, &s->init_stream,
-                        GRPC_ERROR_NONE);
-
   GPR_TIMER_END("init_stream", 0);
 
   return 0;
@@ -557,55 +482,39 @@ static void destroy_stream_locked(grpc_exec_ctx *exec_ctx, void *sp,
 
   GPR_TIMER_BEGIN("destroy_stream", 0);
 
-  GPR_ASSERT((s->global.write_closed && s->global.read_closed) ||
-             s->global.id == 0);
-  GPR_ASSERT(!s->global.in_stream_map);
-  if (grpc_chttp2_unregister_stream(t, s) && t->global.sent_goaway) {
-    close_transport_locked(
-        exec_ctx, t,
-        GRPC_ERROR_CREATE("Last stream closed after sending goaway"));
-  }
-  if (!t->executor.parsing_active && s->global.id) {
-    GPR_ASSERT(grpc_chttp2_stream_map_find(&t->parsing_stream_map,
-                                           s->global.id) == NULL);
+  GPR_ASSERT((s->write_closed && s->read_closed) || s->id == 0);
+  if (s->id != 0) {
+    GPR_ASSERT(grpc_chttp2_stream_map_find(&t->stream_map, s->id) == NULL);
   }
 
-  while (
-      (bs = grpc_chttp2_incoming_frame_queue_pop(&s->global.incoming_frames))) {
+  while ((bs = grpc_chttp2_incoming_frame_queue_pop(&s->incoming_frames))) {
     incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
   }
 
-  grpc_chttp2_list_remove_unannounced_incoming_window_available(&t->global,
-                                                                &s->global);
-  grpc_chttp2_list_remove_stalled_by_transport(&t->global, &s->global);
-  grpc_chttp2_list_remove_check_read_ops(&t->global, &s->global);
+  grpc_chttp2_list_remove_stalled_by_transport(t, s);
 
   for (int i = 0; i < STREAM_LIST_COUNT; i++) {
     if (s->included[i]) {
       gpr_log(GPR_ERROR, "%s stream %d still included in list %d",
-              t->global.is_client ? "client" : "server", s->global.id, i);
+              t->is_client ? "client" : "server", s->id, i);
       abort();
     }
   }
 
-  GPR_ASSERT(s->global.send_initial_metadata_finished == NULL);
-  GPR_ASSERT(s->global.send_message_finished == NULL);
-  GPR_ASSERT(s->global.send_trailing_metadata_finished == NULL);
-  GPR_ASSERT(s->global.recv_initial_metadata_ready == NULL);
-  GPR_ASSERT(s->global.recv_message_ready == NULL);
-  GPR_ASSERT(s->global.recv_trailing_metadata_finished == NULL);
-  grpc_chttp2_data_parser_destroy(exec_ctx, &s->parsing.data_parser);
-  grpc_chttp2_incoming_metadata_buffer_destroy(&s->parsing.metadata_buffer[0]);
-  grpc_chttp2_incoming_metadata_buffer_destroy(&s->parsing.metadata_buffer[1]);
-  grpc_chttp2_incoming_metadata_buffer_destroy(
-      &s->global.received_initial_metadata);
-  grpc_chttp2_incoming_metadata_buffer_destroy(
-      &s->global.received_trailing_metadata);
-  gpr_slice_buffer_destroy(&s->writing.flow_controlled_buffer);
-  GRPC_ERROR_UNREF(s->global.read_closed_error);
-  GRPC_ERROR_UNREF(s->global.write_closed_error);
-
-  UNREF_TRANSPORT(exec_ctx, t, "stream");
+  GPR_ASSERT(s->send_initial_metadata_finished == NULL);
+  GPR_ASSERT(s->fetching_send_message == NULL);
+  GPR_ASSERT(s->send_trailing_metadata_finished == NULL);
+  GPR_ASSERT(s->recv_initial_metadata_ready == NULL);
+  GPR_ASSERT(s->recv_message_ready == NULL);
+  GPR_ASSERT(s->recv_trailing_metadata_finished == NULL);
+  grpc_chttp2_data_parser_destroy(exec_ctx, &s->data_parser);
+  grpc_chttp2_incoming_metadata_buffer_destroy(&s->metadata_buffer[0]);
+  grpc_chttp2_incoming_metadata_buffer_destroy(&s->metadata_buffer[1]);
+  gpr_slice_buffer_destroy(&s->flow_controlled_buffer);
+  GRPC_ERROR_UNREF(s->read_closed_error);
+  GRPC_ERROR_UNREF(s->write_closed_error);
+
+  GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "stream");
 
   GPR_TIMER_END("destroy_stream", 0);
 
@@ -620,280 +529,215 @@ static void destroy_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
 
   s->destroy_stream_arg = and_free_memory;
   grpc_closure_init(&s->destroy_stream, destroy_stream_locked, s);
-  grpc_combiner_execute(exec_ctx, t->executor.combiner, &s->destroy_stream,
-                        GRPC_ERROR_NONE);
+  grpc_combiner_execute(exec_ctx, t->combiner, &s->destroy_stream,
+                        GRPC_ERROR_NONE, false);
   GPR_TIMER_END("destroy_stream", 0);
 }
 
-grpc_chttp2_stream_parsing *grpc_chttp2_parsing_lookup_stream(
-    grpc_chttp2_transport_parsing *transport_parsing, uint32_t id) {
-  grpc_chttp2_transport *t = TRANSPORT_FROM_PARSING(transport_parsing);
-  grpc_chttp2_stream *s =
-      grpc_chttp2_stream_map_find(&t->parsing_stream_map, id);
-  return s ? &s->parsing : NULL;
+grpc_chttp2_stream *grpc_chttp2_parsing_lookup_stream(grpc_chttp2_transport *t,
+                                                      uint32_t id) {
+  return grpc_chttp2_stream_map_find(&t->stream_map, id);
 }
 
-grpc_chttp2_stream_parsing *grpc_chttp2_parsing_accept_stream(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    uint32_t id) {
+grpc_chttp2_stream *grpc_chttp2_parsing_accept_stream(grpc_exec_ctx *exec_ctx,
+                                                      grpc_chttp2_transport *t,
+                                                      uint32_t id) {
+  if (t->channel_callback.accept_stream == NULL) {
+    return NULL;
+  }
   grpc_chttp2_stream *accepting;
-  grpc_chttp2_transport *t = TRANSPORT_FROM_PARSING(transport_parsing);
   GPR_ASSERT(t->accepting_stream == NULL);
   t->accepting_stream = &accepting;
   t->channel_callback.accept_stream(exec_ctx,
                                     t->channel_callback.accept_stream_user_data,
                                     &t->base, (void *)(uintptr_t)id);
   t->accepting_stream = NULL;
-  return &accepting->parsing;
+  return accepting;
 }
 
 /*******************************************************************************
- * LOCK MANAGEMENT
+ * OUTPUT PROCESSING
  */
 
-static const char *write_state_name(grpc_chttp2_write_state state) {
-  switch (state) {
-    case GRPC_CHTTP2_WRITES_CORKED:
-      return "CORKED";
-    case GRPC_CHTTP2_WRITING_INACTIVE:
-      return "INACTIVE";
-    case GRPC_CHTTP2_WRITE_SCHEDULED:
-      return "SCHEDULED";
-    case GRPC_CHTTP2_WRITING:
+static const char *write_state_name(grpc_chttp2_write_state st) {
+  switch (st) {
+    case GRPC_CHTTP2_WRITE_STATE_IDLE:
+      return "IDLE";
+    case GRPC_CHTTP2_WRITE_STATE_WRITING:
       return "WRITING";
-    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
-      return "WRITING[p=1]";
-    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
-      return "WRITING[p=0]";
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE:
+      return "WRITING+MORE";
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER:
+      return "WRITING+MORE+COVERED";
   }
   GPR_UNREACHABLE_CODE(return "UNKNOWN");
 }
 
-static void set_write_state(grpc_chttp2_transport *t,
-                            grpc_chttp2_write_state state, const char *reason) {
-  if (grpc_http_write_state_trace) {
-    gpr_log(GPR_DEBUG, "W:%p %s -> %s because %s", t,
-            write_state_name(t->executor.write_state), write_state_name(state),
-            reason);
+static void set_write_state(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                            grpc_chttp2_write_state st, const char *reason) {
+  GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_DEBUG, "W:%p %s state %s -> %s [%s]", t,
+                                 t->is_client ? "CLIENT" : "SERVER",
+                                 write_state_name(t->write_state),
+                                 write_state_name(st), reason));
+  t->write_state = st;
+  if (st == GRPC_CHTTP2_WRITE_STATE_IDLE &&
+      t->close_transport_on_writes_finished != NULL) {
+    grpc_error *err = t->close_transport_on_writes_finished;
+    t->close_transport_on_writes_finished = NULL;
+    close_transport_locked(exec_ctx, t, err);
   }
-  t->executor.write_state = state;
-}
-
-static void initiate_writing_locked(grpc_exec_ctx *exec_ctx, void *tp,
-                                    grpc_error *error) {
-  grpc_chttp2_transport *t = tp;
-  GPR_ASSERT(t->executor.write_state == GRPC_CHTTP2_WRITE_SCHEDULED);
-  start_writing(exec_ctx, t);
 }
 
-static void initiate_read_flush_locked(grpc_exec_ctx *exec_ctx, void *tp,
-                                       grpc_error *error) {
-  grpc_chttp2_transport *t = tp;
-  t->executor.check_read_ops_scheduled = false;
-  check_read_ops(exec_ctx, &t->global);
-}
-
-/*******************************************************************************
- * OUTPUT PROCESSING
- */
-
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport_global *transport_global,
+                                grpc_chttp2_transport *t,
                                 bool covered_by_poller, const char *reason) {
   GPR_TIMER_BEGIN("grpc_chttp2_initiate_write", 0);
 
-  /* Perform state checks, and transition to a scheduled state if appropriate.
-     If we are inactive, schedule a write chain to begin once the transport
-     combiner finishes any executions in its current batch (which may be
-     scheduled AFTER this code executes). The write chain will:
-      - call start_writing, which verifies (under the global lock) that there
-        are things that need to be written by calling
-        grpc_chttp2_unlocking_check_writes, and if so schedules writing_action
-        against the current exec_ctx, to be executed OUTSIDE of the global lock
-      - eventually writing_action results in grpc_chttp2_terminate_writing being
-        called, which re-takes the global lock, updates state, checks if we need
-        to do *another* write immediately, and if so loops back to
-        start_writing.
-
-     Current problems:
-       - too much lock entry/exiting
-       - the writing thread can become stuck indefinitely (punt through the
-         workqueue periodically to fix) */
-
-  grpc_chttp2_transport *t = TRANSPORT_FROM_GLOBAL(transport_global);
-  switch (t->executor.write_state) {
-    case GRPC_CHTTP2_WRITES_CORKED:
+  switch (t->write_state) {
+    case GRPC_CHTTP2_WRITE_STATE_IDLE:
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING, reason);
+      GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
+      grpc_combiner_execute_finally(exec_ctx, t->combiner,
+                                    &t->write_action_begin_locked,
+                                    GRPC_ERROR_NONE, covered_by_poller);
       break;
-    case GRPC_CHTTP2_WRITING_INACTIVE:
-      set_write_state(t, GRPC_CHTTP2_WRITE_SCHEDULED, reason);
-      REF_TRANSPORT(t, "writing");
-      grpc_combiner_execute_finally(exec_ctx, t->executor.combiner,
-                                    &t->initiate_writing, GRPC_ERROR_NONE,
-                                    covered_by_poller);
+    case GRPC_CHTTP2_WRITE_STATE_WRITING:
+      set_write_state(
+          exec_ctx, t,
+          covered_by_poller
+              ? GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER
+              : GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE,
+          reason);
       break;
-    case GRPC_CHTTP2_WRITE_SCHEDULED:
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE:
       if (covered_by_poller) {
-        /* upgrade to note poller is available to cover the write */
-        grpc_combiner_force_async_finally(t->executor.combiner);
+        set_write_state(
+            exec_ctx, t,
+            GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER,
+            reason);
       }
       break;
-    case GRPC_CHTTP2_WRITING:
-      set_write_state(t,
-                      covered_by_poller ? GRPC_CHTTP2_WRITING_STALE_WITH_POLLER
-                                        : GRPC_CHTTP2_WRITING_STALE_NO_POLLER,
-                      reason);
-      break;
-    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
-      /* nothing to do: write already requested */
-      break;
-    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
-      if (covered_by_poller) {
-        /* upgrade to note poller is available to cover the write */
-        set_write_state(t, GRPC_CHTTP2_WRITING_STALE_WITH_POLLER, reason);
-      }
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER:
       break;
   }
   GPR_TIMER_END("grpc_chttp2_initiate_write", 0);
 }
 
-static void start_writing(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) {
-  GPR_TIMER_BEGIN("start_writing", 0);
-  GPR_ASSERT(t->executor.write_state == GRPC_CHTTP2_WRITE_SCHEDULED);
-  if (!t->closed &&
-      grpc_chttp2_unlocking_check_writes(exec_ctx, &t->global, &t->writing)) {
-    set_write_state(t, GRPC_CHTTP2_WRITING, "start_writing");
-    prevent_endpoint_shutdown(t);
-    grpc_exec_ctx_sched(exec_ctx, &t->writing_action, GRPC_ERROR_NONE, NULL);
-  } else {
-    if (t->closed) {
-      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE,
-                      "start_writing:transport_closed");
-    } else {
-      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE,
-                      "start_writing:nothing_to_write");
-    }
-    end_waiting_for_write(exec_ctx, t, GRPC_ERROR_NONE);
-    UNREF_TRANSPORT(exec_ctx, t, "writing");
+void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t,
+                                 grpc_chttp2_stream *s, bool covered_by_poller,
+                                 const char *reason) {
+  if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
+    GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:become");
+    grpc_chttp2_initiate_write(exec_ctx, t, covered_by_poller, reason);
   }
-  GPR_TIMER_END("start_writing", 0);
 }
 
-void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport_global *transport_global,
-                                 grpc_chttp2_stream_global *stream_global,
-                                 bool covered_by_poller, const char *reason) {
-  if (!TRANSPORT_FROM_GLOBAL(transport_global)->closed &&
-      grpc_chttp2_list_add_writable_stream(transport_global, stream_global)) {
-    GRPC_CHTTP2_STREAM_REF(stream_global, "chttp2_writing");
-    grpc_chttp2_initiate_write(exec_ctx, transport_global, covered_by_poller,
-                               reason);
+static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *gt,
+                                      grpc_error *error_ignored) {
+  GPR_TIMER_BEGIN("write_action_begin_locked", 0);
+  grpc_chttp2_transport *t = gt;
+  GPR_ASSERT(t->write_state != GRPC_CHTTP2_WRITE_STATE_IDLE);
+  if (!t->closed && grpc_chttp2_begin_write(exec_ctx, t)) {
+    set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING,
+                    "begin writing");
+    grpc_exec_ctx_sched(exec_ctx, &t->write_action, GRPC_ERROR_NONE, NULL);
+  } else {
+    set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_IDLE,
+                    "begin writing nothing");
+    GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "writing");
   }
+  GPR_TIMER_END("write_action_begin_locked", 0);
 }
 
-static void push_setting(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                         grpc_chttp2_setting_id id, uint32_t value) {
-  const grpc_chttp2_setting_parameters *sp =
-      &grpc_chttp2_settings_parameters[id];
-  uint32_t use_value = GPR_CLAMP(value, sp->min_value, sp->max_value);
-  if (use_value != value) {
-    gpr_log(GPR_INFO, "Requested parameter %s clamped from %d to %d", sp->name,
-            value, use_value);
-  }
-  if (use_value != t->global.settings[GRPC_LOCAL_SETTINGS][id]) {
-    t->global.settings[GRPC_LOCAL_SETTINGS][id] = use_value;
-    t->global.dirtied_local_settings = 1;
-    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "push_setting");
-  }
+static void write_action(grpc_exec_ctx *exec_ctx, void *gt, grpc_error *error) {
+  grpc_chttp2_transport *t = gt;
+  GPR_TIMER_BEGIN("write_action", 0);
+  grpc_endpoint_write(exec_ctx, t->ep, &t->outbuf, &t->write_action_end);
+  GPR_TIMER_END("write_action", 0);
 }
 
-/* error may be GRPC_ERROR_NONE if there is no error allocated yet.
-   In that case, use "reason" as the text for a new error. */
-static void end_waiting_for_write(grpc_exec_ctx *exec_ctx,
-                                  grpc_chttp2_transport *t, grpc_error *error) {
-  grpc_chttp2_stream_global *stream_global;
-  while (grpc_chttp2_list_pop_closed_waiting_for_writing(&t->global,
-                                                         &stream_global)) {
-    fail_pending_writes(exec_ctx, &t->global, stream_global,
-                        GRPC_ERROR_REF(error));
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "finish_writes");
-  }
-  GRPC_ERROR_UNREF(error);
+static void write_action_end(grpc_exec_ctx *exec_ctx, void *gt,
+                             grpc_error *error) {
+  grpc_chttp2_transport *t = gt;
+  GPR_TIMER_BEGIN("write_action_end", 0);
+  grpc_combiner_execute(exec_ctx, t->combiner, &t->write_action_end_locked,
+                        GRPC_ERROR_REF(error), false);
+  GPR_TIMER_END("write_action_end", 0);
 }
 
-static void terminate_writing_with_lock(grpc_exec_ctx *exec_ctx, void *tp,
-                                        grpc_error *error) {
+static void write_action_end_locked(grpc_exec_ctx *exec_ctx, void *tp,
+                                    grpc_error *error) {
   GPR_TIMER_BEGIN("terminate_writing_with_lock", 0);
   grpc_chttp2_transport *t = tp;
-  allow_endpoint_shutdown_locked(exec_ctx, t);
 
   if (error != GRPC_ERROR_NONE) {
-    drop_connection(exec_ctx, t, GRPC_ERROR_REF(error));
+    close_transport_locked(exec_ctx, t, GRPC_ERROR_REF(error));
   }
 
-  grpc_chttp2_cleanup_writing(exec_ctx, &t->global, &t->writing);
+  grpc_chttp2_end_write(exec_ctx, t, GRPC_ERROR_REF(error));
 
-  end_waiting_for_write(exec_ctx, t, GRPC_ERROR_REF(error));
-
-  switch (t->executor.write_state) {
-    case GRPC_CHTTP2_WRITES_CORKED:
-    case GRPC_CHTTP2_WRITING_INACTIVE:
-    case GRPC_CHTTP2_WRITE_SCHEDULED:
+  switch (t->write_state) {
+    case GRPC_CHTTP2_WRITE_STATE_IDLE:
       GPR_UNREACHABLE_CODE(break);
-    case GRPC_CHTTP2_WRITING:
+    case GRPC_CHTTP2_WRITE_STATE_WRITING:
       GPR_TIMER_MARK("state=writing", 0);
-      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE, "terminate_writing");
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_IDLE,
+                      "finish writing");
       break;
-    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
-      GPR_TIMER_MARK("state=writing_stale_with_poller", 0);
-      set_write_state(t, GRPC_CHTTP2_WRITE_SCHEDULED, "terminate_writing");
-      REF_TRANSPORT(t, "writing");
-      grpc_combiner_execute_finally(exec_ctx, t->executor.combiner,
-                                    &t->initiate_writing, GRPC_ERROR_NONE,
-                                    true);
-      break;
-    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE:
       GPR_TIMER_MARK("state=writing_stale_no_poller", 0);
-      set_write_state(t, GRPC_CHTTP2_WRITE_SCHEDULED, "terminate_writing");
-      REF_TRANSPORT(t, "writing");
-      grpc_combiner_execute_finally(exec_ctx, t->executor.combiner,
-                                    &t->initiate_writing, GRPC_ERROR_NONE,
-                                    false);
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING,
+                      "continue writing [!covered]");
+      GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
+      grpc_combiner_execute_finally(exec_ctx, t->combiner,
+                                    &t->write_action_begin_locked,
+                                    GRPC_ERROR_NONE, false);
+      break;
+    case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER:
+      GPR_TIMER_MARK("state=writing_stale_with_poller", 0);
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING,
+                      "continue writing [covered]");
+      GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
+      grpc_combiner_execute_finally(exec_ctx, t->combiner,
+                                    &t->write_action_begin_locked,
+                                    GRPC_ERROR_NONE, true);
       break;
   }
 
-  UNREF_TRANSPORT(exec_ctx, t, "writing");
+  GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "writing");
   GPR_TIMER_END("terminate_writing_with_lock", 0);
 }
 
-void grpc_chttp2_terminate_writing(grpc_exec_ctx *exec_ctx,
-                                   void *transport_writing, grpc_error *error) {
-  GPR_TIMER_BEGIN("grpc_chttp2_terminate_writing", 0);
-  grpc_chttp2_transport *t = TRANSPORT_FROM_WRITING(transport_writing);
-  grpc_combiner_execute(exec_ctx, t->executor.combiner, &t->terminate_writing,
-                        GRPC_ERROR_REF(error));
-  GPR_TIMER_END("grpc_chttp2_terminate_writing", 0);
-}
-
-static void writing_action(grpc_exec_ctx *exec_ctx, void *gt,
-                           grpc_error *error) {
-  grpc_chttp2_transport *t = gt;
-  GPR_TIMER_BEGIN("writing_action", 0);
-  grpc_chttp2_perform_writes(exec_ctx, &t->writing, t->ep);
-  GPR_TIMER_END("writing_action", 0);
+static void push_setting(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                         grpc_chttp2_setting_id id, uint32_t value) {
+  const grpc_chttp2_setting_parameters *sp =
+      &grpc_chttp2_settings_parameters[id];
+  uint32_t use_value = GPR_CLAMP(value, sp->min_value, sp->max_value);
+  if (use_value != value) {
+    gpr_log(GPR_INFO, "Requested parameter %s clamped from %d to %d", sp->name,
+            value, use_value);
+  }
+  if (use_value != t->settings[GRPC_LOCAL_SETTINGS][id]) {
+    t->settings[GRPC_LOCAL_SETTINGS][id] = use_value;
+    t->dirtied_local_settings = 1;
+    grpc_chttp2_initiate_write(exec_ctx, t, false, "push_setting");
+  }
 }
 
-void grpc_chttp2_add_incoming_goaway(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    uint32_t goaway_error, gpr_slice goaway_text) {
+void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t,
+                                     uint32_t goaway_error,
+                                     gpr_slice goaway_text) {
   char *msg = gpr_dump_slice(goaway_text, GPR_DUMP_HEX | GPR_DUMP_ASCII);
   GRPC_CHTTP2_IF_TRACING(
       gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg));
   gpr_slice_unref(goaway_text);
-  transport_global->seen_goaway = 1;
+  t->seen_goaway = 1;
   /* lie: use transient failure from the transport to indicate goaway has been
    * received */
   connectivity_state_set(
-      exec_ctx, transport_global, GRPC_CHANNEL_TRANSIENT_FAILURE,
+      exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE,
       grpc_error_set_str(
           grpc_error_set_int(GRPC_ERROR_CREATE("GOAWAY received"),
                              GRPC_ERROR_INT_HTTP2_ERROR,
@@ -903,61 +747,49 @@ void grpc_chttp2_add_incoming_goaway(
   gpr_free(msg);
 }
 
-static void maybe_start_some_streams(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global) {
-  grpc_chttp2_stream_global *stream_global;
+static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t) {
+  grpc_chttp2_stream *s;
   uint32_t stream_incoming_window;
   /* start streams where we have free grpc_chttp2_stream ids and free
    * concurrency */
-  while (transport_global->next_stream_id <= MAX_CLIENT_STREAM_ID &&
-         transport_global->concurrent_stream_count <
-             transport_global
-                 ->settings[GRPC_PEER_SETTINGS]
-                           [GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS] &&
-         grpc_chttp2_list_pop_waiting_for_concurrency(transport_global,
-                                                      &stream_global)) {
+  while (t->next_stream_id <= MAX_CLIENT_STREAM_ID &&
+         grpc_chttp2_stream_map_size(&t->stream_map) <
+             t->settings[GRPC_PEER_SETTINGS]
+                        [GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS] &&
+         grpc_chttp2_list_pop_waiting_for_concurrency(t, &s)) {
     /* safe since we can't (legally) be parsing this stream yet */
-    grpc_chttp2_stream_parsing *stream_parsing =
-        &STREAM_FROM_GLOBAL(stream_global)->parsing;
     GRPC_CHTTP2_IF_TRACING(gpr_log(
         GPR_DEBUG, "HTTP:%s: Allocating new grpc_chttp2_stream %p to id %d",
-        transport_global->is_client ? "CLI" : "SVR", stream_global,
-        transport_global->next_stream_id));
+        t->is_client ? "CLI" : "SVR", s, t->next_stream_id));
 
-    GPR_ASSERT(stream_global->id == 0);
-    stream_global->id = stream_parsing->id = transport_global->next_stream_id;
-    transport_global->next_stream_id += 2;
+    GPR_ASSERT(s->id == 0);
+    s->id = t->next_stream_id;
+    t->next_stream_id += 2;
 
-    if (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID) {
-      connectivity_state_set(
-          exec_ctx, transport_global, GRPC_CHANNEL_TRANSIENT_FAILURE,
-          GRPC_ERROR_CREATE("Stream IDs exhausted"), "no_more_stream_ids");
+    if (t->next_stream_id >= MAX_CLIENT_STREAM_ID) {
+      connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE,
+                             GRPC_ERROR_CREATE("Stream IDs exhausted"),
+                             "no_more_stream_ids");
     }
 
-    stream_global->outgoing_window =
-        transport_global->settings[GRPC_PEER_SETTINGS]
-                                  [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
-    stream_parsing->incoming_window = stream_incoming_window =
-        transport_global->settings[GRPC_SENT_SETTINGS]
-                                  [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
-    stream_global->max_recv_bytes =
-        GPR_MAX(stream_incoming_window, stream_global->max_recv_bytes);
-    grpc_chttp2_stream_map_add(
-        &TRANSPORT_FROM_GLOBAL(transport_global)->new_stream_map,
-        stream_global->id, STREAM_FROM_GLOBAL(stream_global));
-    stream_global->in_stream_map = true;
-    transport_global->concurrent_stream_count++;
-    grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global, true,
-                                "new_stream");
+    s->outgoing_window = t->settings[GRPC_PEER_SETTINGS]
+                                    [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
+    s->incoming_window = stream_incoming_window =
+        t->settings[GRPC_SENT_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
+    s->max_recv_bytes = GPR_MAX(stream_incoming_window, s->max_recv_bytes);
+    grpc_chttp2_stream_map_add(&t->stream_map, s->id, s);
+    grpc_chttp2_become_writable(exec_ctx, t, s, true, "new_stream");
   }
   /* cancel out streams that will never be started */
-  while (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID &&
-         grpc_chttp2_list_pop_waiting_for_concurrency(transport_global,
-                                                      &stream_global)) {
-    cancel_from_api(exec_ctx, transport_global, stream_global,
-                    grpc_error_set_int(
-                        GRPC_ERROR_CREATE("Stream IDs exhausted"),
-                        GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE));
+  while (t->next_stream_id >= MAX_CLIENT_STREAM_ID &&
+         grpc_chttp2_list_pop_waiting_for_concurrency(t, &s)) {
+    grpc_chttp2_cancel_stream(
+        exec_ctx, t, s,
+        grpc_error_set_int(GRPC_ERROR_CREATE("Stream IDs exhausted"),
+                           GRPC_ERROR_INT_GRPC_STATUS,
+                           GRPC_STATUS_UNAVAILABLE));
   }
 }
 
@@ -969,48 +801,126 @@ static grpc_closure *add_closure_barrier(grpc_closure *closure) {
   return closure;
 }
 
-void grpc_chttp2_complete_closure_step(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, grpc_closure **pclosure,
-    grpc_error *error) {
+static void null_then_run_closure(grpc_exec_ctx *exec_ctx,
+                                  grpc_closure **closure, grpc_error *error) {
+  grpc_closure *c = *closure;
+  *closure = NULL;
+  grpc_closure_run(exec_ctx, c, error);
+}
+
+void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_transport *t,
+                                       grpc_chttp2_stream *s,
+                                       grpc_closure **pclosure,
+                                       grpc_error *error, const char *desc) {
   grpc_closure *closure = *pclosure;
+  *pclosure = NULL;
   if (closure == NULL) {
     GRPC_ERROR_UNREF(error);
     return;
   }
   closure->next_data.scratch -= CLOSURE_BARRIER_FIRST_REF_BIT;
   if (error != GRPC_ERROR_NONE) {
-    if (closure->error == GRPC_ERROR_NONE) {
-      closure->error =
+    if (closure->error_data.error == GRPC_ERROR_NONE) {
+      closure->error_data.error =
           GRPC_ERROR_CREATE("Error in HTTP transport completing operation");
-      closure->error = grpc_error_set_str(
-          closure->error, GRPC_ERROR_STR_TARGET_ADDRESS,
-          TRANSPORT_FROM_GLOBAL(transport_global)->peer_string);
+      closure->error_data.error =
+          grpc_error_set_str(closure->error_data.error,
+                             GRPC_ERROR_STR_TARGET_ADDRESS, t->peer_string);
     }
-    closure->error = grpc_error_add_child(closure->error, error);
+    closure->error_data.error =
+        grpc_error_add_child(closure->error_data.error, error);
   }
   if (closure->next_data.scratch < CLOSURE_BARRIER_FIRST_REF_BIT) {
     if (closure->next_data.scratch & CLOSURE_BARRIER_STATS_BIT) {
-      grpc_transport_move_stats(&stream_global->stats,
-                                stream_global->collecting_stats);
-      stream_global->collecting_stats = NULL;
+      grpc_transport_move_stats(&s->stats, s->collecting_stats);
+      s->collecting_stats = NULL;
     }
-    grpc_exec_ctx_sched(exec_ctx, closure, closure->error, NULL);
+    grpc_closure_run(exec_ctx, closure, closure->error_data.error);
   }
-  *pclosure = NULL;
 }
 
-static int contains_non_ok_status(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_metadata_batch *batch) {
+static bool contains_non_ok_status(grpc_metadata_batch *batch) {
   grpc_linked_mdelem *l;
   for (l = batch->list.head; l; l = l->next) {
     if (l->md->key == GRPC_MDSTR_GRPC_STATUS &&
         l->md != GRPC_MDELEM_GRPC_STATUS_0) {
-      return 1;
+      return true;
     }
   }
-  return 0;
+  return false;
+}
+
+static void add_fetched_slice_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t,
+                                     grpc_chttp2_stream *s);
+
+static void continue_fetching_send_locked(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s) {
+  if (s->fetching_send_message == NULL) {
+    /* Stream was cancelled before message fetch completed */
+    abort(); /* TODO(ctiller): what cleanup here? */
+    return;
+  }
+  if (s->fetched_send_message_length == s->fetching_send_message->length) {
+    int64_t notify_offset = s->next_message_end_offset;
+    if (notify_offset <= s->flow_controlled_bytes_written) {
+      grpc_chttp2_complete_closure_step(
+          exec_ctx, t, s, &s->fetching_send_message_finished, GRPC_ERROR_NONE,
+          "fetching_send_message_finished");
+    } else {
+      grpc_chttp2_write_cb *cb = t->write_cb_pool;
+      if (cb == NULL) {
+        cb = gpr_malloc(sizeof(*cb));
+      } else {
+        t->write_cb_pool = cb->next;
+      }
+      cb->call_at_byte = notify_offset;
+      cb->closure = s->fetching_send_message_finished;
+      s->fetching_send_message_finished = NULL;
+      cb->next = s->on_write_finished_cbs;
+      s->on_write_finished_cbs = cb;
+    }
+    s->fetching_send_message = NULL;
+  } else if (grpc_byte_stream_next(exec_ctx, s->fetching_send_message,
+                                   &s->fetching_slice, UINT32_MAX,
+                                   &s->complete_fetch)) {
+    add_fetched_slice_locked(exec_ctx, t, s);
+  }
+}
+
+static void add_fetched_slice_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t,
+                                     grpc_chttp2_stream *s) {
+  s->fetched_send_message_length +=
+      (uint32_t)GPR_SLICE_LENGTH(s->fetching_slice);
+  gpr_slice_buffer_add(&s->flow_controlled_buffer, s->fetching_slice);
+  if (s->id != 0) {
+    grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
+  }
+  continue_fetching_send_locked(exec_ctx, t, s);
+}
+
+static void complete_fetch_locked(grpc_exec_ctx *exec_ctx, void *gs,
+                                  grpc_error *error) {
+  grpc_chttp2_stream *s = gs;
+  grpc_chttp2_transport *t = s->t;
+  if (error == GRPC_ERROR_NONE) {
+    add_fetched_slice_locked(exec_ctx, t, s);
+  } else {
+    /* TODO(ctiller): what to do here */
+    abort();
+  }
+}
+
+static void complete_fetch(grpc_exec_ctx *exec_ctx, void *gs,
+                           grpc_error *error) {
+  grpc_chttp2_stream *s = gs;
+  grpc_chttp2_transport *t = s->t;
+  grpc_combiner_execute(exec_ctx, t->combiner, &s->complete_fetch_locked,
+                        GRPC_ERROR_REF(error),
+                        s->complete_fetch_covered_by_poller);
 }
 
 static void do_nothing(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {}
@@ -1022,12 +932,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
   grpc_transport_stream_op *op = stream_op;
   grpc_chttp2_transport *t = op->transport_private.args[0];
   grpc_chttp2_stream *s = op->transport_private.args[1];
-  grpc_chttp2_transport_global *transport_global = &t->global;
-  grpc_chttp2_stream_global *stream_global = &s->global;
 
   if (grpc_http_trace) {
     char *str = grpc_transport_stream_op_string(op);
-    gpr_log(GPR_DEBUG, "perform_stream_op_locked: %s", str);
+    gpr_log(GPR_DEBUG, "perform_stream_op_locked: %s; on_complete = %p", str,
+            op->on_complete);
     gpr_free(str);
   }
 
@@ -1035,45 +944,42 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
   if (on_complete == NULL) {
     on_complete = grpc_closure_create(do_nothing, NULL);
   }
+
   /* use final_data as a barrier until enqueue time; the inital counter is
      dropped at the end of this function */
   on_complete->next_data.scratch = CLOSURE_BARRIER_FIRST_REF_BIT;
-  on_complete->error = GRPC_ERROR_NONE;
+  on_complete->error_data.error = GRPC_ERROR_NONE;
 
   if (op->collect_stats != NULL) {
-    GPR_ASSERT(stream_global->collecting_stats == NULL);
-    stream_global->collecting_stats = op->collect_stats;
+    GPR_ASSERT(s->collecting_stats == NULL);
+    s->collecting_stats = op->collect_stats;
     on_complete->next_data.scratch |= CLOSURE_BARRIER_STATS_BIT;
   }
 
   if (op->cancel_error != GRPC_ERROR_NONE) {
-    cancel_from_api(exec_ctx, transport_global, stream_global,
-                    GRPC_ERROR_REF(op->cancel_error));
+    grpc_chttp2_cancel_stream(exec_ctx, t, s, GRPC_ERROR_REF(op->cancel_error));
   }
 
   if (op->close_error != GRPC_ERROR_NONE) {
-    close_from_api(exec_ctx, transport_global, stream_global,
-                   GRPC_ERROR_REF(op->close_error));
+    close_from_api(exec_ctx, t, s, GRPC_ERROR_REF(op->close_error));
   }
 
   if (op->send_initial_metadata != NULL) {
-    GPR_ASSERT(stream_global->send_initial_metadata_finished == NULL);
-    stream_global->send_initial_metadata_finished =
-        add_closure_barrier(on_complete);
-    stream_global->send_initial_metadata = op->send_initial_metadata;
+    GPR_ASSERT(s->send_initial_metadata_finished == NULL);
+    s->send_initial_metadata_finished = add_closure_barrier(on_complete);
+    s->send_initial_metadata = op->send_initial_metadata;
     const size_t metadata_size =
         grpc_metadata_batch_size(op->send_initial_metadata);
     const size_t metadata_peer_limit =
-        transport_global->settings[GRPC_PEER_SETTINGS]
-                                  [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
-    if (transport_global->is_client) {
-      stream_global->deadline =
-          gpr_time_min(stream_global->deadline,
-                       stream_global->send_initial_metadata->deadline);
+        t->settings[GRPC_PEER_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
+    if (t->is_client) {
+      s->deadline =
+          gpr_time_min(s->deadline, s->send_initial_metadata->deadline);
     }
     if (metadata_size > metadata_peer_limit) {
-      cancel_from_api(
-          exec_ctx, transport_global, stream_global,
+      grpc_chttp2_cancel_stream(
+          exec_ctx, t, s,
           grpc_error_set_int(
               grpc_error_set_int(
                   grpc_error_set_int(
@@ -1083,64 +989,78 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
-      if (contains_non_ok_status(transport_global, op->send_initial_metadata)) {
-        stream_global->seen_error = true;
-        grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                            stream_global);
+      if (contains_non_ok_status(op->send_initial_metadata)) {
+        s->seen_error = true;
       }
-      if (!stream_global->write_closed) {
-        if (transport_global->is_client) {
-          GPR_ASSERT(stream_global->id == 0);
-          grpc_chttp2_list_add_waiting_for_concurrency(transport_global,
-                                                       stream_global);
-          maybe_start_some_streams(exec_ctx, transport_global);
+      if (!s->write_closed) {
+        if (t->is_client) {
+          GPR_ASSERT(s->id == 0);
+          grpc_chttp2_list_add_waiting_for_concurrency(t, s);
+          maybe_start_some_streams(exec_ctx, t);
         } else {
-          GPR_ASSERT(stream_global->id != 0);
-          grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                      true, "op.send_initial_metadata");
+          GPR_ASSERT(s->id != 0);
+          grpc_chttp2_become_writable(exec_ctx, t, s, true,
+                                      "op.send_initial_metadata");
         }
       } else {
-        stream_global->send_trailing_metadata = NULL;
+        s->send_trailing_metadata = NULL;
         grpc_chttp2_complete_closure_step(
-            exec_ctx, transport_global, stream_global,
-            &stream_global->send_initial_metadata_finished,
+            exec_ctx, t, s, &s->send_initial_metadata_finished,
             GRPC_ERROR_CREATE(
-                "Attempt to send initial metadata after stream was closed"));
+                "Attempt to send initial metadata after stream was closed"),
+            "send_initial_metadata_finished");
       }
     }
   }
 
   if (op->send_message != NULL) {
-    GPR_ASSERT(stream_global->send_message_finished == NULL);
-    GPR_ASSERT(stream_global->send_message == NULL);
-    stream_global->send_message_finished = add_closure_barrier(on_complete);
-    if (stream_global->write_closed) {
+    s->fetching_send_message_finished = add_closure_barrier(op->on_complete);
+    if (s->write_closed) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, transport_global, stream_global,
-          &stream_global->send_message_finished,
-          GRPC_ERROR_CREATE("Attempt to send message after stream was closed"));
+          exec_ctx, t, s, &s->fetching_send_message_finished,
+          GRPC_ERROR_CREATE("Attempt to send message after stream was closed"),
+          "fetching_send_message_finished");
     } else {
-      stream_global->send_message = op->send_message;
-      if (stream_global->id != 0) {
-        grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                    true, "op.send_message");
+      GPR_ASSERT(s->fetching_send_message == NULL);
+      uint8_t *frame_hdr =
+          gpr_slice_buffer_tiny_add(&s->flow_controlled_buffer, 5);
+      uint32_t flags = op->send_message->flags;
+      frame_hdr[0] = (flags & GRPC_WRITE_INTERNAL_COMPRESS) != 0;
+      size_t len = op->send_message->length;
+      frame_hdr[1] = (uint8_t)(len >> 24);
+      frame_hdr[2] = (uint8_t)(len >> 16);
+      frame_hdr[3] = (uint8_t)(len >> 8);
+      frame_hdr[4] = (uint8_t)(len);
+      s->fetching_send_message = op->send_message;
+      s->fetched_send_message_length = 0;
+      s->next_message_end_offset = s->flow_controlled_bytes_written +
+                                   (int64_t)s->flow_controlled_buffer.length +
+                                   (int64_t)len;
+      s->complete_fetch_covered_by_poller = op->covered_by_poller;
+      if (flags & GRPC_WRITE_BUFFER_HINT) {
+        /* allow up to 64kb to be buffered */
+        /* TODO(ctiller): make this configurable */
+        s->next_message_end_offset -= 65536;
+      }
+      continue_fetching_send_locked(exec_ctx, t, s);
+      if (s->id != 0) {
+        grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
       }
     }
   }
 
   if (op->send_trailing_metadata != NULL) {
-    GPR_ASSERT(stream_global->send_trailing_metadata_finished == NULL);
-    stream_global->send_trailing_metadata_finished =
-        add_closure_barrier(on_complete);
-    stream_global->send_trailing_metadata = op->send_trailing_metadata;
+    GPR_ASSERT(s->send_trailing_metadata_finished == NULL);
+    s->send_trailing_metadata_finished = add_closure_barrier(on_complete);
+    s->send_trailing_metadata = op->send_trailing_metadata;
     const size_t metadata_size =
         grpc_metadata_batch_size(op->send_trailing_metadata);
     const size_t metadata_peer_limit =
-        transport_global->settings[GRPC_PEER_SETTINGS]
-                                  [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
+        t->settings[GRPC_PEER_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
     if (metadata_size > metadata_peer_limit) {
-      cancel_from_api(
-          exec_ctx, transport_global, stream_global,
+      grpc_chttp2_cancel_stream(
+          exec_ctx, t, s,
           grpc_error_set_int(
               grpc_error_set_int(
                   grpc_error_set_int(
@@ -1150,69 +1070,59 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
-      if (contains_non_ok_status(transport_global,
-                                 op->send_trailing_metadata)) {
-        stream_global->seen_error = true;
-        grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                            stream_global);
+      if (contains_non_ok_status(op->send_trailing_metadata)) {
+        s->seen_error = true;
       }
-      if (stream_global->write_closed) {
-        stream_global->send_trailing_metadata = NULL;
+      if (s->write_closed) {
+        s->send_trailing_metadata = NULL;
         grpc_chttp2_complete_closure_step(
-            exec_ctx, transport_global, stream_global,
-            &stream_global->send_trailing_metadata_finished,
+            exec_ctx, t, s, &s->send_trailing_metadata_finished,
             grpc_metadata_batch_is_empty(op->send_trailing_metadata)
                 ? GRPC_ERROR_NONE
                 : GRPC_ERROR_CREATE("Attempt to send trailing metadata after "
-                                    "stream was closed"));
-      } else if (stream_global->id != 0) {
+                                    "stream was closed"),
+            "send_trailing_metadata_finished");
+      } else if (s->id != 0) {
         /* TODO(ctiller): check if there's flow control for any outstanding
            bytes before going writable */
-        grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                    true, "op.send_trailing_metadata");
+        grpc_chttp2_become_writable(exec_ctx, t, s, true,
+                                    "op.send_trailing_metadata");
       }
     }
   }
 
   if (op->recv_initial_metadata != NULL) {
-    GPR_ASSERT(stream_global->recv_initial_metadata_ready == NULL);
-    stream_global->recv_initial_metadata_ready =
-        op->recv_initial_metadata_ready;
-    stream_global->recv_initial_metadata = op->recv_initial_metadata;
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+    GPR_ASSERT(s->recv_initial_metadata_ready == NULL);
+    s->recv_initial_metadata_ready = op->recv_initial_metadata_ready;
+    s->recv_initial_metadata = op->recv_initial_metadata;
+    grpc_chttp2_maybe_complete_recv_initial_metadata(exec_ctx, t, s);
   }
 
   if (op->recv_message != NULL) {
-    GPR_ASSERT(stream_global->recv_message_ready == NULL);
-    stream_global->recv_message_ready = op->recv_message_ready;
-    stream_global->recv_message = op->recv_message;
-    if (stream_global->id != 0 &&
-        (stream_global->incoming_frames.head == NULL ||
-         stream_global->incoming_frames.head->is_tail)) {
-      incoming_byte_stream_update_flow_control(
-          exec_ctx, transport_global, stream_global,
-          transport_global->stream_lookahead, 0);
+    GPR_ASSERT(s->recv_message_ready == NULL);
+    s->recv_message_ready = op->recv_message_ready;
+    s->recv_message = op->recv_message;
+    if (s->id != 0 &&
+        (s->incoming_frames.head == NULL || s->incoming_frames.head->is_tail)) {
+      incoming_byte_stream_update_flow_control(exec_ctx, t, s,
+                                               t->stream_lookahead, 0);
     }
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+    grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
   }
 
   if (op->recv_trailing_metadata != NULL) {
-    GPR_ASSERT(stream_global->recv_trailing_metadata_finished == NULL);
-    stream_global->recv_trailing_metadata_finished =
-        add_closure_barrier(on_complete);
-    stream_global->recv_trailing_metadata = op->recv_trailing_metadata;
-    stream_global->final_metadata_requested = true;
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+    GPR_ASSERT(s->recv_trailing_metadata_finished == NULL);
+    s->recv_trailing_metadata_finished = add_closure_barrier(on_complete);
+    s->recv_trailing_metadata = op->recv_trailing_metadata;
+    s->final_metadata_requested = true;
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
 
-  grpc_chttp2_complete_closure_step(exec_ctx, transport_global, stream_global,
-                                    &on_complete, GRPC_ERROR_NONE);
+  grpc_chttp2_complete_closure_step(exec_ctx, t, s, &on_complete,
+                                    GRPC_ERROR_NONE, "op->on_complete");
 
   GPR_TIMER_END("perform_stream_op_locked", 0);
-  GRPC_CHTTP2_STREAM_UNREF(exec_ctx, &s->global, "perform_stream_op");
+  GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "perform_stream_op");
 }
 
 static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
@@ -1220,70 +1130,60 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   GPR_TIMER_BEGIN("perform_stream_op", 0);
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)gt;
   grpc_chttp2_stream *s = (grpc_chttp2_stream *)gs;
+
+  if (grpc_http_trace) {
+    char *str = grpc_transport_stream_op_string(op);
+    gpr_log(GPR_DEBUG, "perform_stream_op[s=%p/%d]: %s", s, s->id, str);
+    gpr_free(str);
+  }
+
   grpc_closure_init(&op->transport_private.closure, perform_stream_op_locked,
                     op);
   op->transport_private.args[0] = gt;
   op->transport_private.args[1] = gs;
-  GRPC_CHTTP2_STREAM_REF(&s->global, "perform_stream_op");
-  grpc_combiner_execute(exec_ctx, t->executor.combiner,
-                        &op->transport_private.closure, GRPC_ERROR_NONE);
+  GRPC_CHTTP2_STREAM_REF(s, "perform_stream_op");
+  grpc_combiner_execute(exec_ctx, t->combiner, &op->transport_private.closure,
+                        GRPC_ERROR_NONE, op->covered_by_poller);
   GPR_TIMER_END("perform_stream_op", 0);
 }
 
 static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              grpc_closure *on_recv) {
   grpc_chttp2_outstanding_ping *p = gpr_malloc(sizeof(*p));
-  p->next = &t->global.pings;
+  p->next = &t->pings;
   p->prev = p->next->prev;
   p->prev->next = p->next->prev = p;
-  p->id[0] = (uint8_t)((t->global.ping_counter >> 56) & 0xff);
-  p->id[1] = (uint8_t)((t->global.ping_counter >> 48) & 0xff);
-  p->id[2] = (uint8_t)((t->global.ping_counter >> 40) & 0xff);
-  p->id[3] = (uint8_t)((t->global.ping_counter >> 32) & 0xff);
-  p->id[4] = (uint8_t)((t->global.ping_counter >> 24) & 0xff);
-  p->id[5] = (uint8_t)((t->global.ping_counter >> 16) & 0xff);
-  p->id[6] = (uint8_t)((t->global.ping_counter >> 8) & 0xff);
-  p->id[7] = (uint8_t)(t->global.ping_counter & 0xff);
+  p->id[0] = (uint8_t)((t->ping_counter >> 56) & 0xff);
+  p->id[1] = (uint8_t)((t->ping_counter >> 48) & 0xff);
+  p->id[2] = (uint8_t)((t->ping_counter >> 40) & 0xff);
+  p->id[3] = (uint8_t)((t->ping_counter >> 32) & 0xff);
+  p->id[4] = (uint8_t)((t->ping_counter >> 24) & 0xff);
+  p->id[5] = (uint8_t)((t->ping_counter >> 16) & 0xff);
+  p->id[6] = (uint8_t)((t->ping_counter >> 8) & 0xff);
+  p->id[7] = (uint8_t)(t->ping_counter & 0xff);
+  t->ping_counter++;
   p->on_recv = on_recv;
-  gpr_slice_buffer_add(&t->global.qbuf, grpc_chttp2_ping_create(0, p->id));
-  grpc_chttp2_initiate_write(exec_ctx, &t->global, true, "send_ping");
+  gpr_slice_buffer_add(&t->qbuf, grpc_chttp2_ping_create(0, p->id));
+  grpc_chttp2_initiate_write(exec_ctx, t, true, "send_ping");
 }
 
-typedef struct ack_ping_args {
-  grpc_closure closure;
-  grpc_chttp2_transport *t;
-  uint8_t opaque_8bytes[8];
-} ack_ping_args;
-
-static void ack_ping_locked(grpc_exec_ctx *exec_ctx, void *a,
-                            grpc_error *error_ignored) {
-  ack_ping_args *args = a;
+void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                          const uint8_t *opaque_8bytes) {
   grpc_chttp2_outstanding_ping *ping;
-  grpc_chttp2_transport_global *transport_global = &args->t->global;
-  for (ping = transport_global->pings.next; ping != &transport_global->pings;
-       ping = ping->next) {
-    if (0 == memcmp(args->opaque_8bytes, ping->id, 8)) {
+  for (ping = t->pings.next; ping != &t->pings; ping = ping->next) {
+    if (0 == memcmp(opaque_8bytes, ping->id, 8)) {
       grpc_exec_ctx_sched(exec_ctx, ping->on_recv, GRPC_ERROR_NONE, NULL);
       ping->next->prev = ping->prev;
       ping->prev->next = ping->next;
       gpr_free(ping);
-      break;
+      return;
     }
   }
-  UNREF_TRANSPORT(exec_ctx, args->t, "ack_ping");
-  gpr_free(args);
-}
-
-void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx,
-                          grpc_chttp2_transport_parsing *transport_parsing,
-                          const uint8_t *opaque_8bytes) {
-  ack_ping_args *args = gpr_malloc(sizeof(*args));
-  args->t = TRANSPORT_FROM_PARSING(transport_parsing);
-  memcpy(args->opaque_8bytes, opaque_8bytes, sizeof(args->opaque_8bytes));
-  grpc_closure_init(&args->closure, ack_ping_locked, args);
-  REF_TRANSPORT(args->t, "ack_ping");
-  grpc_combiner_execute(exec_ctx, args->t->executor.combiner, &args->closure,
-                        GRPC_ERROR_NONE);
+  char *msg = gpr_dump((const char *)opaque_8bytes, 8, GPR_DUMP_HEX);
+  char *from = grpc_endpoint_get_peer(t->ep);
+  gpr_log(GPR_DEBUG, "Unknown ping response from %s: %s", from, msg);
+  gpr_free(from);
+  gpr_free(msg);
 }
 
 static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
@@ -1293,15 +1193,6 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
   grpc_chttp2_transport *t = op->transport_private.args[0];
   grpc_error *close_transport = op->disconnect_with_error;
 
-  /* If there's a set_accept_stream ensure that we're not parsing
-     to avoid changing things out from underneath */
-  if (t->executor.parsing_active && op->set_accept_stream) {
-    GPR_ASSERT(t->post_parsing_op == NULL);
-    t->post_parsing_op = gpr_malloc(sizeof(*op));
-    memcpy(t->post_parsing_op, op, sizeof(*op));
-    return;
-  }
-
   if (op->on_connectivity_state_change != NULL) {
     grpc_connectivity_state_notify_on_state_change(
         exec_ctx, &t->channel_callback.state_tracker, op->connectivity_state,
@@ -1309,15 +1200,15 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->send_goaway) {
-    t->global.sent_goaway = 1;
+    t->sent_goaway = 1;
     grpc_chttp2_goaway_append(
-        t->global.last_incoming_stream_id,
+        t->last_new_stream_id,
         (uint32_t)grpc_chttp2_grpc_status_to_http2_error(op->goaway_status),
-        gpr_slice_ref(*op->goaway_message), &t->global.qbuf);
-    close_transport = grpc_chttp2_has_streams(t)
-                          ? GRPC_ERROR_NONE
-                          : GRPC_ERROR_CREATE("GOAWAY sent");
-    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "goaway_sent");
+        gpr_slice_ref(*op->goaway_message), &t->qbuf);
+    close_transport = grpc_chttp2_stream_map_size(&t->stream_map) == 0
+                          ? GRPC_ERROR_CREATE("GOAWAY sent")
+                          : GRPC_ERROR_NONE;
+    grpc_chttp2_initiate_write(exec_ctx, t, false, "goaway_sent");
   }
 
   if (op->set_accept_stream) {
@@ -1342,154 +1233,127 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
     close_transport_locked(exec_ctx, t, close_transport);
   }
 
-  grpc_exec_ctx_sched(exec_ctx, op->on_consumed, GRPC_ERROR_NONE, NULL);
+  grpc_closure_run(exec_ctx, op->on_consumed, GRPC_ERROR_NONE);
 
-  UNREF_TRANSPORT(exec_ctx, t, "transport_op");
+  GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "transport_op");
 }
 
 static void perform_transport_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                  grpc_transport_op *op) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)gt;
+  char *msg = grpc_transport_op_string(op);
+  gpr_free(msg);
   op->transport_private.args[0] = gt;
   grpc_closure_init(&op->transport_private.closure, perform_transport_op_locked,
                     op);
-  REF_TRANSPORT(t, "transport_op");
-  grpc_combiner_execute(exec_ctx, t->executor.combiner,
-                        &op->transport_private.closure, GRPC_ERROR_NONE);
+  GRPC_CHTTP2_REF_TRANSPORT(t, "transport_op");
+  grpc_combiner_execute(exec_ctx, t->combiner, &op->transport_private.closure,
+                        GRPC_ERROR_NONE, false);
 }
 
 /*******************************************************************************
  * INPUT PROCESSING - GENERAL
  */
 
-static void check_read_ops(grpc_exec_ctx *exec_ctx,
-                           grpc_chttp2_transport_global *transport_global) {
-  GPR_TIMER_BEGIN("check_read_ops", 0);
-  grpc_chttp2_stream_global *stream_global;
+void grpc_chttp2_maybe_complete_recv_initial_metadata(grpc_exec_ctx *exec_ctx,
+                                                      grpc_chttp2_transport *t,
+                                                      grpc_chttp2_stream *s) {
   grpc_byte_stream *bs;
-  while (
-      grpc_chttp2_list_pop_check_read_ops(transport_global, &stream_global)) {
-    if (stream_global->recv_initial_metadata_ready != NULL &&
-        stream_global->published_initial_metadata) {
-      if (stream_global->seen_error) {
-        while ((bs = grpc_chttp2_incoming_frame_queue_pop(
-                    &stream_global->incoming_frames)) != NULL) {
-          incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
-        }
-        if (stream_global->exceeded_metadata_size) {
-          cancel_from_api(
-              exec_ctx, transport_global, stream_global,
-              grpc_error_set_int(
-                  GRPC_ERROR_CREATE(
-                      "received initial metadata size exceeds limit"),
-                  GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
-        }
+  if (s->recv_initial_metadata_ready != NULL &&
+      s->published_metadata[0] != GRPC_METADATA_NOT_PUBLISHED) {
+    if (s->seen_error) {
+      while ((bs = grpc_chttp2_incoming_frame_queue_pop(&s->incoming_frames)) !=
+             NULL) {
+        incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
       }
-      grpc_chttp2_incoming_metadata_buffer_publish(
-          &stream_global->received_initial_metadata,
-          stream_global->recv_initial_metadata);
-      grpc_exec_ctx_sched(exec_ctx, stream_global->recv_initial_metadata_ready,
-                          GRPC_ERROR_NONE, NULL);
-      stream_global->recv_initial_metadata_ready = NULL;
     }
-    if (stream_global->recv_message_ready != NULL) {
-      while (stream_global->final_metadata_requested &&
-             stream_global->seen_error &&
-             (bs = grpc_chttp2_incoming_frame_queue_pop(
-                  &stream_global->incoming_frames)) != NULL) {
+    grpc_chttp2_incoming_metadata_buffer_publish(&s->metadata_buffer[0],
+                                                 s->recv_initial_metadata);
+    null_then_run_closure(exec_ctx, &s->recv_initial_metadata_ready,
+                          GRPC_ERROR_NONE);
+  }
+}
+
+void grpc_chttp2_maybe_complete_recv_message(grpc_exec_ctx *exec_ctx,
+                                             grpc_chttp2_transport *t,
+                                             grpc_chttp2_stream *s) {
+  grpc_byte_stream *bs;
+  if (s->recv_message_ready != NULL) {
+    while (s->final_metadata_requested && s->seen_error &&
+           (bs = grpc_chttp2_incoming_frame_queue_pop(&s->incoming_frames)) !=
+               NULL) {
+      incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
+    }
+    if (s->incoming_frames.head != NULL) {
+      *s->recv_message =
+          grpc_chttp2_incoming_frame_queue_pop(&s->incoming_frames);
+      GPR_ASSERT(*s->recv_message != NULL);
+      null_then_run_closure(exec_ctx, &s->recv_message_ready, GRPC_ERROR_NONE);
+    } else if (s->published_metadata[1] != GRPC_METADATA_NOT_PUBLISHED) {
+      *s->recv_message = NULL;
+      null_then_run_closure(exec_ctx, &s->recv_message_ready, GRPC_ERROR_NONE);
+    }
+  }
+}
+
+void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
+                                                       grpc_chttp2_transport *t,
+                                                       grpc_chttp2_stream *s) {
+  grpc_byte_stream *bs;
+  grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
+  if (s->recv_trailing_metadata_finished != NULL && s->read_closed &&
+      s->write_closed) {
+    if (s->seen_error) {
+      while ((bs = grpc_chttp2_incoming_frame_queue_pop(&s->incoming_frames)) !=
+             NULL) {
         incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
       }
-      if (stream_global->incoming_frames.head != NULL) {
-        *stream_global->recv_message = grpc_chttp2_incoming_frame_queue_pop(
-            &stream_global->incoming_frames);
-        GPR_ASSERT(*stream_global->recv_message != NULL);
-        grpc_exec_ctx_sched(exec_ctx, stream_global->recv_message_ready,
-                            GRPC_ERROR_NONE, NULL);
-        stream_global->recv_message_ready = NULL;
-      } else if (stream_global->published_trailing_metadata) {
-        *stream_global->recv_message = NULL;
-        grpc_exec_ctx_sched(exec_ctx, stream_global->recv_message_ready,
-                            GRPC_ERROR_NONE, NULL);
-        stream_global->recv_message_ready = NULL;
-      }
     }
-    if (stream_global->recv_trailing_metadata_finished != NULL &&
-        stream_global->read_closed && stream_global->write_closed) {
-      if (stream_global->seen_error) {
-        while ((bs = grpc_chttp2_incoming_frame_queue_pop(
-                    &stream_global->incoming_frames)) != NULL) {
-          incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
-        }
-        if (stream_global->exceeded_metadata_size) {
-          cancel_from_api(
-              exec_ctx, transport_global, stream_global,
-              grpc_error_set_int(
-                  GRPC_ERROR_CREATE(
-                      "received trailing metadata size exceeds limit"),
-                  GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
-        }
-      }
-      if (stream_global->all_incoming_byte_streams_finished) {
-        grpc_chttp2_incoming_metadata_buffer_publish(
-            &stream_global->received_trailing_metadata,
-            stream_global->recv_trailing_metadata);
-        grpc_chttp2_complete_closure_step(
-            exec_ctx, transport_global, stream_global,
-            &stream_global->recv_trailing_metadata_finished, GRPC_ERROR_NONE);
-      }
+    if (s->all_incoming_byte_streams_finished &&
+        s->recv_trailing_metadata_finished != NULL) {
+      grpc_chttp2_incoming_metadata_buffer_publish(&s->metadata_buffer[1],
+                                                   s->recv_trailing_metadata);
+      grpc_chttp2_complete_closure_step(
+          exec_ctx, t, s, &s->recv_trailing_metadata_finished, GRPC_ERROR_NONE,
+          "recv_trailing_metadata_finished");
     }
   }
-  GPR_TIMER_END("check_read_ops", 0);
 }
 
-static void decrement_active_streams_locked(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  if ((stream_global->all_incoming_byte_streams_finished =
-           gpr_unref(&stream_global->active_streams))) {
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+static void decrement_active_streams_locked(grpc_exec_ctx *exec_ctx,
+                                            grpc_chttp2_transport *t,
+                                            grpc_chttp2_stream *s) {
+  if ((s->all_incoming_byte_streams_finished = gpr_unref(&s->active_streams))) {
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
 }
 
 static void remove_stream(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           uint32_t id, grpc_error *error) {
-  size_t new_stream_count;
-  grpc_chttp2_stream *s =
-      grpc_chttp2_stream_map_delete(&t->parsing_stream_map, id);
-  if (!s) {
-    s = grpc_chttp2_stream_map_delete(&t->new_stream_map, id);
-  }
+  grpc_chttp2_stream *s = grpc_chttp2_stream_map_delete(&t->stream_map, id);
   GPR_ASSERT(s);
-  s->global.in_stream_map = false;
-  if (t->parsing.incoming_stream == &s->parsing) {
-    t->parsing.incoming_stream = NULL;
-    grpc_chttp2_parsing_become_skip_parser(exec_ctx, &t->parsing);
+  if (t->incoming_stream == s) {
+    t->incoming_stream = NULL;
+    grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
   }
-  if (s->parsing.data_parser.parsing_frame != NULL) {
+  if (s->data_parser.parsing_frame != NULL) {
     grpc_chttp2_incoming_byte_stream_finished(
-        exec_ctx, s->parsing.data_parser.parsing_frame, GRPC_ERROR_REF(error),
-        0);
-    s->parsing.data_parser.parsing_frame = NULL;
+        exec_ctx, s->data_parser.parsing_frame, GRPC_ERROR_REF(error));
+    s->data_parser.parsing_frame = NULL;
   }
 
-  if (grpc_chttp2_unregister_stream(t, s) && t->global.sent_goaway) {
+  if (grpc_chttp2_stream_map_size(&t->stream_map) == 0 && t->sent_goaway) {
     close_transport_locked(
         exec_ctx, t, GRPC_ERROR_CREATE_REFERENCING(
                          "Last stream closed after sending GOAWAY", &error, 1));
   }
-  if (grpc_chttp2_list_remove_writable_stream(&t->global, &s->global)) {
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, &s->global, "chttp2_writing");
+  if (grpc_chttp2_list_remove_writable_stream(t, s)) {
+    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:remove_stream");
   }
 
-  new_stream_count = grpc_chttp2_stream_map_size(&t->parsing_stream_map) +
-                     grpc_chttp2_stream_map_size(&t->new_stream_map);
-  GPR_ASSERT(new_stream_count <= UINT32_MAX);
-  if (new_stream_count != t->global.concurrent_stream_count) {
-    t->global.concurrent_stream_count = (uint32_t)new_stream_count;
-    maybe_start_some_streams(exec_ctx, &t->global);
-  }
   GRPC_ERROR_UNREF(error);
+
+  maybe_start_some_streams(exec_ctx, t);
 }
 
 static void status_codes_from_error(grpc_error *error, gpr_timespec deadline,
@@ -1519,23 +1383,20 @@ static void status_codes_from_error(grpc_error *error, gpr_timespec deadline,
   }
 }
 
-static void cancel_from_api(grpc_exec_ctx *exec_ctx,
-                            grpc_chttp2_transport_global *transport_global,
-                            grpc_chttp2_stream_global *stream_global,
-                            grpc_error *due_to_error) {
-  if (!stream_global->read_closed || !stream_global->write_closed) {
+void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+                               grpc_error *due_to_error) {
+  if (!s->read_closed || !s->write_closed) {
     grpc_status_code grpc_status;
     grpc_chttp2_error_code http_error;
-    status_codes_from_error(due_to_error, stream_global->deadline, &http_error,
+    status_codes_from_error(due_to_error, s->deadline, &http_error,
                             &grpc_status);
 
-    if (stream_global->id != 0) {
+    if (s->id != 0) {
       gpr_slice_buffer_add(
-          &transport_global->qbuf,
-          grpc_chttp2_rst_stream_create(stream_global->id, (uint32_t)http_error,
-                                        &stream_global->stats.outgoing));
-      grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                                 "rst_stream");
+          &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
+                                                  &s->stats.outgoing));
+      grpc_chttp2_initiate_write(exec_ctx, t, false, "rst_stream");
     }
 
     const char *msg =
@@ -1546,27 +1407,21 @@ static void cancel_from_api(grpc_exec_ctx *exec_ctx,
       msg = grpc_error_string(due_to_error);
     }
     gpr_slice msg_slice = gpr_slice_from_copied_string(msg);
-    grpc_chttp2_fake_status(exec_ctx, transport_global, stream_global,
-                            grpc_status, &msg_slice);
+    grpc_chttp2_fake_status(exec_ctx, t, s, grpc_status, &msg_slice);
     if (free_msg) grpc_error_free_string(msg);
   }
-  if (due_to_error != GRPC_ERROR_NONE && !stream_global->seen_error) {
-    stream_global->seen_error = true;
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+  if (due_to_error != GRPC_ERROR_NONE && !s->seen_error) {
+    s->seen_error = true;
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
-  grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global, 1,
-                                 1, due_to_error);
+  grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, due_to_error);
 }
 
-void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx,
-                             grpc_chttp2_transport_global *transport_global,
-                             grpc_chttp2_stream_global *stream_global,
-                             grpc_status_code status, gpr_slice *slice) {
+void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_chttp2_stream *s, grpc_status_code status,
+                             gpr_slice *slice) {
   if (status != GRPC_STATUS_OK) {
-    stream_global->seen_error = true;
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+    s->seen_error = true;
   }
   /* stream_global->recv_trailing_metadata_finished gives us a
      last chance replacement: we've received trailing metadata,
@@ -1574,24 +1429,23 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx,
      to the upper layers - drop what we've got, and then publish
      what we want - which is safe because we haven't told anyone
      about the metadata yet */
-  if (!stream_global->published_trailing_metadata ||
-      stream_global->recv_trailing_metadata_finished != NULL) {
+  if (s->published_metadata[1] == GRPC_METADATA_NOT_PUBLISHED ||
+      s->recv_trailing_metadata_finished != NULL) {
     char status_string[GPR_LTOA_MIN_BUFSIZE];
     gpr_ltoa(status, status_string);
     grpc_chttp2_incoming_metadata_buffer_add(
-        &stream_global->received_trailing_metadata,
+        &s->metadata_buffer[1],
         grpc_mdelem_from_metadata_strings(
             GRPC_MDSTR_GRPC_STATUS, grpc_mdstr_from_string(status_string)));
     if (slice) {
       grpc_chttp2_incoming_metadata_buffer_add(
-          &stream_global->received_trailing_metadata,
+          &s->metadata_buffer[1],
           grpc_mdelem_from_metadata_strings(
               GRPC_MDSTR_GRPC_MESSAGE,
               grpc_mdstr_from_slice(gpr_slice_ref(*slice))));
     }
-    stream_global->published_trailing_metadata = true;
-    grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                        stream_global);
+    s->published_metadata[1] = GRPC_METADATA_SYNTHESIZED_FROM_FAKE;
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
   if (slice) {
     gpr_slice_unref(*slice);
@@ -1609,91 +1463,88 @@ static void add_error(grpc_error *error, grpc_error **refs, size_t *nrefs) {
   ++*nrefs;
 }
 
-static grpc_error *removal_error(grpc_error *extra_error,
-                                 grpc_chttp2_stream_global *stream_global) {
+static grpc_error *removal_error(grpc_error *extra_error, grpc_chttp2_stream *s,
+                                 const char *master_error_msg) {
   grpc_error *refs[3];
   size_t nrefs = 0;
-  add_error(stream_global->read_closed_error, refs, &nrefs);
-  add_error(stream_global->write_closed_error, refs, &nrefs);
+  add_error(s->read_closed_error, refs, &nrefs);
+  add_error(s->write_closed_error, refs, &nrefs);
   add_error(extra_error, refs, &nrefs);
   grpc_error *error = GRPC_ERROR_NONE;
   if (nrefs > 0) {
-    error = GRPC_ERROR_CREATE_REFERENCING("Failed due to stream removal", refs,
-                                          nrefs);
+    error = GRPC_ERROR_CREATE_REFERENCING(master_error_msg, refs, nrefs);
   }
   GRPC_ERROR_UNREF(extra_error);
   return error;
 }
 
 static void fail_pending_writes(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport_global *transport_global,
-                                grpc_chttp2_stream_global *stream_global,
+                                grpc_chttp2_transport *t, grpc_chttp2_stream *s,
                                 grpc_error *error) {
-  error = removal_error(error, stream_global);
-  stream_global->send_message = NULL;
+  error =
+      removal_error(error, s, "Pending writes failed due to stream closure");
+  s->fetching_send_message = NULL;
   grpc_chttp2_complete_closure_step(
-      exec_ctx, transport_global, stream_global,
-      &stream_global->send_initial_metadata_finished, GRPC_ERROR_REF(error));
+      exec_ctx, t, s, &s->send_initial_metadata_finished, GRPC_ERROR_REF(error),
+      "send_initial_metadata_finished");
   grpc_chttp2_complete_closure_step(
-      exec_ctx, transport_global, stream_global,
-      &stream_global->send_trailing_metadata_finished, GRPC_ERROR_REF(error));
-  grpc_chttp2_complete_closure_step(exec_ctx, transport_global, stream_global,
-                                    &stream_global->send_message_finished,
-                                    error);
+      exec_ctx, t, s, &s->send_trailing_metadata_finished,
+      GRPC_ERROR_REF(error), "send_trailing_metadata_finished");
+  grpc_chttp2_complete_closure_step(
+      exec_ctx, t, s, &s->fetching_send_message_finished, GRPC_ERROR_REF(error),
+      "fetching_send_message_finished");
+  while (s->on_write_finished_cbs) {
+    grpc_chttp2_write_cb *cb = s->on_write_finished_cbs;
+    s->on_write_finished_cbs = cb->next;
+    grpc_chttp2_complete_closure_step(exec_ctx, t, s, &cb->closure,
+                                      GRPC_ERROR_REF(error),
+                                      "on_write_finished_cb");
+    cb->next = t->write_cb_pool;
+    t->write_cb_pool = cb;
+  }
+  GRPC_ERROR_UNREF(error);
 }
 
-void grpc_chttp2_mark_stream_closed(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, int close_reads, int close_writes,
-    grpc_error *error) {
-  if (stream_global->read_closed && stream_global->write_closed) {
+void grpc_chttp2_mark_stream_closed(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_transport *t,
+                                    grpc_chttp2_stream *s, int close_reads,
+                                    int close_writes, grpc_error *error) {
+  if (s->read_closed && s->write_closed) {
     /* already closed */
     GRPC_ERROR_UNREF(error);
     return;
   }
-  grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                      stream_global);
-  if (close_reads && !stream_global->read_closed) {
-    stream_global->read_closed_error = GRPC_ERROR_REF(error);
-    stream_global->read_closed = true;
-    stream_global->published_initial_metadata = true;
-    stream_global->published_trailing_metadata = true;
-    decrement_active_streams_locked(exec_ctx, transport_global, stream_global);
-  }
-  if (close_writes && !stream_global->write_closed) {
-    stream_global->write_closed_error = GRPC_ERROR_REF(error);
-    stream_global->write_closed = true;
-    if (TRANSPORT_FROM_GLOBAL(transport_global)->executor.write_state !=
-        GRPC_CHTTP2_WRITING_INACTIVE) {
-      GRPC_CHTTP2_STREAM_REF(stream_global, "finish_writes");
-      grpc_chttp2_list_add_closed_waiting_for_writing(transport_global,
-                                                      stream_global);
-    } else {
-      fail_pending_writes(exec_ctx, transport_global, stream_global,
-                          GRPC_ERROR_REF(error));
-    }
-  }
-  if (stream_global->read_closed && stream_global->write_closed) {
-    if (stream_global->id != 0 &&
-        TRANSPORT_FROM_GLOBAL(transport_global)->executor.parsing_active) {
-      grpc_chttp2_list_add_closed_waiting_for_parsing(transport_global,
-                                                      stream_global);
-    } else {
-      if (stream_global->id != 0) {
-        remove_stream(exec_ctx, TRANSPORT_FROM_GLOBAL(transport_global),
-                      stream_global->id,
-                      removal_error(GRPC_ERROR_REF(error), stream_global));
+  if (close_reads && !s->read_closed) {
+    s->read_closed_error = GRPC_ERROR_REF(error);
+    s->read_closed = true;
+    for (int i = 0; i < 2; i++) {
+      if (s->published_metadata[i] == GRPC_METADATA_NOT_PUBLISHED) {
+        s->published_metadata[i] = GPRC_METADATA_PUBLISHED_AT_CLOSE;
       }
-      GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2");
     }
+    decrement_active_streams_locked(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_initial_metadata(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
+  }
+  if (close_writes && !s->write_closed) {
+    s->write_closed_error = GRPC_ERROR_REF(error);
+    s->write_closed = true;
+    fail_pending_writes(exec_ctx, t, s, GRPC_ERROR_REF(error));
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
+  }
+  if (s->read_closed && s->write_closed) {
+    if (s->id != 0) {
+      remove_stream(exec_ctx, t, s->id,
+                    removal_error(GRPC_ERROR_REF(error), s, "Stream removed"));
+    }
+    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2");
   }
   GRPC_ERROR_UNREF(error);
 }
 
-static void close_from_api(grpc_exec_ctx *exec_ctx,
-                           grpc_chttp2_transport_global *transport_global,
-                           grpc_chttp2_stream_global *stream_global,
-                           grpc_error *error) {
+static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                           grpc_chttp2_stream *s, grpc_error *error) {
   gpr_slice hdr;
   gpr_slice status_hdr;
   gpr_slice message_pfx;
@@ -1701,16 +1552,17 @@ static void close_from_api(grpc_exec_ctx *exec_ctx,
   uint32_t len = 0;
   grpc_status_code grpc_status;
   grpc_chttp2_error_code http_error;
-  status_codes_from_error(error, stream_global->deadline, &http_error,
-                          &grpc_status);
+  status_codes_from_error(error, s->deadline, &http_error, &grpc_status);
 
   GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100);
 
-  if (stream_global->id != 0 && !transport_global->is_client) {
+  if (s->id != 0 && !t->is_client) {
     /* Hand roll a header block.
-       This is unnecessarily ugly - at some point we should find a more elegant
+       This is unnecessarily ugly - at some point we should find a more
+       elegant
        solution.
-       It's complicated by the fact that our send machinery would be dead by the
+       It's complicated by the fact that our send machinery would be dead by
+       the
        time we got around to sending this, so instead we ignore HPACK
        compression
        and just write the uncompressed bytes onto the wire. */
@@ -1775,23 +1627,22 @@ static void close_from_api(grpc_exec_ctx *exec_ctx,
     *p++ = (uint8_t)(len);
     *p++ = GRPC_CHTTP2_FRAME_HEADER;
     *p++ = GRPC_CHTTP2_DATA_FLAG_END_STREAM | GRPC_CHTTP2_DATA_FLAG_END_HEADERS;
-    *p++ = (uint8_t)(stream_global->id >> 24);
-    *p++ = (uint8_t)(stream_global->id >> 16);
-    *p++ = (uint8_t)(stream_global->id >> 8);
-    *p++ = (uint8_t)(stream_global->id);
+    *p++ = (uint8_t)(s->id >> 24);
+    *p++ = (uint8_t)(s->id >> 16);
+    *p++ = (uint8_t)(s->id >> 8);
+    *p++ = (uint8_t)(s->id);
     GPR_ASSERT(p == GPR_SLICE_END_PTR(hdr));
 
-    gpr_slice_buffer_add(&transport_global->qbuf, hdr);
-    gpr_slice_buffer_add(&transport_global->qbuf, status_hdr);
+    gpr_slice_buffer_add(&t->qbuf, hdr);
+    gpr_slice_buffer_add(&t->qbuf, status_hdr);
     if (optional_message) {
-      gpr_slice_buffer_add(&transport_global->qbuf, message_pfx);
-      gpr_slice_buffer_add(&transport_global->qbuf,
+      gpr_slice_buffer_add(&t->qbuf, message_pfx);
+      gpr_slice_buffer_add(&t->qbuf,
                            gpr_slice_from_copied_string(optional_message));
     }
     gpr_slice_buffer_add(
-        &transport_global->qbuf,
-        grpc_chttp2_rst_stream_create(stream_global->id, GRPC_CHTTP2_NO_ERROR,
-                                      &stream_global->stats.outgoing));
+        &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_CHTTP2_NO_ERROR,
+                                                &s->stats.outgoing));
   }
 
   const char *msg = grpc_error_get_str(error, GRPC_ERROR_STR_GRPC_MESSAGE);
@@ -1801,46 +1652,33 @@ static void close_from_api(grpc_exec_ctx *exec_ctx,
     msg = grpc_error_string(error);
   }
   gpr_slice msg_slice = gpr_slice_from_copied_string(msg);
-  grpc_chttp2_fake_status(exec_ctx, transport_global, stream_global,
-                          grpc_status, &msg_slice);
+  grpc_chttp2_fake_status(exec_ctx, t, s, grpc_status, &msg_slice);
   if (free_msg) grpc_error_free_string(msg);
 
-  grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global, 1,
-                                 1, error);
-  grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                             "close_from_api");
+  grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, error);
+  grpc_chttp2_initiate_write(exec_ctx, t, false, "close_from_api");
 }
 
 typedef struct {
   grpc_exec_ctx *exec_ctx;
   grpc_error *error;
+  grpc_chttp2_transport *t;
 } cancel_stream_cb_args;
 
-static void cancel_stream_cb(grpc_chttp2_transport_global *transport_global,
-                             void *user_data,
-                             grpc_chttp2_stream_global *stream_global) {
+static void cancel_stream_cb(void *user_data, uint32_t key, void *stream) {
   cancel_stream_cb_args *args = user_data;
-  cancel_from_api(args->exec_ctx, transport_global, stream_global,
-                  GRPC_ERROR_REF(args->error));
+  grpc_chttp2_stream *s = stream;
+  grpc_chttp2_cancel_stream(args->exec_ctx, args->t, s,
+                            GRPC_ERROR_REF(args->error));
 }
 
 static void end_all_the_calls(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                               grpc_error *error) {
-  cancel_stream_cb_args args = {exec_ctx, error};
-  grpc_chttp2_for_all_streams(&t->global, &args, cancel_stream_cb);
+  cancel_stream_cb_args args = {exec_ctx, error, t};
+  grpc_chttp2_stream_map_for_each(&t->stream_map, cancel_stream_cb, &args);
   GRPC_ERROR_UNREF(error);
 }
 
-static void drop_connection(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                            grpc_error *error) {
-  if (!grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, NULL)) {
-    error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS,
-                               GRPC_STATUS_UNAVAILABLE);
-  }
-  close_transport_locked(exec_ctx, t, GRPC_ERROR_REF(error));
-  end_all_the_calls(exec_ctx, t, error);
-}
-
 /** update window from a settings change */
 typedef struct {
   grpc_chttp2_transport *t;
@@ -1851,20 +1689,23 @@ static void update_global_window(void *args, uint32_t id, void *stream) {
   update_global_window_args *a = args;
   grpc_chttp2_transport *t = a->t;
   grpc_chttp2_stream *s = stream;
-  grpc_chttp2_transport_global *transport_global = &t->global;
-  grpc_chttp2_stream_global *stream_global = &s->global;
   int was_zero;
   int is_zero;
-  int64_t initial_window_update = t->parsing.initial_window_update;
+  int64_t initial_window_update = t->initial_window_update;
 
-  was_zero = stream_global->outgoing_window <= 0;
-  GRPC_CHTTP2_FLOW_CREDIT_STREAM("settings", transport_global, stream_global,
-                                 outgoing_window, initial_window_update);
-  is_zero = stream_global->outgoing_window <= 0;
+  if (initial_window_update > 0) {
+    was_zero = s->outgoing_window <= 0;
+    GRPC_CHTTP2_FLOW_CREDIT_STREAM("settings", t, s, outgoing_window,
+                                   initial_window_update);
+    is_zero = s->outgoing_window <= 0;
 
-  if (was_zero && !is_zero) {
-    grpc_chttp2_become_writable(a->exec_ctx, transport_global, stream_global,
-                                true, "update_global_window");
+    if (was_zero && !is_zero) {
+      grpc_chttp2_become_writable(a->exec_ctx, t, s, true,
+                                  "update_global_window");
+    }
+  } else {
+    GRPC_CHTTP2_FLOW_DEBIT_STREAM("settings", t, s, outgoing_window,
+                                  -initial_window_update);
   }
 }
 
@@ -1872,50 +1713,19 @@ static void update_global_window(void *args, uint32_t id, void *stream) {
  * INPUT PROCESSING - PARSING
  */
 
-static void parsing_action(grpc_exec_ctx *exec_ctx, void *arg,
-                           grpc_error *error);
-static void post_reading_action_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                       grpc_error *error);
-static void post_parse_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error);
-
-static void reading_action(grpc_exec_ctx *exec_ctx, void *tp,
-                           grpc_error *error) {
+static void read_action_begin(grpc_exec_ctx *exec_ctx, void *tp,
+                              grpc_error *error) {
   /* Control flow:
      reading_action_locked ->
        (parse_unlocked -> post_parse_locked)? ->
        post_reading_action_locked */
   GPR_TIMER_BEGIN("reading_action", 0);
   grpc_chttp2_transport *t = tp;
-  grpc_combiner_execute(exec_ctx, t->executor.combiner,
-                        &t->reading_action_locked, GRPC_ERROR_REF(error));
+  grpc_combiner_execute(exec_ctx, t->combiner, &t->read_action_locked,
+                        GRPC_ERROR_REF(error), false);
   GPR_TIMER_END("reading_action", 0);
 }
 
-static void reading_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
-                                  grpc_error *error) {
-  GPR_TIMER_BEGIN("reading_action_locked", 0);
-
-  grpc_chttp2_transport *t = tp;
-  grpc_chttp2_transport_global *transport_global = &t->global;
-  grpc_chttp2_transport_parsing *transport_parsing = &t->parsing;
-
-  GPR_ASSERT(!t->executor.parsing_active);
-  if (!t->closed) {
-    t->executor.parsing_active = 1;
-    /* merge stream lists */
-    grpc_chttp2_stream_map_move_into(&t->new_stream_map,
-                                     &t->parsing_stream_map);
-    grpc_chttp2_prepare_to_read(transport_global, transport_parsing);
-    grpc_exec_ctx_sched(exec_ctx, &t->parsing_action, GRPC_ERROR_REF(error),
-                        NULL);
-  } else {
-    post_reading_action_locked(exec_ctx, t, error);
-  }
-
-  GPR_TIMER_END("reading_action_locked", 0);
-}
-
 static grpc_error *try_http_parsing(grpc_exec_ctx *exec_ctx,
                                     grpc_chttp2_transport *t) {
   grpc_http_parser parser;
@@ -1944,131 +1754,102 @@ static grpc_error *try_http_parsing(grpc_exec_ctx *exec_ctx,
   return error;
 }
 
-static void parsing_action(grpc_exec_ctx *exec_ctx, void *arg,
-                           grpc_error *error) {
-  grpc_chttp2_transport *t = arg;
-  grpc_error *err = GRPC_ERROR_NONE;
-  GPR_TIMER_BEGIN("reading_action.parse", 0);
-  size_t i = 0;
-  grpc_error *errors[3] = {GRPC_ERROR_REF(error), GRPC_ERROR_NONE,
-                           GRPC_ERROR_NONE};
-  for (; i < t->read_buffer.count && errors[1] == GRPC_ERROR_NONE; i++) {
-    errors[1] = grpc_chttp2_perform_read(exec_ctx, &t->parsing,
-                                         t->read_buffer.slices[i]);
-  };
-  if (errors[1] == GRPC_ERROR_NONE) {
-    err = GRPC_ERROR_REF(error);
-  } else {
-    errors[2] = try_http_parsing(exec_ctx, t);
-    err = GRPC_ERROR_CREATE_REFERENCING("Failed parsing HTTP/2", errors,
-                                        GPR_ARRAY_SIZE(errors));
+static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
+                               grpc_error *error) {
+  GPR_TIMER_BEGIN("reading_action_locked", 0);
+
+  grpc_chttp2_transport *t = tp;
+
+  GRPC_ERROR_REF(error);
+
+  grpc_error *err = error;
+  if (err != GRPC_ERROR_NONE) {
+    err = grpc_error_set_int(
+        GRPC_ERROR_CREATE_REFERENCING("Endpoint read failed", &err, 1),
+        GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state);
   }
-  for (i = 0; i < GPR_ARRAY_SIZE(errors); i++) {
-    GRPC_ERROR_UNREF(errors[i]);
+  GPR_SWAP(grpc_error *, err, error);
+  GRPC_ERROR_UNREF(err);
+  if (!t->closed) {
+    GPR_TIMER_BEGIN("reading_action.parse", 0);
+    size_t i = 0;
+    grpc_error *errors[3] = {GRPC_ERROR_REF(error), GRPC_ERROR_NONE,
+                             GRPC_ERROR_NONE};
+    for (; i < t->read_buffer.count && errors[1] == GRPC_ERROR_NONE; i++) {
+      errors[1] =
+          grpc_chttp2_perform_read(exec_ctx, t, t->read_buffer.slices[i]);
+    };
+    if (errors[1] != GRPC_ERROR_NONE) {
+      errors[2] = try_http_parsing(exec_ctx, t);
+      GRPC_ERROR_UNREF(error);
+      error = GRPC_ERROR_CREATE_REFERENCING("Failed parsing HTTP/2", errors,
+                                            GPR_ARRAY_SIZE(errors));
+    }
+    for (i = 0; i < GPR_ARRAY_SIZE(errors); i++) {
+      GRPC_ERROR_UNREF(errors[i]);
+    }
+    GPR_TIMER_END("reading_action.parse", 0);
+
+    GPR_TIMER_BEGIN("post_parse_locked", 0);
+    if (t->initial_window_update != 0) {
+      update_global_window_args args = {t, exec_ctx};
+      grpc_chttp2_stream_map_for_each(&t->stream_map, update_global_window,
+                                      &args);
+      t->initial_window_update = 0;
+    }
+    /* handle higher level things */
+    if (t->incoming_window < t->connection_window_target * 3 / 4) {
+      int64_t announce_bytes = t->connection_window_target - t->incoming_window;
+      GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parsed", t, announce_incoming_window,
+                                        announce_bytes);
+      GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parsed", t, incoming_window,
+                                        announce_bytes);
+      grpc_chttp2_initiate_write(exec_ctx, t, false, "global incoming window");
+    }
+
+    GPR_TIMER_END("post_parse_locked", 0);
   }
-  grpc_combiner_execute(exec_ctx, t->executor.combiner, &t->post_parse_locked,
-                        err);
-  GPR_TIMER_END("reading_action.parse", 0);
-}
 
-static void post_parse_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error) {
-  GPR_TIMER_BEGIN("post_parse_locked", 0);
-  grpc_chttp2_transport *t = arg;
-  grpc_chttp2_transport_global *transport_global = &t->global;
-  grpc_chttp2_transport_parsing *transport_parsing = &t->parsing;
-  /* copy parsing qbuf to global qbuf */
-  if (t->parsing.qbuf.count > 0) {
-    gpr_slice_buffer_move_into(&t->parsing.qbuf, &t->global.qbuf);
-    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                               "parsing_qbuf");
-  }
-  /* merge stream lists */
-  grpc_chttp2_stream_map_move_into(&t->new_stream_map, &t->parsing_stream_map);
-  transport_global->concurrent_stream_count =
-      (uint32_t)grpc_chttp2_stream_map_size(&t->parsing_stream_map);
-  if (transport_parsing->initial_window_update != 0) {
-    update_global_window_args args = {t, exec_ctx};
-    grpc_chttp2_stream_map_for_each(&t->parsing_stream_map,
-                                    update_global_window, &args);
-    transport_parsing->initial_window_update = 0;
-  }
-  /* handle higher level things */
-  grpc_chttp2_publish_reads(exec_ctx, transport_global, transport_parsing);
-  t->executor.parsing_active = 0;
-  /* handle delayed transport ops (if there is one) */
-  if (t->post_parsing_op) {
-    grpc_transport_op *op = t->post_parsing_op;
-    t->post_parsing_op = NULL;
-    perform_transport_op_locked(exec_ctx, op, GRPC_ERROR_NONE);
-    gpr_free(op);
-  }
-  /* if a stream is in the stream map, and gets cancelled, we need to
-   * ensure we are not parsing before continuing the cancellation to keep
-   * things in a sane state */
-  grpc_chttp2_stream_global *stream_global;
-  while (grpc_chttp2_list_pop_closed_waiting_for_parsing(transport_global,
-                                                         &stream_global)) {
-    GPR_ASSERT(stream_global->in_stream_map);
-    GPR_ASSERT(stream_global->write_closed);
-    GPR_ASSERT(stream_global->read_closed);
-    remove_stream(exec_ctx, t, stream_global->id,
-                  removal_error(GRPC_ERROR_NONE, stream_global));
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2");
-  }
-
-  post_reading_action_locked(exec_ctx, t, error);
-  GPR_TIMER_END("post_parse_locked", 0);
-}
-
-static void post_reading_action_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                       grpc_error *error) {
   GPR_TIMER_BEGIN("post_reading_action_locked", 0);
-  grpc_chttp2_transport *t = arg;
   bool keep_reading = false;
-  GRPC_ERROR_REF(error);
   if (error == GRPC_ERROR_NONE && t->closed) {
     error = GRPC_ERROR_CREATE("Transport closed");
   }
   if (error != GRPC_ERROR_NONE) {
-    drop_connection(exec_ctx, t, GRPC_ERROR_REF(error));
+    close_transport_locked(exec_ctx, t, GRPC_ERROR_REF(error));
     t->endpoint_reading = 0;
-    if (grpc_http_write_state_trace) {
-      gpr_log(GPR_DEBUG, "R:%p -> 0 ws=%s", t,
-              write_state_name(t->executor.write_state));
-    }
   } else if (!t->closed) {
     keep_reading = true;
-    REF_TRANSPORT(t, "keep_reading");
-    prevent_endpoint_shutdown(t);
+    GRPC_CHTTP2_REF_TRANSPORT(t, "keep_reading");
   }
   gpr_slice_buffer_reset_and_unref(&t->read_buffer);
 
   if (keep_reading) {
-    grpc_endpoint_read(exec_ctx, t->ep, &t->read_buffer, &t->reading_action);
-    allow_endpoint_shutdown_locked(exec_ctx, t);
-    UNREF_TRANSPORT(exec_ctx, t, "keep_reading");
+    grpc_endpoint_read(exec_ctx, t->ep, &t->read_buffer, &t->read_action_begin);
+    GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "keep_reading");
   } else {
-    UNREF_TRANSPORT(exec_ctx, t, "reading_action");
+    GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "reading_action");
   }
-  GRPC_ERROR_UNREF(error);
 
   GPR_TIMER_END("post_reading_action_locked", 0);
+
+  GRPC_ERROR_UNREF(error);
+
+  GPR_TIMER_END("reading_action_locked", 0);
 }
 
 /*******************************************************************************
  * CALLBACK LOOP
  */
 
-static void connectivity_state_set(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_connectivity_state state, grpc_error *error, const char *reason) {
+static void connectivity_state_set(grpc_exec_ctx *exec_ctx,
+                                   grpc_chttp2_transport *t,
+                                   grpc_connectivity_state state,
+                                   grpc_error *error, const char *reason) {
   GRPC_CHTTP2_IF_TRACING(
       gpr_log(GPR_DEBUG, "set connectivity_state=%d", state));
-  grpc_connectivity_state_set(
-      exec_ctx,
-      &TRANSPORT_FROM_GLOBAL(transport_global)->channel_callback.state_tracker,
-      state, error, reason);
+  grpc_connectivity_state_set(exec_ctx, &t->channel_callback.state_tracker,
+                              state, error, reason);
 }
 
 /*******************************************************************************
@@ -2101,15 +1882,16 @@ static void incoming_byte_stream_unref(grpc_exec_ctx *exec_ctx,
   }
 }
 
-static void incoming_byte_stream_update_flow_control(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, size_t max_size_hint,
-    size_t have_already) {
+static void incoming_byte_stream_update_flow_control(grpc_exec_ctx *exec_ctx,
+                                                     grpc_chttp2_transport *t,
+                                                     grpc_chttp2_stream *s,
+                                                     size_t max_size_hint,
+                                                     size_t have_already) {
   uint32_t max_recv_bytes;
 
   /* clamp max recv hint to an allowable size */
-  if (max_size_hint >= UINT32_MAX - transport_global->stream_lookahead) {
-    max_recv_bytes = UINT32_MAX - transport_global->stream_lookahead;
+  if (max_size_hint >= UINT32_MAX - t->stream_lookahead) {
+    max_recv_bytes = UINT32_MAX - t->stream_lookahead;
   } else {
     max_recv_bytes = (uint32_t)max_size_hint;
   }
@@ -2122,23 +1904,21 @@ static void incoming_byte_stream_update_flow_control(
   }
 
   /* add some small lookahead to keep pipelines flowing */
-  GPR_ASSERT(max_recv_bytes <= UINT32_MAX - transport_global->stream_lookahead);
-  max_recv_bytes += transport_global->stream_lookahead;
-  if (stream_global->max_recv_bytes < max_recv_bytes) {
-    uint32_t add_max_recv_bytes =
-        max_recv_bytes - stream_global->max_recv_bytes;
-    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", transport_global, stream_global,
-                                   max_recv_bytes, add_max_recv_bytes);
-    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", transport_global, stream_global,
-                                   unannounced_incoming_window_for_parse,
+  GPR_ASSERT(max_recv_bytes <= UINT32_MAX - t->stream_lookahead);
+  max_recv_bytes += t->stream_lookahead;
+  if (s->max_recv_bytes < max_recv_bytes) {
+    uint32_t add_max_recv_bytes = max_recv_bytes - s->max_recv_bytes;
+    bool new_window_write_is_covered_by_poller =
+        s->max_recv_bytes < have_already;
+    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", t, s, max_recv_bytes,
+                                   add_max_recv_bytes);
+    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", t, s, incoming_window,
                                    add_max_recv_bytes);
-    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", transport_global, stream_global,
-                                   unannounced_incoming_window_for_writing,
+    GRPC_CHTTP2_FLOW_CREDIT_STREAM("op", t, s, announce_window,
                                    add_max_recv_bytes);
-    grpc_chttp2_list_add_unannounced_incoming_window_available(transport_global,
-                                                               stream_global);
-    grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                false, "read_incoming_stream");
+    grpc_chttp2_become_writable(exec_ctx, t, s,
+                                new_window_write_is_covered_by_poller,
+                                "read_incoming_stream");
   }
 }
 
@@ -2146,25 +1926,23 @@ static void incoming_byte_stream_next_locked(grpc_exec_ctx *exec_ctx,
                                              void *argp,
                                              grpc_error *error_ignored) {
   grpc_chttp2_incoming_byte_stream *bs = argp;
-  grpc_chttp2_transport_global *transport_global = &bs->transport->global;
-  grpc_chttp2_stream_global *stream_global = &bs->stream->global;
+  grpc_chttp2_transport *t = bs->transport;
+  grpc_chttp2_stream *s = bs->stream;
 
   if (bs->is_tail) {
     gpr_mu_lock(&bs->slice_mu);
     size_t cur_length = bs->slices.length;
     gpr_mu_unlock(&bs->slice_mu);
     incoming_byte_stream_update_flow_control(
-        exec_ctx, transport_global, stream_global,
-        bs->next_action.max_size_hint, cur_length);
+        exec_ctx, t, s, bs->next_action.max_size_hint, cur_length);
   }
   gpr_mu_lock(&bs->slice_mu);
   if (bs->slices.count > 0) {
     *bs->next_action.slice = gpr_slice_buffer_take_first(&bs->slices);
-    grpc_exec_ctx_sched(exec_ctx, bs->next_action.on_complete, GRPC_ERROR_NONE,
-                        NULL);
+    grpc_closure_run(exec_ctx, bs->next_action.on_complete, GRPC_ERROR_NONE);
   } else if (bs->error != GRPC_ERROR_NONE) {
-    grpc_exec_ctx_sched(exec_ctx, bs->next_action.on_complete,
-                        GRPC_ERROR_REF(bs->error), NULL);
+    grpc_closure_run(exec_ctx, bs->next_action.on_complete,
+                     GRPC_ERROR_REF(bs->error));
   } else {
     bs->on_next = bs->next_action.on_complete;
     bs->next = bs->next_action.slice;
@@ -2186,8 +1964,8 @@ static int incoming_byte_stream_next(grpc_exec_ctx *exec_ctx,
   bs->next_action.on_complete = on_complete;
   grpc_closure_init(&bs->next_action.closure, incoming_byte_stream_next_locked,
                     bs);
-  grpc_combiner_execute(exec_ctx, bs->transport->executor.combiner,
-                        &bs->next_action.closure, GRPC_ERROR_NONE);
+  grpc_combiner_execute(exec_ctx, bs->transport->combiner,
+                        &bs->next_action.closure, GRPC_ERROR_NONE, false);
   GPR_TIMER_END("incoming_byte_stream_next", 0);
   return 0;
 }
@@ -2200,8 +1978,7 @@ static void incoming_byte_stream_destroy_locked(grpc_exec_ctx *exec_ctx,
                                                 grpc_error *error_ignored) {
   grpc_chttp2_incoming_byte_stream *bs = byte_stream;
   GPR_ASSERT(bs->base.destroy == incoming_byte_stream_destroy);
-  decrement_active_streams_locked(exec_ctx, &bs->transport->global,
-                                  &bs->stream->global);
+  decrement_active_streams_locked(exec_ctx, bs->transport, bs->stream);
   incoming_byte_stream_unref(exec_ctx, bs);
 }
 
@@ -2212,84 +1989,86 @@ static void incoming_byte_stream_destroy(grpc_exec_ctx *exec_ctx,
       (grpc_chttp2_incoming_byte_stream *)byte_stream;
   grpc_closure_init(&bs->destroy_action, incoming_byte_stream_destroy_locked,
                     bs);
-  grpc_combiner_execute(exec_ctx, bs->transport->executor.combiner,
-                        &bs->destroy_action, GRPC_ERROR_NONE);
+  grpc_combiner_execute(exec_ctx, bs->transport->combiner, &bs->destroy_action,
+                        GRPC_ERROR_NONE, false);
   GPR_TIMER_END("incoming_byte_stream_destroy", 0);
 }
 
-typedef struct {
-  grpc_chttp2_incoming_byte_stream *byte_stream;
-  gpr_slice slice;
-} incoming_byte_stream_push_arg;
+static void incoming_byte_stream_publish_error(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_byte_stream *bs,
+    grpc_error *error) {
+  GPR_ASSERT(error != GRPC_ERROR_NONE);
+  grpc_exec_ctx_sched(exec_ctx, bs->on_next, GRPC_ERROR_REF(error), NULL);
+  bs->on_next = NULL;
+  GRPC_ERROR_UNREF(bs->error);
+  bs->error = error;
+}
 
 void grpc_chttp2_incoming_byte_stream_push(grpc_exec_ctx *exec_ctx,
                                            grpc_chttp2_incoming_byte_stream *bs,
                                            gpr_slice slice) {
   gpr_mu_lock(&bs->slice_mu);
-  if (bs->on_next != NULL) {
-    *bs->next = slice;
-    grpc_exec_ctx_sched(exec_ctx, bs->on_next, GRPC_ERROR_NONE, NULL);
-    bs->on_next = NULL;
+  if (bs->remaining_bytes < GPR_SLICE_LENGTH(slice)) {
+    incoming_byte_stream_publish_error(
+        exec_ctx, bs, GRPC_ERROR_CREATE("Too many bytes in stream"));
   } else {
-    gpr_slice_buffer_add(&bs->slices, slice);
+    bs->remaining_bytes -= (uint32_t)GPR_SLICE_LENGTH(slice);
+    if (bs->on_next != NULL) {
+      *bs->next = slice;
+      grpc_exec_ctx_sched(exec_ctx, bs->on_next, GRPC_ERROR_NONE, NULL);
+      bs->on_next = NULL;
+    } else {
+      gpr_slice_buffer_add(&bs->slices, slice);
+    }
   }
   gpr_mu_unlock(&bs->slice_mu);
 }
 
-static void incoming_byte_stream_finished_locked(grpc_exec_ctx *exec_ctx,
-                                                 void *bsp, grpc_error *error) {
-  grpc_chttp2_incoming_byte_stream *bs = bsp;
-  if (error != GRPC_ERROR_NONE) {
-    grpc_exec_ctx_sched(exec_ctx, bs->on_next, GRPC_ERROR_REF(error), NULL);
-    bs->on_next = NULL;
-    GRPC_ERROR_UNREF(bs->error);
-    bs->error = error;
-  }
-  incoming_byte_stream_unref(exec_ctx, bs);
-}
-
 void grpc_chttp2_incoming_byte_stream_finished(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_byte_stream *bs,
-    grpc_error *error, int from_parsing_thread) {
-  GPR_TIMER_BEGIN("grpc_chttp2_incoming_byte_stream_finished", 0);
-  if (from_parsing_thread) {
-    grpc_closure_init(&bs->finished_action,
-                      incoming_byte_stream_finished_locked, bs);
-    grpc_combiner_execute(exec_ctx, bs->transport->executor.combiner,
-                          &bs->finished_action, GRPC_ERROR_REF(error));
-  } else {
-    incoming_byte_stream_finished_locked(exec_ctx, bs, error);
+    grpc_error *error) {
+  if (error == GRPC_ERROR_NONE) {
+    gpr_mu_lock(&bs->slice_mu);
+    if (bs->remaining_bytes != 0) {
+      error = GRPC_ERROR_CREATE("Truncated message");
+    }
+    gpr_mu_unlock(&bs->slice_mu);
+  }
+  if (error != GRPC_ERROR_NONE) {
+    incoming_byte_stream_publish_error(exec_ctx, bs, error);
   }
-  GPR_TIMER_END("grpc_chttp2_incoming_byte_stream_finished", 0);
+  incoming_byte_stream_unref(exec_ctx, bs);
 }
 
 grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, uint32_t frame_size,
-    uint32_t flags, grpc_chttp2_incoming_frame_queue *add_to_queue) {
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+    uint32_t frame_size, uint32_t flags) {
   grpc_chttp2_incoming_byte_stream *incoming_byte_stream =
       gpr_malloc(sizeof(*incoming_byte_stream));
   incoming_byte_stream->base.length = frame_size;
+  incoming_byte_stream->remaining_bytes = frame_size;
   incoming_byte_stream->base.flags = flags;
   incoming_byte_stream->base.next = incoming_byte_stream_next;
   incoming_byte_stream->base.destroy = incoming_byte_stream_destroy;
   gpr_mu_init(&incoming_byte_stream->slice_mu);
   gpr_ref_init(&incoming_byte_stream->refs, 2);
   incoming_byte_stream->next_message = NULL;
-  incoming_byte_stream->transport = TRANSPORT_FROM_PARSING(transport_parsing);
-  incoming_byte_stream->stream = STREAM_FROM_PARSING(stream_parsing);
-  gpr_ref(&incoming_byte_stream->stream->global.active_streams);
+  incoming_byte_stream->transport = t;
+  incoming_byte_stream->stream = s;
+  gpr_ref(&incoming_byte_stream->stream->active_streams);
   gpr_slice_buffer_init(&incoming_byte_stream->slices);
   incoming_byte_stream->on_next = NULL;
   incoming_byte_stream->is_tail = 1;
   incoming_byte_stream->error = GRPC_ERROR_NONE;
-  if (add_to_queue->head == NULL) {
-    add_to_queue->head = incoming_byte_stream;
+  grpc_chttp2_incoming_frame_queue *q = &s->incoming_frames;
+  if (q->head == NULL) {
+    q->head = incoming_byte_stream;
   } else {
-    add_to_queue->tail->is_tail = 0;
-    add_to_queue->tail->next_message = incoming_byte_stream;
+    q->tail->is_tail = 0;
+    q->tail->next_message = incoming_byte_stream;
   }
-  add_to_queue->tail = incoming_byte_stream;
+  q->tail = incoming_byte_stream;
+  grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
   return incoming_byte_stream;
 }
 
@@ -2298,40 +2077,30 @@ grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
  */
 
 static char *format_flowctl_context_var(const char *context, const char *var,
-                                        int64_t val, uint32_t id,
-                                        char **scope) {
-  char *underscore_pos;
-  char *buf;
-  char *result;
+                                        int64_t val, uint32_t id) {
+  char *name;
   if (context == NULL) {
-    *scope = NULL;
-    gpr_asprintf(&buf, "%s(%" PRId64 ")", var, val);
-    result = gpr_leftpad(buf, ' ', 60);
-    gpr_free(buf);
-    return result;
-  }
-  underscore_pos = strchr(context, '_');
-  *scope = gpr_strdup(context);
-  (*scope)[underscore_pos - context] = 0;
-  if (id != 0) {
-    char *tmp = *scope;
-    gpr_asprintf(scope, "%s[%d]", tmp, id);
-    gpr_free(tmp);
-  }
-  gpr_asprintf(&buf, "%s.%s(%" PRId64 ")", underscore_pos + 1, var, val);
-  result = gpr_leftpad(buf, ' ', 60);
-  gpr_free(buf);
-  return result;
-}
-
-static int samestr(char *a, char *b) {
-  if (a == NULL) {
-    return b == NULL;
-  }
-  if (b == NULL) {
-    return 0;
+    name = gpr_strdup(var);
+  } else if (0 == strcmp(context, "t")) {
+    GPR_ASSERT(id == 0);
+    gpr_asprintf(&name, "TRANSPORT:%s", var);
+  } else if (0 == strcmp(context, "s")) {
+    GPR_ASSERT(id != 0);
+    gpr_asprintf(&name, "STREAM[%d]:%s", id, var);
+  } else {
+    gpr_asprintf(&name, "BAD_CONTEXT[%s][%d]:%s", context, id, var);
   }
-  return 0 == strcmp(a, b);
+  char *name_fld = gpr_leftpad(name, ' ', 64);
+  char *value;
+  gpr_asprintf(&value, "%" PRId64, val);
+  char *value_fld = gpr_leftpad(value, ' ', 8);
+  char *result;
+  gpr_asprintf(&result, "%s %s", name_fld, value_fld);
+  gpr_free(name);
+  gpr_free(name_fld);
+  gpr_free(value);
+  gpr_free(value_fld);
+  return result;
 }
 
 void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
@@ -2339,26 +2108,18 @@ void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
                                const char *var1, const char *context2,
                                const char *var2, int is_client,
                                uint32_t stream_id, int64_t val1, int64_t val2) {
-  char *scope1;
-  char *scope2;
   char *tmp_phase;
-  char *tmp_scope1;
-  char *label1 =
-      format_flowctl_context_var(context1, var1, val1, stream_id, &scope1);
-  char *label2 =
-      format_flowctl_context_var(context2, var2, val2, stream_id, &scope2);
+  char *label1 = format_flowctl_context_var(context1, var1, val1, stream_id);
+  char *label2 = format_flowctl_context_var(context2, var2, val2, stream_id);
   char *clisvr = is_client ? "client" : "server";
   char *prefix;
 
   tmp_phase = gpr_leftpad(phase, ' ', 8);
-  tmp_scope1 = gpr_leftpad(scope1, ' ', 11);
-  gpr_asprintf(&prefix, "FLOW %s: %s %s ", tmp_phase, clisvr, scope1);
+  gpr_asprintf(&prefix, "FLOW %s: %s ", tmp_phase, clisvr);
   gpr_free(tmp_phase);
-  gpr_free(tmp_scope1);
 
   switch (op) {
     case GRPC_CHTTP2_FLOWCTL_MOVE:
-      GPR_ASSERT(samestr(scope1, scope2));
       if (val2 != 0) {
         gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
                 "%sMOVE   %s <- %s giving %" PRId64, prefix, label1, label2,
@@ -2383,8 +2144,6 @@ void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
       break;
   }
 
-  gpr_free(scope1);
-  gpr_free(scope2);
   gpr_free(label1);
   gpr_free(label2);
   gpr_free(prefix);
@@ -2421,10 +2180,11 @@ void grpc_chttp2_transport_start_reading(grpc_exec_ctx *exec_ctx,
                                          grpc_transport *transport,
                                          gpr_slice_buffer *read_buffer) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)transport;
-  REF_TRANSPORT(t, "reading_action"); /* matches unref inside reading_action */
+  GRPC_CHTTP2_REF_TRANSPORT(
+      t, "reading_action"); /* matches unref inside reading_action */
   if (read_buffer != NULL) {
     gpr_slice_buffer_move_into(read_buffer, &t->read_buffer);
     gpr_free(read_buffer);
   }
-  reading_action(exec_ctx, t, GRPC_ERROR_NONE);
+  read_action_begin(exec_ctx, t, GRPC_ERROR_NONE);
 }
diff --git a/src/core/ext/transport/chttp2/transport/frame.h b/src/core/ext/transport/chttp2/transport/frame.h
index 507aae4100..1e444a91fd 100644
--- a/src/core/ext/transport/chttp2/transport/frame.h
+++ b/src/core/ext/transport/chttp2/transport/frame.h
@@ -40,8 +40,8 @@
 #include "src/core/lib/iomgr/error.h"
 
 /* defined in internal.h */
-typedef struct grpc_chttp2_stream_parsing grpc_chttp2_stream_parsing;
-typedef struct grpc_chttp2_transport_parsing grpc_chttp2_transport_parsing;
+typedef struct grpc_chttp2_stream grpc_chttp2_stream;
+typedef struct grpc_chttp2_transport grpc_chttp2_transport;
 
 #define GRPC_CHTTP2_FRAME_DATA 0
 #define GRPC_CHTTP2_FRAME_HEADER 1
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.c b/src/core/ext/transport/chttp2/transport/frame_data.c
index 9046fbc453..8668816930 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.c
+++ b/src/core/ext/transport/chttp2/transport/frame_data.c
@@ -51,16 +51,11 @@ grpc_error *grpc_chttp2_data_parser_init(grpc_chttp2_data_parser *parser) {
 
 void grpc_chttp2_data_parser_destroy(grpc_exec_ctx *exec_ctx,
                                      grpc_chttp2_data_parser *parser) {
-  grpc_byte_stream *bs;
-  if (parser->parsing_frame) {
+  if (parser->parsing_frame != NULL) {
     grpc_chttp2_incoming_byte_stream_finished(
-        exec_ctx, parser->parsing_frame, GRPC_ERROR_CREATE("Parser destroyed"),
-        1);
-  }
-  while (
-      (bs = grpc_chttp2_incoming_frame_queue_pop(&parser->incoming_frames))) {
-    grpc_byte_stream_destroy(exec_ctx, bs);
+        exec_ctx, parser->parsing_frame, GRPC_ERROR_CREATE("Parser destroyed"));
   }
+  GRPC_ERROR_UNREF(parser->error);
 }
 
 grpc_error *grpc_chttp2_data_parser_begin_frame(grpc_chttp2_data_parser *parser,
@@ -145,22 +140,17 @@ void grpc_chttp2_encode_data(uint32_t id, gpr_slice_buffer *inbuf,
   stats->data_bytes += write_bytes;
 }
 
-grpc_error *grpc_chttp2_data_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+static grpc_error *parse_inner(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_data_parser *p,
+                               grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+                               gpr_slice slice) {
   uint8_t *const beg = GPR_SLICE_START_PTR(slice);
   uint8_t *const end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
-  grpc_chttp2_data_parser *p = parser;
   uint32_t message_flags;
   grpc_chttp2_incoming_byte_stream *incoming_byte_stream;
   char *msg;
 
-  if (is_last && p->is_last_frame) {
-    stream_parsing->received_close = 1;
-  }
-
   if (cur == end) {
     return GRPC_ERROR_NONE;
   }
@@ -171,7 +161,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
       return GRPC_ERROR_REF(p->error);
     fh_0:
     case GRPC_CHTTP2_DATA_FH_0:
-      stream_parsing->stats.incoming.framing_bytes++;
+      s->stats.incoming.framing_bytes++;
       p->frame_type = *cur;
       switch (p->frame_type) {
         case 0:
@@ -184,7 +174,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
           gpr_asprintf(&msg, "Bad GRPC frame type 0x%02x", p->frame_type);
           p->error = GRPC_ERROR_CREATE(msg);
           p->error = grpc_error_set_int(p->error, GRPC_ERROR_INT_STREAM_ID,
-                                        (intptr_t)stream_parsing->id);
+                                        (intptr_t)s->id);
           gpr_free(msg);
           msg = gpr_dump_slice(slice, GPR_DUMP_HEX | GPR_DUMP_ASCII);
           p->error =
@@ -201,7 +191,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
       }
     /* fallthrough */
     case GRPC_CHTTP2_DATA_FH_1:
-      stream_parsing->stats.incoming.framing_bytes++;
+      s->stats.incoming.framing_bytes++;
       p->frame_size = ((uint32_t)*cur) << 24;
       if (++cur == end) {
         p->state = GRPC_CHTTP2_DATA_FH_2;
@@ -209,7 +199,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
       }
     /* fallthrough */
     case GRPC_CHTTP2_DATA_FH_2:
-      stream_parsing->stats.incoming.framing_bytes++;
+      s->stats.incoming.framing_bytes++;
       p->frame_size |= ((uint32_t)*cur) << 16;
       if (++cur == end) {
         p->state = GRPC_CHTTP2_DATA_FH_3;
@@ -217,7 +207,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
       }
     /* fallthrough */
     case GRPC_CHTTP2_DATA_FH_3:
-      stream_parsing->stats.incoming.framing_bytes++;
+      s->stats.incoming.framing_bytes++;
       p->frame_size |= ((uint32_t)*cur) << 8;
       if (++cur == end) {
         p->state = GRPC_CHTTP2_DATA_FH_4;
@@ -225,7 +215,7 @@ grpc_error *grpc_chttp2_data_parser_parse(
       }
     /* fallthrough */
     case GRPC_CHTTP2_DATA_FH_4:
-      stream_parsing->stats.incoming.framing_bytes++;
+      s->stats.incoming.framing_bytes++;
       p->frame_size |= ((uint32_t)*cur);
       p->state = GRPC_CHTTP2_DATA_FRAME;
       ++cur;
@@ -234,35 +224,32 @@ grpc_error *grpc_chttp2_data_parser_parse(
         message_flags |= GRPC_WRITE_INTERNAL_COMPRESS;
       }
       p->parsing_frame = incoming_byte_stream =
-          grpc_chttp2_incoming_byte_stream_create(
-              exec_ctx, transport_parsing, stream_parsing, p->frame_size,
-              message_flags, &p->incoming_frames);
+          grpc_chttp2_incoming_byte_stream_create(exec_ctx, t, s, p->frame_size,
+                                                  message_flags);
     /* fallthrough */
     case GRPC_CHTTP2_DATA_FRAME:
-      grpc_chttp2_list_add_parsing_seen_stream(transport_parsing,
-                                               stream_parsing);
       if (cur == end) {
         return GRPC_ERROR_NONE;
       }
       uint32_t remaining = (uint32_t)(end - cur);
       if (remaining == p->frame_size) {
-        stream_parsing->stats.incoming.data_bytes += p->frame_size;
+        s->stats.incoming.data_bytes += p->frame_size;
         grpc_chttp2_incoming_byte_stream_push(
             exec_ctx, p->parsing_frame,
             gpr_slice_sub(slice, (size_t)(cur - beg), (size_t)(end - beg)));
         grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame,
-                                                  GRPC_ERROR_NONE, 1);
+                                                  GRPC_ERROR_NONE);
         p->parsing_frame = NULL;
         p->state = GRPC_CHTTP2_DATA_FH_0;
         return GRPC_ERROR_NONE;
       } else if (remaining > p->frame_size) {
-        stream_parsing->stats.incoming.data_bytes += p->frame_size;
+        s->stats.incoming.data_bytes += p->frame_size;
         grpc_chttp2_incoming_byte_stream_push(
             exec_ctx, p->parsing_frame,
             gpr_slice_sub(slice, (size_t)(cur - beg),
                           (size_t)(cur + p->frame_size - beg)));
         grpc_chttp2_incoming_byte_stream_finished(exec_ctx, p->parsing_frame,
-                                                  GRPC_ERROR_NONE, 1);
+                                                  GRPC_ERROR_NONE);
         p->parsing_frame = NULL;
         cur += p->frame_size;
         goto fh_0; /* loop */
@@ -272,10 +259,25 @@ grpc_error *grpc_chttp2_data_parser_parse(
             exec_ctx, p->parsing_frame,
             gpr_slice_sub(slice, (size_t)(cur - beg), (size_t)(end - beg)));
         p->frame_size -= remaining;
-        stream_parsing->stats.incoming.data_bytes += remaining;
+        s->stats.incoming.data_bytes += remaining;
         return GRPC_ERROR_NONE;
       }
   }
 
   GPR_UNREACHABLE_CODE(return GRPC_ERROR_CREATE("Should never reach here"));
 }
+
+grpc_error *grpc_chttp2_data_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s,
+                                          gpr_slice slice, int is_last) {
+  grpc_chttp2_data_parser *p = parser;
+  grpc_error *error = parse_inner(exec_ctx, p, t, s, slice);
+
+  if (is_last && p->is_last_frame) {
+    grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, false,
+                                   GRPC_ERROR_NONE);
+  }
+
+  return error;
+}
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.h b/src/core/ext/transport/chttp2/transport/frame_data.h
index a21a7942b9..eb2d97d898 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.h
+++ b/src/core/ext/transport/chttp2/transport/frame_data.h
@@ -69,7 +69,6 @@ typedef struct {
   grpc_error *error;
 
   int is_frame_compressed;
-  grpc_chttp2_incoming_frame_queue incoming_frames;
   grpc_chttp2_incoming_byte_stream *parsing_frame;
 } grpc_chttp2_data_parser;
 
@@ -92,10 +91,10 @@ grpc_error *grpc_chttp2_data_parser_begin_frame(grpc_chttp2_data_parser *parser,
 
 /* handle a slice of a data frame - is_last indicates the last slice of a
    frame */
-grpc_error *grpc_chttp2_data_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_data_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s,
+                                          gpr_slice slice, int is_last);
 
 void grpc_chttp2_encode_data(uint32_t id, gpr_slice_buffer *inbuf,
                              uint32_t write_bytes, int is_eof,
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.c b/src/core/ext/transport/chttp2/transport/frame_goaway.c
index 299e27ad70..33d2269169 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.c
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.c
@@ -67,10 +67,11 @@ grpc_error *grpc_chttp2_goaway_parser_begin_frame(grpc_chttp2_goaway_parser *p,
   return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_chttp2_goaway_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+grpc_error *grpc_chttp2_goaway_parser_parse(grpc_exec_ctx *exec_ctx,
+                                            void *parser,
+                                            grpc_chttp2_transport *t,
+                                            grpc_chttp2_stream *s,
+                                            gpr_slice slice, int is_last) {
   uint8_t *const beg = GPR_SLICE_START_PTR(slice);
   uint8_t *const end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
@@ -148,12 +149,9 @@ grpc_error *grpc_chttp2_goaway_parser_parse(
       p->debug_pos += (uint32_t)(end - cur);
       p->state = GRPC_CHTTP2_GOAWAY_DEBUG;
       if (is_last) {
-        transport_parsing->goaway_received = 1;
-        transport_parsing->goaway_last_stream_index = p->last_stream_id;
-        gpr_slice_unref(transport_parsing->goaway_text);
-        transport_parsing->goaway_error = (grpc_status_code)p->error_code;
-        transport_parsing->goaway_text =
-            gpr_slice_new(p->debug_data, p->debug_length, gpr_free);
+        grpc_chttp2_add_incoming_goaway(
+            exec_ctx, t, (uint32_t)p->error_code,
+            gpr_slice_new(p->debug_data, p->debug_length, gpr_free));
         p->debug_data = NULL;
       }
       return GRPC_ERROR_NONE;
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.h b/src/core/ext/transport/chttp2/transport/frame_goaway.h
index eb4303405a..355104a5a7 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.h
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.h
@@ -65,10 +65,11 @@ void grpc_chttp2_goaway_parser_init(grpc_chttp2_goaway_parser *p);
 void grpc_chttp2_goaway_parser_destroy(grpc_chttp2_goaway_parser *p);
 grpc_error *grpc_chttp2_goaway_parser_begin_frame(
     grpc_chttp2_goaway_parser *parser, uint32_t length, uint8_t flags);
-grpc_error *grpc_chttp2_goaway_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_goaway_parser_parse(grpc_exec_ctx *exec_ctx,
+                                            void *parser,
+                                            grpc_chttp2_transport *t,
+                                            grpc_chttp2_stream *s,
+                                            gpr_slice slice, int is_last);
 
 void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
                                gpr_slice debug_data,
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.c
index 1f814ab1bd..624f42649d 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.c
@@ -73,10 +73,10 @@ grpc_error *grpc_chttp2_ping_parser_begin_frame(grpc_chttp2_ping_parser *parser,
   return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_chttp2_ping_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s,
+                                          gpr_slice slice, int is_last) {
   uint8_t *const beg = GPR_SLICE_START_PTR(slice);
   uint8_t *const end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
@@ -91,10 +91,11 @@ grpc_error *grpc_chttp2_ping_parser_parse(
   if (p->byte == 8) {
     GPR_ASSERT(is_last);
     if (p->is_ack) {
-      grpc_chttp2_ack_ping(exec_ctx, transport_parsing, p->opaque_8bytes);
+      grpc_chttp2_ack_ping(exec_ctx, t, p->opaque_8bytes);
     } else {
-      gpr_slice_buffer_add(&transport_parsing->qbuf,
+      gpr_slice_buffer_add(&t->qbuf,
                            grpc_chttp2_ping_create(1, p->opaque_8bytes));
+      grpc_chttp2_initiate_write(exec_ctx, t, false, "ping response");
     }
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.h b/src/core/ext/transport/chttp2/transport/frame_ping.h
index 5a8723421c..2071f647fb 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.h
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.h
@@ -48,9 +48,9 @@ gpr_slice grpc_chttp2_ping_create(uint8_t ack, uint8_t *opaque_8bytes);
 
 grpc_error *grpc_chttp2_ping_parser_begin_frame(grpc_chttp2_ping_parser *parser,
                                                 uint32_t length, uint8_t flags);
-grpc_error *grpc_chttp2_ping_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s,
+                                          gpr_slice slice, int is_last);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_PING_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
index e3a3c9e4a7..9eac050797 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
@@ -39,6 +39,8 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/ext/transport/chttp2/transport/frame.h"
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
+#include "src/core/ext/transport/chttp2/transport/status_conversion.h"
 
 gpr_slice grpc_chttp2_rst_stream_create(uint32_t id, uint32_t code,
                                         grpc_transport_one_way_stats *stats) {
@@ -83,10 +85,11 @@ grpc_error *grpc_chttp2_rst_stream_parser_begin_frame(
   return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_chttp2_rst_stream_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
+                                                void *parser,
+                                                grpc_chttp2_transport *t,
+                                                grpc_chttp2_stream *s,
+                                                gpr_slice slice, int is_last) {
   uint8_t *const beg = GPR_SLICE_START_PTR(slice);
   uint8_t *const end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
@@ -97,19 +100,28 @@ grpc_error *grpc_chttp2_rst_stream_parser_parse(
     cur++;
     p->byte++;
   }
-  stream_parsing->stats.incoming.framing_bytes += (uint64_t)(end - cur);
+  s->stats.incoming.framing_bytes += (uint64_t)(end - cur);
 
   if (p->byte == 4) {
     GPR_ASSERT(is_last);
-    stream_parsing->received_close = 1;
-    if (stream_parsing->forced_close_error == GRPC_ERROR_NONE) {
-      stream_parsing->forced_close_error = grpc_error_set_int(
-          GRPC_ERROR_CREATE("RST_STREAM"), GRPC_ERROR_INT_HTTP2_ERROR,
-          (intptr_t)((((uint32_t)p->reason_bytes[0]) << 24) |
-                     (((uint32_t)p->reason_bytes[1]) << 16) |
-                     (((uint32_t)p->reason_bytes[2]) << 8) |
-                     (((uint32_t)p->reason_bytes[3]))));
+    uint32_t reason = (((uint32_t)p->reason_bytes[0]) << 24) |
+                      (((uint32_t)p->reason_bytes[1]) << 16) |
+                      (((uint32_t)p->reason_bytes[2]) << 8) |
+                      (((uint32_t)p->reason_bytes[3]));
+    grpc_error *error = GRPC_ERROR_NONE;
+    if (reason != GRPC_CHTTP2_NO_ERROR) {
+      error = grpc_error_set_int(GRPC_ERROR_CREATE("RST_STREAM"),
+                                 GRPC_ERROR_INT_HTTP2_ERROR, (intptr_t)reason);
+      grpc_status_code status_code = grpc_chttp2_http2_error_to_grpc_status(
+          (grpc_chttp2_error_code)reason, s->deadline);
+      char *status_details;
+      gpr_asprintf(&status_details, "Received RST_STREAM with error code %d",
+                   reason);
+      gpr_slice slice_details = gpr_slice_from_copied_string(status_details);
+      gpr_free(status_details);
+      grpc_chttp2_fake_status(exec_ctx, t, s, status_code, &slice_details);
     }
+    grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, true, error);
   }
 
   return GRPC_ERROR_NONE;
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
index 11cf94f3ea..5a1f578a29 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
@@ -49,9 +49,10 @@ gpr_slice grpc_chttp2_rst_stream_create(uint32_t stream_id, uint32_t code,
 
 grpc_error *grpc_chttp2_rst_stream_parser_begin_frame(
     grpc_chttp2_rst_stream_parser *parser, uint32_t length, uint8_t flags);
-grpc_error *grpc_chttp2_rst_stream_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
+                                                void *parser,
+                                                grpc_chttp2_transport *t,
+                                                grpc_chttp2_stream *s,
+                                                gpr_slice slice, int is_last);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_RST_STREAM_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.c b/src/core/ext/transport/chttp2/transport/frame_settings.c
index 04b96c4cd9..92022f90c9 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.c
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.c
@@ -143,10 +143,10 @@ grpc_error *grpc_chttp2_settings_parser_begin_frame(
   }
 }
 
-grpc_error *grpc_chttp2_settings_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *p,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+grpc_error *grpc_chttp2_settings_parser_parse(grpc_exec_ctx *exec_ctx, void *p,
+                                              grpc_chttp2_transport *t,
+                                              grpc_chttp2_stream *s,
+                                              gpr_slice slice, int is_last) {
   grpc_chttp2_settings_parser *parser = p;
   const uint8_t *cur = GPR_SLICE_START_PTR(slice);
   const uint8_t *end = GPR_SLICE_END_PTR(slice);
@@ -162,11 +162,9 @@ grpc_error *grpc_chttp2_settings_parser_parse(
         if (cur == end) {
           parser->state = GRPC_CHTTP2_SPS_ID0;
           if (is_last) {
-            transport_parsing->settings_updated = 1;
             memcpy(parser->target_settings, parser->incoming_settings,
                    GRPC_CHTTP2_NUM_SETTINGS * sizeof(uint32_t));
-            gpr_slice_buffer_add(&transport_parsing->qbuf,
-                                 grpc_chttp2_settings_ack_create());
+            gpr_slice_buffer_add(&t->qbuf, grpc_chttp2_settings_ack_create());
           }
           return GRPC_ERROR_NONE;
         }
@@ -226,9 +224,9 @@ grpc_error *grpc_chttp2_settings_parser_parse(
                 break;
               case GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE:
                 grpc_chttp2_goaway_append(
-                    transport_parsing->last_incoming_stream_id, sp->error_value,
+                    t->last_new_stream_id, sp->error_value,
                     gpr_slice_from_static_string("HTTP2 settings error"),
-                    &transport_parsing->qbuf);
+                    &t->qbuf);
                 gpr_asprintf(&msg, "invalid value %u passed for %s",
                              parser->value, sp->name);
                 grpc_error *err = GRPC_ERROR_CREATE(msg);
@@ -238,18 +236,17 @@ grpc_error *grpc_chttp2_settings_parser_parse(
           }
           if (parser->id == GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE &&
               parser->incoming_settings[parser->id] != parser->value) {
-            transport_parsing->initial_window_update =
+            t->initial_window_update =
                 (int64_t)parser->value - parser->incoming_settings[parser->id];
             if (grpc_http_trace) {
               gpr_log(GPR_DEBUG, "adding %d for initial_window change",
-                      (int)transport_parsing->initial_window_update);
+                      (int)t->initial_window_update);
             }
           }
           parser->incoming_settings[parser->id] = parser->value;
           if (grpc_http_trace) {
             gpr_log(GPR_DEBUG, "CHTTP2:%s: got setting %d = %d",
-                    transport_parsing->is_client ? "CLI" : "SVR", parser->id,
-                    parser->value);
+                    t->is_client ? "CLI" : "SVR", parser->id, parser->value);
           }
         } else if (grpc_http_trace) {
           gpr_log(GPR_ERROR, "CHTTP2: Ignoring unknown setting %d (value %d)",
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.h b/src/core/ext/transport/chttp2/transport/frame_settings.h
index f654c598c8..4bfa944cf1 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.h
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.h
@@ -95,9 +95,10 @@ gpr_slice grpc_chttp2_settings_ack_create(void);
 grpc_error *grpc_chttp2_settings_parser_begin_frame(
     grpc_chttp2_settings_parser *parser, uint32_t length, uint8_t flags,
     uint32_t *settings);
-grpc_error *grpc_chttp2_settings_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_settings_parser_parse(grpc_exec_ctx *exec_ctx,
+                                              void *parser,
+                                              grpc_chttp2_transport *t,
+                                              grpc_chttp2_stream *s,
+                                              gpr_slice slice, int is_last);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_SETTINGS_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.c b/src/core/ext/transport/chttp2/transport/frame_window_update.c
index 3cf848fd5c..418166a6df 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.c
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.c
@@ -80,9 +80,8 @@ grpc_error *grpc_chttp2_window_update_parser_begin_frame(
 }
 
 grpc_error *grpc_chttp2_window_update_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+    grpc_exec_ctx *exec_ctx, void *parser, grpc_chttp2_transport *t,
+    grpc_chttp2_stream *s, gpr_slice slice, int is_last) {
   uint8_t *const beg = GPR_SLICE_START_PTR(slice);
   uint8_t *const end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
@@ -94,8 +93,8 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
     p->byte++;
   }
 
-  if (stream_parsing != NULL) {
-    stream_parsing->stats.incoming.framing_bytes += (uint32_t)(end - cur);
+  if (s != NULL) {
+    s->stats.incoming.framing_bytes += (uint32_t)(end - cur);
   }
 
   if (p->byte == 4) {
@@ -109,17 +108,26 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
     }
     GPR_ASSERT(is_last);
 
-    if (transport_parsing->incoming_stream_id != 0) {
-      if (stream_parsing != NULL) {
-        GRPC_CHTTP2_FLOW_CREDIT_STREAM("parse", transport_parsing,
-                                       stream_parsing, outgoing_window,
+    if (t->incoming_stream_id != 0) {
+      if (s != NULL) {
+        bool was_zero = s->outgoing_window <= 0;
+        GRPC_CHTTP2_FLOW_CREDIT_STREAM("parse", t, s, outgoing_window,
                                        received_update);
-        grpc_chttp2_list_add_parsing_seen_stream(transport_parsing,
-                                                 stream_parsing);
+        bool is_zero = s->outgoing_window <= 0;
+        if (was_zero && !is_zero) {
+          grpc_chttp2_become_writable(exec_ctx, t, s, false,
+                                      "stream.read_flow_control");
+        }
       }
     } else {
-      GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parse", transport_parsing,
-                                        outgoing_window, received_update);
+      bool was_zero = t->outgoing_window <= 0;
+      GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parse", t, outgoing_window,
+                                        received_update);
+      bool is_zero = t->outgoing_window <= 0;
+      if (was_zero && !is_zero) {
+        grpc_chttp2_initiate_write(exec_ctx, t, false,
+                                   "new_global_flow_control");
+      }
     }
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.h b/src/core/ext/transport/chttp2/transport/frame_window_update.h
index 1bcbbf9247..6e62f31872 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.h
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.h
@@ -51,8 +51,7 @@ gpr_slice grpc_chttp2_window_update_create(uint32_t id, uint32_t window_delta,
 grpc_error *grpc_chttp2_window_update_parser_begin_frame(
     grpc_chttp2_window_update_parser *parser, uint32_t length, uint8_t flags);
 grpc_error *grpc_chttp2_window_update_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+    grpc_exec_ctx *exec_ctx, void *parser, grpc_chttp2_transport *t,
+    grpc_chttp2_stream *s, gpr_slice slice, int is_last);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_WINDOW_UPDATE_H */
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.c
index 522455f7dc..8180f78fc0 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.c
@@ -78,69 +78,96 @@ typedef enum {
    a set of indirect jumps, and so not waste stack space. */
 
 /* forward declarations for parsing states */
-static grpc_error *parse_begin(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_begin(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                const uint8_t *end);
-static grpc_error *parse_error(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_error(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                const uint8_t *end, grpc_error *error);
-static grpc_error *still_parse_error(grpc_chttp2_hpack_parser *p,
+static grpc_error *still_parse_error(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_illegal_op(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_illegal_op(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_hpack_parser *p,
                                     const uint8_t *cur, const uint8_t *end);
 
-static grpc_error *parse_string_prefix(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_string_prefix(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_key_string(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_key_string(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_hpack_parser *p,
                                     const uint8_t *cur, const uint8_t *end);
 static grpc_error *parse_value_string_with_indexed_key(
-    grpc_chttp2_hpack_parser *p, const uint8_t *cur, const uint8_t *end);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+    const uint8_t *end);
 static grpc_error *parse_value_string_with_literal_key(
-    grpc_chttp2_hpack_parser *p, const uint8_t *cur, const uint8_t *end);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+    const uint8_t *end);
 
-static grpc_error *parse_value0(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value0(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end);
-static grpc_error *parse_value1(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value1(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end);
-static grpc_error *parse_value2(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value2(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end);
-static grpc_error *parse_value3(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value3(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end);
-static grpc_error *parse_value4(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value4(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end);
-static grpc_error *parse_value5up(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_value5up(grpc_exec_ctx *exec_ctx,
+                                  grpc_chttp2_hpack_parser *p,
                                   const uint8_t *cur, const uint8_t *end);
 
-static grpc_error *parse_indexed_field(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_indexed_field(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_indexed_field_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_indexed_field_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_incidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_lithdr_incidx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_incidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_notidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_lithdr_notidx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_notidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_nvridx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_lithdr_nvridx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_lithdr_nvridx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end);
-static grpc_error *parse_max_tbl_size(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_max_tbl_size(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_hpack_parser *p,
                                       const uint8_t *cur, const uint8_t *end);
-static grpc_error *parse_max_tbl_size_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_max_tbl_size_x(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur, const uint8_t *end);
 
 /* we translate the first byte of a hpack field into one of these decoding
@@ -639,8 +666,8 @@ static const uint8_t inverse_base64[256] = {
 };
 
 /* emission helpers */
-static grpc_error *on_hdr(grpc_chttp2_hpack_parser *p, grpc_mdelem *md,
-                          int add_to_table) {
+static grpc_error *on_hdr(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p,
+                          grpc_mdelem *md, int add_to_table) {
   if (add_to_table) {
     grpc_error *err = grpc_chttp2_hptbl_add(&p->table, md);
     if (err != GRPC_ERROR_NONE) return err;
@@ -649,7 +676,7 @@ static grpc_error *on_hdr(grpc_chttp2_hpack_parser *p, grpc_mdelem *md,
     GRPC_MDELEM_UNREF(md);
     return GRPC_ERROR_CREATE("on_header callback not set");
   }
-  p->on_header(p->on_header_user_data, md);
+  p->on_header(exec_ctx, p->on_header_user_data, md);
   return GRPC_ERROR_NONE;
 }
 
@@ -661,78 +688,86 @@ static grpc_mdstr *take_string(grpc_chttp2_hpack_parser *p,
 }
 
 /* jump to the next state */
-static grpc_error *parse_next(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_next(grpc_exec_ctx *exec_ctx,
+                              grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                               const uint8_t *end) {
   p->state = *p->next_state++;
-  return p->state(p, cur, end);
+  return p->state(exec_ctx, p, cur, end);
 }
 
 /* begin parsing a header: all functionality is encoded into lookup tables
    above */
-static grpc_error *parse_begin(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_begin(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                const uint8_t *end) {
   if (cur == end) {
     p->state = parse_begin;
     return GRPC_ERROR_NONE;
   }
 
-  return first_byte_action[first_byte_lut[*cur]](p, cur, end);
+  return first_byte_action[first_byte_lut[*cur]](exec_ctx, p, cur, end);
 }
 
 /* stream dependency and prioritization data: we just skip it */
-static grpc_error *parse_stream_weight(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_stream_weight(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_stream_weight;
     return GRPC_ERROR_NONE;
   }
 
-  return p->after_prioritization(p, cur + 1, end);
+  return p->after_prioritization(exec_ctx, p, cur + 1, end);
 }
 
-static grpc_error *parse_stream_dep3(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_stream_dep3(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_stream_dep3;
     return GRPC_ERROR_NONE;
   }
 
-  return parse_stream_weight(p, cur + 1, end);
+  return parse_stream_weight(exec_ctx, p, cur + 1, end);
 }
 
-static grpc_error *parse_stream_dep2(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_stream_dep2(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_stream_dep2;
     return GRPC_ERROR_NONE;
   }
 
-  return parse_stream_dep3(p, cur + 1, end);
+  return parse_stream_dep3(exec_ctx, p, cur + 1, end);
 }
 
-static grpc_error *parse_stream_dep1(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_stream_dep1(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_stream_dep1;
     return GRPC_ERROR_NONE;
   }
 
-  return parse_stream_dep2(p, cur + 1, end);
+  return parse_stream_dep2(exec_ctx, p, cur + 1, end);
 }
 
-static grpc_error *parse_stream_dep0(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_stream_dep0(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_stream_dep0;
     return GRPC_ERROR_NONE;
   }
 
-  return parse_stream_dep1(p, cur + 1, end);
+  return parse_stream_dep1(exec_ctx, p, cur + 1, end);
 }
 
 /* emit an indexed field; for now just logs it to console; jumps to
    begin the next field on completion */
-static grpc_error *finish_indexed_field(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_indexed_field(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
   grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
@@ -743,21 +778,23 @@ static grpc_error *finish_indexed_field(grpc_chttp2_hpack_parser *p,
         GRPC_ERROR_INT_SIZE, (intptr_t)p->table.num_ents);
   }
   GRPC_MDELEM_REF(md);
-  grpc_error *err = on_hdr(p, md, 0);
+  grpc_error *err = on_hdr(exec_ctx, p, md, 0);
   if (err != GRPC_ERROR_NONE) return err;
-  return parse_begin(p, cur, end);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* parse an indexed field with index < 127 */
-static grpc_error *parse_indexed_field(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_indexed_field(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   p->dynamic_table_update_allowed = 0;
   p->index = (*cur) & 0x7f;
-  return finish_indexed_field(p, cur + 1, end);
+  return finish_indexed_field(exec_ctx, p, cur + 1, end);
 }
 
 /* parse an indexed field with index >= 127 */
-static grpc_error *parse_indexed_field_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_indexed_field_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -766,49 +803,53 @@ static grpc_error *parse_indexed_field_x(grpc_chttp2_hpack_parser *p,
   p->next_state = and_then;
   p->index = 0x7f;
   p->parsing.value = &p->index;
-  return parse_value0(p, cur + 1, end);
+  return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
 /* finish a literal header with incremental indexing: just log, and jump to '
    begin */
-static grpc_error *finish_lithdr_incidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_incidx(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
   grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   GPR_ASSERT(md != NULL); /* handled in string parsing */
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
-                                                  take_string(p, &p->value)),
-             1);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
+                                                     take_string(p, &p->value)),
+      1);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* finish a literal header with incremental indexing with no index */
-static grpc_error *finish_lithdr_incidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_incidx_v(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
-                                                  take_string(p, &p->value)),
-             1);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
+                                                     take_string(p, &p->value)),
+      1);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* parse a literal header with incremental indexing; index < 63 */
-static grpc_error *parse_lithdr_incidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
       parse_value_string_with_indexed_key, finish_lithdr_incidx};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
   p->index = (*cur) & 0x3f;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header with incremental indexing; index >= 63 */
-static grpc_error *parse_lithdr_incidx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -818,11 +859,12 @@ static grpc_error *parse_lithdr_incidx_x(grpc_chttp2_hpack_parser *p,
   p->next_state = and_then;
   p->index = 0x3f;
   p->parsing.value = &p->index;
-  return parse_value0(p, cur + 1, end);
+  return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header with incremental indexing; index = 0 */
-static grpc_error *parse_lithdr_incidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_incidx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -830,48 +872,52 @@ static grpc_error *parse_lithdr_incidx_v(grpc_chttp2_hpack_parser *p,
       parse_value_string_with_literal_key, finish_lithdr_incidx_v};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* finish a literal header without incremental indexing */
-static grpc_error *finish_lithdr_notidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_notidx(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
   grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   GPR_ASSERT(md != NULL); /* handled in string parsing */
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
-                                                  take_string(p, &p->value)),
-             0);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
+                                                     take_string(p, &p->value)),
+      0);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* finish a literal header without incremental indexing with index = 0 */
-static grpc_error *finish_lithdr_notidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_notidx_v(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
-                                                  take_string(p, &p->value)),
-             0);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
+                                                     take_string(p, &p->value)),
+      0);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* parse a literal header without incremental indexing; index < 15 */
-static grpc_error *parse_lithdr_notidx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
       parse_value_string_with_indexed_key, finish_lithdr_notidx};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
   p->index = (*cur) & 0xf;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header without incremental indexing; index >= 15 */
-static grpc_error *parse_lithdr_notidx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -881,11 +927,12 @@ static grpc_error *parse_lithdr_notidx_x(grpc_chttp2_hpack_parser *p,
   p->next_state = and_then;
   p->index = 0xf;
   p->parsing.value = &p->index;
-  return parse_value0(p, cur + 1, end);
+  return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header without incremental indexing; index == 0 */
-static grpc_error *parse_lithdr_notidx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_notidx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -893,48 +940,52 @@ static grpc_error *parse_lithdr_notidx_v(grpc_chttp2_hpack_parser *p,
       parse_value_string_with_literal_key, finish_lithdr_notidx_v};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* finish a literal header that is never indexed */
-static grpc_error *finish_lithdr_nvridx(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_nvridx(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
   grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   GPR_ASSERT(md != NULL); /* handled in string parsing */
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
-                                                  take_string(p, &p->value)),
-             0);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(GRPC_MDSTR_REF(md->key),
+                                                     take_string(p, &p->value)),
+      0);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* finish a literal header that is never indexed with an extra value */
-static grpc_error *finish_lithdr_nvridx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_lithdr_nvridx_v(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err =
-      on_hdr(p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
-                                                  take_string(p, &p->value)),
-             0);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  grpc_error *err = on_hdr(
+      exec_ctx, p, grpc_mdelem_from_metadata_strings(take_string(p, &p->key),
+                                                     take_string(p, &p->value)),
+      0);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* parse a literal header that is never indexed; index < 15 */
-static grpc_error *parse_lithdr_nvridx(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
       parse_value_string_with_indexed_key, finish_lithdr_nvridx};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
   p->index = (*cur) & 0xf;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header that is never indexed; index >= 15 */
-static grpc_error *parse_lithdr_nvridx_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx_x(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -944,11 +995,12 @@ static grpc_error *parse_lithdr_nvridx_x(grpc_chttp2_hpack_parser *p,
   p->next_state = and_then;
   p->index = 0xf;
   p->parsing.value = &p->index;
-  return parse_value0(p, cur + 1, end);
+  return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a literal header that is never indexed; index == 0 */
-static grpc_error *parse_lithdr_nvridx_v(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_lithdr_nvridx_v(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_hpack_parser *p,
                                          const uint8_t *cur,
                                          const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
@@ -956,44 +1008,47 @@ static grpc_error *parse_lithdr_nvridx_v(grpc_chttp2_hpack_parser *p,
       parse_value_string_with_literal_key, finish_lithdr_nvridx_v};
   p->dynamic_table_update_allowed = 0;
   p->next_state = and_then;
-  return parse_string_prefix(p, cur + 1, end);
+  return parse_string_prefix(exec_ctx, p, cur + 1, end);
 }
 
 /* finish parsing a max table size change */
-static grpc_error *finish_max_tbl_size(grpc_chttp2_hpack_parser *p,
+static grpc_error *finish_max_tbl_size(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   if (grpc_http_trace) {
     gpr_log(GPR_INFO, "MAX TABLE SIZE: %d", p->index);
   }
   grpc_error *err =
       grpc_chttp2_hptbl_set_current_table_size(&p->table, p->index);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_begin(p, cur, end);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_begin(exec_ctx, p, cur, end);
 }
 
 /* parse a max table size change, max size < 15 */
-static grpc_error *parse_max_tbl_size(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_max_tbl_size(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_hpack_parser *p,
                                       const uint8_t *cur, const uint8_t *end) {
   if (p->dynamic_table_update_allowed == 0) {
     return parse_error(
-        p, cur, end,
+        exec_ctx, p, cur, end,
         GRPC_ERROR_CREATE(
             "More than two max table size changes in a single frame"));
   }
   p->dynamic_table_update_allowed--;
   p->index = (*cur) & 0x1f;
-  return finish_max_tbl_size(p, cur + 1, end);
+  return finish_max_tbl_size(exec_ctx, p, cur + 1, end);
 }
 
 /* parse a max table size change, max size >= 15 */
-static grpc_error *parse_max_tbl_size_x(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_max_tbl_size_x(grpc_exec_ctx *exec_ctx,
+                                        grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
   static const grpc_chttp2_hpack_parser_state and_then[] = {
       finish_max_tbl_size};
   if (p->dynamic_table_update_allowed == 0) {
     return parse_error(
-        p, cur, end,
+        exec_ctx, p, cur, end,
         GRPC_ERROR_CREATE(
             "More than two max table size changes in a single frame"));
   }
@@ -1001,11 +1056,12 @@ static grpc_error *parse_max_tbl_size_x(grpc_chttp2_hpack_parser *p,
   p->next_state = and_then;
   p->index = 0x1f;
   p->parsing.value = &p->index;
-  return parse_value0(p, cur + 1, end);
+  return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
 /* a parse error: jam the parse state into parse_error, and return error */
-static grpc_error *parse_error(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_error(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                const uint8_t *end, grpc_error *err) {
   GPR_ASSERT(err != GRPC_ERROR_NONE);
   if (p->last_error == GRPC_ERROR_NONE) {
@@ -1015,24 +1071,27 @@ static grpc_error *parse_error(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   return err;
 }
 
-static grpc_error *still_parse_error(grpc_chttp2_hpack_parser *p,
+static grpc_error *still_parse_error(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_hpack_parser *p,
                                      const uint8_t *cur, const uint8_t *end) {
   return GRPC_ERROR_REF(p->last_error);
 }
 
-static grpc_error *parse_illegal_op(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_illegal_op(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_hpack_parser *p,
                                     const uint8_t *cur, const uint8_t *end) {
   GPR_ASSERT(cur != end);
   char *msg;
   gpr_asprintf(&msg, "Illegal hpack op code %d", *cur);
   grpc_error *err = GRPC_ERROR_CREATE(msg);
   gpr_free(msg);
-  return parse_error(p, cur, end, err);
+  return parse_error(exec_ctx, p, cur, end, err);
 }
 
 /* parse the 1st byte of a varint into p->parsing.value
    no overflow is possible */
-static grpc_error *parse_value0(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value0(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   if (cur == end) {
     p->state = parse_value0;
@@ -1042,15 +1101,16 @@ static grpc_error *parse_value0(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   *p->parsing.value += (*cur) & 0x7f;
 
   if ((*cur) & 0x80) {
-    return parse_value1(p, cur + 1, end);
+    return parse_value1(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 }
 
 /* parse the 2nd byte of a varint into p->parsing.value
    no overflow is possible */
-static grpc_error *parse_value1(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value1(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   if (cur == end) {
     p->state = parse_value1;
@@ -1060,15 +1120,16 @@ static grpc_error *parse_value1(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   *p->parsing.value += (((uint32_t)*cur) & 0x7f) << 7;
 
   if ((*cur) & 0x80) {
-    return parse_value2(p, cur + 1, end);
+    return parse_value2(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 }
 
 /* parse the 3rd byte of a varint into p->parsing.value
    no overflow is possible */
-static grpc_error *parse_value2(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value2(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   if (cur == end) {
     p->state = parse_value2;
@@ -1078,15 +1139,16 @@ static grpc_error *parse_value2(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   *p->parsing.value += (((uint32_t)*cur) & 0x7f) << 14;
 
   if ((*cur) & 0x80) {
-    return parse_value3(p, cur + 1, end);
+    return parse_value3(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 }
 
 /* parse the 4th byte of a varint into p->parsing.value
    no overflow is possible */
-static grpc_error *parse_value3(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value3(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   if (cur == end) {
     p->state = parse_value3;
@@ -1096,15 +1158,16 @@ static grpc_error *parse_value3(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   *p->parsing.value += (((uint32_t)*cur) & 0x7f) << 21;
 
   if ((*cur) & 0x80) {
-    return parse_value4(p, cur + 1, end);
+    return parse_value4(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 }
 
 /* parse the 5th byte of a varint into p->parsing.value
    depending on the byte, we may overflow, and care must be taken */
-static grpc_error *parse_value4(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_value4(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   uint8_t c;
   uint32_t cur_value;
@@ -1130,9 +1193,9 @@ static grpc_error *parse_value4(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
   *p->parsing.value = cur_value + add_value;
 
   if ((*cur) & 0x80) {
-    return parse_value5up(p, cur + 1, end);
+    return parse_value5up(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 
 error:
@@ -1142,13 +1205,14 @@ error:
                *p->parsing.value, *cur);
   grpc_error *err = GRPC_ERROR_CREATE(msg);
   gpr_free(msg);
-  return parse_error(p, cur, end, err);
+  return parse_error(exec_ctx, p, cur, end, err);
 }
 
 /* parse any trailing bytes in a varint: it's possible to append an arbitrary
    number of 0x80's and not affect the value - a zero will terminate - and
    anything else will overflow */
-static grpc_error *parse_value5up(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_value5up(grpc_exec_ctx *exec_ctx,
+                                  grpc_chttp2_hpack_parser *p,
                                   const uint8_t *cur, const uint8_t *end) {
   while (cur != end && *cur == 0x80) {
     ++cur;
@@ -1160,7 +1224,7 @@ static grpc_error *parse_value5up(grpc_chttp2_hpack_parser *p,
   }
 
   if (*cur == 0) {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 
   char *msg;
@@ -1170,11 +1234,12 @@ static grpc_error *parse_value5up(grpc_chttp2_hpack_parser *p,
                *p->parsing.value, *cur);
   grpc_error *err = GRPC_ERROR_CREATE(msg);
   gpr_free(msg);
-  return parse_error(p, cur, end, err);
+  return parse_error(exec_ctx, p, cur, end, err);
 }
 
 /* parse a string prefix */
-static grpc_error *parse_string_prefix(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_string_prefix(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_hpack_parser *p,
                                        const uint8_t *cur, const uint8_t *end) {
   if (cur == end) {
     p->state = parse_string_prefix;
@@ -1185,9 +1250,9 @@ static grpc_error *parse_string_prefix(grpc_chttp2_hpack_parser *p,
   p->huff = (*cur) >> 7;
   if (p->strlen == 0x7f) {
     p->parsing.value = &p->strlen;
-    return parse_value0(p, cur + 1, end);
+    return parse_value0(exec_ctx, p, cur + 1, end);
   } else {
-    return parse_next(p, cur + 1, end);
+    return parse_next(exec_ctx, p, cur + 1, end);
   }
 }
 
@@ -1205,7 +1270,8 @@ static void append_bytes(grpc_chttp2_hpack_parser_string *str,
   str->length += (uint32_t)length;
 }
 
-static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
+static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_hpack_parser *p,
                                  const uint8_t *cur, const uint8_t *end) {
   grpc_chttp2_hpack_parser_string *str = p->parsing.str;
   uint32_t bits;
@@ -1223,7 +1289,7 @@ static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(p, cur, end,
+        return parse_error(exec_ctx, p, cur, end,
                            GRPC_ERROR_CREATE("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte0;
@@ -1238,7 +1304,7 @@ static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(p, cur, end,
+        return parse_error(exec_ctx, p, cur, end,
                            GRPC_ERROR_CREATE("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte1;
@@ -1253,7 +1319,7 @@ static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(p, cur, end,
+        return parse_error(exec_ctx, p, cur, end,
                            GRPC_ERROR_CREATE("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte2;
@@ -1268,7 +1334,7 @@ static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
       bits = inverse_base64[*cur];
       ++cur;
       if (bits == 255)
-        return parse_error(p, cur, end,
+        return parse_error(exec_ctx, p, cur, end,
                            GRPC_ERROR_CREATE("Illegal base64 character"));
       else if (bits == 64)
         goto b64_byte3;
@@ -1281,11 +1347,12 @@ static grpc_error *append_string(grpc_chttp2_hpack_parser *p,
       goto b64_byte0;
   }
   GPR_UNREACHABLE_CODE(return parse_error(
-      p, cur, end, GRPC_ERROR_CREATE("Should never reach here")));
+      exec_ctx, p, cur, end, GRPC_ERROR_CREATE("Should never reach here")));
 }
 
 /* append a null terminator to a string */
-static grpc_error *finish_str(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
+                              grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                               const uint8_t *end) {
   uint8_t terminator = 0;
   uint8_t decoded[2];
@@ -1298,7 +1365,7 @@ static grpc_error *finish_str(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
       break;
     case B64_BYTE1:
       return parse_error(
-          p, cur, end,
+          exec_ctx, p, cur, end,
           GRPC_ERROR_CREATE("illegal base64 encoding")); /* illegal encoding */
     case B64_BYTE2:
       bits = p->base64_buffer;
@@ -1308,7 +1375,7 @@ static grpc_error *finish_str(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                      bits & 0xffff);
         grpc_error *err = GRPC_ERROR_CREATE(msg);
         gpr_free(msg);
-        return parse_error(p, cur, end, err);
+        return parse_error(exec_ctx, p, cur, end, err);
       }
       decoded[0] = (uint8_t)(bits >> 16);
       append_bytes(str, decoded, 1);
@@ -1321,7 +1388,7 @@ static grpc_error *finish_str(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                      bits & 0xff);
         grpc_error *err = GRPC_ERROR_CREATE(msg);
         gpr_free(msg);
-        return parse_error(p, cur, end, err);
+        return parse_error(exec_ctx, p, cur, end, err);
       }
       decoded[0] = (uint8_t)(bits >> 16);
       decoded[1] = (uint8_t)(bits >> 8);
@@ -1334,13 +1401,14 @@ static grpc_error *finish_str(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
 }
 
 /* decode a nibble from a huffman encoded stream */
-static grpc_error *huff_nibble(grpc_chttp2_hpack_parser *p, uint8_t nibble) {
+static grpc_error *huff_nibble(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_parser *p, uint8_t nibble) {
   int16_t emit = emit_sub_tbl[16 * emit_tbl[p->huff_state] + nibble];
   int16_t next = next_sub_tbl[16 * next_tbl[p->huff_state] + nibble];
   if (emit != -1) {
     if (emit >= 0 && emit < 256) {
       uint8_t c = (uint8_t)emit;
-      grpc_error *err = append_string(p, &c, (&c) + 1);
+      grpc_error *err = append_string(exec_ctx, p, &c, (&c) + 1);
       if (err != GRPC_ERROR_NONE) return err;
     } else {
       assert(emit == 256);
@@ -1351,42 +1419,45 @@ static grpc_error *huff_nibble(grpc_chttp2_hpack_parser *p, uint8_t nibble) {
 }
 
 /* decode full bytes from a huffman encoded stream */
-static grpc_error *add_huff_bytes(grpc_chttp2_hpack_parser *p,
+static grpc_error *add_huff_bytes(grpc_exec_ctx *exec_ctx,
+                                  grpc_chttp2_hpack_parser *p,
                                   const uint8_t *cur, const uint8_t *end) {
   for (; cur != end; ++cur) {
-    grpc_error *err = huff_nibble(p, *cur >> 4);
-    if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-    err = huff_nibble(p, *cur & 0xf);
-    if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
+    grpc_error *err = huff_nibble(exec_ctx, p, *cur >> 4);
+    if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+    err = huff_nibble(exec_ctx, p, *cur & 0xf);
+    if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   }
   return GRPC_ERROR_NONE;
 }
 
 /* decode some string bytes based on the current decoding mode
    (huffman or not) */
-static grpc_error *add_str_bytes(grpc_chttp2_hpack_parser *p,
+static grpc_error *add_str_bytes(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_hpack_parser *p,
                                  const uint8_t *cur, const uint8_t *end) {
   if (p->huff) {
-    return add_huff_bytes(p, cur, end);
+    return add_huff_bytes(exec_ctx, p, cur, end);
   } else {
-    return append_string(p, cur, end);
+    return append_string(exec_ctx, p, cur, end);
   }
 }
 
 /* parse a string - tries to do large chunks at a time */
-static grpc_error *parse_string(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+static grpc_error *parse_string(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                                 const uint8_t *end) {
   size_t remaining = p->strlen - p->strgot;
   size_t given = (size_t)(end - cur);
   if (remaining <= given) {
-    grpc_error *err = add_str_bytes(p, cur, cur + remaining);
-    if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-    err = finish_str(p, cur + remaining, end);
-    if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-    return parse_next(p, cur + remaining, end);
+    grpc_error *err = add_str_bytes(exec_ctx, p, cur, cur + remaining);
+    if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+    err = finish_str(exec_ctx, p, cur + remaining, end);
+    if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+    return parse_next(exec_ctx, p, cur + remaining, end);
   } else {
-    grpc_error *err = add_str_bytes(p, cur, cur + given);
-    if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
+    grpc_error *err = add_str_bytes(exec_ctx, p, cur, cur + given);
+    if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
     GPR_ASSERT(given <= UINT32_MAX - p->strgot);
     p->strgot += (uint32_t)given;
     p->state = parse_string;
@@ -1395,7 +1466,8 @@ static grpc_error *parse_string(grpc_chttp2_hpack_parser *p, const uint8_t *cur,
 }
 
 /* begin parsing a string - performs setup, calls parse_string */
-static grpc_error *begin_parse_string(grpc_chttp2_hpack_parser *p,
+static grpc_error *begin_parse_string(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_hpack_parser *p,
                                       const uint8_t *cur, const uint8_t *end,
                                       uint8_t binary,
                                       grpc_chttp2_hpack_parser_string *str) {
@@ -1404,13 +1476,14 @@ static grpc_error *begin_parse_string(grpc_chttp2_hpack_parser *p,
   p->parsing.str = str;
   p->huff_state = 0;
   p->binary = binary;
-  return parse_string(p, cur, end);
+  return parse_string(exec_ctx, p, cur, end);
 }
 
 /* parse the key string */
-static grpc_error *parse_key_string(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_key_string(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_hpack_parser *p,
                                     const uint8_t *cur, const uint8_t *end) {
-  return begin_parse_string(p, cur, end, NOT_BINARY, &p->key);
+  return begin_parse_string(exec_ctx, p, cur, end, NOT_BINARY, &p->key);
 }
 
 /* check if a key represents a binary header or not */
@@ -1435,24 +1508,27 @@ static grpc_error *is_binary_indexed_header(grpc_chttp2_hpack_parser *p,
 }
 
 /* parse the value string */
-static grpc_error *parse_value_string(grpc_chttp2_hpack_parser *p,
+static grpc_error *parse_value_string(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_hpack_parser *p,
                                       const uint8_t *cur, const uint8_t *end,
                                       bool is_binary) {
-  return begin_parse_string(p, cur, end, is_binary ? B64_BYTE0 : NOT_BINARY,
-                            &p->value);
+  return begin_parse_string(exec_ctx, p, cur, end,
+                            is_binary ? B64_BYTE0 : NOT_BINARY, &p->value);
 }
 
 static grpc_error *parse_value_string_with_indexed_key(
-    grpc_chttp2_hpack_parser *p, const uint8_t *cur, const uint8_t *end) {
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+    const uint8_t *end) {
   bool is_binary = false;
   grpc_error *err = is_binary_indexed_header(p, &is_binary);
-  if (err != GRPC_ERROR_NONE) return parse_error(p, cur, end, err);
-  return parse_value_string(p, cur, end, is_binary);
+  if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
+  return parse_value_string(exec_ctx, p, cur, end, is_binary);
 }
 
 static grpc_error *parse_value_string_with_literal_key(
-    grpc_chttp2_hpack_parser *p, const uint8_t *cur, const uint8_t *end) {
-  return parse_value_string(p, cur, end, is_binary_literal_header(p));
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *cur,
+    const uint8_t *end) {
+  return parse_value_string(exec_ctx, p, cur, end, is_binary_literal_header(p));
 }
 
 /* PUBLIC INTERFACE */
@@ -1484,27 +1560,36 @@ void grpc_chttp2_hpack_parser_destroy(grpc_chttp2_hpack_parser *p) {
   gpr_free(p->value.str);
 }
 
-grpc_error *grpc_chttp2_hpack_parser_parse(grpc_chttp2_hpack_parser *p,
+grpc_error *grpc_chttp2_hpack_parser_parse(grpc_exec_ctx *exec_ctx,
+                                           grpc_chttp2_hpack_parser *p,
                                            const uint8_t *beg,
                                            const uint8_t *end) {
   /* TODO(ctiller): limit the distance of end from beg, and perform multiple
      steps in the event of a large chunk of data to limit
      stack space usage when no tail call optimization is
      available */
-  return p->state(p, beg, end);
+  return p->state(exec_ctx, p, beg, end);
 }
 
-grpc_error *grpc_chttp2_header_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *hpack_parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last) {
+typedef void (*maybe_complete_func_type)(grpc_exec_ctx *exec_ctx,
+                                         grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream *s);
+static const maybe_complete_func_type maybe_complete_funcs[] = {
+    grpc_chttp2_maybe_complete_recv_initial_metadata,
+    grpc_chttp2_maybe_complete_recv_trailing_metadata};
+
+grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
+                                            void *hpack_parser,
+                                            grpc_chttp2_transport *t,
+                                            grpc_chttp2_stream *s,
+                                            gpr_slice slice, int is_last) {
   grpc_chttp2_hpack_parser *parser = hpack_parser;
   GPR_TIMER_BEGIN("grpc_chttp2_hpack_parser_parse", 0);
-  if (stream_parsing != NULL) {
-    stream_parsing->stats.incoming.header_bytes += GPR_SLICE_LENGTH(slice);
+  if (s != NULL) {
+    s->stats.incoming.header_bytes += GPR_SLICE_LENGTH(slice);
   }
   grpc_error *error = grpc_chttp2_hpack_parser_parse(
-      parser, GPR_SLICE_START_PTR(slice), GPR_SLICE_END_PTR(slice));
+      exec_ctx, parser, GPR_SLICE_START_PTR(slice), GPR_SLICE_END_PTR(slice));
   if (error != GRPC_ERROR_NONE) {
     GPR_TIMER_END("grpc_chttp2_hpack_parser_parse", 0);
     return error;
@@ -1517,20 +1602,19 @@ grpc_error *grpc_chttp2_header_parser_parse(
     }
     /* need to check for null stream: this can occur if we receive an invalid
        stream id on a header */
-    if (stream_parsing != NULL) {
+    if (s != NULL) {
       if (parser->is_boundary) {
-        if (stream_parsing->header_frames_received ==
-            GPR_ARRAY_SIZE(stream_parsing->got_metadata_on_parse)) {
+        if (s->header_frames_received == GPR_ARRAY_SIZE(s->metadata_buffer)) {
           return GRPC_ERROR_CREATE("Too many trailer frames");
         }
-        stream_parsing
-            ->got_metadata_on_parse[stream_parsing->header_frames_received] = 1;
-        stream_parsing->header_frames_received++;
-        grpc_chttp2_list_add_parsing_seen_stream(transport_parsing,
-                                                 stream_parsing);
+        s->published_metadata[s->header_frames_received] =
+            GRPC_METADATA_PUBLISHED_FROM_WIRE;
+        maybe_complete_funcs[s->header_frames_received](exec_ctx, t, s);
+        s->header_frames_received++;
       }
       if (parser->is_eof) {
-        stream_parsing->received_close = 1;
+        grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, false,
+                                       GRPC_ERROR_NONE);
       }
     }
     parser->on_header = NULL;
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.h b/src/core/ext/transport/chttp2/transport/hpack_parser.h
index 78eb38db5e..0290c78d5a 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.h
@@ -45,7 +45,8 @@
 typedef struct grpc_chttp2_hpack_parser grpc_chttp2_hpack_parser;
 
 typedef grpc_error *(*grpc_chttp2_hpack_parser_state)(
-    grpc_chttp2_hpack_parser *p, const uint8_t *beg, const uint8_t *end);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *beg,
+    const uint8_t *end);
 
 typedef struct {
   char *str;
@@ -55,7 +56,7 @@ typedef struct {
 
 struct grpc_chttp2_hpack_parser {
   /* user specified callback for each header output */
-  void (*on_header)(void *user_data, grpc_mdelem *md);
+  void (*on_header)(grpc_exec_ctx *exec_ctx, void *user_data, grpc_mdelem *md);
   void *on_header_user_data;
 
   grpc_error *last_error;
@@ -104,15 +105,17 @@ void grpc_chttp2_hpack_parser_destroy(grpc_chttp2_hpack_parser *p);
 void grpc_chttp2_hpack_parser_set_has_priority(grpc_chttp2_hpack_parser *p);
 
 /* returns 1 on success, 0 on error */
-grpc_error *grpc_chttp2_hpack_parser_parse(grpc_chttp2_hpack_parser *p,
+grpc_error *grpc_chttp2_hpack_parser_parse(grpc_exec_ctx *exec_ctx,
+                                           grpc_chttp2_hpack_parser *p,
                                            const uint8_t *beg,
                                            const uint8_t *end);
 
 /* wraps grpc_chttp2_hpack_parser_parse to provide a frame level parser for
    the transport */
-grpc_error *grpc_chttp2_header_parser_parse(
-    grpc_exec_ctx *exec_ctx, void *hpack_parser,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, gpr_slice slice, int is_last);
+grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
+                                            void *hpack_parser,
+                                            grpc_chttp2_transport *t,
+                                            grpc_chttp2_stream *s,
+                                            gpr_slice slice, int is_last);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 04b788b702..01f521c360 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -53,31 +53,25 @@
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/transport_impl.h"
 
-typedef struct grpc_chttp2_transport grpc_chttp2_transport;
-typedef struct grpc_chttp2_stream grpc_chttp2_stream;
-
 /* streams are kept in various linked lists depending on what things need to
    happen to them... this enum labels each list */
 typedef enum {
-  GRPC_CHTTP2_LIST_ALL_STREAMS,
-  GRPC_CHTTP2_LIST_CHECK_READ_OPS,
-  GRPC_CHTTP2_LIST_UNANNOUNCED_INCOMING_WINDOW_AVAILABLE,
   GRPC_CHTTP2_LIST_WRITABLE,
   GRPC_CHTTP2_LIST_WRITING,
-  GRPC_CHTTP2_LIST_WRITTEN,
-  GRPC_CHTTP2_LIST_PARSING_SEEN,
-  GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_PARSING,
-  GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_WRITING,
   GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT,
-  /* streams waiting for the outgoing window in the writing path, they will be
-   * merged to the stalled list or writable list under transport lock. */
-  GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT,
   /** streams that are waiting to start because there are too many concurrent
       streams on the connection */
   GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY,
   STREAM_LIST_COUNT /* must be last */
 } grpc_chttp2_stream_list_id;
 
+typedef enum {
+  GRPC_CHTTP2_WRITE_STATE_IDLE,
+  GRPC_CHTTP2_WRITE_STATE_WRITING,
+  GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE,
+  GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_AND_COVERED_BY_POLLER,
+} grpc_chttp2_write_state;
+
 /* deframer state for the overall http2 stream of bytes */
 typedef enum {
   /* prefix: one entry per http2 connection prefix byte */
@@ -152,6 +146,12 @@ typedef struct grpc_chttp2_outstanding_ping {
   struct grpc_chttp2_outstanding_ping *prev;
 } grpc_chttp2_outstanding_ping;
 
+typedef struct grpc_chttp2_write_cb {
+  int64_t call_at_byte;
+  grpc_closure *closure;
+  struct grpc_chttp2_write_cb *next;
+} grpc_chttp2_write_cb;
+
 /* forward declared in frame_data.h */
 struct grpc_chttp2_incoming_byte_stream {
   grpc_byte_stream base;
@@ -161,12 +161,13 @@ struct grpc_chttp2_incoming_byte_stream {
 
   grpc_chttp2_transport *transport;
   grpc_chttp2_stream *stream;
-  int is_tail;
+  bool is_tail;
 
   gpr_mu slice_mu;  // protects slices, on_next
   gpr_slice_buffer slices;
   grpc_closure *on_next;
   gpr_slice *next;
+  uint32_t remaining_bytes;
 
   struct {
     grpc_closure closure;
@@ -178,12 +179,68 @@ struct grpc_chttp2_incoming_byte_stream {
   grpc_closure finished_action;
 };
 
-typedef struct {
+struct grpc_chttp2_transport {
+  grpc_transport base; /* must be first */
+  gpr_refcount refs;
+  grpc_endpoint *ep;
+  char *peer_string;
+
+  grpc_combiner *combiner;
+
+  /** write execution state of the transport */
+  grpc_chttp2_write_state write_state;
+
+  /** is the transport destroying itself? */
+  uint8_t destroying;
+  /** has the upper layer closed the transport? */
+  uint8_t closed;
+
+  /** is there a read request to the endpoint outstanding? */
+  uint8_t endpoint_reading;
+
+  /** various lists of streams */
+  grpc_chttp2_stream_list lists[STREAM_LIST_COUNT];
+
+  /** maps stream id to grpc_chttp2_stream objects */
+  grpc_chttp2_stream_map stream_map;
+
+  grpc_closure write_action_begin_locked;
+  grpc_closure write_action;
+  grpc_closure write_action_end;
+  grpc_closure write_action_end_locked;
+
+  grpc_closure read_action_begin;
+  grpc_closure read_action_locked;
+
+  /** incoming read bytes */
+  gpr_slice_buffer read_buffer;
+
+  /** address to place a newly accepted stream - set and unset by
+      grpc_chttp2_parsing_accept_stream; used by init_stream to
+      publish the accepted server stream */
+  grpc_chttp2_stream **accepting_stream;
+
+  struct {
+    /* accept stream callback */
+    void (*accept_stream)(grpc_exec_ctx *exec_ctx, void *user_data,
+                          grpc_transport *transport, const void *server_data);
+    void *accept_stream_user_data;
+
+    /** connectivity tracking */
+    grpc_connectivity_state_tracker state_tracker;
+  } channel_callback;
+
+  /** data to write now */
+  gpr_slice_buffer outbuf;
+  /** hpack encoding */
+  grpc_chttp2_hpack_compressor hpack_compressor;
+  int64_t outgoing_window;
+  /** is this a client? */
+  uint8_t is_client;
+
   /** data to write next write */
   gpr_slice_buffer qbuf;
 
-  /** window available for us to send to peer */
-  int64_t outgoing_window;
   /** window available to announce to peer */
   int64_t announce_incoming_window;
   /** how much window would we like to have for incoming_window */
@@ -194,8 +251,6 @@ typedef struct {
   /** have we sent a goaway */
   uint8_t sent_goaway;
 
-  /** is this transport a client? */
-  uint8_t is_client;
   /** are the local settings dirty and need to be sent? */
   uint8_t dirtied_local_settings;
   /** have local settings been sent? */
@@ -212,49 +267,14 @@ typedef struct {
   /** how far to lookahead in a stream? */
   uint32_t stream_lookahead;
 
-  /** last received stream id */
-  uint32_t last_incoming_stream_id;
+  /** last new stream id */
+  uint32_t last_new_stream_id;
 
   /** pings awaiting responses */
   grpc_chttp2_outstanding_ping pings;
   /** next payload for an outgoing ping */
   uint64_t ping_counter;
 
-  /** concurrent stream count: updated when not parsing,
-      so this is a strict over-estimation on the client */
-  uint32_t concurrent_stream_count;
-} grpc_chttp2_transport_global;
-
-typedef struct {
-  /** data to write now */
-  gpr_slice_buffer outbuf;
-  /** hpack encoding */
-  grpc_chttp2_hpack_compressor hpack_compressor;
-  int64_t outgoing_window;
-  /** is this a client? */
-  uint8_t is_client;
-  /** callback for when writing is done */
-  grpc_closure done_cb;
-  /** maximum frame size */
-  uint32_t max_frame_size;
-} grpc_chttp2_transport_writing;
-
-struct grpc_chttp2_transport_parsing {
-  /** is this transport a client? (boolean) */
-  uint8_t is_client;
-
-  /** were settings updated? */
-  uint8_t settings_updated;
-  /** was a settings ack received? */
-  uint8_t settings_ack_received;
-  /** was a goaway frame received? */
-  uint8_t goaway_received;
-
-  /** initial window change */
-  int64_t initial_window_update;
-
-  /** data to write later - after parsing */
-  gpr_slice_buffer qbuf;
   /** parser for headers */
   grpc_chttp2_hpack_parser hpack_parser;
   /** simple one shot parsers */
@@ -267,13 +287,12 @@ struct grpc_chttp2_transport_parsing {
   /** parser for goaway frames */
   grpc_chttp2_goaway_parser goaway_parser;
 
+  /** initial window change */
+  int64_t initial_window_update;
+
   /** window available for peer to send to us */
   int64_t incoming_window;
 
-  /** next stream id available at the time of beginning parsing */
-  uint32_t next_stream_id;
-  uint32_t last_incoming_stream_id;
-
   /* deframing */
   grpc_chttp2_deframe_transport_state deframe_state;
   uint8_t incoming_frame_type;
@@ -284,135 +303,42 @@ struct grpc_chttp2_transport_parsing {
   uint32_t incoming_frame_size;
   uint32_t incoming_stream_id;
 
-  /* current max frame size */
-  uint32_t max_frame_size;
-
   /* active parser */
   void *parser_data;
-  grpc_chttp2_stream_parsing *incoming_stream;
+  grpc_chttp2_stream *incoming_stream;
   grpc_error *(*parser)(grpc_exec_ctx *exec_ctx, void *parser_user_data,
-                        grpc_chttp2_transport_parsing *transport_parsing,
-                        grpc_chttp2_stream_parsing *stream_parsing,
+                        grpc_chttp2_transport *t, grpc_chttp2_stream *s,
                         gpr_slice slice, int is_last);
 
-  /* received settings */
-  uint32_t settings[GRPC_CHTTP2_NUM_SETTINGS];
-  /* last settings that were sent */
-  uint32_t last_sent_settings[GRPC_CHTTP2_NUM_SETTINGS];
-
   /* goaway data */
   grpc_status_code goaway_error;
   uint32_t goaway_last_stream_index;
   gpr_slice goaway_text;
 
-  int64_t outgoing_window;
+  grpc_chttp2_write_cb *write_cb_pool;
+
+  /* if non-NULL, close the transport with this error when writes are finished
+   */
+  grpc_error *close_transport_on_writes_finished;
 };
 
 typedef enum {
-  /** no writing activity allowed */
-  GRPC_CHTTP2_WRITES_CORKED,
-  /** no writing activity */
-  GRPC_CHTTP2_WRITING_INACTIVE,
-  /** write has been requested and scheduled against the workqueue */
-  GRPC_CHTTP2_WRITE_SCHEDULED,
-  /** write has been initiated after being reaped from the workqueue */
-  GRPC_CHTTP2_WRITING,
-  /** write has been initiated, AND another write needs to be started once it's
-      done */
-  GRPC_CHTTP2_WRITING_STALE_WITH_POLLER,
-  GRPC_CHTTP2_WRITING_STALE_NO_POLLER,
-} grpc_chttp2_write_state;
-
-struct grpc_chttp2_transport {
-  grpc_transport base; /* must be first */
-  gpr_refcount refs;
-  grpc_endpoint *ep;
-  char *peer_string;
-
-  /** when this drops to zero it's safe to shutdown the endpoint */
-  gpr_refcount shutdown_ep_refs;
-
-  struct {
-    grpc_combiner *combiner;
-
-    /** is a thread currently in the global lock */
-    bool global_active;
-    /** is a thread currently parsing */
-    bool parsing_active;
-    /** write execution state of the transport */
-    grpc_chttp2_write_state write_state;
-    /** has a check_read_ops been scheduled */
-    bool check_read_ops_scheduled;
-  } executor;
-
-  /** is the transport destroying itself? */
-  uint8_t destroying;
-  /** has the upper layer closed the transport? */
-  uint8_t closed;
+  GRPC_METADATA_NOT_PUBLISHED,
+  GRPC_METADATA_SYNTHESIZED_FROM_FAKE,
+  GRPC_METADATA_PUBLISHED_FROM_WIRE,
+  GPRC_METADATA_PUBLISHED_AT_CLOSE
+} grpc_published_metadata_method;
 
-  /** is there a read request to the endpoint outstanding? */
-  uint8_t endpoint_reading;
-
-  /** various lists of streams */
-  grpc_chttp2_stream_list lists[STREAM_LIST_COUNT];
-
-  /** global state for reading/writing */
-  grpc_chttp2_transport_global global;
-  /** state only accessible by the chain of execution that
-      set writing_state >= GRPC_WRITING, and only by the writing closure
-      chain. */
-  grpc_chttp2_transport_writing writing;
-  /** state only accessible by the chain of execution that
-      set parsing_active=1 */
-  grpc_chttp2_transport_parsing parsing;
-
-  /** maps stream id to grpc_chttp2_stream objects;
-      owned by the parsing thread when parsing */
-  grpc_chttp2_stream_map parsing_stream_map;
-
-  /** streams created by the client (possibly during parsing);
-      merged with parsing_stream_map during unlock when no
-      parsing is occurring */
-  grpc_chttp2_stream_map new_stream_map;
-
-  /** closure to execute writing */
-  grpc_closure writing_action;
-  /** closure to start reading from the endpoint */
-  grpc_closure reading_action;
-  grpc_closure reading_action_locked;
-  grpc_closure post_parse_locked;
-  /** closure to actually do parsing */
-  grpc_closure parsing_action;
-  /** closure to initiate writing */
-  grpc_closure initiate_writing;
-  /** closure to finish writing */
-  grpc_closure terminate_writing;
-  /** closure to flush read state up the stack */
-  grpc_closure initiate_read_flush_locked;
-
-  /** incoming read bytes */
-  gpr_slice_buffer read_buffer;
-
-  /** address to place a newly accepted stream - set and unset by
-      grpc_chttp2_parsing_accept_stream; used by init_stream to
-      publish the accepted server stream */
-  grpc_chttp2_stream **accepting_stream;
-
-  struct {
-    /* accept stream callback */
-    void (*accept_stream)(grpc_exec_ctx *exec_ctx, void *user_data,
-                          grpc_transport *transport, const void *server_data);
-    void *accept_stream_user_data;
+struct grpc_chttp2_stream {
+  grpc_chttp2_transport *t;
+  grpc_stream_refcount *refcount;
 
-    /** connectivity tracking */
-    grpc_connectivity_state_tracker state_tracker;
-  } channel_callback;
+  grpc_closure destroy_stream;
+  void *destroy_stream_arg;
 
-  /** Transport op to be applied post-parsing */
-  grpc_transport_op *post_parsing_op;
-};
+  grpc_chttp2_stream_link links[STREAM_LIST_COUNT];
+  uint8_t included[STREAM_LIST_COUNT];
 
-typedef struct {
   /** HTTP2 stream id for this stream, or zero if one has not been assigned */
   uint32_t id;
 
@@ -422,20 +348,22 @@ typedef struct {
       As the upper layer offers more bytes, this value increases.
       As bytes are read, this value decreases. */
   uint32_t max_recv_bytes;
-  /** The number of bytes the upper layer has offered to read but we have
-      not yet announced to HTTP2 flow control.
-      As the upper layers offer to read more bytes, this value increases.
-      As we advertise incoming flow control window, this value decreases. */
-  uint32_t unannounced_incoming_window_for_parse;
-  uint32_t unannounced_incoming_window_for_writing;
   /** things the upper layers would like to send */
   grpc_metadata_batch *send_initial_metadata;
   grpc_closure *send_initial_metadata_finished;
-  grpc_byte_stream *send_message;
-  grpc_closure *send_message_finished;
   grpc_metadata_batch *send_trailing_metadata;
   grpc_closure *send_trailing_metadata_finished;
 
+  grpc_byte_stream *fetching_send_message;
+  uint32_t fetched_send_message_length;
+  gpr_slice fetching_slice;
+  int64_t next_message_end_offset;
+  int64_t flow_controlled_bytes_written;
+  bool complete_fetch_covered_by_poller;
+  grpc_closure complete_fetch;
+  grpc_closure complete_fetch_locked;
+  grpc_closure *fetching_send_message_finished;
+
   grpc_metadata_batch *recv_initial_metadata;
   grpc_closure *recv_initial_metadata_ready;
   grpc_byte_stream **recv_message;
@@ -455,95 +383,44 @@ typedef struct {
   bool read_closed;
   /** Are all published incoming byte streams closed. */
   bool all_incoming_byte_streams_finished;
-  /** Is this stream in the stream map. */
-  bool in_stream_map;
   /** Has this stream seen an error.
       If true, then pending incoming frames can be thrown away. */
   bool seen_error;
-  bool exceeded_metadata_size;
 
   /** the error that resulted in this stream being read-closed */
   grpc_error *read_closed_error;
   /** the error that resulted in this stream being write-closed */
   grpc_error *write_closed_error;
 
-  bool published_initial_metadata;
-  bool published_trailing_metadata;
+  grpc_published_metadata_method published_metadata[2];
   bool final_metadata_requested;
 
-  grpc_chttp2_incoming_metadata_buffer received_initial_metadata;
-  grpc_chttp2_incoming_metadata_buffer received_trailing_metadata;
+  grpc_chttp2_incoming_metadata_buffer metadata_buffer[2];
 
   grpc_chttp2_incoming_frame_queue incoming_frames;
 
   gpr_timespec deadline;
-} grpc_chttp2_stream_global;
-
-typedef struct {
-  /** HTTP2 stream id for this stream, or zero if one has not been assigned */
-  uint32_t id;
-  uint8_t fetching;
-  bool sent_initial_metadata;
-  uint8_t sent_message;
-  uint8_t sent_trailing_metadata;
-  uint8_t read_closed;
-  /** send this initial metadata */
-  grpc_metadata_batch *send_initial_metadata;
-  grpc_byte_stream *send_message;
-  grpc_metadata_batch *send_trailing_metadata;
-  int64_t outgoing_window;
-  /** how much window should we announce? */
-  uint32_t announce_window;
-  gpr_slice_buffer flow_controlled_buffer;
-  gpr_slice fetching_slice;
-  size_t stream_fetched;
-  grpc_closure finished_fetch;
-  /** stats gathered during the write */
-  grpc_transport_one_way_stats stats;
-} grpc_chttp2_stream_writing;
 
-struct grpc_chttp2_stream_parsing {
   /** saw some stream level error */
   grpc_error *forced_close_error;
-  /** HTTP2 stream id for this stream, or zero if one has not been assigned */
-  uint32_t id;
-  /** has this stream received a close */
-  uint8_t received_close;
   /** how many header frames have we received? */
   uint8_t header_frames_received;
-  /** which metadata did we get (on this parse) */
-  uint8_t got_metadata_on_parse[2];
-  /** should we raise the seen_error flag in transport_global */
-  bool seen_error;
-  bool exceeded_metadata_size;
   /** window available for peer to send to us */
   int64_t incoming_window;
   /** parsing state for data frames */
   grpc_chttp2_data_parser data_parser;
-  /** amount of window given */
-  int64_t outgoing_window;
   /** number of bytes received - reset at end of parse thread execution */
   int64_t received_bytes;
-  /** stats gathered during the parse */
-  grpc_transport_stream_stats stats;
 
-  /** incoming metadata */
-  grpc_chttp2_incoming_metadata_buffer metadata_buffer[2];
-};
-
-struct grpc_chttp2_stream {
-  grpc_chttp2_transport *t;
-  grpc_stream_refcount *refcount;
-  grpc_chttp2_stream_global global;
-  grpc_chttp2_stream_writing writing;
-  grpc_chttp2_stream_parsing parsing;
-
-  grpc_closure init_stream;
-  grpc_closure destroy_stream;
-  void *destroy_stream_arg;
+  bool sent_initial_metadata;
+  bool sent_trailing_metadata;
+  /** how much window should we announce? */
+  uint32_t announce_window;
+  gpr_slice_buffer flow_controlled_buffer;
 
-  grpc_chttp2_stream_link links[STREAM_LIST_COUNT];
-  uint8_t included[STREAM_LIST_COUNT];
+  grpc_chttp2_write_cb *on_write_finished_cbs;
+  grpc_chttp2_write_cb *finish_after_write;
+  size_t sending_bytes;
 };
 
 /** Transport writing call flow:
@@ -559,162 +436,71 @@ struct grpc_chttp2_stream {
     The actual call chain is documented in the implementation of this function.
     */
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport_global *transport_global,
+                                grpc_chttp2_transport *t,
                                 bool covered_by_poller, const char *reason);
 
 /** Someone is unlocking the transport mutex: check to see if writes
-    are required, and schedule them if so */
-int grpc_chttp2_unlocking_check_writes(grpc_exec_ctx *exec_ctx,
-                                       grpc_chttp2_transport_global *global,
-                                       grpc_chttp2_transport_writing *writing);
-void grpc_chttp2_perform_writes(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing,
-    grpc_endpoint *endpoint);
-void grpc_chttp2_terminate_writing(grpc_exec_ctx *exec_ctx,
-                                   void *transport_writing, grpc_error *error);
-void grpc_chttp2_cleanup_writing(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport_global *global,
-                                 grpc_chttp2_transport_writing *writing);
-
-void grpc_chttp2_prepare_to_read(grpc_chttp2_transport_global *global,
-                                 grpc_chttp2_transport_parsing *parsing);
+    are required, and frame them if so */
+bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t);
+void grpc_chttp2_end_write(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                           grpc_error *error);
+
 /** Process one slice of incoming data; return 1 if the connection is still
     viable after reading, or 0 if the connection should be torn down */
-grpc_error *grpc_chttp2_perform_read(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    gpr_slice slice);
-void grpc_chttp2_publish_reads(grpc_exec_ctx *exec_ctx,
-                               grpc_chttp2_transport_global *global,
-                               grpc_chttp2_transport_parsing *parsing);
-
-bool grpc_chttp2_list_add_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
+grpc_error *grpc_chttp2_perform_read(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t, gpr_slice slice);
+
+bool grpc_chttp2_list_add_writable_stream(grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s);
 /** Get a writable stream
     returns non-zero if there was a stream available */
-int grpc_chttp2_list_pop_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_writing **stream_writing);
+int grpc_chttp2_list_pop_writable_stream(grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream **s);
 bool grpc_chttp2_list_remove_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) GRPC_MUST_USE_RESULT;
-
-void grpc_chttp2_list_add_writing_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing);
-int grpc_chttp2_list_have_writing_streams(
-    grpc_chttp2_transport_writing *transport_writing);
-int grpc_chttp2_list_pop_writing_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing **stream_writing);
-
-void grpc_chttp2_list_add_written_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing);
-int grpc_chttp2_list_pop_written_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_writing **stream_writing);
-
-void grpc_chttp2_list_add_parsing_seen_stream(
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing);
-int grpc_chttp2_list_pop_parsing_seen_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_parsing **stream_parsing);
-
-void grpc_chttp2_list_add_waiting_for_concurrency(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-int grpc_chttp2_list_pop_waiting_for_concurrency(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global);
-
-void grpc_chttp2_list_add_check_read_ops(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-bool grpc_chttp2_list_remove_check_read_ops(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-int grpc_chttp2_list_pop_check_read_ops(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global);
-
-void grpc_chttp2_list_add_writing_stalled_by_transport(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing);
-bool grpc_chttp2_list_flush_writing_stalled_by_transport(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing);
-
-void grpc_chttp2_list_add_stalled_by_transport(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing);
-int grpc_chttp2_list_pop_stalled_by_transport(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global);
-void grpc_chttp2_list_remove_stalled_by_transport(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-
-void grpc_chttp2_list_add_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-void grpc_chttp2_list_remove_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-int grpc_chttp2_list_pop_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_parsing **stream_parsing);
-
-void grpc_chttp2_list_add_closed_waiting_for_parsing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-int grpc_chttp2_list_pop_closed_waiting_for_parsing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global);
-
-void grpc_chttp2_list_add_closed_waiting_for_writing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global);
-int grpc_chttp2_list_pop_closed_waiting_for_writing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global);
-
-grpc_chttp2_stream_parsing *grpc_chttp2_parsing_lookup_stream(
-    grpc_chttp2_transport_parsing *transport_parsing, uint32_t id);
-grpc_chttp2_stream_parsing *grpc_chttp2_parsing_accept_stream(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    uint32_t id);
-
-void grpc_chttp2_add_incoming_goaway(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    uint32_t goaway_error, gpr_slice goaway_text);
-
-void grpc_chttp2_register_stream(grpc_chttp2_transport *t,
-                                 grpc_chttp2_stream *s);
-/* returns 1 if this is the last stream, 0 otherwise */
-int grpc_chttp2_unregister_stream(grpc_chttp2_transport *t,
-                                  grpc_chttp2_stream *s) GRPC_MUST_USE_RESULT;
-int grpc_chttp2_has_streams(grpc_chttp2_transport *t);
-void grpc_chttp2_for_all_streams(
-    grpc_chttp2_transport_global *transport_global, void *user_data,
-    void (*cb)(grpc_chttp2_transport_global *transport_global, void *user_data,
-               grpc_chttp2_stream_global *stream_global));
-
-void grpc_chttp2_parsing_become_skip_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-
-void grpc_chttp2_complete_closure_step(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, grpc_closure **pclosure,
-    grpc_error *error);
+    grpc_chttp2_transport *t, grpc_chttp2_stream *s) GRPC_MUST_USE_RESULT;
+
+bool grpc_chttp2_list_add_writing_stream(grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream *s);
+int grpc_chttp2_list_have_writing_streams(grpc_chttp2_transport *t);
+int grpc_chttp2_list_pop_writing_stream(grpc_chttp2_transport *t,
+                                        grpc_chttp2_stream **s);
+
+void grpc_chttp2_list_add_written_stream(grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream *s);
+int grpc_chttp2_list_pop_written_stream(grpc_chttp2_transport *t,
+                                        grpc_chttp2_stream **s);
+
+void grpc_chttp2_list_add_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                  grpc_chttp2_stream *s);
+int grpc_chttp2_list_pop_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                 grpc_chttp2_stream **s);
+
+void grpc_chttp2_list_add_stalled_by_transport(grpc_chttp2_transport *t,
+                                               grpc_chttp2_stream *s);
+int grpc_chttp2_list_pop_stalled_by_transport(grpc_chttp2_transport *t,
+                                              grpc_chttp2_stream **s);
+void grpc_chttp2_list_remove_stalled_by_transport(grpc_chttp2_transport *t,
+                                                  grpc_chttp2_stream *s);
+
+grpc_chttp2_stream *grpc_chttp2_parsing_lookup_stream(grpc_chttp2_transport *t,
+                                                      uint32_t id);
+grpc_chttp2_stream *grpc_chttp2_parsing_accept_stream(grpc_exec_ctx *exec_ctx,
+                                                      grpc_chttp2_transport *t,
+                                                      uint32_t id);
+
+void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t,
+                                     uint32_t goaway_error,
+                                     gpr_slice goaway_text);
+
+void grpc_chttp2_parsing_become_skip_parser(grpc_exec_ctx *exec_ctx,
+                                            grpc_chttp2_transport *t);
+
+void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_transport *t,
+                                       grpc_chttp2_stream *s,
+                                       grpc_closure **pclosure,
+                                       grpc_error *error, const char *desc);
 
 #define GRPC_CHTTP2_CLIENT_CONNECT_STRING "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
 #define GRPC_CHTTP2_CLIENT_CONNECT_STRLEN \
@@ -805,57 +591,83 @@ void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
                                const char *var2, int is_client,
                                uint32_t stream_id, int64_t val1, int64_t val2);
 
-void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx,
-                             grpc_chttp2_transport_global *transport_global,
-                             grpc_chttp2_stream_global *stream,
+void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_chttp2_stream *stream,
                              grpc_status_code status, gpr_slice *details);
-void grpc_chttp2_mark_stream_closed(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global, int close_reads, int close_writes,
-    grpc_error *error);
+void grpc_chttp2_mark_stream_closed(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_transport *t,
+                                    grpc_chttp2_stream *s, int close_reads,
+                                    int close_writes, grpc_error *error);
 void grpc_chttp2_start_writing(grpc_exec_ctx *exec_ctx,
-                               grpc_chttp2_transport_global *transport_global);
+                               grpc_chttp2_transport *t);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
-#define GRPC_CHTTP2_STREAM_REF(stream_global, reason) \
-  grpc_chttp2_stream_ref(stream_global, reason)
-#define GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, reason) \
-  grpc_chttp2_stream_unref(exec_ctx, stream_global, reason)
-void grpc_chttp2_stream_ref(grpc_chttp2_stream_global *stream_global,
-                            const char *reason);
-void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx,
-                              grpc_chttp2_stream_global *stream_global,
+#define GRPC_CHTTP2_STREAM_REF(stream, reason) \
+  grpc_chttp2_stream_ref(stream, reason)
+#define GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream, reason) \
+  grpc_chttp2_stream_unref(exec_ctx, stream, reason)
+void grpc_chttp2_stream_ref(grpc_chttp2_stream *s, const char *reason);
+void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx, grpc_chttp2_stream *s,
                               const char *reason);
 #else
-#define GRPC_CHTTP2_STREAM_REF(stream_global, reason) \
-  grpc_chttp2_stream_ref(stream_global)
-#define GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, reason) \
-  grpc_chttp2_stream_unref(exec_ctx, stream_global)
-void grpc_chttp2_stream_ref(grpc_chttp2_stream_global *stream_global);
-void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx,
-                              grpc_chttp2_stream_global *stream_global);
+#define GRPC_CHTTP2_STREAM_REF(stream, reason) grpc_chttp2_stream_ref(stream)
+#define GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream, reason) \
+  grpc_chttp2_stream_unref(exec_ctx, stream)
+void grpc_chttp2_stream_ref(grpc_chttp2_stream *s);
+void grpc_chttp2_stream_unref(grpc_exec_ctx *exec_ctx, grpc_chttp2_stream *s);
+#endif
+
+//#define GRPC_CHTTP2_REFCOUNTING_DEBUG 1
+#ifdef GRPC_CHTTP2_REFCOUNTING_DEBUG
+#define GRPC_CHTTP2_REF_TRANSPORT(t, r) \
+  grpc_chttp2_ref_transport(t, r, __FILE__, __LINE__)
+#define GRPC_CHTTP2_UNREF_TRANSPORT(cl, t, r) \
+  grpc_chttp2_unref_transport(cl, t, r, __FILE__, __LINE__)
+void grpc_chttp2_unref_transport(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t, const char *reason,
+                                 const char *file, int line);
+void grpc_chttp2_ref_transport(grpc_chttp2_transport *t, const char *reason,
+                               const char *file, int line);
+#else
+#define GRPC_CHTTP2_REF_TRANSPORT(t, r) grpc_chttp2_ref_transport(t)
+#define GRPC_CHTTP2_UNREF_TRANSPORT(cl, t, r) grpc_chttp2_unref_transport(cl, t)
+void grpc_chttp2_unref_transport(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t);
+void grpc_chttp2_ref_transport(grpc_chttp2_transport *t);
 #endif
 
 grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing, uint32_t frame_size,
-    uint32_t flags, grpc_chttp2_incoming_frame_queue *add_to_queue);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+    uint32_t frame_size, uint32_t flags);
 void grpc_chttp2_incoming_byte_stream_push(grpc_exec_ctx *exec_ctx,
                                            grpc_chttp2_incoming_byte_stream *bs,
                                            gpr_slice slice);
 void grpc_chttp2_incoming_byte_stream_finished(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_byte_stream *bs,
-    grpc_error *error, int from_parsing_thread);
+    grpc_error *error);
 
-void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx,
-                          grpc_chttp2_transport_parsing *parsing,
+void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           const uint8_t *opaque_8bytes);
 
 /** add a ref to the stream and add it to the writable list;
     ref will be dropped in writing.c */
 void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport_global *transport_global,
-                                 grpc_chttp2_stream_global *stream_global,
-                                 bool covered_by_poller, const char *reason);
+                                 grpc_chttp2_transport *t,
+                                 grpc_chttp2_stream *s, bool covered_by_poller,
+                                 const char *reason);
+
+void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+                               grpc_error *due_to_error);
+
+void grpc_chttp2_maybe_complete_recv_initial_metadata(grpc_exec_ctx *exec_ctx,
+                                                      grpc_chttp2_transport *t,
+                                                      grpc_chttp2_stream *s);
+void grpc_chttp2_maybe_complete_recv_message(grpc_exec_ctx *exec_ctx,
+                                             grpc_chttp2_transport *t,
+                                             grpc_chttp2_stream *s);
+void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
+                                                       grpc_chttp2_transport *t,
+                                                       grpc_chttp2_stream *s);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_H */
diff --git a/src/core/ext/transport/chttp2/transport/parsing.c b/src/core/ext/transport/chttp2/transport/parsing.c
index 0e6d579ba9..8005350ae7 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.c
@@ -45,227 +45,34 @@
 #include "src/core/lib/transport/static_metadata.h"
 #include "src/core/lib/transport/timeout_encoding.h"
 
-#define TRANSPORT_FROM_PARSING(tp)                                        \
-  ((grpc_chttp2_transport *)((char *)(tp)-offsetof(grpc_chttp2_transport, \
-                                                   parsing)))
-
-static grpc_error *init_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_header_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    int is_continuation);
-static grpc_error *init_data_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_rst_stream_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_settings_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_window_update_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_ping_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_goaway_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
-static grpc_error *init_skip_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    int is_header);
-
-static grpc_error *parse_frame_slice(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    gpr_slice slice, int is_last);
-
-void grpc_chttp2_prepare_to_read(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing) {
-  grpc_chttp2_stream_global *stream_global;
-  grpc_chttp2_stream_parsing *stream_parsing;
-
-  GPR_TIMER_BEGIN("grpc_chttp2_prepare_to_read", 0);
-
-  transport_parsing->next_stream_id = transport_global->next_stream_id;
-  memcpy(transport_parsing->last_sent_settings,
-         transport_global->settings[GRPC_SENT_SETTINGS],
-         sizeof(transport_parsing->last_sent_settings));
-  transport_parsing->max_frame_size =
-      transport_global->settings[GRPC_ACKED_SETTINGS]
-                                [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE];
-
-  /* update the parsing view of incoming window */
-  while (grpc_chttp2_list_pop_unannounced_incoming_window_available(
-      transport_global, transport_parsing, &stream_global, &stream_parsing)) {
-    GRPC_CHTTP2_FLOW_MOVE_STREAM("parse", transport_parsing, stream_parsing,
-                                 incoming_window, stream_global,
-                                 unannounced_incoming_window_for_parse);
-  }
-
-  GPR_TIMER_END("grpc_chttp2_prepare_to_read", 0);
-}
-
-void grpc_chttp2_publish_reads(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing) {
-  grpc_chttp2_stream_global *stream_global;
-  grpc_chttp2_stream_parsing *stream_parsing;
-  int was_zero;
-  int is_zero;
-
-  /* transport_parsing->last_incoming_stream_id is used as
-     last-grpc_chttp2_stream-id when
-     sending GOAWAY frame.
-     https://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-6.8
-     says that last-grpc_chttp2_stream-id is peer-initiated grpc_chttp2_stream
-     ID.  So,
-     since we don't have server pushed streams, client should send
-     GOAWAY last-grpc_chttp2_stream-id=0 in this case. */
-  if (!transport_parsing->is_client) {
-    transport_global->last_incoming_stream_id =
-        transport_parsing->last_incoming_stream_id;
-  }
-
-  /* update global settings */
-  if (transport_parsing->settings_updated) {
-    memcpy(transport_global->settings[GRPC_PEER_SETTINGS],
-           transport_parsing->settings, sizeof(transport_parsing->settings));
-    transport_parsing->settings_updated = 0;
-  }
-
-  /* update settings based on ack if received */
-  if (transport_parsing->settings_ack_received) {
-    memcpy(transport_global->settings[GRPC_ACKED_SETTINGS],
-           transport_global->settings[GRPC_SENT_SETTINGS],
-           GRPC_CHTTP2_NUM_SETTINGS * sizeof(uint32_t));
-    transport_parsing->settings_ack_received = 0;
-    transport_global->sent_local_settings = 0;
-  }
-
-  /* move goaway to the global state if we received one (it will be
-     published later */
-  if (transport_parsing->goaway_received) {
-    grpc_chttp2_add_incoming_goaway(exec_ctx, transport_global,
-                                    (uint32_t)transport_parsing->goaway_error,
-                                    transport_parsing->goaway_text);
-    transport_parsing->goaway_text = gpr_empty_slice();
-    transport_parsing->goaway_received = 0;
-  }
-
-  /* propagate flow control tokens to global state */
-  was_zero = transport_global->outgoing_window <= 0;
-  GRPC_CHTTP2_FLOW_MOVE_TRANSPORT("parsed", transport_global, outgoing_window,
-                                  transport_parsing, outgoing_window);
-  is_zero = transport_global->outgoing_window <= 0;
-  if (was_zero && !is_zero) {
-    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                               "new_global_flow_control");
-  }
-
-  if (transport_parsing->incoming_window <
-      transport_global->connection_window_target * 3 / 4) {
-    int64_t announce_bytes = transport_global->connection_window_target -
-                             transport_parsing->incoming_window;
-    GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parsed", transport_global,
-                                      announce_incoming_window, announce_bytes);
-    GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parsed", transport_parsing,
-                                      incoming_window, announce_bytes);
-    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                               "global incoming window");
-  }
-
-  /* for each stream that saw an update, fixup global state */
-  while (grpc_chttp2_list_pop_parsing_seen_stream(
-      transport_global, transport_parsing, &stream_global, &stream_parsing)) {
-    if (stream_parsing->seen_error) {
-      stream_global->seen_error = true;
-      stream_global->exceeded_metadata_size =
-          stream_parsing->exceeded_metadata_size;
-      grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                          stream_global);
-    }
-
-    /* flush stats to global stream state */
-    grpc_transport_move_stats(&stream_parsing->stats, &stream_global->stats);
-
-    /* update outgoing flow control window */
-    was_zero = stream_global->outgoing_window <= 0;
-    GRPC_CHTTP2_FLOW_MOVE_STREAM("parsed", transport_global, stream_global,
-                                 outgoing_window, stream_parsing,
-                                 outgoing_window);
-    is_zero = stream_global->outgoing_window <= 0;
-    if (was_zero && !is_zero) {
-      grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                  false, "stream.read_flow_control");
-    }
-
-    stream_global->max_recv_bytes -= (uint32_t)GPR_MIN(
-        stream_global->max_recv_bytes, stream_parsing->received_bytes);
-    stream_parsing->received_bytes = 0;
-
-    /* publish incoming stream ops */
-    if (stream_global->incoming_frames.tail != NULL) {
-      stream_global->incoming_frames.tail->is_tail = 0;
-    }
-    if (stream_parsing->data_parser.incoming_frames.head != NULL) {
-      grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                          stream_global);
-    }
-    grpc_chttp2_incoming_frame_queue_merge(
-        &stream_global->incoming_frames,
-        &stream_parsing->data_parser.incoming_frames);
-    if (stream_global->incoming_frames.tail != NULL) {
-      stream_global->incoming_frames.tail->is_tail = 1;
-    }
-
-    if (!stream_global->published_initial_metadata &&
-        stream_parsing->got_metadata_on_parse[0]) {
-      stream_parsing->got_metadata_on_parse[0] = 0;
-      stream_global->published_initial_metadata = 1;
-      GPR_SWAP(grpc_chttp2_incoming_metadata_buffer,
-               stream_parsing->metadata_buffer[0],
-               stream_global->received_initial_metadata);
-      grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                          stream_global);
-    }
-    if (!stream_global->published_trailing_metadata &&
-        stream_parsing->got_metadata_on_parse[1]) {
-      stream_parsing->got_metadata_on_parse[1] = 0;
-      stream_global->published_trailing_metadata = 1;
-      GPR_SWAP(grpc_chttp2_incoming_metadata_buffer,
-               stream_parsing->metadata_buffer[1],
-               stream_global->received_trailing_metadata);
-      grpc_chttp2_list_add_check_read_ops(exec_ctx, transport_global,
-                                          stream_global);
-    }
-
-    if (stream_parsing->forced_close_error != GRPC_ERROR_NONE) {
-      intptr_t reason;
-      bool has_reason = grpc_error_get_int(stream_parsing->forced_close_error,
-                                           GRPC_ERROR_INT_HTTP2_ERROR, &reason);
-      if (has_reason && reason != GRPC_CHTTP2_NO_ERROR) {
-        grpc_status_code status_code =
-            has_reason
-                ? grpc_chttp2_http2_error_to_grpc_status(
-                      (grpc_chttp2_error_code)reason, stream_global->deadline)
-                : GRPC_STATUS_INTERNAL;
-        const char *status_details =
-            grpc_error_string(stream_parsing->forced_close_error);
-        gpr_slice slice_details = gpr_slice_from_copied_string(status_details);
-        grpc_error_free_string(status_details);
-        grpc_chttp2_fake_status(exec_ctx, transport_global, stream_global,
-                                status_code, &slice_details);
-      }
-      grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global,
-                                     1, 1, stream_parsing->forced_close_error);
-    }
-
-    if (stream_parsing->received_close) {
-      grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global,
-                                     1, 0, GRPC_ERROR_NONE);
-    }
-  }
-}
-
-grpc_error *grpc_chttp2_perform_read(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    gpr_slice slice) {
+static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t);
+static grpc_error *init_header_frame_parser(grpc_exec_ctx *exec_ctx,
+                                            grpc_chttp2_transport *t,
+                                            int is_continuation);
+static grpc_error *init_data_frame_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t);
+static grpc_error *init_rst_stream_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t);
+static grpc_error *init_settings_frame_parser(grpc_exec_ctx *exec_ctx,
+                                              grpc_chttp2_transport *t);
+static grpc_error *init_window_update_frame_parser(grpc_exec_ctx *exec_ctx,
+                                                   grpc_chttp2_transport *t);
+static grpc_error *init_ping_parser(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_transport *t);
+static grpc_error *init_goaway_parser(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t);
+static grpc_error *init_skip_frame_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t,
+                                          int is_header);
+
+static grpc_error *parse_frame_slice(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t, gpr_slice slice,
+                                     int is_last);
+
+grpc_error *grpc_chttp2_perform_read(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t,
+                                     gpr_slice slice) {
   uint8_t *beg = GPR_SLICE_START_PTR(slice);
   uint8_t *end = GPR_SLICE_END_PTR(slice);
   uint8_t *cur = beg;
@@ -273,7 +80,7 @@ grpc_error *grpc_chttp2_perform_read(
 
   if (cur == end) return GRPC_ERROR_NONE;
 
-  switch (transport_parsing->deframe_state) {
+  switch (t->deframe_state) {
     case GRPC_DTS_CLIENT_PREFIX_0:
     case GRPC_DTS_CLIENT_PREFIX_1:
     case GRPC_DTS_CLIENT_PREFIX_2:
@@ -298,25 +105,22 @@ grpc_error *grpc_chttp2_perform_read(
     case GRPC_DTS_CLIENT_PREFIX_21:
     case GRPC_DTS_CLIENT_PREFIX_22:
     case GRPC_DTS_CLIENT_PREFIX_23:
-      while (cur != end && transport_parsing->deframe_state != GRPC_DTS_FH_0) {
-        if (*cur != GRPC_CHTTP2_CLIENT_CONNECT_STRING[transport_parsing
-                                                          ->deframe_state]) {
+      while (cur != end && t->deframe_state != GRPC_DTS_FH_0) {
+        if (*cur != GRPC_CHTTP2_CLIENT_CONNECT_STRING[t->deframe_state]) {
           char *msg;
           gpr_asprintf(
               &msg,
               "Connect string mismatch: expected '%c' (%d) got '%c' (%d) "
               "at byte %d",
-              GRPC_CHTTP2_CLIENT_CONNECT_STRING[transport_parsing
-                                                    ->deframe_state],
-              (int)(uint8_t)GRPC_CHTTP2_CLIENT_CONNECT_STRING
-                  [transport_parsing->deframe_state],
-              *cur, (int)*cur, transport_parsing->deframe_state);
+              GRPC_CHTTP2_CLIENT_CONNECT_STRING[t->deframe_state],
+              (int)(uint8_t)GRPC_CHTTP2_CLIENT_CONNECT_STRING[t->deframe_state],
+              *cur, (int)*cur, t->deframe_state);
           err = GRPC_ERROR_CREATE(msg);
           gpr_free(msg);
           return err;
         }
         ++cur;
-        ++transport_parsing->deframe_state;
+        ++t->deframe_state;
       }
       if (cur == end) {
         return GRPC_ERROR_NONE;
@@ -325,100 +129,95 @@ grpc_error *grpc_chttp2_perform_read(
     dts_fh_0:
     case GRPC_DTS_FH_0:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_frame_size = ((uint32_t)*cur) << 16;
+      t->incoming_frame_size = ((uint32_t)*cur) << 16;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_1;
+        t->deframe_state = GRPC_DTS_FH_1;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_1:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_frame_size |= ((uint32_t)*cur) << 8;
+      t->incoming_frame_size |= ((uint32_t)*cur) << 8;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_2;
+        t->deframe_state = GRPC_DTS_FH_2;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_2:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_frame_size |= *cur;
+      t->incoming_frame_size |= *cur;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_3;
+        t->deframe_state = GRPC_DTS_FH_3;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_3:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_frame_type = *cur;
+      t->incoming_frame_type = *cur;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_4;
+        t->deframe_state = GRPC_DTS_FH_4;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_4:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_frame_flags = *cur;
+      t->incoming_frame_flags = *cur;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_5;
+        t->deframe_state = GRPC_DTS_FH_5;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_5:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_stream_id = (((uint32_t)*cur) & 0x7f) << 24;
+      t->incoming_stream_id = (((uint32_t)*cur) & 0x7f) << 24;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_6;
+        t->deframe_state = GRPC_DTS_FH_6;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_6:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_stream_id |= ((uint32_t)*cur) << 16;
+      t->incoming_stream_id |= ((uint32_t)*cur) << 16;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_7;
+        t->deframe_state = GRPC_DTS_FH_7;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_7:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_stream_id |= ((uint32_t)*cur) << 8;
+      t->incoming_stream_id |= ((uint32_t)*cur) << 8;
       if (++cur == end) {
-        transport_parsing->deframe_state = GRPC_DTS_FH_8;
+        t->deframe_state = GRPC_DTS_FH_8;
         return GRPC_ERROR_NONE;
       }
     /* fallthrough */
     case GRPC_DTS_FH_8:
       GPR_ASSERT(cur < end);
-      transport_parsing->incoming_stream_id |= ((uint32_t)*cur);
-      transport_parsing->deframe_state = GRPC_DTS_FRAME;
-      err = init_frame_parser(exec_ctx, transport_parsing);
+      t->incoming_stream_id |= ((uint32_t)*cur);
+      t->deframe_state = GRPC_DTS_FRAME;
+      err = init_frame_parser(exec_ctx, t);
       if (err != GRPC_ERROR_NONE) {
         return err;
       }
-      if (transport_parsing->incoming_stream_id != 0 &&
-          transport_parsing->incoming_stream_id >
-              transport_parsing->last_incoming_stream_id) {
-        transport_parsing->last_incoming_stream_id =
-            transport_parsing->incoming_stream_id;
-      }
-      if (transport_parsing->incoming_frame_size == 0) {
-        err = parse_frame_slice(exec_ctx, transport_parsing, gpr_empty_slice(),
-                                1);
+      if (t->incoming_frame_size == 0) {
+        err = parse_frame_slice(exec_ctx, t, gpr_empty_slice(), 1);
         if (err != GRPC_ERROR_NONE) {
           return err;
         }
-        transport_parsing->incoming_stream = NULL;
+        t->incoming_stream = NULL;
         if (++cur == end) {
-          transport_parsing->deframe_state = GRPC_DTS_FH_0;
+          t->deframe_state = GRPC_DTS_FH_0;
           return GRPC_ERROR_NONE;
         }
         goto dts_fh_0; /* loop */
-      } else if (transport_parsing->incoming_frame_size >
-                 transport_parsing->max_frame_size) {
+      } else if (t->incoming_frame_size >
+                 t->settings[GRPC_ACKED_SETTINGS]
+                            [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE]) {
         char *msg;
         gpr_asprintf(&msg, "Frame size %d is larger than max frame size %d",
-                     transport_parsing->incoming_frame_size,
-                     transport_parsing->max_frame_size);
+                     t->incoming_frame_size,
+                     t->settings[GRPC_ACKED_SETTINGS]
+                                [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE]);
         err = GRPC_ERROR_CREATE(msg);
         gpr_free(msg);
         return err;
@@ -429,41 +228,39 @@ grpc_error *grpc_chttp2_perform_read(
     /* fallthrough */
     case GRPC_DTS_FRAME:
       GPR_ASSERT(cur < end);
-      if ((uint32_t)(end - cur) == transport_parsing->incoming_frame_size) {
-        err = parse_frame_slice(exec_ctx, transport_parsing,
+      if ((uint32_t)(end - cur) == t->incoming_frame_size) {
+        err = parse_frame_slice(exec_ctx, t,
                                 gpr_slice_sub_no_ref(slice, (size_t)(cur - beg),
                                                      (size_t)(end - beg)),
                                 1);
         if (err != GRPC_ERROR_NONE) {
           return err;
         }
-        transport_parsing->deframe_state = GRPC_DTS_FH_0;
-        transport_parsing->incoming_stream = NULL;
+        t->deframe_state = GRPC_DTS_FH_0;
+        t->incoming_stream = NULL;
         return GRPC_ERROR_NONE;
-      } else if ((uint32_t)(end - cur) >
-                 transport_parsing->incoming_frame_size) {
+      } else if ((uint32_t)(end - cur) > t->incoming_frame_size) {
         size_t cur_offset = (size_t)(cur - beg);
         err = parse_frame_slice(
-            exec_ctx, transport_parsing,
-            gpr_slice_sub_no_ref(
-                slice, cur_offset,
-                cur_offset + transport_parsing->incoming_frame_size),
+            exec_ctx, t,
+            gpr_slice_sub_no_ref(slice, cur_offset,
+                                 cur_offset + t->incoming_frame_size),
             1);
         if (err != GRPC_ERROR_NONE) {
           return err;
         }
-        cur += transport_parsing->incoming_frame_size;
-        transport_parsing->incoming_stream = NULL;
+        cur += t->incoming_frame_size;
+        t->incoming_stream = NULL;
         goto dts_fh_0; /* loop */
       } else {
-        err = parse_frame_slice(exec_ctx, transport_parsing,
+        err = parse_frame_slice(exec_ctx, t,
                                 gpr_slice_sub_no_ref(slice, (size_t)(cur - beg),
                                                      (size_t)(end - beg)),
                                 0);
         if (err != GRPC_ERROR_NONE) {
           return err;
         }
-        transport_parsing->incoming_frame_size -= (uint32_t)(end - cur);
+        t->incoming_frame_size -= (uint32_t)(end - cur);
         return GRPC_ERROR_NONE;
       }
       GPR_UNREACHABLE_CODE(return 0);
@@ -472,175 +269,172 @@ grpc_error *grpc_chttp2_perform_read(
   GPR_UNREACHABLE_CODE(return 0);
 }
 
-static grpc_error *init_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
-  if (transport_parsing->is_first_frame &&
-      transport_parsing->incoming_frame_type != GRPC_CHTTP2_FRAME_SETTINGS) {
+static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t) {
+  if (t->is_first_frame &&
+      t->incoming_frame_type != GRPC_CHTTP2_FRAME_SETTINGS) {
     char *msg;
     gpr_asprintf(
         &msg, "Expected SETTINGS frame as the first frame, got frame type %d",
-        transport_parsing->incoming_frame_type);
+        t->incoming_frame_type);
     grpc_error *err = GRPC_ERROR_CREATE(msg);
     gpr_free(msg);
     return err;
   }
-  transport_parsing->is_first_frame = false;
-  if (transport_parsing->expect_continuation_stream_id != 0) {
-    if (transport_parsing->incoming_frame_type !=
-        GRPC_CHTTP2_FRAME_CONTINUATION) {
+  t->is_first_frame = false;
+  if (t->expect_continuation_stream_id != 0) {
+    if (t->incoming_frame_type != GRPC_CHTTP2_FRAME_CONTINUATION) {
       char *msg;
       gpr_asprintf(&msg, "Expected CONTINUATION frame, got frame type %02x",
-                   transport_parsing->incoming_frame_type);
+                   t->incoming_frame_type);
       grpc_error *err = GRPC_ERROR_CREATE(msg);
       gpr_free(msg);
       return err;
     }
-    if (transport_parsing->expect_continuation_stream_id !=
-        transport_parsing->incoming_stream_id) {
+    if (t->expect_continuation_stream_id != t->incoming_stream_id) {
       char *msg;
       gpr_asprintf(
           &msg,
           "Expected CONTINUATION frame for grpc_chttp2_stream %08x, got "
           "grpc_chttp2_stream %08x",
-          transport_parsing->expect_continuation_stream_id,
-          transport_parsing->incoming_stream_id);
+          t->expect_continuation_stream_id, t->incoming_stream_id);
       grpc_error *err = GRPC_ERROR_CREATE(msg);
       gpr_free(msg);
       return err;
     }
-    return init_header_frame_parser(exec_ctx, transport_parsing, 1);
+    return init_header_frame_parser(exec_ctx, t, 1);
   }
-  switch (transport_parsing->incoming_frame_type) {
+  switch (t->incoming_frame_type) {
     case GRPC_CHTTP2_FRAME_DATA:
-      return init_data_frame_parser(exec_ctx, transport_parsing);
+      return init_data_frame_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_HEADER:
-      return init_header_frame_parser(exec_ctx, transport_parsing, 0);
+      return init_header_frame_parser(exec_ctx, t, 0);
     case GRPC_CHTTP2_FRAME_CONTINUATION:
       return GRPC_ERROR_CREATE("Unexpected CONTINUATION frame");
     case GRPC_CHTTP2_FRAME_RST_STREAM:
-      return init_rst_stream_parser(exec_ctx, transport_parsing);
+      return init_rst_stream_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_SETTINGS:
-      return init_settings_frame_parser(exec_ctx, transport_parsing);
+      return init_settings_frame_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_WINDOW_UPDATE:
-      return init_window_update_frame_parser(exec_ctx, transport_parsing);
+      return init_window_update_frame_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_PING:
-      return init_ping_parser(exec_ctx, transport_parsing);
+      return init_ping_parser(exec_ctx, t);
     case GRPC_CHTTP2_FRAME_GOAWAY:
-      return init_goaway_parser(exec_ctx, transport_parsing);
+      return init_goaway_parser(exec_ctx, t);
     default:
       if (grpc_http_trace) {
-        gpr_log(GPR_ERROR, "Unknown frame type %02x",
-                transport_parsing->incoming_frame_type);
+        gpr_log(GPR_ERROR, "Unknown frame type %02x", t->incoming_frame_type);
       }
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
+      return init_skip_frame_parser(exec_ctx, t, 0);
   }
 }
 
 static grpc_error *skip_parser(grpc_exec_ctx *exec_ctx, void *parser,
-                               grpc_chttp2_transport_parsing *transport_parsing,
-                               grpc_chttp2_stream_parsing *stream_parsing,
+                               grpc_chttp2_transport *t, grpc_chttp2_stream *s,
                                gpr_slice slice, int is_last) {
   return GRPC_ERROR_NONE;
 }
 
-static void skip_header(void *tp, grpc_mdelem *md) { GRPC_MDELEM_UNREF(md); }
+static void skip_header(grpc_exec_ctx *exec_ctx, void *tp, grpc_mdelem *md) {
+  GRPC_MDELEM_UNREF(md);
+}
 
-static grpc_error *init_skip_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    int is_header) {
+static grpc_error *init_skip_frame_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t,
+                                          int is_header) {
   if (is_header) {
-    uint8_t is_eoh = transport_parsing->expect_continuation_stream_id != 0;
-    transport_parsing->parser = grpc_chttp2_header_parser_parse;
-    transport_parsing->parser_data = &transport_parsing->hpack_parser;
-    transport_parsing->hpack_parser.on_header = skip_header;
-    transport_parsing->hpack_parser.on_header_user_data = NULL;
-    transport_parsing->hpack_parser.is_boundary = is_eoh;
-    transport_parsing->hpack_parser.is_eof =
-        (uint8_t)(is_eoh ? transport_parsing->header_eof : 0);
+    uint8_t is_eoh = t->expect_continuation_stream_id != 0;
+    t->parser = grpc_chttp2_header_parser_parse;
+    t->parser_data = &t->hpack_parser;
+    t->hpack_parser.on_header = skip_header;
+    t->hpack_parser.on_header_user_data = NULL;
+    t->hpack_parser.is_boundary = is_eoh;
+    t->hpack_parser.is_eof = (uint8_t)(is_eoh ? t->header_eof : 0);
   } else {
-    transport_parsing->parser = skip_parser;
+    t->parser = skip_parser;
   }
   return GRPC_ERROR_NONE;
 }
 
-void grpc_chttp2_parsing_become_skip_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
-  init_skip_frame_parser(
-      exec_ctx, transport_parsing,
-      transport_parsing->parser == grpc_chttp2_header_parser_parse);
+void grpc_chttp2_parsing_become_skip_parser(grpc_exec_ctx *exec_ctx,
+                                            grpc_chttp2_transport *t) {
+  init_skip_frame_parser(exec_ctx, t,
+                         t->parser == grpc_chttp2_header_parser_parse);
 }
 
-static grpc_error *update_incoming_window(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing) {
-  uint32_t incoming_frame_size = transport_parsing->incoming_frame_size;
-  if (incoming_frame_size > transport_parsing->incoming_window) {
-    char *msg;
-    gpr_asprintf(&msg, "frame of size %d overflows incoming window of %" PRId64,
-                 transport_parsing->incoming_frame_size,
-                 transport_parsing->incoming_window);
-    grpc_error *err = GRPC_ERROR_CREATE(msg);
-    gpr_free(msg);
-    return err;
-  }
-
-  if (incoming_frame_size > stream_parsing->incoming_window) {
+static grpc_error *update_incoming_window(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s) {
+  uint32_t incoming_frame_size = t->incoming_frame_size;
+  if (incoming_frame_size > t->incoming_window) {
     char *msg;
     gpr_asprintf(&msg, "frame of size %d overflows incoming window of %" PRId64,
-                 transport_parsing->incoming_frame_size,
-                 stream_parsing->incoming_window);
+                 t->incoming_frame_size, t->incoming_window);
     grpc_error *err = GRPC_ERROR_CREATE(msg);
     gpr_free(msg);
     return err;
   }
 
-  GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("parse", transport_parsing, incoming_window,
+  GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("parse", t, incoming_window,
                                    incoming_frame_size);
-  GRPC_CHTTP2_FLOW_DEBIT_STREAM("parse", transport_parsing, stream_parsing,
-                                incoming_window, incoming_frame_size);
-  stream_parsing->received_bytes += incoming_frame_size;
 
-  grpc_chttp2_list_add_parsing_seen_stream(transport_parsing, stream_parsing);
+  if (s != NULL) {
+    if (incoming_frame_size > s->incoming_window) {
+      char *msg;
+      gpr_asprintf(&msg,
+                   "frame of size %d overflows incoming window of %" PRId64,
+                   t->incoming_frame_size, s->incoming_window);
+      grpc_error *err = GRPC_ERROR_CREATE(msg);
+      gpr_free(msg);
+      return err;
+    }
+
+    GRPC_CHTTP2_FLOW_DEBIT_STREAM("parse", t, s, incoming_window,
+                                  incoming_frame_size);
+    s->received_bytes += incoming_frame_size;
+    s->max_recv_bytes -=
+        (uint32_t)GPR_MIN(s->max_recv_bytes, incoming_frame_size);
+  }
 
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_data_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
-  grpc_chttp2_stream_parsing *stream_parsing =
-      grpc_chttp2_parsing_lookup_stream(transport_parsing,
-                                        transport_parsing->incoming_stream_id);
+static grpc_error *init_data_frame_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t) {
+  grpc_chttp2_stream *s =
+      grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
   grpc_error *err = GRPC_ERROR_NONE;
-  if (stream_parsing == NULL) {
-    return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
+  err = update_incoming_window(exec_ctx, t, s);
+  if (err != GRPC_ERROR_NONE) {
+    goto error_handler;
   }
-  stream_parsing->stats.incoming.framing_bytes += 9;
-  if (stream_parsing->received_close) {
-    return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
+  if (s == NULL) {
+    return init_skip_frame_parser(exec_ctx, t, 0);
   }
-  if (err == GRPC_ERROR_NONE) {
-    err = update_incoming_window(exec_ctx, transport_parsing, stream_parsing);
+  s->stats.incoming.framing_bytes += 9;
+  if (err == GRPC_ERROR_NONE && s->read_closed) {
+    return init_skip_frame_parser(exec_ctx, t, 0);
   }
   if (err == GRPC_ERROR_NONE) {
-    err = grpc_chttp2_data_parser_begin_frame(
-        &stream_parsing->data_parser, transport_parsing->incoming_frame_flags,
-        stream_parsing->id);
+    err = grpc_chttp2_data_parser_begin_frame(&s->data_parser,
+                                              t->incoming_frame_flags, s->id);
   }
+error_handler:
   if (err == GRPC_ERROR_NONE) {
-    transport_parsing->incoming_stream = stream_parsing;
-    transport_parsing->parser = grpc_chttp2_data_parser_parse;
-    transport_parsing->parser_data = &stream_parsing->data_parser;
+    t->incoming_stream = s;
+    t->parser = grpc_chttp2_data_parser_parse;
+    t->parser_data = &s->data_parser;
     return GRPC_ERROR_NONE;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, NULL)) {
     /* handle stream errors by closing the stream */
-    stream_parsing->received_close = 1;
-    stream_parsing->forced_close_error = err;
+    if (s != NULL) {
+      grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, false, err);
+    }
     gpr_slice_buffer_add(
-        &transport_parsing->qbuf,
-        grpc_chttp2_rst_stream_create(transport_parsing->incoming_stream_id,
-                                      GRPC_CHTTP2_PROTOCOL_ERROR,
-                                      &stream_parsing->stats.outgoing));
-    return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
+        &t->qbuf, grpc_chttp2_rst_stream_create(t->incoming_stream_id,
+                                                GRPC_CHTTP2_PROTOCOL_ERROR,
+                                                &s->stats.outgoing));
+    return init_skip_frame_parser(exec_ctx, t, 0);
   } else {
     return err;
   }
@@ -648,23 +442,22 @@ static grpc_error *init_data_frame_parser(
 
 static void free_timeout(void *p) { gpr_free(p); }
 
-static void on_initial_header(void *tp, grpc_mdelem *md) {
-  grpc_chttp2_transport_parsing *transport_parsing = tp;
-  grpc_chttp2_stream_parsing *stream_parsing =
-      transport_parsing->incoming_stream;
+static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
+                              grpc_mdelem *md) {
+  grpc_chttp2_transport *t = tp;
+  grpc_chttp2_stream *s = t->incoming_stream;
 
   GPR_TIMER_BEGIN("on_initial_header", 0);
 
-  GPR_ASSERT(stream_parsing);
+  GPR_ASSERT(s != NULL);
 
   GRPC_CHTTP2_IF_TRACING(gpr_log(
-      GPR_INFO, "HTTP:%d:HDR:%s: %s: %s", stream_parsing->id,
-      transport_parsing->is_client ? "CLI" : "SVR",
+      GPR_INFO, "HTTP:%d:HDR:%s: %s: %s", s->id, t->is_client ? "CLI" : "SVR",
       grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value)));
 
   if (md->key == GRPC_MDSTR_GRPC_STATUS && md != GRPC_MDELEM_GRPC_STATUS_0) {
     /* TODO(ctiller): check for a status like " 0" */
-    stream_parsing->seen_error = true;
+    s->seen_error = true;
   }
 
   if (md->key == GRPC_MDSTR_GRPC_TIMEOUT) {
@@ -681,306 +474,273 @@ static void on_initial_header(void *tp, grpc_mdelem *md) {
       grpc_mdelem_set_user_data(md, free_timeout, cached_timeout);
     }
     grpc_chttp2_incoming_metadata_buffer_set_deadline(
-        &stream_parsing->metadata_buffer[0],
+        &s->metadata_buffer[0],
         gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), *cached_timeout));
     GRPC_MDELEM_UNREF(md);
   } else {
-    const size_t new_size =
-        stream_parsing->metadata_buffer[0].size + GRPC_MDELEM_LENGTH(md);
-    grpc_chttp2_transport_global *transport_global =
-        &TRANSPORT_FROM_PARSING(transport_parsing)->global;
+    const size_t new_size = s->metadata_buffer[0].size + GRPC_MDELEM_LENGTH(md);
     const size_t metadata_size_limit =
-        transport_global->settings[GRPC_LOCAL_SETTINGS]
-                                  [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
+        t->settings[GRPC_ACKED_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
     if (new_size > metadata_size_limit) {
-      if (!stream_parsing->exceeded_metadata_size) {
-        gpr_log(GPR_DEBUG,
-                "received initial metadata size exceeds limit (%" PRIuPTR
-                " vs. %" PRIuPTR ")",
-                new_size, metadata_size_limit);
-        stream_parsing->seen_error = true;
-        stream_parsing->exceeded_metadata_size = true;
-      }
+      gpr_log(GPR_DEBUG,
+              "received initial metadata size exceeds limit (%" PRIuPTR
+              " vs. %" PRIuPTR ")",
+              new_size, metadata_size_limit);
+      grpc_chttp2_cancel_stream(
+          exec_ctx, t, s,
+          grpc_error_set_int(
+              GRPC_ERROR_CREATE("received initial metadata size exceeds limit"),
+              GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
+      grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
+      s->seen_error = true;
       GRPC_MDELEM_UNREF(md);
     } else {
-      grpc_chttp2_incoming_metadata_buffer_add(
-          &stream_parsing->metadata_buffer[0], md);
+      grpc_chttp2_incoming_metadata_buffer_add(&s->metadata_buffer[0], md);
     }
   }
 
-  grpc_chttp2_list_add_parsing_seen_stream(transport_parsing, stream_parsing);
-
   GPR_TIMER_END("on_initial_header", 0);
 }
 
-static void on_trailing_header(void *tp, grpc_mdelem *md) {
-  grpc_chttp2_transport_parsing *transport_parsing = tp;
-  grpc_chttp2_stream_parsing *stream_parsing =
-      transport_parsing->incoming_stream;
+static void on_trailing_header(grpc_exec_ctx *exec_ctx, void *tp,
+                               grpc_mdelem *md) {
+  grpc_chttp2_transport *t = tp;
+  grpc_chttp2_stream *s = t->incoming_stream;
 
   GPR_TIMER_BEGIN("on_trailing_header", 0);
 
-  GPR_ASSERT(stream_parsing);
+  GPR_ASSERT(s != NULL);
 
   GRPC_CHTTP2_IF_TRACING(gpr_log(
-      GPR_INFO, "HTTP:%d:TRL:%s: %s: %s", stream_parsing->id,
-      transport_parsing->is_client ? "CLI" : "SVR",
+      GPR_INFO, "HTTP:%d:TRL:%s: %s: %s", s->id, t->is_client ? "CLI" : "SVR",
       grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value)));
 
   if (md->key == GRPC_MDSTR_GRPC_STATUS && md != GRPC_MDELEM_GRPC_STATUS_0) {
     /* TODO(ctiller): check for a status like " 0" */
-    stream_parsing->seen_error = true;
+    s->seen_error = true;
   }
 
-  const size_t new_size =
-      stream_parsing->metadata_buffer[1].size + GRPC_MDELEM_LENGTH(md);
-  grpc_chttp2_transport_global *transport_global =
-      &TRANSPORT_FROM_PARSING(transport_parsing)->global;
+  const size_t new_size = s->metadata_buffer[1].size + GRPC_MDELEM_LENGTH(md);
   const size_t metadata_size_limit =
-      transport_global->settings[GRPC_LOCAL_SETTINGS]
-                                [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
+      t->settings[GRPC_ACKED_SETTINGS]
+                 [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
   if (new_size > metadata_size_limit) {
-    if (!stream_parsing->exceeded_metadata_size) {
-      gpr_log(GPR_DEBUG,
-              "received trailing metadata size exceeds limit (%" PRIuPTR
-              " vs. %" PRIuPTR ")",
-              new_size, metadata_size_limit);
-      stream_parsing->seen_error = true;
-      stream_parsing->exceeded_metadata_size = true;
-    }
+    gpr_log(GPR_DEBUG,
+            "received trailing metadata size exceeds limit (%" PRIuPTR
+            " vs. %" PRIuPTR ")",
+            new_size, metadata_size_limit);
+    grpc_chttp2_cancel_stream(
+        exec_ctx, t, s,
+        grpc_error_set_int(
+            GRPC_ERROR_CREATE("received trailing metadata size exceeds limit"),
+            GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
+    grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
+    s->seen_error = true;
     GRPC_MDELEM_UNREF(md);
   } else {
-    grpc_chttp2_incoming_metadata_buffer_add(
-        &stream_parsing->metadata_buffer[1], md);
+    grpc_chttp2_incoming_metadata_buffer_add(&s->metadata_buffer[1], md);
   }
 
-  grpc_chttp2_list_add_parsing_seen_stream(transport_parsing, stream_parsing);
-
   GPR_TIMER_END("on_trailing_header", 0);
 }
 
-static grpc_error *init_header_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    int is_continuation) {
-  uint8_t is_eoh = (transport_parsing->incoming_frame_flags &
-                    GRPC_CHTTP2_DATA_FLAG_END_HEADERS) != 0;
-  int via_accept = 0;
-  grpc_chttp2_stream_parsing *stream_parsing;
+static grpc_error *init_header_frame_parser(grpc_exec_ctx *exec_ctx,
+                                            grpc_chttp2_transport *t,
+                                            int is_continuation) {
+  uint8_t is_eoh =
+      (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_HEADERS) != 0;
+  grpc_chttp2_stream *s;
 
   /* TODO(ctiller): when to increment header_frames_received? */
 
   if (is_eoh) {
-    transport_parsing->expect_continuation_stream_id = 0;
+    t->expect_continuation_stream_id = 0;
   } else {
-    transport_parsing->expect_continuation_stream_id =
-        transport_parsing->incoming_stream_id;
+    t->expect_continuation_stream_id = t->incoming_stream_id;
   }
 
   if (!is_continuation) {
-    transport_parsing->header_eof = (transport_parsing->incoming_frame_flags &
-                                     GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0;
+    t->header_eof =
+        (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0;
   }
 
   /* could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream */
-  stream_parsing = grpc_chttp2_parsing_lookup_stream(
-      transport_parsing, transport_parsing->incoming_stream_id);
-  if (stream_parsing == NULL) {
+  s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
+  if (s == NULL) {
     if (is_continuation) {
-      gpr_log(GPR_ERROR,
-              "grpc_chttp2_stream disbanded before CONTINUATION received");
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
+      GRPC_CHTTP2_IF_TRACING(
+          gpr_log(GPR_ERROR,
+                  "grpc_chttp2_stream disbanded before CONTINUATION received"));
+      return init_skip_frame_parser(exec_ctx, t, 1);
     }
-    if (transport_parsing->is_client) {
-      if ((transport_parsing->incoming_stream_id & 1) &&
-          transport_parsing->incoming_stream_id <
-              transport_parsing->next_stream_id) {
+    if (t->is_client) {
+      if ((t->incoming_stream_id & 1) &&
+          t->incoming_stream_id < t->next_stream_id) {
         /* this is an old (probably cancelled) grpc_chttp2_stream */
       } else {
-        gpr_log(GPR_ERROR,
-                "ignoring new grpc_chttp2_stream creation on client");
+        GRPC_CHTTP2_IF_TRACING(gpr_log(
+            GPR_ERROR, "ignoring new grpc_chttp2_stream creation on client"));
       }
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
-    } else if (transport_parsing->last_incoming_stream_id >
-               transport_parsing->incoming_stream_id) {
-      gpr_log(GPR_ERROR,
-              "ignoring out of order new grpc_chttp2_stream request on server; "
-              "last grpc_chttp2_stream "
-              "id=%d, new grpc_chttp2_stream id=%d",
-              transport_parsing->last_incoming_stream_id,
-              transport_parsing->incoming_stream_id);
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
-    } else if ((transport_parsing->incoming_stream_id & 1) == 0) {
-      gpr_log(GPR_ERROR,
-              "ignoring grpc_chttp2_stream with non-client generated index %d",
-              transport_parsing->incoming_stream_id);
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
+      return init_skip_frame_parser(exec_ctx, t, 1);
+    } else if (t->last_new_stream_id >= t->incoming_stream_id) {
+      GRPC_CHTTP2_IF_TRACING(gpr_log(
+          GPR_ERROR,
+          "ignoring out of order new grpc_chttp2_stream request on server; "
+          "last grpc_chttp2_stream "
+          "id=%d, new grpc_chttp2_stream id=%d",
+          t->last_new_stream_id, t->incoming_stream_id));
+      return init_skip_frame_parser(exec_ctx, t, 1);
+    } else if ((t->incoming_stream_id & 1) == 0) {
+      GRPC_CHTTP2_IF_TRACING(gpr_log(
+          GPR_ERROR,
+          "ignoring grpc_chttp2_stream with non-client generated index %d",
+          t->incoming_stream_id));
+      return init_skip_frame_parser(exec_ctx, t, 1);
     }
-    stream_parsing = transport_parsing->incoming_stream =
-        grpc_chttp2_parsing_accept_stream(
-            exec_ctx, transport_parsing, transport_parsing->incoming_stream_id);
-    if (stream_parsing == NULL) {
-      gpr_log(GPR_ERROR, "grpc_chttp2_stream not accepted");
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
+    t->last_new_stream_id = t->incoming_stream_id;
+    s = t->incoming_stream =
+        grpc_chttp2_parsing_accept_stream(exec_ctx, t, t->incoming_stream_id);
+    if (s == NULL) {
+      GRPC_CHTTP2_IF_TRACING(
+          gpr_log(GPR_ERROR, "grpc_chttp2_stream not accepted"));
+      return init_skip_frame_parser(exec_ctx, t, 1);
     }
-    via_accept = 1;
   } else {
-    transport_parsing->incoming_stream = stream_parsing;
-  }
-  GPR_ASSERT(stream_parsing != NULL && (via_accept == 0 || via_accept == 1));
-  stream_parsing->stats.incoming.framing_bytes += 9;
-  if (stream_parsing->received_close) {
-    gpr_log(GPR_ERROR, "skipping already closed grpc_chttp2_stream header");
-    transport_parsing->incoming_stream = NULL;
-    return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
-  }
-  transport_parsing->parser = grpc_chttp2_header_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->hpack_parser;
-  switch (stream_parsing->header_frames_received) {
+    t->incoming_stream = s;
+  }
+  GPR_ASSERT(s != NULL);
+  s->stats.incoming.framing_bytes += 9;
+  if (s->read_closed) {
+    GRPC_CHTTP2_IF_TRACING(gpr_log(
+        GPR_ERROR, "skipping already closed grpc_chttp2_stream header"));
+    t->incoming_stream = NULL;
+    return init_skip_frame_parser(exec_ctx, t, 1);
+  }
+  t->parser = grpc_chttp2_header_parser_parse;
+  t->parser_data = &t->hpack_parser;
+  switch (s->header_frames_received) {
     case 0:
-      transport_parsing->hpack_parser.on_header = on_initial_header;
+      t->hpack_parser.on_header = on_initial_header;
       break;
     case 1:
-      transport_parsing->hpack_parser.on_header = on_trailing_header;
+      t->hpack_parser.on_header = on_trailing_header;
       break;
     case 2:
       gpr_log(GPR_ERROR, "too many header frames received");
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 1);
+      return init_skip_frame_parser(exec_ctx, t, 1);
   }
-  transport_parsing->hpack_parser.on_header_user_data = transport_parsing;
-  transport_parsing->hpack_parser.is_boundary = is_eoh;
-  transport_parsing->hpack_parser.is_eof =
-      (uint8_t)(is_eoh ? transport_parsing->header_eof : 0);
-  if (!is_continuation && (transport_parsing->incoming_frame_flags &
-                           GRPC_CHTTP2_FLAG_HAS_PRIORITY)) {
-    grpc_chttp2_hpack_parser_set_has_priority(&transport_parsing->hpack_parser);
+  t->hpack_parser.on_header_user_data = t;
+  t->hpack_parser.is_boundary = is_eoh;
+  t->hpack_parser.is_eof = (uint8_t)(is_eoh ? t->header_eof : 0);
+  if (!is_continuation &&
+      (t->incoming_frame_flags & GRPC_CHTTP2_FLAG_HAS_PRIORITY)) {
+    grpc_chttp2_hpack_parser_set_has_priority(&t->hpack_parser);
   }
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_window_update_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
+static grpc_error *init_window_update_frame_parser(grpc_exec_ctx *exec_ctx,
+                                                   grpc_chttp2_transport *t) {
   grpc_error *err = grpc_chttp2_window_update_parser_begin_frame(
-      &transport_parsing->simple.window_update,
-      transport_parsing->incoming_frame_size,
-      transport_parsing->incoming_frame_flags);
+      &t->simple.window_update, t->incoming_frame_size,
+      t->incoming_frame_flags);
   if (err != GRPC_ERROR_NONE) return err;
-  if (transport_parsing->incoming_stream_id != 0) {
-    grpc_chttp2_stream_parsing *stream_parsing =
-        transport_parsing->incoming_stream = grpc_chttp2_parsing_lookup_stream(
-            transport_parsing, transport_parsing->incoming_stream_id);
-    if (stream_parsing == NULL) {
-      return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
+  if (t->incoming_stream_id != 0) {
+    grpc_chttp2_stream *s = t->incoming_stream =
+        grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
+    if (s == NULL) {
+      return init_skip_frame_parser(exec_ctx, t, 0);
     }
-    stream_parsing->stats.incoming.framing_bytes += 9;
+    s->stats.incoming.framing_bytes += 9;
   }
-  transport_parsing->parser = grpc_chttp2_window_update_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->simple.window_update;
+  t->parser = grpc_chttp2_window_update_parser_parse;
+  t->parser_data = &t->simple.window_update;
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_ping_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
+static grpc_error *init_ping_parser(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_transport *t) {
   grpc_error *err = grpc_chttp2_ping_parser_begin_frame(
-      &transport_parsing->simple.ping, transport_parsing->incoming_frame_size,
-      transport_parsing->incoming_frame_flags);
+      &t->simple.ping, t->incoming_frame_size, t->incoming_frame_flags);
   if (err != GRPC_ERROR_NONE) return err;
-  transport_parsing->parser = grpc_chttp2_ping_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->simple.ping;
+  t->parser = grpc_chttp2_ping_parser_parse;
+  t->parser_data = &t->simple.ping;
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_rst_stream_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
+static grpc_error *init_rst_stream_parser(grpc_exec_ctx *exec_ctx,
+                                          grpc_chttp2_transport *t) {
   grpc_error *err = grpc_chttp2_rst_stream_parser_begin_frame(
-      &transport_parsing->simple.rst_stream,
-      transport_parsing->incoming_frame_size,
-      transport_parsing->incoming_frame_flags);
+      &t->simple.rst_stream, t->incoming_frame_size, t->incoming_frame_flags);
   if (err != GRPC_ERROR_NONE) return err;
-  grpc_chttp2_stream_parsing *stream_parsing =
-      transport_parsing->incoming_stream = grpc_chttp2_parsing_lookup_stream(
-          transport_parsing, transport_parsing->incoming_stream_id);
-  if (!transport_parsing->incoming_stream) {
-    return init_skip_frame_parser(exec_ctx, transport_parsing, 0);
-  }
-  stream_parsing->stats.incoming.framing_bytes += 9;
-  transport_parsing->parser = grpc_chttp2_rst_stream_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->simple.rst_stream;
+  grpc_chttp2_stream *s = t->incoming_stream =
+      grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
+  if (!t->incoming_stream) {
+    return init_skip_frame_parser(exec_ctx, t, 0);
+  }
+  s->stats.incoming.framing_bytes += 9;
+  t->parser = grpc_chttp2_rst_stream_parser_parse;
+  t->parser_data = &t->simple.rst_stream;
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_goaway_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
+static grpc_error *init_goaway_parser(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t) {
   grpc_error *err = grpc_chttp2_goaway_parser_begin_frame(
-      &transport_parsing->goaway_parser, transport_parsing->incoming_frame_size,
-      transport_parsing->incoming_frame_flags);
+      &t->goaway_parser, t->incoming_frame_size, t->incoming_frame_flags);
   if (err != GRPC_ERROR_NONE) return err;
-  transport_parsing->parser = grpc_chttp2_goaway_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->goaway_parser;
+  t->parser = grpc_chttp2_goaway_parser_parse;
+  t->parser_data = &t->goaway_parser;
   return GRPC_ERROR_NONE;
 }
 
-static grpc_error *init_settings_frame_parser(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing) {
-  if (transport_parsing->incoming_stream_id != 0) {
+static grpc_error *init_settings_frame_parser(grpc_exec_ctx *exec_ctx,
+                                              grpc_chttp2_transport *t) {
+  if (t->incoming_stream_id != 0) {
     return GRPC_ERROR_CREATE("Settings frame received for grpc_chttp2_stream");
   }
 
   grpc_error *err = grpc_chttp2_settings_parser_begin_frame(
-      &transport_parsing->simple.settings,
-      transport_parsing->incoming_frame_size,
-      transport_parsing->incoming_frame_flags, transport_parsing->settings);
+      &t->simple.settings, t->incoming_frame_size, t->incoming_frame_flags,
+      t->settings[GRPC_PEER_SETTINGS]);
   if (err != GRPC_ERROR_NONE) {
     return err;
   }
-  if (transport_parsing->incoming_frame_flags & GRPC_CHTTP2_FLAG_ACK) {
-    transport_parsing->settings_ack_received = 1;
+  if (t->incoming_frame_flags & GRPC_CHTTP2_FLAG_ACK) {
+    memcpy(t->settings[GRPC_ACKED_SETTINGS], t->settings[GRPC_SENT_SETTINGS],
+           GRPC_CHTTP2_NUM_SETTINGS * sizeof(uint32_t));
     grpc_chttp2_hptbl_set_max_bytes(
-        &transport_parsing->hpack_parser.table,
-        transport_parsing
-            ->last_sent_settings[GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
-    transport_parsing->max_frame_size =
-        transport_parsing
-            ->last_sent_settings[GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE];
+        &t->hpack_parser.table,
+        t->settings[GRPC_ACKED_SETTINGS]
+                   [GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
+    t->sent_local_settings = 0;
   }
-  transport_parsing->parser = grpc_chttp2_settings_parser_parse;
-  transport_parsing->parser_data = &transport_parsing->simple.settings;
+  t->parser = grpc_chttp2_settings_parser_parse;
+  t->parser_data = &t->simple.settings;
   return GRPC_ERROR_NONE;
 }
 
-/*
-static int is_window_update_legal(int64_t window_update, int64_t window) {
-  return window + window_update < MAX_WINDOW;
-}
-*/
-
-static grpc_error *parse_frame_slice(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing,
-    gpr_slice slice, int is_last) {
-  grpc_chttp2_stream_parsing *stream_parsing =
-      transport_parsing->incoming_stream;
-  grpc_error *err = transport_parsing->parser(
-      exec_ctx, transport_parsing->parser_data, transport_parsing,
-      stream_parsing, slice, is_last);
+static grpc_error *parse_frame_slice(grpc_exec_ctx *exec_ctx,
+                                     grpc_chttp2_transport *t, gpr_slice slice,
+                                     int is_last) {
+  grpc_chttp2_stream *s = t->incoming_stream;
+  grpc_error *err = t->parser(exec_ctx, t->parser_data, t, s, slice, is_last);
   if (err == GRPC_ERROR_NONE) {
-    if (stream_parsing) {
-      grpc_chttp2_list_add_parsing_seen_stream(transport_parsing,
-                                               stream_parsing);
-    }
-    return GRPC_ERROR_NONE;
+    return err;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, NULL)) {
     if (grpc_http_trace) {
       const char *msg = grpc_error_string(err);
       gpr_log(GPR_ERROR, "%s", msg);
       grpc_error_free_string(msg);
     }
-    grpc_chttp2_parsing_become_skip_parser(exec_ctx, transport_parsing);
-    if (stream_parsing) {
-      stream_parsing->forced_close_error = err;
+    grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
+    if (s) {
+      s->forced_close_error = err;
       gpr_slice_buffer_add(
-          &transport_parsing->qbuf,
-          grpc_chttp2_rst_stream_create(transport_parsing->incoming_stream_id,
-                                        GRPC_CHTTP2_PROTOCOL_ERROR,
-                                        &stream_parsing->stats.outgoing));
+          &t->qbuf, grpc_chttp2_rst_stream_create(t->incoming_stream_id,
+                                                  GRPC_CHTTP2_PROTOCOL_ERROR,
+                                                  &s->stats.outgoing));
     } else {
       GRPC_ERROR_UNREF(err);
     }
diff --git a/src/core/ext/transport/chttp2/transport/stream_lists.c b/src/core/ext/transport/chttp2/transport/stream_lists.c
index 4dc4968248..6d25b3ae57 100644
--- a/src/core/ext/transport/chttp2/transport/stream_lists.c
+++ b/src/core/ext/transport/chttp2/transport/stream_lists.c
@@ -35,27 +35,6 @@
 
 #include <grpc/support/log.h>
 
-#define TRANSPORT_FROM_GLOBAL(tg)                                         \
-  ((grpc_chttp2_transport *)((char *)(tg)-offsetof(grpc_chttp2_transport, \
-                                                   global)))
-
-#define STREAM_FROM_GLOBAL(sg) \
-  ((grpc_chttp2_stream *)((char *)(sg)-offsetof(grpc_chttp2_stream, global)))
-
-#define TRANSPORT_FROM_WRITING(tw)                                        \
-  ((grpc_chttp2_transport *)((char *)(tw)-offsetof(grpc_chttp2_transport, \
-                                                   writing)))
-
-#define STREAM_FROM_WRITING(sw) \
-  ((grpc_chttp2_stream *)((char *)(sw)-offsetof(grpc_chttp2_stream, writing)))
-
-#define TRANSPORT_FROM_PARSING(tp)                                        \
-  ((grpc_chttp2_transport *)((char *)(tp)-offsetof(grpc_chttp2_transport, \
-                                                   parsing)))
-
-#define STREAM_FROM_PARSING(sp) \
-  ((grpc_chttp2_stream *)((char *)(sp)-offsetof(grpc_chttp2_stream, parsing)))
-
 /* core list management */
 
 static int stream_list_empty(grpc_chttp2_transport *t,
@@ -139,321 +118,57 @@ static bool stream_list_add(grpc_chttp2_transport *t, grpc_chttp2_stream *s,
 
 /* wrappers for specializations */
 
-bool grpc_chttp2_list_add_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  GPR_ASSERT(stream_global->id != 0);
-  return stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                         STREAM_FROM_GLOBAL(stream_global),
-                         GRPC_CHTTP2_LIST_WRITABLE);
-}
-
-int grpc_chttp2_list_pop_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_writing **stream_writing) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_WRITABLE);
-  if (r != 0) {
-    *stream_global = &stream->global;
-    *stream_writing = &stream->writing;
-  }
-  return r;
-}
-
-bool grpc_chttp2_list_remove_writable_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  return stream_list_maybe_remove(TRANSPORT_FROM_GLOBAL(transport_global),
-                                  STREAM_FROM_GLOBAL(stream_global),
-                                  GRPC_CHTTP2_LIST_WRITABLE);
-}
-
-void grpc_chttp2_list_add_writing_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing) {
-  GPR_ASSERT(stream_list_add(TRANSPORT_FROM_WRITING(transport_writing),
-                             STREAM_FROM_WRITING(stream_writing),
-                             GRPC_CHTTP2_LIST_WRITING));
-}
-
-int grpc_chttp2_list_have_writing_streams(
-    grpc_chttp2_transport_writing *transport_writing) {
-  return !stream_list_empty(TRANSPORT_FROM_WRITING(transport_writing),
-                            GRPC_CHTTP2_LIST_WRITING);
-}
-
-int grpc_chttp2_list_pop_writing_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing **stream_writing) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_WRITING(transport_writing), &stream,
-                          GRPC_CHTTP2_LIST_WRITING);
-  if (r != 0) {
-    *stream_writing = &stream->writing;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_written_stream(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing) {
-  stream_list_add(TRANSPORT_FROM_WRITING(transport_writing),
-                  STREAM_FROM_WRITING(stream_writing),
-                  GRPC_CHTTP2_LIST_WRITTEN);
-}
-
-int grpc_chttp2_list_pop_written_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_writing **stream_writing) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_WRITING(transport_writing), &stream,
-                          GRPC_CHTTP2_LIST_WRITTEN);
-  if (r != 0) {
-    *stream_global = &stream->global;
-    *stream_writing = &stream->writing;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  GPR_ASSERT(stream_global->id != 0);
-  stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                  STREAM_FROM_GLOBAL(stream_global),
-                  GRPC_CHTTP2_LIST_UNANNOUNCED_INCOMING_WINDOW_AVAILABLE);
-}
-
-void grpc_chttp2_list_remove_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  stream_list_maybe_remove(
-      TRANSPORT_FROM_GLOBAL(transport_global),
-      STREAM_FROM_GLOBAL(stream_global),
-      GRPC_CHTTP2_LIST_UNANNOUNCED_INCOMING_WINDOW_AVAILABLE);
-}
-
-int grpc_chttp2_list_pop_unannounced_incoming_window_available(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_parsing **stream_parsing) {
-  grpc_chttp2_stream *stream;
-  int r =
-      stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                      GRPC_CHTTP2_LIST_UNANNOUNCED_INCOMING_WINDOW_AVAILABLE);
-  if (r != 0) {
-    *stream_global = &stream->global;
-    *stream_parsing = &stream->parsing;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_parsing_seen_stream(
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_parsing *stream_parsing) {
-  stream_list_add(TRANSPORT_FROM_PARSING(transport_parsing),
-                  STREAM_FROM_PARSING(stream_parsing),
-                  GRPC_CHTTP2_LIST_PARSING_SEEN);
-}
-
-int grpc_chttp2_list_pop_parsing_seen_stream(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_parsing *transport_parsing,
-    grpc_chttp2_stream_global **stream_global,
-    grpc_chttp2_stream_parsing **stream_parsing) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_PARSING(transport_parsing), &stream,
-                          GRPC_CHTTP2_LIST_PARSING_SEEN);
-  if (r != 0) {
-    *stream_global = &stream->global;
-    *stream_parsing = &stream->parsing;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_waiting_for_concurrency(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                  STREAM_FROM_GLOBAL(stream_global),
-                  GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
-}
-
-int grpc_chttp2_list_pop_waiting_for_concurrency(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
-  if (r != 0) {
-    *stream_global = &stream->global;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_check_read_ops(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  grpc_chttp2_transport *t = TRANSPORT_FROM_GLOBAL(transport_global);
-  if (!t->executor.check_read_ops_scheduled) {
-    grpc_combiner_execute_finally(exec_ctx, t->executor.combiner,
-                                  &t->initiate_read_flush_locked,
-                                  GRPC_ERROR_NONE, false);
-    t->executor.check_read_ops_scheduled = true;
-  }
-  stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                  STREAM_FROM_GLOBAL(stream_global),
-                  GRPC_CHTTP2_LIST_CHECK_READ_OPS);
-}
-
-bool grpc_chttp2_list_remove_check_read_ops(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  return stream_list_maybe_remove(TRANSPORT_FROM_GLOBAL(transport_global),
-                                  STREAM_FROM_GLOBAL(stream_global),
-                                  GRPC_CHTTP2_LIST_CHECK_READ_OPS);
+bool grpc_chttp2_list_add_writable_stream(grpc_chttp2_transport *t,
+                                          grpc_chttp2_stream *s) {
+  GPR_ASSERT(s->id != 0);
+  return stream_list_add(t, s, GRPC_CHTTP2_LIST_WRITABLE);
 }
 
-int grpc_chttp2_list_pop_check_read_ops(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_CHECK_READ_OPS);
-  if (r != 0) {
-    *stream_global = &stream->global;
-  }
-  return r;
-}
-
-void grpc_chttp2_list_add_writing_stalled_by_transport(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing) {
-  grpc_chttp2_stream *stream = STREAM_FROM_WRITING(stream_writing);
-  gpr_log(GPR_DEBUG, "writing stalled %d", stream->global.id);
-  if (!stream->included[GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT]) {
-    GRPC_CHTTP2_STREAM_REF(&stream->global, "chttp2_writing_stalled");
-  }
-  stream_list_add(TRANSPORT_FROM_WRITING(transport_writing), stream,
-                  GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT);
+int grpc_chttp2_list_pop_writable_stream(grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream **s) {
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_WRITABLE);
 }
 
-bool grpc_chttp2_list_flush_writing_stalled_by_transport(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing) {
-  grpc_chttp2_stream *stream;
-  bool out = false;
-  grpc_chttp2_transport *transport = TRANSPORT_FROM_WRITING(transport_writing);
-  while (stream_list_pop(transport, &stream,
-                         GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT)) {
-    gpr_log(GPR_DEBUG, "move %d from writing stalled to just stalled",
-            stream->global.id);
-    grpc_chttp2_list_add_stalled_by_transport(transport_writing,
-                                              &stream->writing);
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, &stream->global,
-                             "chttp2_writing_stalled");
-    out = true;
-  }
-  return out;
+bool grpc_chttp2_list_remove_writable_stream(grpc_chttp2_transport *t,
+                                             grpc_chttp2_stream *s) {
+  return stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_WRITABLE);
 }
 
-void grpc_chttp2_list_add_stalled_by_transport(
-    grpc_chttp2_transport_writing *transport_writing,
-    grpc_chttp2_stream_writing *stream_writing) {
-  gpr_log(GPR_DEBUG, "stalled %d", stream_writing->id);
-  stream_list_add(TRANSPORT_FROM_WRITING(transport_writing),
-                  STREAM_FROM_WRITING(stream_writing),
-                  GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
+bool grpc_chttp2_list_add_writing_stream(grpc_chttp2_transport *t,
+                                         grpc_chttp2_stream *s) {
+  return stream_list_add(t, s, GRPC_CHTTP2_LIST_WRITING);
 }
 
-int grpc_chttp2_list_pop_stalled_by_transport(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
-  if (r != 0) {
-    *stream_global = &stream->global;
-  }
-  return r;
+int grpc_chttp2_list_have_writing_streams(grpc_chttp2_transport *t) {
+  return !stream_list_empty(t, GRPC_CHTTP2_LIST_WRITING);
 }
 
-void grpc_chttp2_list_remove_stalled_by_transport(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  stream_list_maybe_remove(TRANSPORT_FROM_GLOBAL(transport_global),
-                           STREAM_FROM_GLOBAL(stream_global),
-                           GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
+int grpc_chttp2_list_pop_writing_stream(grpc_chttp2_transport *t,
+                                        grpc_chttp2_stream **s) {
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_WRITING);
 }
 
-void grpc_chttp2_list_add_closed_waiting_for_parsing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                  STREAM_FROM_GLOBAL(stream_global),
-                  GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_PARSING);
+void grpc_chttp2_list_add_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                  grpc_chttp2_stream *s) {
+  stream_list_add(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
 }
 
-int grpc_chttp2_list_pop_closed_waiting_for_parsing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_PARSING);
-  if (r != 0) {
-    *stream_global = &stream->global;
-  }
-  return r;
+int grpc_chttp2_list_pop_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                 grpc_chttp2_stream **s) {
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
 }
 
-void grpc_chttp2_list_add_closed_waiting_for_writing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global *stream_global) {
-  stream_list_add(TRANSPORT_FROM_GLOBAL(transport_global),
-                  STREAM_FROM_GLOBAL(stream_global),
-                  GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_WRITING);
+void grpc_chttp2_list_add_stalled_by_transport(grpc_chttp2_transport *t,
+                                               grpc_chttp2_stream *s) {
+  stream_list_add(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
 }
 
-int grpc_chttp2_list_pop_closed_waiting_for_writing(
-    grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_stream_global **stream_global) {
-  grpc_chttp2_stream *stream;
-  int r = stream_list_pop(TRANSPORT_FROM_GLOBAL(transport_global), &stream,
-                          GRPC_CHTTP2_LIST_CLOSED_WAITING_FOR_WRITING);
-  if (r != 0) {
-    *stream_global = &stream->global;
-  }
-  return r;
+int grpc_chttp2_list_pop_stalled_by_transport(grpc_chttp2_transport *t,
+                                              grpc_chttp2_stream **s) {
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
 }
 
-void grpc_chttp2_register_stream(grpc_chttp2_transport *t,
-                                 grpc_chttp2_stream *s) {
-  stream_list_add_tail(t, s, GRPC_CHTTP2_LIST_ALL_STREAMS);
-}
-
-int grpc_chttp2_unregister_stream(grpc_chttp2_transport *t,
-                                  grpc_chttp2_stream *s) {
-  stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_ALL_STREAMS);
-  return stream_list_empty(t, GRPC_CHTTP2_LIST_ALL_STREAMS);
-}
-
-int grpc_chttp2_has_streams(grpc_chttp2_transport *t) {
-  return !stream_list_empty(t, GRPC_CHTTP2_LIST_ALL_STREAMS);
-}
-
-void grpc_chttp2_for_all_streams(
-    grpc_chttp2_transport_global *transport_global, void *user_data,
-    void (*cb)(grpc_chttp2_transport_global *transport_global, void *user_data,
-               grpc_chttp2_stream_global *stream_global)) {
-  grpc_chttp2_stream *s;
-  grpc_chttp2_transport *t = TRANSPORT_FROM_GLOBAL(transport_global);
-  for (s = t->lists[GRPC_CHTTP2_LIST_ALL_STREAMS].head; s != NULL;
-       s = s->links[GRPC_CHTTP2_LIST_ALL_STREAMS].next) {
-    cb(transport_global, user_data, &s->global);
-  }
+void grpc_chttp2_list_remove_stalled_by_transport(grpc_chttp2_transport *t,
+                                                  grpc_chttp2_stream *s) {
+  stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
 }
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.c b/src/core/ext/transport/chttp2/transport/stream_map.c
index f70791c422..59b3a14e0a 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.c
+++ b/src/core/ext/transport/chttp2/transport/stream_map.c
@@ -77,6 +77,7 @@ void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key,
 
   GPR_ASSERT(count == 0 || keys[count - 1] < key);
   GPR_ASSERT(value);
+  GPR_ASSERT(grpc_chttp2_stream_map_find(map, key) == NULL);
 
   if (count == capacity) {
     if (map->free > capacity / 4) {
@@ -96,40 +97,6 @@ void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key,
   map->count = count + 1;
 }
 
-void grpc_chttp2_stream_map_move_into(grpc_chttp2_stream_map *src,
-                                      grpc_chttp2_stream_map *dst) {
-  /* if src is empty we dont need to do anything */
-  if (src->count == src->free) {
-    return;
-  }
-  /* if dst is empty we simply need to swap */
-  if (dst->count == dst->free) {
-    GPR_SWAP(grpc_chttp2_stream_map, *src, *dst);
-    return;
-  }
-  /* the first element of src must be greater than the last of dst...
-   * however the maps may need compacting for this property to hold */
-  if (src->keys[0] <= dst->keys[dst->count - 1]) {
-    src->count = compact(src->keys, src->values, src->count);
-    src->free = 0;
-    dst->count = compact(dst->keys, dst->values, dst->count);
-    dst->free = 0;
-  }
-  GPR_ASSERT(src->keys[0] > dst->keys[dst->count - 1]);
-  /* if dst doesn't have capacity, resize */
-  if (dst->count + src->count > dst->capacity) {
-    dst->capacity = GPR_MAX(dst->capacity * 3 / 2, dst->count + src->count);
-    dst->keys = gpr_realloc(dst->keys, dst->capacity * sizeof(uint32_t));
-    dst->values = gpr_realloc(dst->values, dst->capacity * sizeof(void *));
-  }
-  memcpy(dst->keys + dst->count, src->keys, src->count * sizeof(uint32_t));
-  memcpy(dst->values + dst->count, src->values, src->count * sizeof(void *));
-  dst->count += src->count;
-  dst->free += src->free;
-  src->count = 0;
-  src->free = 0;
-}
-
 static void **find(grpc_chttp2_stream_map *map, uint32_t key) {
   size_t min_idx = 0;
   size_t max_idx = map->count;
@@ -170,6 +137,7 @@ void *grpc_chttp2_stream_map_delete(grpc_chttp2_stream_map *map, uint32_t key) {
     if (map->free == map->count) {
       map->free = map->count = 0;
     }
+    GPR_ASSERT(grpc_chttp2_stream_map_find(map, key) == NULL);
   }
   return out;
 }
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.h b/src/core/ext/transport/chttp2/transport/stream_map.h
index b1d59ca6a3..e76312dd1a 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.h
+++ b/src/core/ext/transport/chttp2/transport/stream_map.h
@@ -65,10 +65,6 @@ void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key,
    or NULL otherwise */
 void *grpc_chttp2_stream_map_delete(grpc_chttp2_stream_map *map, uint32_t key);
 
-/* Move all elements of src into dst */
-void grpc_chttp2_stream_map_move_into(grpc_chttp2_stream_map *src,
-                                      grpc_chttp2_stream_map *dst);
-
 /* Return an existing key, or NULL if it does not exist */
 void *grpc_chttp2_stream_map_find(grpc_chttp2_stream_map *map, uint32_t key);
 
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 979515bd54..b39695a1a5 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -40,349 +40,221 @@
 #include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/lib/profiling/timers.h"
 
-static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
-                            grpc_chttp2_transport_writing *transport_writing);
+static void add_to_write_list(grpc_chttp2_write_cb **list,
+                              grpc_chttp2_write_cb *cb) {
+  cb->next = *list;
+  *list = cb;
+}
+
+static void finish_write_cb(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                            grpc_chttp2_stream *s, grpc_chttp2_write_cb *cb,
+                            grpc_error *error) {
+  grpc_chttp2_complete_closure_step(exec_ctx, t, s, &cb->closure, error,
+                                    "finish_write_cb");
+  cb->next = t->write_cb_pool;
+  t->write_cb_pool = cb;
+}
 
-int grpc_chttp2_unlocking_check_writes(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing) {
-  grpc_chttp2_stream_global *stream_global;
-  grpc_chttp2_stream_writing *stream_writing;
+static void update_list(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                        grpc_chttp2_stream *s, int64_t send_bytes,
+                        grpc_chttp2_write_cb **list, grpc_error *error) {
+  grpc_chttp2_write_cb *cb = *list;
+  *list = NULL;
+  s->flow_controlled_bytes_written += send_bytes;
+  while (cb) {
+    grpc_chttp2_write_cb *next = cb->next;
+    if (cb->call_at_byte <= s->flow_controlled_bytes_written) {
+      finish_write_cb(exec_ctx, t, s, cb, GRPC_ERROR_REF(error));
+    } else {
+      add_to_write_list(list, cb);
+    }
+    cb = next;
+  }
+  GRPC_ERROR_UNREF(error);
+}
 
-  GPR_TIMER_BEGIN("grpc_chttp2_unlocking_check_writes", 0);
+bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
+                             grpc_chttp2_transport *t) {
+  grpc_chttp2_stream *s;
 
-  transport_writing->max_frame_size =
-      transport_global->settings[GRPC_ACKED_SETTINGS]
-                                [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE];
+  GPR_TIMER_BEGIN("grpc_chttp2_begin_write", 0);
 
-  if (transport_global->dirtied_local_settings &&
-      !transport_global->sent_local_settings) {
+  if (t->dirtied_local_settings && !t->sent_local_settings) {
     gpr_slice_buffer_add(
-        &transport_writing->outbuf,
+        &t->outbuf,
         grpc_chttp2_settings_create(
-            transport_global->settings[GRPC_SENT_SETTINGS],
-            transport_global->settings[GRPC_LOCAL_SETTINGS],
-            transport_global->force_send_settings, GRPC_CHTTP2_NUM_SETTINGS));
-    transport_global->force_send_settings = 0;
-    transport_global->dirtied_local_settings = 0;
-    transport_global->sent_local_settings = 1;
+            t->settings[GRPC_SENT_SETTINGS], t->settings[GRPC_LOCAL_SETTINGS],
+            t->force_send_settings, GRPC_CHTTP2_NUM_SETTINGS));
+    t->force_send_settings = 0;
+    t->dirtied_local_settings = 0;
+    t->sent_local_settings = 1;
   }
 
   /* simple writes are queued to qbuf, and flushed here */
-  gpr_slice_buffer_move_into(&transport_global->qbuf,
-                             &transport_writing->outbuf);
-  GPR_ASSERT(transport_global->qbuf.count == 0);
+  gpr_slice_buffer_move_into(&t->qbuf, &t->outbuf);
+  GPR_ASSERT(t->qbuf.count == 0);
 
   grpc_chttp2_hpack_compressor_set_max_table_size(
-      &transport_writing->hpack_compressor,
-      transport_global->settings[GRPC_PEER_SETTINGS]
-                                [GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
+      &t->hpack_compressor,
+      t->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE]);
 
-  GRPC_CHTTP2_FLOW_MOVE_TRANSPORT("write", transport_writing, outgoing_window,
-                                  transport_global, outgoing_window);
-  if (transport_writing->outgoing_window > 0) {
-    while (grpc_chttp2_list_pop_stalled_by_transport(transport_global,
-                                                     &stream_global)) {
-      grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
-                                  false, "transport.read_flow_control");
+  if (t->outgoing_window > 0) {
+    while (grpc_chttp2_list_pop_stalled_by_transport(t, &s)) {
+      grpc_chttp2_become_writable(exec_ctx, t, s, false,
+                                  "transport.read_flow_control");
     }
   }
 
   /* for each grpc_chttp2_stream that's become writable, frame it's data
      (according to available window sizes) and add to the output buffer */
-  while (grpc_chttp2_list_pop_writable_stream(
-      transport_global, transport_writing, &stream_global, &stream_writing)) {
-    bool sent_initial_metadata = stream_writing->sent_initial_metadata;
-    bool become_writable = false;
+  while (grpc_chttp2_list_pop_writable_stream(t, &s)) {
+    bool sent_initial_metadata = s->sent_initial_metadata;
+    bool now_writing = false;
 
-    stream_writing->id = stream_global->id;
-    stream_writing->read_closed = stream_global->read_closed;
+    GRPC_CHTTP2_IF_TRACING(gpr_log(
+        GPR_DEBUG, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t,
+        t->is_client ? "CLIENT" : "SERVER", s->id, sent_initial_metadata,
+        s->send_initial_metadata != NULL, s->announce_window));
 
-    GRPC_CHTTP2_FLOW_MOVE_STREAM("write", transport_writing, stream_writing,
-                                 outgoing_window, stream_global,
-                                 outgoing_window);
-
-    if (!sent_initial_metadata && stream_global->send_initial_metadata) {
-      stream_writing->send_initial_metadata =
-          stream_global->send_initial_metadata;
-      stream_global->send_initial_metadata = NULL;
-      become_writable = true;
+    /* send initial metadata if it's available */
+    if (!sent_initial_metadata && s->send_initial_metadata) {
+      grpc_chttp2_encode_header(
+          &t->hpack_compressor, s->id, s->send_initial_metadata, 0,
+          t->settings[GRPC_ACKED_SETTINGS][GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+          &s->stats.outgoing, &t->outbuf);
+      s->send_initial_metadata = NULL;
+      s->sent_initial_metadata = true;
       sent_initial_metadata = true;
+      now_writing = true;
+    }
+    /* send any window updates */
+    if (s->announce_window > 0) {
+      uint32_t announce = s->announce_window;
+      gpr_slice_buffer_add(&t->outbuf,
+                           grpc_chttp2_window_update_create(
+                               s->id, s->announce_window, &s->stats.outgoing));
+      GRPC_CHTTP2_FLOW_DEBIT_STREAM("write", t, s, announce_window, announce);
     }
     if (sent_initial_metadata) {
-      if (stream_global->send_message != NULL) {
-        gpr_slice hdr = gpr_slice_malloc(5);
-        uint8_t *p = GPR_SLICE_START_PTR(hdr);
-        uint32_t len = stream_global->send_message->length;
-        GPR_ASSERT(stream_writing->send_message == NULL);
-        p[0] = (stream_global->send_message->flags &
-                GRPC_WRITE_INTERNAL_COMPRESS) != 0;
-        p[1] = (uint8_t)(len >> 24);
-        p[2] = (uint8_t)(len >> 16);
-        p[3] = (uint8_t)(len >> 8);
-        p[4] = (uint8_t)(len);
-        gpr_slice_buffer_add(&stream_writing->flow_controlled_buffer, hdr);
-        if (stream_global->send_message->length > 0) {
-          stream_writing->send_message = stream_global->send_message;
-        } else {
-          stream_writing->send_message = NULL;
+      /* send any body bytes, if allowed by flow control */
+      if (s->flow_controlled_buffer.length > 0) {
+        uint32_t max_outgoing =
+            (uint32_t)GPR_MIN(t->settings[GRPC_ACKED_SETTINGS]
+                                         [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+                              GPR_MIN(s->outgoing_window, t->outgoing_window));
+        if (max_outgoing > 0) {
+          uint32_t send_bytes =
+              (uint32_t)GPR_MIN(max_outgoing, s->flow_controlled_buffer.length);
+          bool is_last_data_frame =
+              s->fetching_send_message == NULL &&
+              send_bytes == s->flow_controlled_buffer.length;
+          bool is_last_frame =
+              is_last_data_frame && s->send_trailing_metadata != NULL &&
+              grpc_metadata_batch_is_empty(s->send_trailing_metadata);
+          grpc_chttp2_encode_data(s->id, &s->flow_controlled_buffer, send_bytes,
+                                  is_last_frame, &s->stats.outgoing,
+                                  &t->outbuf);
+          GRPC_CHTTP2_FLOW_DEBIT_STREAM("write", t, s, outgoing_window,
+                                        send_bytes);
+          GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("write", t, outgoing_window,
+                                           send_bytes);
+          if (is_last_frame) {
+            s->send_trailing_metadata = NULL;
+            s->sent_trailing_metadata = true;
+            if (!t->is_client && !s->read_closed) {
+              gpr_slice_buffer_add(&t->outbuf, grpc_chttp2_rst_stream_create(
+                                                   s->id, GRPC_CHTTP2_NO_ERROR,
+                                                   &s->stats.outgoing));
+            }
+          }
+          s->sending_bytes += send_bytes;
+          now_writing = true;
+          if (s->flow_controlled_buffer.length > 0) {
+            GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:fork");
+            grpc_chttp2_list_add_writable_stream(t, s);
+          }
+        } else if (t->outgoing_window == 0) {
+          grpc_chttp2_list_add_stalled_by_transport(t, s);
+          now_writing = true;
         }
-        stream_writing->stream_fetched = 0;
-        stream_global->send_message = NULL;
       }
-      if ((stream_writing->send_message != NULL ||
-           stream_writing->flow_controlled_buffer.length > 0) &&
-          stream_writing->outgoing_window > 0) {
-        if (transport_writing->outgoing_window > 0) {
-          become_writable = true;
+      if (s->send_trailing_metadata != NULL &&
+          s->fetching_send_message == NULL &&
+          s->flow_controlled_buffer.length == 0) {
+        if (grpc_metadata_batch_is_empty(s->send_trailing_metadata)) {
+          grpc_chttp2_encode_data(s->id, &s->flow_controlled_buffer, 0, true,
+                                  &s->stats.outgoing, &t->outbuf);
         } else {
-          grpc_chttp2_list_add_stalled_by_transport(transport_writing,
-                                                    stream_writing);
+          grpc_chttp2_encode_header(
+              &t->hpack_compressor, s->id, s->send_trailing_metadata, true,
+              t->settings[GRPC_ACKED_SETTINGS]
+                         [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+              &s->stats.outgoing, &t->outbuf);
         }
+        s->send_trailing_metadata = NULL;
+        s->sent_trailing_metadata = true;
+        if (!t->is_client && !s->read_closed) {
+          gpr_slice_buffer_add(
+              &t->outbuf, grpc_chttp2_rst_stream_create(
+                              s->id, GRPC_CHTTP2_NO_ERROR, &s->stats.outgoing));
+        }
+        now_writing = true;
       }
-      if (stream_global->send_trailing_metadata) {
-        stream_writing->send_trailing_metadata =
-            stream_global->send_trailing_metadata;
-        stream_global->send_trailing_metadata = NULL;
-        become_writable = true;
-      }
-    }
-
-    if (!stream_global->read_closed &&
-        stream_global->unannounced_incoming_window_for_writing > 1024) {
-      GRPC_CHTTP2_FLOW_MOVE_STREAM("write", transport_global, stream_writing,
-                                   announce_window, stream_global,
-                                   unannounced_incoming_window_for_writing);
-      become_writable = true;
     }
 
-    if (become_writable) {
-      grpc_chttp2_list_add_writing_stream(transport_writing, stream_writing);
+    if (now_writing) {
+      if (!grpc_chttp2_list_add_writing_stream(t, s)) {
+        /* already in writing list: drop ref */
+        GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:already_writing");
+      }
     } else {
-      GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2_writing");
+      GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:no_write");
     }
   }
 
   /* if the grpc_chttp2_transport is ready to send a window update, do so here
      also; 3/4 is a magic number that will likely get tuned soon */
-  if (transport_global->announce_incoming_window > 0) {
-    uint32_t announced = (uint32_t)GPR_MIN(
-        transport_global->announce_incoming_window, UINT32_MAX);
-    GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("write", transport_global,
-                                     announce_incoming_window, announced);
+  if (t->announce_incoming_window > 0) {
+    uint32_t announced =
+        (uint32_t)GPR_MIN(t->announce_incoming_window, UINT32_MAX);
+    GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("write", t, announce_incoming_window,
+                                     announced);
     grpc_transport_one_way_stats throwaway_stats;
-    gpr_slice_buffer_add(
-        &transport_writing->outbuf,
-        grpc_chttp2_window_update_create(0, announced, &throwaway_stats));
-  }
-
-  GPR_TIMER_END("grpc_chttp2_unlocking_check_writes", 0);
-
-  return transport_writing->outbuf.count > 0 ||
-         grpc_chttp2_list_have_writing_streams(transport_writing);
-}
-
-void grpc_chttp2_perform_writes(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing,
-    grpc_endpoint *endpoint) {
-  GPR_ASSERT(transport_writing->outbuf.count > 0 ||
-             grpc_chttp2_list_have_writing_streams(transport_writing));
-
-  finalize_outbuf(exec_ctx, transport_writing);
-
-  GPR_ASSERT(endpoint);
-
-  if (transport_writing->outbuf.count > 0) {
-    grpc_endpoint_write(exec_ctx, endpoint, &transport_writing->outbuf,
-                        &transport_writing->done_cb);
-  } else {
-    grpc_exec_ctx_sched(exec_ctx, &transport_writing->done_cb, GRPC_ERROR_NONE,
-                        NULL);
+    gpr_slice_buffer_add(&t->outbuf, grpc_chttp2_window_update_create(
+                                         0, announced, &throwaway_stats));
   }
-}
-
-static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
-                            grpc_chttp2_transport_writing *transport_writing) {
-  grpc_chttp2_stream_writing *stream_writing;
 
-  GPR_TIMER_BEGIN("finalize_outbuf", 0);
+  GPR_TIMER_END("grpc_chttp2_begin_write", 0);
 
-  bool is_first_data_frame = true;
-  while (
-      grpc_chttp2_list_pop_writing_stream(transport_writing, &stream_writing)) {
-    uint32_t max_outgoing =
-        (uint32_t)GPR_MIN(transport_writing->max_frame_size,
-                          GPR_MIN(stream_writing->outgoing_window,
-                                  transport_writing->outgoing_window));
-    /* send initial metadata if it's available */
-    if (stream_writing->send_initial_metadata != NULL) {
-      grpc_chttp2_encode_header(
-          &transport_writing->hpack_compressor, stream_writing->id,
-          stream_writing->send_initial_metadata, 0,
-          transport_writing->max_frame_size, &stream_writing->stats,
-          &transport_writing->outbuf);
-      stream_writing->send_initial_metadata = NULL;
-      stream_writing->sent_initial_metadata = 1;
-    }
-    /* send any window updates */
-    if (stream_writing->announce_window > 0 &&
-        stream_writing->send_initial_metadata == NULL) {
-      uint32_t announce = stream_writing->announce_window;
-      gpr_slice_buffer_add(
-          &transport_writing->outbuf,
-          grpc_chttp2_window_update_create(stream_writing->id,
-                                           stream_writing->announce_window,
-                                           &stream_writing->stats));
-      GRPC_CHTTP2_FLOW_DEBIT_STREAM("write", transport_writing, stream_writing,
-                                    announce_window, announce);
-      stream_writing->announce_window = 0;
-    }
-    /* fetch any body bytes */
-    while (!stream_writing->fetching && stream_writing->send_message &&
-           stream_writing->flow_controlled_buffer.length < max_outgoing &&
-           stream_writing->stream_fetched <
-               stream_writing->send_message->length) {
-      if (grpc_byte_stream_next(exec_ctx, stream_writing->send_message,
-                                &stream_writing->fetching_slice, max_outgoing,
-                                &stream_writing->finished_fetch)) {
-        stream_writing->stream_fetched +=
-            GPR_SLICE_LENGTH(stream_writing->fetching_slice);
-        if (stream_writing->stream_fetched ==
-            stream_writing->send_message->length) {
-          stream_writing->send_message = NULL;
-        }
-        gpr_slice_buffer_add(&stream_writing->flow_controlled_buffer,
-                             stream_writing->fetching_slice);
-      } else {
-        stream_writing->fetching = 1;
-      }
-    }
-    /* send any body bytes */
-    if (stream_writing->flow_controlled_buffer.length > 0) {
-      if (max_outgoing > 0) {
-        uint32_t send_bytes = (uint32_t)GPR_MIN(
-            max_outgoing, stream_writing->flow_controlled_buffer.length);
-        int is_last_data_frame =
-            stream_writing->send_message == NULL &&
-            send_bytes == stream_writing->flow_controlled_buffer.length;
-        int is_last_frame = is_last_data_frame &&
-                            stream_writing->send_trailing_metadata != NULL &&
-                            grpc_metadata_batch_is_empty(
-                                stream_writing->send_trailing_metadata);
-        grpc_chttp2_encode_data(
-            stream_writing->id, &stream_writing->flow_controlled_buffer,
-            send_bytes, is_last_frame, &stream_writing->stats,
-            &transport_writing->outbuf);
-        if (is_first_data_frame) {
-          /* TODO(dgq): this is a hack. It'll be fix in a future refactoring */
-          stream_writing->stats.data_bytes -= 5; /* discount grpc framing */
-          is_first_data_frame = false;
-        }
-        GRPC_CHTTP2_FLOW_DEBIT_STREAM("write", transport_writing,
-                                      stream_writing, outgoing_window,
-                                      send_bytes);
-        GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("write", transport_writing,
-                                         outgoing_window, send_bytes);
-        if (is_last_frame) {
-          stream_writing->send_trailing_metadata = NULL;
-          stream_writing->sent_trailing_metadata = 1;
-        }
-        if (is_last_data_frame) {
-          GPR_ASSERT(stream_writing->send_message == NULL);
-          stream_writing->sent_message = 1;
-        }
-      } else if (transport_writing->outgoing_window == 0) {
-        grpc_chttp2_list_add_writing_stalled_by_transport(transport_writing,
-                                                          stream_writing);
-        grpc_chttp2_list_add_written_stream(transport_writing, stream_writing);
-      }
-    }
-    /* send trailing metadata if it's available and we're ready for it */
-    if (stream_writing->send_message == NULL &&
-        stream_writing->flow_controlled_buffer.length == 0 &&
-        stream_writing->send_trailing_metadata != NULL) {
-      if (grpc_metadata_batch_is_empty(
-              stream_writing->send_trailing_metadata)) {
-        grpc_chttp2_encode_data(
-            stream_writing->id, &stream_writing->flow_controlled_buffer, 0, 1,
-            &stream_writing->stats, &transport_writing->outbuf);
-      } else {
-        grpc_chttp2_encode_header(
-            &transport_writing->hpack_compressor, stream_writing->id,
-            stream_writing->send_trailing_metadata, 1,
-            transport_writing->max_frame_size, &stream_writing->stats,
-            &transport_writing->outbuf);
-      }
-      if (!transport_writing->is_client && !stream_writing->read_closed) {
-        gpr_slice_buffer_add(&transport_writing->outbuf,
-                             grpc_chttp2_rst_stream_create(
-                                 stream_writing->id, GRPC_CHTTP2_NO_ERROR,
-                                 &stream_writing->stats));
-      }
-      stream_writing->send_trailing_metadata = NULL;
-      stream_writing->sent_trailing_metadata = 1;
-    }
-    /* if there's more to write, then loop, otherwise prepare to finish the
-     * write */
-    if ((stream_writing->flow_controlled_buffer.length > 0 ||
-         (stream_writing->send_message && !stream_writing->fetching)) &&
-        stream_writing->outgoing_window > 0) {
-      if (transport_writing->outgoing_window > 0) {
-        grpc_chttp2_list_add_writing_stream(transport_writing, stream_writing);
-      } else {
-        grpc_chttp2_list_add_writing_stalled_by_transport(transport_writing,
-                                                          stream_writing);
-        grpc_chttp2_list_add_written_stream(transport_writing, stream_writing);
-      }
-    } else {
-      grpc_chttp2_list_add_written_stream(transport_writing, stream_writing);
-    }
-  }
-
-  GPR_TIMER_END("finalize_outbuf", 0);
+  return t->outbuf.count > 0;
 }
 
-void grpc_chttp2_cleanup_writing(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
-    grpc_chttp2_transport_writing *transport_writing) {
-  GPR_TIMER_BEGIN("grpc_chttp2_cleanup_writing", 0);
-  grpc_chttp2_stream_writing *stream_writing;
-  grpc_chttp2_stream_global *stream_global;
-
-  if (grpc_chttp2_list_flush_writing_stalled_by_transport(exec_ctx,
-                                                          transport_writing)) {
-    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
-                               "resume_stalled_stream");
-  }
+void grpc_chttp2_end_write(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                           grpc_error *error) {
+  GPR_TIMER_BEGIN("grpc_chttp2_end_write", 0);
+  grpc_chttp2_stream *s;
 
-  while (grpc_chttp2_list_pop_written_stream(
-      transport_global, transport_writing, &stream_global, &stream_writing)) {
-    if (stream_writing->sent_initial_metadata) {
+  while (grpc_chttp2_list_pop_writing_stream(t, &s)) {
+    if (s->sent_initial_metadata) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, transport_global, stream_global,
-          &stream_global->send_initial_metadata_finished, GRPC_ERROR_NONE);
+          exec_ctx, t, s, &s->send_initial_metadata_finished,
+          GRPC_ERROR_REF(error), "send_initial_metadata_finished");
     }
-    grpc_transport_move_one_way_stats(&stream_writing->stats,
-                                      &stream_global->stats.outgoing);
-    if (stream_writing->sent_message) {
-      GPR_ASSERT(stream_writing->send_message == NULL);
-      grpc_chttp2_complete_closure_step(
-          exec_ctx, transport_global, stream_global,
-          &stream_global->send_message_finished, GRPC_ERROR_NONE);
-      stream_writing->sent_message = 0;
+    if (s->sending_bytes != 0) {
+      update_list(exec_ctx, t, s, (int64_t)s->sending_bytes,
+                  &s->on_write_finished_cbs, GRPC_ERROR_REF(error));
+      s->sending_bytes = 0;
     }
-    if (stream_writing->sent_trailing_metadata) {
+    if (s->sent_trailing_metadata) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, transport_global, stream_global,
-          &stream_global->send_trailing_metadata_finished, GRPC_ERROR_NONE);
-    }
-    if (stream_writing->sent_trailing_metadata) {
-      grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global,
-                                     !transport_global->is_client, 1,
-                                     GRPC_ERROR_NONE);
+          exec_ctx, t, s, &s->send_trailing_metadata_finished,
+          GRPC_ERROR_REF(error), "send_trailing_metadata_finished");
+      grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
+                                     GRPC_ERROR_REF(error));
     }
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2_writing");
+    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:end");
   }
-  gpr_slice_buffer_reset_and_unref(&transport_writing->outbuf);
-  GPR_TIMER_END("grpc_chttp2_cleanup_writing", 0);
+  gpr_slice_buffer_reset_and_unref(&t->outbuf);
+  GRPC_ERROR_UNREF(error);
+  GPR_TIMER_END("grpc_chttp2_end_write", 0);
 }
diff --git a/src/core/lib/iomgr/closure.c b/src/core/lib/iomgr/closure.c
index 1ba0a5c141..c6ddc76732 100644
--- a/src/core/lib/iomgr/closure.c
+++ b/src/core/lib/iomgr/closure.c
@@ -35,6 +35,8 @@
 
 #include <grpc/support/alloc.h>
 
+#include "src/core/lib/profiling/timers.h"
+
 void grpc_closure_init(grpc_closure *closure, grpc_iomgr_cb_func cb,
                        void *cb_arg) {
   closure->cb = cb;
@@ -51,7 +53,7 @@ void grpc_closure_list_append(grpc_closure_list *closure_list,
     GRPC_ERROR_UNREF(error);
     return;
   }
-  closure->error = error;
+  closure->error_data.error = error;
   closure->next_data.next = NULL;
   if (closure_list->head == NULL) {
     closure_list->head = closure;
@@ -64,8 +66,8 @@ void grpc_closure_list_append(grpc_closure_list *closure_list,
 void grpc_closure_list_fail_all(grpc_closure_list *list,
                                 grpc_error *forced_failure) {
   for (grpc_closure *c = list->head; c != NULL; c = c->next_data.next) {
-    if (c->error == GRPC_ERROR_NONE) {
-      c->error = GRPC_ERROR_REF(forced_failure);
+    if (c->error_data.error == GRPC_ERROR_NONE) {
+      c->error_data.error = GRPC_ERROR_REF(forced_failure);
     }
   }
   GRPC_ERROR_UNREF(forced_failure);
@@ -110,3 +112,13 @@ grpc_closure *grpc_closure_create(grpc_iomgr_cb_func cb, void *cb_arg) {
   grpc_closure_init(&wc->wrapper, closure_wrapper, wc);
   return &wc->wrapper;
 }
+
+void grpc_closure_run(grpc_exec_ctx *exec_ctx, grpc_closure *c,
+                      grpc_error *error) {
+  GPR_TIMER_BEGIN("grpc_closure_run", 0);
+  if (c != NULL) {
+    c->cb(exec_ctx, c->cb_arg, error);
+  }
+  GRPC_ERROR_UNREF(error);
+  GPR_TIMER_END("grpc_closure_run", 0);
+}
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index c1a22b6021..2b4b271eaa 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -76,7 +76,10 @@ struct grpc_closure {
   void *cb_arg;
 
   /** Once queued, the result of the closure. Before then: scratch space */
-  grpc_error *error;
+  union {
+    grpc_error *error;
+    uintptr_t scratch;
+  } error_data;
 };
 
 /** Initializes \a closure with \a cb and \a cb_arg. */
@@ -106,4 +109,10 @@ void grpc_closure_list_move(grpc_closure_list *src, grpc_closure_list *dst);
 /** return whether \a list is empty. */
 bool grpc_closure_list_empty(grpc_closure_list list);
 
+/** Run a closure directly. Caller ensures that no locks are being held above.
+ *  Note that calling this at the end of a closure callback function itself is
+ *  by definition safe. */
+void grpc_closure_run(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
+                      grpc_error *error);
+
 #endif /* GRPC_CORE_LIB_IOMGR_CLOSURE_H */
diff --git a/src/core/lib/iomgr/combiner.c b/src/core/lib/iomgr/combiner.c
index 831bdb4aff..60ee14eb23 100644
--- a/src/core/lib/iomgr/combiner.c
+++ b/src/core/lib/iomgr/combiner.c
@@ -50,25 +50,57 @@ int grpc_combiner_trace = 0;
     }                           \
   } while (0)
 
+#define STATE_UNORPHANED 1
+#define STATE_ELEM_COUNT_LOW_BIT 2
+
 struct grpc_combiner {
+  grpc_combiner *next_combiner_on_this_exec_ctx;
   grpc_workqueue *optional_workqueue;
   gpr_mpscq queue;
   // state is:
-  // lower bit - zero if orphaned
-  // other bits - number of items queued on the lock
+  // lower bit - zero if orphaned (STATE_UNORPHANED)
+  // other bits - number of items queued on the lock (STATE_ELEM_COUNT_LOW_BIT)
   gpr_atm state;
-  bool take_async_break_before_final_list;
+  // number of elements in the list that are covered by a poller: if >0, we can
+  // offload safely
+  gpr_atm elements_covered_by_poller;
+  bool time_to_execute_final_list;
+  bool final_list_covered_by_poller;
   grpc_closure_list final_list;
-  grpc_closure continue_finishing;
+  grpc_closure offload;
 };
 
+static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
+
+typedef struct {
+  grpc_error *error;
+  bool covered_by_poller;
+} error_data;
+
+static uintptr_t pack_error_data(error_data d) {
+  return ((uintptr_t)d.error) | (d.covered_by_poller ? 1 : 0);
+}
+
+static error_data unpack_error_data(uintptr_t p) {
+  return (error_data){(grpc_error *)(p & ~(uintptr_t)1), p & 1};
+}
+
+static bool is_covered_by_poller(grpc_combiner *lock) {
+  return lock->final_list_covered_by_poller ||
+         gpr_atm_acq_load(&lock->elements_covered_by_poller) > 0;
+}
+
 grpc_combiner *grpc_combiner_create(grpc_workqueue *optional_workqueue) {
   grpc_combiner *lock = gpr_malloc(sizeof(*lock));
+  lock->next_combiner_on_this_exec_ctx = NULL;
+  lock->time_to_execute_final_list = false;
   lock->optional_workqueue = optional_workqueue;
-  gpr_atm_no_barrier_store(&lock->state, 1);
+  lock->final_list_covered_by_poller = false;
+  gpr_atm_no_barrier_store(&lock->state, STATE_UNORPHANED);
+  gpr_atm_no_barrier_store(&lock->elements_covered_by_poller, 0);
   gpr_mpscq_init(&lock->queue);
-  lock->take_async_break_before_final_list = false;
   grpc_closure_list_init(&lock->final_list);
+  grpc_closure_init(&lock->offload, offload, lock);
   GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p create", lock));
   return lock;
 }
@@ -82,7 +114,7 @@ static void really_destroy(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
 }
 
 void grpc_combiner_destroy(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
-  gpr_atm old_state = gpr_atm_full_fetch_add(&lock->state, -1);
+  gpr_atm old_state = gpr_atm_full_fetch_add(&lock->state, -STATE_UNORPHANED);
   GRPC_COMBINER_TRACE(gpr_log(
       GPR_DEBUG, "C:%p really_destroy old_state=%" PRIdPTR, lock, old_state));
   if (old_state == 1) {
@@ -90,170 +122,186 @@ void grpc_combiner_destroy(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
   }
 }
 
-static bool maybe_finish_one(grpc_exec_ctx *exec_ctx, grpc_combiner *lock);
-static void finish(grpc_exec_ctx *exec_ctx, grpc_combiner *lock);
+static void push_last_on_exec_ctx(grpc_exec_ctx *exec_ctx,
+                                  grpc_combiner *lock) {
+  lock->next_combiner_on_this_exec_ctx = NULL;
+  if (exec_ctx->active_combiner == NULL) {
+    exec_ctx->active_combiner = exec_ctx->last_combiner = lock;
+  } else {
+    exec_ctx->last_combiner->next_combiner_on_this_exec_ctx = lock;
+    exec_ctx->last_combiner = lock;
+  }
+}
 
-static void continue_finishing_mainline(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
-  GPR_TIMER_BEGIN("combiner.continue_executing_mainline", 0);
-  grpc_combiner *lock = arg;
-  GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG, "C:%p continue_finishing_mainline", lock));
-  GPR_ASSERT(exec_ctx->active_combiner == NULL);
+static void push_first_on_exec_ctx(grpc_exec_ctx *exec_ctx,
+                                   grpc_combiner *lock) {
+  lock->next_combiner_on_this_exec_ctx = exec_ctx->active_combiner;
   exec_ctx->active_combiner = lock;
-  if (maybe_finish_one(exec_ctx, lock)) finish(exec_ctx, lock);
-  GPR_ASSERT(exec_ctx->active_combiner == lock);
-  exec_ctx->active_combiner = NULL;
-  GPR_TIMER_END("combiner.continue_executing_mainline", 0);
+  if (lock->next_combiner_on_this_exec_ctx == NULL) {
+    exec_ctx->last_combiner = lock;
+  }
 }
 
-static void execute_final(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
-  GPR_TIMER_BEGIN("combiner.execute_final", 0);
-  grpc_closure *c = lock->final_list.head;
-  GPR_ASSERT(c != NULL);
-  grpc_closure_list_init(&lock->final_list);
-  lock->take_async_break_before_final_list = false;
-  int loops = 0;
-  while (c != NULL) {
-    GRPC_COMBINER_TRACE(
-        gpr_log(GPR_DEBUG, "C:%p execute_final[%d] c=%p", lock, loops, c));
-    grpc_closure *next = c->next_data.next;
-    grpc_error *error = c->error;
-    c->cb(exec_ctx, c->cb_arg, error);
-    GRPC_ERROR_UNREF(error);
-    c = next;
-    loops++;
+void grpc_combiner_execute(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
+                           grpc_closure *cl, grpc_error *error,
+                           bool covered_by_poller) {
+  GPR_TIMER_BEGIN("combiner.execute", 0);
+  gpr_atm last = gpr_atm_full_fetch_add(&lock->state, STATE_ELEM_COUNT_LOW_BIT);
+  GRPC_COMBINER_TRACE(gpr_log(
+      GPR_DEBUG, "C:%p grpc_combiner_execute c=%p cov=%d last=%" PRIdPTR, lock,
+      cl, covered_by_poller, last));
+  GPR_ASSERT(last & STATE_UNORPHANED);  // ensure lock has not been destroyed
+  cl->error_data.scratch =
+      pack_error_data((error_data){error, covered_by_poller});
+  if (covered_by_poller) {
+    gpr_atm_no_barrier_fetch_add(&lock->elements_covered_by_poller, 1);
+  }
+  gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
+  if (last == 1) {
+    // first element on this list: add it to the list of combiner locks
+    // executing within this exec_ctx
+    push_last_on_exec_ctx(exec_ctx, lock);
   }
-  GPR_TIMER_END("combiner.execute_final", 0);
+  GPR_TIMER_END("combiner.execute", 0);
 }
 
-static void continue_executing_final(grpc_exec_ctx *exec_ctx, void *arg,
-                                     grpc_error *error) {
-  GPR_TIMER_BEGIN("combiner.continue_executing_final", 0);
-  grpc_combiner *lock = arg;
-  GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG, "C:%p continue_executing_final", lock));
-  GPR_ASSERT(exec_ctx->active_combiner == NULL);
-  exec_ctx->active_combiner = lock;
-  // quick peek to see if new things have turned up on the queue: if so, go back
-  // to executing them before the final list
-  if ((gpr_atm_acq_load(&lock->state) >> 1) > 1) {
-    if (maybe_finish_one(exec_ctx, lock)) finish(exec_ctx, lock);
-  } else {
-    execute_final(exec_ctx, lock);
-    finish(exec_ctx, lock);
+static void move_next(grpc_exec_ctx *exec_ctx) {
+  exec_ctx->active_combiner =
+      exec_ctx->active_combiner->next_combiner_on_this_exec_ctx;
+  if (exec_ctx->active_combiner == NULL) {
+    exec_ctx->last_combiner = NULL;
   }
-  GPR_ASSERT(exec_ctx->active_combiner == lock);
-  exec_ctx->active_combiner = NULL;
-  GPR_TIMER_END("combiner.continue_executing_final", 0);
 }
 
-static bool start_execute_final(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
-  GPR_TIMER_BEGIN("combiner.start_execute_final", 0);
-  GPR_ASSERT(exec_ctx->active_combiner == lock);
-  GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG,
-              "C:%p start_execute_final take_async_break_before_final_list=%d",
-              lock, lock->take_async_break_before_final_list));
-  if (lock->take_async_break_before_final_list) {
-    grpc_closure_init(&lock->continue_finishing, continue_executing_final,
-                      lock);
-    grpc_exec_ctx_sched(exec_ctx, &lock->continue_finishing, GRPC_ERROR_NONE,
-                        GRPC_WORKQUEUE_REF(lock->optional_workqueue, "sched"));
-    GPR_TIMER_END("combiner.start_execute_final", 0);
+static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
+  grpc_combiner *lock = arg;
+  push_last_on_exec_ctx(exec_ctx, lock);
+}
+
+static void queue_offload(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
+  move_next(exec_ctx);
+  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG, "C:%p queue_offload --> %p", lock,
+                              lock->optional_workqueue));
+  grpc_workqueue_enqueue(exec_ctx, lock->optional_workqueue, &lock->offload,
+                         GRPC_ERROR_NONE);
+}
+
+bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx) {
+  GPR_TIMER_BEGIN("combiner.continue_exec_ctx", 0);
+  grpc_combiner *lock = exec_ctx->active_combiner;
+  if (lock == NULL) {
+    GPR_TIMER_END("combiner.continue_exec_ctx", 0);
     return false;
-  } else {
-    execute_final(exec_ctx, lock);
-    GPR_TIMER_END("combiner.start_execute_final", 0);
-    return true;
   }
-}
 
-static bool maybe_finish_one(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
-  GPR_TIMER_BEGIN("combiner.maybe_finish_one", 0);
-  gpr_mpscq_node *n = gpr_mpscq_pop(&lock->queue);
   GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG, "C:%p maybe_finish_one n=%p", lock, n));
-  GPR_ASSERT(exec_ctx->active_combiner == lock);
-  if (n == NULL) {
-    // Queue is in an transiently inconsistent state: a new item is being queued
-    // but is not visible to this thread yet.
-    // Use this as a cue that we should go off and do something else for a while
-    // (and come back later)
-    grpc_closure_init(&lock->continue_finishing, continue_finishing_mainline,
-                      lock);
-    grpc_exec_ctx_sched(exec_ctx, &lock->continue_finishing, GRPC_ERROR_NONE,
-                        GRPC_WORKQUEUE_REF(lock->optional_workqueue, "sched"));
-    GPR_TIMER_END("combiner.maybe_finish_one", 0);
-    return false;
+      gpr_log(GPR_DEBUG,
+              "C:%p grpc_combiner_continue_exec_ctx workqueue=%p "
+              "is_covered_by_poller=%d exec_ctx_ready_to_finish=%d "
+              "time_to_execute_final_list=%d",
+              lock, lock->optional_workqueue, is_covered_by_poller(lock),
+              grpc_exec_ctx_ready_to_finish(exec_ctx),
+              lock->time_to_execute_final_list));
+
+  if (lock->optional_workqueue != NULL && is_covered_by_poller(lock) &&
+      grpc_exec_ctx_ready_to_finish(exec_ctx)) {
+    GPR_TIMER_MARK("offload_from_finished_exec_ctx", 0);
+    // this execution context wants to move on, and we have a workqueue (and
+    // so can help the execution context out): schedule remaining work to be
+    // picked up on the workqueue
+    queue_offload(exec_ctx, lock);
+    GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+    return true;
   }
-  grpc_closure *cl = (grpc_closure *)n;
-  grpc_error *error = cl->error;
-  cl->cb(exec_ctx, cl->cb_arg, error);
-  GRPC_ERROR_UNREF(error);
-  GPR_TIMER_END("combiner.maybe_finish_one", 0);
-  return true;
-}
 
-static void finish(grpc_exec_ctx *exec_ctx, grpc_combiner *lock) {
-  bool (*executor)(grpc_exec_ctx * exec_ctx, grpc_combiner * lock);
-  GPR_TIMER_BEGIN("combiner.finish", 0);
-  int loops = 0;
-  do {
-    executor = maybe_finish_one;
-    gpr_atm old_state = gpr_atm_full_fetch_add(&lock->state, -2);
-    GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
-                                "C:%p finish[%d] old_state=%" PRIdPTR, lock,
-                                loops, old_state));
-    switch (old_state) {
-      default:
-        // we have multiple queued work items: just continue executing them
-        break;
-      case 5:  // we're down to one queued item: if it's the final list we
-      case 4:  // should do that
-        if (!grpc_closure_list_empty(lock->final_list)) {
-          executor = start_execute_final;
-        }
-        break;
-      case 3:  // had one count, one unorphaned --> unlocked unorphaned
-        GPR_TIMER_END("combiner.finish", 0);
-        return;
-      case 2:  // and one count, one orphaned --> unlocked and orphaned
-        really_destroy(exec_ctx, lock);
-        GPR_TIMER_END("combiner.finish", 0);
-        return;
-      case 1:
-      case 0:
-        // these values are illegal - representing an already unlocked or
-        // deleted lock
-        GPR_UNREACHABLE_CODE(return );
+  if (!lock->time_to_execute_final_list ||
+      // peek to see if something new has shown up, and execute that with
+      // priority
+      (gpr_atm_acq_load(&lock->state) >> 1) > 1) {
+    gpr_mpscq_node *n = gpr_mpscq_pop(&lock->queue);
+    GRPC_COMBINER_TRACE(
+        gpr_log(GPR_DEBUG, "C:%p maybe_finish_one n=%p", lock, n));
+    if (n == NULL) {
+      // queue is in an inconsistent state: use this as a cue that we should
+      // go off and do something else for a while (and come back later)
+      GPR_TIMER_MARK("delay_busy", 0);
+      if (lock->optional_workqueue != NULL && is_covered_by_poller(lock)) {
+        queue_offload(exec_ctx, lock);
+      }
+      GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+      return true;
     }
-    loops++;
-  } while (executor(exec_ctx, lock));
-  GPR_TIMER_END("combiner.finish", 0);
-}
+    GPR_TIMER_BEGIN("combiner.exec1", 0);
+    grpc_closure *cl = (grpc_closure *)n;
+    error_data err = unpack_error_data(cl->error_data.scratch);
+    cl->cb(exec_ctx, cl->cb_arg, err.error);
+    if (err.covered_by_poller) {
+      gpr_atm_no_barrier_fetch_add(&lock->elements_covered_by_poller, -1);
+    }
+    GRPC_ERROR_UNREF(err.error);
+    GPR_TIMER_END("combiner.exec1", 0);
+  } else {
+    grpc_closure *c = lock->final_list.head;
+    GPR_ASSERT(c != NULL);
+    grpc_closure_list_init(&lock->final_list);
+    lock->final_list_covered_by_poller = false;
+    int loops = 0;
+    while (c != NULL) {
+      GPR_TIMER_BEGIN("combiner.exec_1final", 0);
+      GRPC_COMBINER_TRACE(
+          gpr_log(GPR_DEBUG, "C:%p execute_final[%d] c=%p", lock, loops, c));
+      grpc_closure *next = c->next_data.next;
+      grpc_error *error = c->error_data.error;
+      c->cb(exec_ctx, c->cb_arg, error);
+      GRPC_ERROR_UNREF(error);
+      c = next;
+      GPR_TIMER_END("combiner.exec_1final", 0);
+    }
+  }
 
-void grpc_combiner_execute(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
-                           grpc_closure *cl, grpc_error *error) {
+  GPR_TIMER_MARK("unref", 0);
+  move_next(exec_ctx);
+  lock->time_to_execute_final_list = false;
+  gpr_atm old_state =
+      gpr_atm_full_fetch_add(&lock->state, -STATE_ELEM_COUNT_LOW_BIT);
   GRPC_COMBINER_TRACE(
-      gpr_log(GPR_DEBUG, "C:%p grpc_combiner_execute c=%p", lock, cl));
-  GPR_TIMER_BEGIN("combiner.execute", 0);
-  gpr_atm last = gpr_atm_full_fetch_add(&lock->state, 2);
-  GPR_ASSERT(last & 1);  // ensure lock has not been destroyed
-  if (last == 1) {
-    exec_ctx->active_combiner = lock;
-    GPR_TIMER_BEGIN("combiner.execute_first_cb", 0);
-    cl->cb(exec_ctx, cl->cb_arg, error);
-    GPR_TIMER_END("combiner.execute_first_cb", 0);
-    GRPC_ERROR_UNREF(error);
-    finish(exec_ctx, lock);
-    GPR_ASSERT(exec_ctx->active_combiner == lock);
-    exec_ctx->active_combiner = NULL;
-  } else {
-    cl->error = error;
-    gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
+      gpr_log(GPR_DEBUG, "C:%p finish old_state=%" PRIdPTR, lock, old_state));
+// Define a macro to ease readability of the following switch statement.
+#define OLD_STATE_WAS(orphaned, elem_count) \
+  (((orphaned) ? 0 : STATE_UNORPHANED) |    \
+   ((elem_count)*STATE_ELEM_COUNT_LOW_BIT))
+  // Depending on what the previous state was, we need to perform different
+  // actions.
+  switch (old_state) {
+    default:
+      // we have multiple queued work items: just continue executing them
+      break;
+    case OLD_STATE_WAS(false, 2):
+    case OLD_STATE_WAS(true, 2):
+      // we're down to one queued item: if it's the final list we should do that
+      if (!grpc_closure_list_empty(lock->final_list)) {
+        lock->time_to_execute_final_list = true;
+      }
+      break;
+    case OLD_STATE_WAS(false, 1):
+      // had one count, one unorphaned --> unlocked unorphaned
+      GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+      return true;
+    case OLD_STATE_WAS(true, 1):
+      // and one count, one orphaned --> unlocked and orphaned
+      really_destroy(exec_ctx, lock);
+      GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+      return true;
+    case OLD_STATE_WAS(false, 0):
+    case OLD_STATE_WAS(true, 0):
+      // these values are illegal - representing an already unlocked or
+      // deleted lock
+      GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+      GPR_UNREACHABLE_CODE(return true);
   }
-  GPR_TIMER_END("combiner.execute", 0);
+  push_first_on_exec_ctx(exec_ctx, lock);
+  GPR_TIMER_END("combiner.continue_exec_ctx", 0);
+  return true;
 }
 
 static void enqueue_finally(grpc_exec_ctx *exec_ctx, void *closure,
@@ -264,30 +312,26 @@ static void enqueue_finally(grpc_exec_ctx *exec_ctx, void *closure,
 
 void grpc_combiner_execute_finally(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
                                    grpc_closure *closure, grpc_error *error,
-                                   bool force_async_break) {
+                                   bool covered_by_poller) {
   GRPC_COMBINER_TRACE(gpr_log(
-      GPR_DEBUG,
-      "C:%p grpc_combiner_execute_finally c=%p force_async_break=%d; ac=%p",
-      lock, closure, force_async_break, exec_ctx->active_combiner));
+      GPR_DEBUG, "C:%p grpc_combiner_execute_finally c=%p; ac=%p; cov=%d", lock,
+      closure, exec_ctx->active_combiner, covered_by_poller));
   GPR_TIMER_BEGIN("combiner.execute_finally", 0);
   if (exec_ctx->active_combiner != lock) {
     GPR_TIMER_MARK("slowpath", 0);
     grpc_combiner_execute(exec_ctx, lock,
-                          grpc_closure_create(enqueue_finally, closure), error);
+                          grpc_closure_create(enqueue_finally, closure), error,
+                          false);
     GPR_TIMER_END("combiner.execute_finally", 0);
     return;
   }
 
-  if (force_async_break) {
-    lock->take_async_break_before_final_list = true;
-  }
   if (grpc_closure_list_empty(lock->final_list)) {
-    gpr_atm_full_fetch_add(&lock->state, 2);
+    gpr_atm_full_fetch_add(&lock->state, STATE_ELEM_COUNT_LOW_BIT);
+  }
+  if (covered_by_poller) {
+    lock->final_list_covered_by_poller = true;
   }
   grpc_closure_list_append(&lock->final_list, closure, error);
   GPR_TIMER_END("combiner.execute_finally", 0);
 }
-
-void grpc_combiner_force_async_finally(grpc_combiner *lock) {
-  lock->take_async_break_before_final_list = true;
-}
diff --git a/src/core/lib/iomgr/combiner.h b/src/core/lib/iomgr/combiner.h
index 1409db24b9..d04eeed83a 100644
--- a/src/core/lib/iomgr/combiner.h
+++ b/src/core/lib/iomgr/combiner.h
@@ -52,19 +52,14 @@ grpc_combiner *grpc_combiner_create(grpc_workqueue *optional_workqueue);
 void grpc_combiner_destroy(grpc_exec_ctx *exec_ctx, grpc_combiner *lock);
 // Execute \a action within the lock.
 void grpc_combiner_execute(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
-                           grpc_closure *closure, grpc_error *error);
+                           grpc_closure *closure, grpc_error *error,
+                           bool covered_by_poller);
 // Execute \a action within the lock just prior to unlocking.
-// if \a hint_async_break is true, the combiner tries to hand execution to
-// another thread before finishing the primary queue of combined closures and
-// executing the finally list.
-// Deprecation warning: \a hint_async_break will be removed in a future version
-// Takes a very slow and round-about path if not called from a
-// grpc_combiner_execute closure.
 void grpc_combiner_execute_finally(grpc_exec_ctx *exec_ctx, grpc_combiner *lock,
                                    grpc_closure *closure, grpc_error *error,
-                                   bool hint_async_break);
-// Deprecated: force the finally list execution onto another thread
-void grpc_combiner_force_async_finally(grpc_combiner *lock);
+                                   bool covered_by_poller);
+
+bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx);
 
 extern int grpc_combiner_trace;
 
diff --git a/src/core/lib/iomgr/error.c b/src/core/lib/iomgr/error.c
index 31c80260f8..f6bb3a0477 100644
--- a/src/core/lib/iomgr/error.c
+++ b/src/core/lib/iomgr/error.c
@@ -120,6 +120,8 @@ static const char *error_int_name(grpc_error_ints key) {
       return "http_status";
     case GRPC_ERROR_INT_LIMIT:
       return "limit";
+    case GRPC_ERROR_INT_OCCURRED_DURING_WRITE:
+      return "occurred_during_write";
   }
   GPR_UNREACHABLE_CODE(return "unknown");
 }
@@ -144,6 +146,8 @@ static const char *error_str_name(grpc_error_strs key) {
       return "tsi_error";
     case GRPC_ERROR_STR_FILENAME:
       return "filename";
+    case GRPC_ERROR_STR_QUEUED_BUFFERS:
+      return "queued_buffers";
   }
   GPR_UNREACHABLE_CODE(return "unknown");
 }
@@ -265,7 +269,7 @@ static grpc_error *copy_error_and_unref(grpc_error *in) {
   } else {
     out = gpr_malloc(sizeof(*out));
 #ifdef GRPC_ERROR_REFCOUNT_DEBUG
-    gpr_log(GPR_DEBUG, "%p create copying", out);
+    gpr_log(GPR_DEBUG, "%p create copying %p", out, in);
 #endif
     out->ints = gpr_avl_ref(in->ints);
     out->strs = gpr_avl_ref(in->strs);
@@ -523,21 +527,25 @@ static char *fmt_time(void *p) {
   return out;
 }
 
-static void add_errs(gpr_avl_node *n, char **s, size_t *sz, size_t *cap) {
+static void add_errs(gpr_avl_node *n, char **s, size_t *sz, size_t *cap,
+                     bool *first) {
   if (n == NULL) return;
-  add_errs(n->left, s, sz, cap);
+  add_errs(n->left, s, sz, cap, first);
+  if (!*first) append_chr(',', s, sz, cap);
+  *first = false;
   const char *e = grpc_error_string(n->value);
   append_str(e, s, sz, cap);
   grpc_error_free_string(e);
-  add_errs(n->right, s, sz, cap);
+  add_errs(n->right, s, sz, cap, first);
 }
 
 static char *errs_string(grpc_error *err) {
   char *s = NULL;
   size_t sz = 0;
   size_t cap = 0;
+  bool first = true;
   append_chr('[', &s, &sz, &cap);
-  add_errs(err->errs.root, &s, &sz, &cap);
+  add_errs(err->errs.root, &s, &sz, &cap, &first);
   append_chr(']', &s, &sz, &cap);
   append_chr(0, &s, &sz, &cap);
   return s;
diff --git a/src/core/lib/iomgr/error.h b/src/core/lib/iomgr/error.h
index 00ace8a7a9..f3f3b80a09 100644
--- a/src/core/lib/iomgr/error.h
+++ b/src/core/lib/iomgr/error.h
@@ -100,6 +100,8 @@ typedef enum {
   GRPC_ERROR_INT_HTTP_STATUS,
   /// context sensitive limit associated with the error
   GRPC_ERROR_INT_LIMIT,
+  /// chttp2: did the error occur while a write was in progress
+  GRPC_ERROR_INT_OCCURRED_DURING_WRITE,
 } grpc_error_ints;
 
 typedef enum {
@@ -121,6 +123,8 @@ typedef enum {
   GRPC_ERROR_STR_TSI_ERROR,
   /// filename that we were trying to read/write when this error occurred
   GRPC_ERROR_STR_FILENAME,
+  /// which data was queued for writing when the error occurred
+  GRPC_ERROR_STR_QUEUED_BUFFERS
 } grpc_error_strs;
 
 typedef enum {
@@ -128,9 +132,13 @@ typedef enum {
   GRPC_ERROR_TIME_CREATED,
 } grpc_error_times;
 
+/// The following "special" errors can be propagated without allocating memory.
+/// They are always even so that other code (particularly combiner locks) can
+/// safely use the lower bit for themselves.
+
 #define GRPC_ERROR_NONE ((grpc_error *)NULL)
-#define GRPC_ERROR_OOM ((grpc_error *)1)
-#define GRPC_ERROR_CANCELLED ((grpc_error *)2)
+#define GRPC_ERROR_OOM ((grpc_error *)2)
+#define GRPC_ERROR_CANCELLED ((grpc_error *)4)
 
 const char *grpc_error_string(grpc_error *error);
 void grpc_error_free_string(const char *str);
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index ab77ebc78b..e5909d9380 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -152,20 +152,20 @@ static void fd_global_shutdown(void);
  * Polling island Declarations
  */
 
-//#define GRPC_PI_REF_COUNT_DEBUG
-#ifdef GRPC_PI_REF_COUNT_DEBUG
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
 
 #define PI_ADD_REF(p, r) pi_add_ref_dbg((p), (r), __FILE__, __LINE__)
 #define PI_UNREF(exec_ctx, p, r) \
   pi_unref_dbg((exec_ctx), (p), (r), __FILE__, __LINE__)
 
-#else /* defined(GRPC_PI_REF_COUNT_DEBUG) */
+#else /* defined(GRPC_WORKQUEUE_REFCOUNT_DEBUG) */
 
 #define PI_ADD_REF(p, r) pi_add_ref((p))
 #define PI_UNREF(exec_ctx, p, r) pi_unref((exec_ctx), (p))
 
 #endif /* !defined(GPRC_PI_REF_COUNT_DEBUG) */
 
+/* This is also used as grpc_workqueue (by directly casing it) */
 typedef struct polling_island {
   gpr_mu mu;
   /* Ref count. Use PI_ADD_REF() and PI_UNREF() macros to increment/decrement
@@ -185,8 +185,17 @@ typedef struct polling_island {
    * (except mu and ref_count) are invalid and must be ignored. */
   gpr_atm merged_to;
 
-  /* The workqueue associated with this polling island */
-  grpc_workqueue *workqueue;
+  /* Number of threads currently polling on this island */
+  gpr_atm poller_count;
+  /* Mutex guarding the read end of the workqueue (must be held to pop from
+   * workqueue_items) */
+  gpr_mu workqueue_read_mu;
+  /* Queue of closures to be executed */
+  gpr_mpscq workqueue_items;
+  /* Count of items in workqueue_items */
+  gpr_atm workqueue_item_count;
+  /* Wakeup fd used to wake pollers to check the contents of workqueue_items */
+  grpc_wakeup_fd workqueue_wakeup_fd;
 
   /* The fd of the underlying epoll set */
   int epoll_fd;
@@ -275,6 +284,10 @@ static bool append_error(grpc_error **composite, grpc_error *error,
    threads that woke up MUST NOT call grpc_wakeup_fd_consume_wakeup() */
 static grpc_wakeup_fd polling_island_wakeup_fd;
 
+/* The polling island being polled right now.
+   See comments in workqueue_maybe_wakeup for why this is tracked. */
+static __thread polling_island *g_current_thread_polling_island;
+
 /* Forward declaration */
 static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi);
 
@@ -289,12 +302,12 @@ static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi);
 gpr_atm g_epoll_sync;
 #endif /* defined(GRPC_TSAN) */
 
-#ifdef GRPC_PI_REF_COUNT_DEBUG
 static void pi_add_ref(polling_island *pi);
 static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi);
 
-static void pi_add_ref_dbg(polling_island *pi, char *reason, char *file,
-                           int line) {
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+static void pi_add_ref_dbg(polling_island *pi, const char *reason,
+                           const char *file, int line) {
   long old_cnt = gpr_atm_acq_load(&pi->ref_count);
   pi_add_ref(pi);
   gpr_log(GPR_DEBUG, "Add ref pi: %p, old: %ld -> new:%ld (%s) - (%s, %d)",
@@ -302,12 +315,42 @@ static void pi_add_ref_dbg(polling_island *pi, char *reason, char *file,
 }
 
 static void pi_unref_dbg(grpc_exec_ctx *exec_ctx, polling_island *pi,
-                         char *reason, char *file, int line) {
+                         const char *reason, const char *file, int line) {
   long old_cnt = gpr_atm_acq_load(&pi->ref_count);
   pi_unref(exec_ctx, pi);
   gpr_log(GPR_DEBUG, "Unref pi: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
           (void *)pi, old_cnt, (old_cnt - 1), reason, file, line);
 }
+
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
+                                     const char *file, int line,
+                                     const char *reason) {
+  if (workqueue != NULL) {
+    pi_add_ref_dbg((polling_island *)workqueue, reason, file, line);
+  }
+  return workqueue;
+}
+
+static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            const char *file, int line, const char *reason) {
+  if (workqueue != NULL) {
+    pi_unref_dbg(exec_ctx, (polling_island *)workqueue, reason, file, line);
+  }
+}
+#else
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
+  if (workqueue != NULL) {
+    pi_add_ref((polling_island *)workqueue);
+  }
+  return workqueue;
+}
+
+static void workqueue_unref(grpc_exec_ctx *exec_ctx,
+                            grpc_workqueue *workqueue) {
+  if (workqueue != NULL) {
+    pi_unref(exec_ctx, (polling_island *)workqueue);
+  }
+}
 #endif
 
 static void pi_add_ref(polling_island *pi) {
@@ -315,10 +358,7 @@ static void pi_add_ref(polling_island *pi) {
 }
 
 static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi) {
-  /* If ref count went to one, we're back to just the workqueue owning a ref.
-     Unref the workqueue to break the loop.
-
-     If ref count went to zero, delete the polling island.
+  /* If ref count went to zero, delete the polling island.
      Note that this deletion not be done under a lock. Once the ref count goes
      to zero, we are guaranteed that no one else holds a reference to the
      polling island (and that there is no racing pi_add_ref() call either).
@@ -326,20 +366,12 @@ static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi) {
      Also, if we are deleting the polling island and the merged_to field is
      non-empty, we should remove a ref to the merged_to polling island
    */
-  switch (gpr_atm_full_fetch_add(&pi->ref_count, -1)) {
-    case 2: /* last external ref: the only one now owned is by the workqueue */
-      GRPC_WORKQUEUE_UNREF(exec_ctx, pi->workqueue, "polling_island");
-      break;
-    case 1: {
-      polling_island *next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
-      polling_island_delete(exec_ctx, pi);
-      if (next != NULL) {
-        PI_UNREF(exec_ctx, next, "pi_delete"); /* Recursive call */
-      }
-      break;
+  if (1 == gpr_atm_full_fetch_add(&pi->ref_count, -1)) {
+    polling_island *next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+    polling_island_delete(exec_ctx, pi);
+    if (next != NULL) {
+      PI_UNREF(exec_ctx, next, "pi_delete"); /* Recursive call */
     }
-    case 0:
-      GPR_UNREACHABLE_CODE(return );
   }
 }
 
@@ -488,11 +520,20 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
   pi->fd_capacity = 0;
   pi->fds = NULL;
   pi->epoll_fd = -1;
-  pi->workqueue = NULL;
+
+  gpr_mu_init(&pi->workqueue_read_mu);
+  gpr_mpscq_init(&pi->workqueue_items);
+  gpr_atm_rel_store(&pi->workqueue_item_count, 0);
 
   gpr_atm_rel_store(&pi->ref_count, 0);
+  gpr_atm_rel_store(&pi->poller_count, 0);
   gpr_atm_rel_store(&pi->merged_to, (gpr_atm)NULL);
 
+  if (!append_error(error, grpc_wakeup_fd_init(&pi->workqueue_wakeup_fd),
+                    err_desc)) {
+    goto done;
+  }
+
   pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 
   if (pi->epoll_fd < 0) {
@@ -501,26 +542,14 @@ static polling_island *polling_island_create(grpc_exec_ctx *exec_ctx,
   }
 
   polling_island_add_wakeup_fd_locked(pi, &grpc_global_wakeup_fd, error);
+  polling_island_add_wakeup_fd_locked(pi, &pi->workqueue_wakeup_fd, error);
 
   if (initial_fd != NULL) {
     polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
   }
 
-  if (append_error(error, grpc_workqueue_create(exec_ctx, &pi->workqueue),
-                   err_desc) &&
-      *error == GRPC_ERROR_NONE) {
-    polling_island_add_fds_locked(pi, &pi->workqueue->wakeup_read_fd, 1, true,
-                                  error);
-    GPR_ASSERT(pi->workqueue->wakeup_read_fd->polling_island == NULL);
-    pi->workqueue->wakeup_read_fd->polling_island = pi;
-    PI_ADD_REF(pi, "fd");
-  }
-
 done:
   if (*error != GRPC_ERROR_NONE) {
-    if (pi->workqueue != NULL) {
-      GRPC_WORKQUEUE_UNREF(exec_ctx, pi->workqueue, "polling_island");
-    }
     polling_island_delete(exec_ctx, pi);
     pi = NULL;
   }
@@ -533,7 +562,11 @@ static void polling_island_delete(grpc_exec_ctx *exec_ctx, polling_island *pi) {
   if (pi->epoll_fd >= 0) {
     close(pi->epoll_fd);
   }
+  GPR_ASSERT(gpr_atm_no_barrier_load(&pi->workqueue_item_count) == 0);
+  gpr_mu_destroy(&pi->workqueue_read_mu);
+  gpr_mpscq_destroy(&pi->workqueue_items);
   gpr_mu_destroy(&pi->mu);
+  grpc_wakeup_fd_destroy(&pi->workqueue_wakeup_fd);
   gpr_free(pi->fds);
   gpr_free(pi);
 }
@@ -678,6 +711,45 @@ static void polling_island_unlock_pair(polling_island *p, polling_island *q) {
   }
 }
 
+static void workqueue_maybe_wakeup(polling_island *pi) {
+  /* If this thread is the current poller, then it may be that it's about to
+     decrement the current poller count, so we need to look past this thread */
+  bool is_current_poller = (g_current_thread_polling_island == pi);
+  gpr_atm min_current_pollers_for_wakeup = is_current_poller ? 1 : 0;
+  gpr_atm current_pollers = gpr_atm_no_barrier_load(&pi->poller_count);
+  /* Only issue a wakeup if it's likely that some poller could come in and take
+     it right now. Note that since we do an anticipatory mpscq_pop every poll
+     loop, it's ok if we miss the wakeup here, as we'll get the work item when
+     the next poller enters anyway. */
+  if (current_pollers > min_current_pollers_for_wakeup) {
+    GRPC_LOG_IF_ERROR("workqueue_wakeup_fd",
+                      grpc_wakeup_fd_wakeup(&pi->workqueue_wakeup_fd));
+  }
+}
+
+static void workqueue_move_items_to_parent(polling_island *q) {
+  polling_island *p = (polling_island *)gpr_atm_no_barrier_load(&q->merged_to);
+  if (p == NULL) {
+    return;
+  }
+  gpr_mu_lock(&q->workqueue_read_mu);
+  int num_added = 0;
+  while (gpr_atm_no_barrier_load(&q->workqueue_item_count) > 0) {
+    gpr_mpscq_node *n = gpr_mpscq_pop(&q->workqueue_items);
+    if (n != NULL) {
+      gpr_atm_no_barrier_fetch_add(&q->workqueue_item_count, -1);
+      gpr_atm_no_barrier_fetch_add(&p->workqueue_item_count, 1);
+      gpr_mpscq_push(&p->workqueue_items, n);
+      num_added++;
+    }
+  }
+  gpr_mu_unlock(&q->workqueue_read_mu);
+  if (num_added > 0) {
+    workqueue_maybe_wakeup(p);
+  }
+  workqueue_move_items_to_parent(p);
+}
+
 static polling_island *polling_island_merge(polling_island *p,
                                             polling_island *q,
                                             grpc_error **error) {
@@ -702,6 +774,8 @@ static polling_island *polling_island_merge(polling_island *p,
     /* Add the 'merged_to' link from p --> q */
     gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
     PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
+
+    workqueue_move_items_to_parent(q);
   }
   /* else if p == q, nothing needs to be done */
 
@@ -712,6 +786,26 @@ static polling_island *polling_island_merge(polling_island *p,
   return q;
 }
 
+static void workqueue_enqueue(grpc_exec_ctx *exec_ctx,
+                              grpc_workqueue *workqueue, grpc_closure *closure,
+                              grpc_error *error) {
+  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
+  /* take a ref to the workqueue: otherwise it can happen that whatever events
+   * this kicks off ends up destroying the workqueue before this function
+   * completes */
+  GRPC_WORKQUEUE_REF(workqueue, "enqueue");
+  polling_island *pi = (polling_island *)workqueue;
+  gpr_atm last = gpr_atm_no_barrier_fetch_add(&pi->workqueue_item_count, 1);
+  closure->error_data.error = error;
+  gpr_mpscq_push(&pi->workqueue_items, &closure->next_data.atm_next);
+  if (last == 0) {
+    workqueue_maybe_wakeup(pi);
+  }
+  workqueue_move_items_to_parent(pi);
+  GRPC_WORKQUEUE_UNREF(exec_ctx, workqueue, "enqueue");
+  GPR_TIMER_END("workqueue.enqueue", 0);
+}
+
 static grpc_error *polling_island_global_init() {
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -1042,11 +1136,8 @@ static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
 
 static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) {
   gpr_mu_lock(&fd->mu);
-  grpc_workqueue *workqueue = NULL;
-  if (fd->polling_island != NULL) {
-    workqueue =
-        GRPC_WORKQUEUE_REF(fd->polling_island->workqueue, "get_workqueue");
-  }
+  grpc_workqueue *workqueue = GRPC_WORKQUEUE_REF(
+      (grpc_workqueue *)fd->polling_island, "fd_get_workqueue");
   gpr_mu_unlock(&fd->mu);
   return workqueue;
 }
@@ -1299,7 +1390,29 @@ static void pollset_reset(grpc_pollset *pollset) {
   GPR_ASSERT(pollset->polling_island == NULL);
 }
 
-#define GRPC_EPOLL_MAX_EVENTS 1000
+static bool maybe_do_workqueue_work(grpc_exec_ctx *exec_ctx,
+                                    polling_island *pi) {
+  if (gpr_mu_trylock(&pi->workqueue_read_mu)) {
+    gpr_mpscq_node *n = gpr_mpscq_pop(&pi->workqueue_items);
+    gpr_mu_unlock(&pi->workqueue_read_mu);
+    if (n != NULL) {
+      if (gpr_atm_full_fetch_add(&pi->workqueue_item_count, -1) > 1) {
+        workqueue_maybe_wakeup(pi);
+      }
+      grpc_closure *c = (grpc_closure *)n;
+      grpc_closure_run(exec_ctx, c, c->error_data.error);
+      return true;
+    } else if (gpr_atm_no_barrier_load(&pi->workqueue_item_count) > 0) {
+      /* n == NULL might mean there's work but it's not available to be popped
+       * yet - try to ensure another workqueue wakes up to check shortly if so
+       */
+      workqueue_maybe_wakeup(pi);
+    }
+  }
+  return false;
+}
+
+#define GRPC_EPOLL_MAX_EVENTS 100
 /* Note: sig_mask contains the signal mask to use *during* epoll_wait() */
 static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
                                     grpc_pollset *pollset,
@@ -1354,7 +1467,13 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
   PI_ADD_REF(pi, "ps_work");
   gpr_mu_unlock(&pollset->mu);
 
-  do {
+  /* If we get some workqueue work to do, it might end up completing an item on
+     the completion queue, so there's no need to poll... so we skip that and
+     redo the complete loop to verify */
+  if (!maybe_do_workqueue_work(exec_ctx, pi)) {
+    gpr_atm_no_barrier_fetch_add(&pi->poller_count, 1);
+    g_current_thread_polling_island = pi;
+
     GRPC_SCHEDULING_START_BLOCKING_REGION;
     ep_rv = epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms,
                         sig_mask);
@@ -1386,6 +1505,11 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
         append_error(error,
                      grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd),
                      err_desc);
+      } else if (data_ptr == &pi->workqueue_wakeup_fd) {
+        append_error(error,
+                     grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd),
+                     err_desc);
+        maybe_do_workqueue_work(exec_ctx, pi);
       } else if (data_ptr == &polling_island_wakeup_fd) {
         GRPC_POLLING_TRACE(
             "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
@@ -1408,7 +1532,10 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
         }
       }
     }
-  } while (ep_rv == GRPC_EPOLL_MAX_EVENTS);
+
+    g_current_thread_polling_island = NULL;
+    gpr_atm_no_barrier_fetch_add(&pi->poller_count, -1);
+  }
 
   GPR_ASSERT(pi != NULL);
 
@@ -1868,6 +1995,10 @@ static const grpc_event_engine_vtable vtable = {
 
     .kick_poller = kick_poller,
 
+    .workqueue_ref = workqueue_ref,
+    .workqueue_unref = workqueue_unref,
+    .workqueue_enqueue = workqueue_enqueue,
+
     .shutdown_engine = shutdown_engine,
 };
 
@@ -1892,6 +2023,10 @@ const grpc_event_engine_vtable *grpc_init_epoll_linux(void) {
     return NULL;
   }
 
+  if (!grpc_has_wakeup_fd()) {
+    return NULL;
+  }
+
   if (!is_epoll_available()) {
     return NULL;
   }
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
index c2107e5e39..1829440a6e 100644
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
@@ -1989,6 +1989,32 @@ static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
 }
 
 /*******************************************************************************
+ * workqueue stubs
+ */
+
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
+                                     const char *file, int line,
+                                     const char *reason) {
+  return workqueue;
+}
+static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            const char *file, int line, const char *reason) {}
+#else
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
+  return workqueue;
+}
+static void workqueue_unref(grpc_exec_ctx *exec_ctx,
+                            grpc_workqueue *workqueue) {}
+#endif
+
+static void workqueue_enqueue(grpc_exec_ctx *exec_ctx,
+                              grpc_workqueue *workqueue, grpc_closure *closure,
+                              grpc_error *error) {
+  grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
+}
+
+/*******************************************************************************
  * event engine binding
  */
 
@@ -2029,6 +2055,10 @@ static const grpc_event_engine_vtable vtable = {
 
     .kick_poller = kick_poller,
 
+    .workqueue_ref = workqueue_ref,
+    .workqueue_unref = workqueue_unref,
+    .workqueue_enqueue = workqueue_enqueue,
+
     .shutdown_engine = shutdown_engine,
 };
 
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 16a5e3083e..351b069613 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -47,10 +47,12 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
+#include <grpc/support/thd.h>
 #include <grpc/support/tls.h>
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/wakeup_fd_cv.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/block_annotate.h"
@@ -246,6 +248,28 @@ struct grpc_pollset_set {
 };
 
 /*******************************************************************************
+ * condition variable polling definitions
+ */
+
+#define CV_POLL_PERIOD_MS 1000
+#define CV_DEFAULT_TABLE_SIZE 16
+
+typedef enum poll_status_t { INPROGRESS, COMPLETED, CANCELLED } poll_status_t;
+
+typedef struct poll_args {
+  gpr_refcount refcount;
+  gpr_cv *cv;
+  struct pollfd *fds;
+  nfds_t nfds;
+  int timeout;
+  int retval;
+  int err;
+  gpr_atm status;
+} poll_args;
+
+cv_fd_table g_cvfds;
+
+/*******************************************************************************
  * fd_posix.c
  */
 
@@ -1236,10 +1260,237 @@ static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
 }
 
 /*******************************************************************************
+ * workqueue stubs
+ */
+
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
+                                     const char *file, int line,
+                                     const char *reason) {
+  return workqueue;
+}
+static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            const char *file, int line, const char *reason) {}
+#else
+static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
+  return workqueue;
+}
+static void workqueue_unref(grpc_exec_ctx *exec_ctx,
+                            grpc_workqueue *workqueue) {}
+#endif
+
+static void workqueue_enqueue(grpc_exec_ctx *exec_ctx,
+                              grpc_workqueue *workqueue, grpc_closure *closure,
+                              grpc_error *error) {
+  grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
+}
+
+/*******************************************************************************
+ * Condition Variable polling extensions
+ */
+
+static void decref_poll_args(poll_args *args) {
+  if (gpr_unref(&args->refcount)) {
+    gpr_free(args->fds);
+    gpr_cv_destroy(args->cv);
+    gpr_free(args->cv);
+    gpr_free(args);
+  }
+}
+
+// Poll in a background thread
+static void run_poll(void *arg) {
+  int timeout, retval;
+  poll_args *pargs = (poll_args *)arg;
+  while (gpr_atm_no_barrier_load(&pargs->status) == INPROGRESS) {
+    if (pargs->timeout < 0) {
+      timeout = CV_POLL_PERIOD_MS;
+    } else {
+      timeout = GPR_MIN(CV_POLL_PERIOD_MS, pargs->timeout);
+      pargs->timeout -= timeout;
+    }
+    retval = g_cvfds.poll(pargs->fds, pargs->nfds, timeout);
+    if (retval != 0 || pargs->timeout == 0) {
+      pargs->retval = retval;
+      pargs->err = errno;
+      break;
+    }
+  }
+  gpr_mu_lock(&g_cvfds.mu);
+  if (gpr_atm_no_barrier_load(&pargs->status) == INPROGRESS) {
+    // Signal main thread that the poll completed
+    gpr_atm_no_barrier_store(&pargs->status, COMPLETED);
+    gpr_cv_signal(pargs->cv);
+  }
+  decref_poll_args(pargs);
+  g_cvfds.pollcount--;
+  if (g_cvfds.shutdown && g_cvfds.pollcount == 0) {
+    gpr_cv_signal(&g_cvfds.shutdown_complete);
+  }
+  gpr_mu_unlock(&g_cvfds.mu);
+}
+
+// This function overrides poll() to handle condition variable wakeup fds
+static int cvfd_poll(struct pollfd *fds, nfds_t nfds, int timeout) {
+  unsigned int i;
+  int res, idx;
+  gpr_cv *pollcv;
+  cv_node *cvn, *prev;
+  nfds_t nsockfds = 0;
+  gpr_thd_id t_id;
+  gpr_thd_options opt;
+  poll_args *pargs = NULL;
+  gpr_mu_lock(&g_cvfds.mu);
+  pollcv = gpr_malloc(sizeof(gpr_cv));
+  gpr_cv_init(pollcv);
+  for (i = 0; i < nfds; i++) {
+    fds[i].revents = 0;
+    if (fds[i].fd < 0 && (fds[i].events & POLLIN)) {
+      idx = FD_TO_IDX(fds[i].fd);
+      cvn = gpr_malloc(sizeof(cv_node));
+      cvn->cv = pollcv;
+      cvn->next = g_cvfds.cvfds[idx].cvs;
+      g_cvfds.cvfds[idx].cvs = cvn;
+      // We should return immediately if there are pending events,
+      // but we still need to call poll() to check for socket events
+      if (g_cvfds.cvfds[idx].is_set) {
+        timeout = 0;
+      }
+    } else if (fds[i].fd >= 0) {
+      nsockfds++;
+    }
+  }
+
+  if (nsockfds > 0) {
+    pargs = gpr_malloc(sizeof(struct poll_args));
+    // Both the main thread and calling thread get a reference
+    gpr_ref_init(&pargs->refcount, 2);
+    pargs->cv = pollcv;
+    pargs->fds = gpr_malloc(sizeof(struct pollfd) * nsockfds);
+    pargs->nfds = nsockfds;
+    pargs->timeout = timeout;
+    pargs->retval = 0;
+    pargs->err = 0;
+    gpr_atm_no_barrier_store(&pargs->status, INPROGRESS);
+    idx = 0;
+    for (i = 0; i < nfds; i++) {
+      if (fds[i].fd >= 0) {
+        pargs->fds[idx].fd = fds[i].fd;
+        pargs->fds[idx].events = fds[i].events;
+        pargs->fds[idx].revents = 0;
+        idx++;
+      }
+    }
+    g_cvfds.pollcount++;
+    opt = gpr_thd_options_default();
+    gpr_thd_options_set_detached(&opt);
+    gpr_thd_new(&t_id, &run_poll, pargs, &opt);
+    // We want the poll() thread to trigger the deadline, so wait forever here
+    gpr_cv_wait(pollcv, &g_cvfds.mu, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+    if (gpr_atm_no_barrier_load(&pargs->status) == COMPLETED) {
+      res = pargs->retval;
+      errno = pargs->err;
+    } else {
+      res = 0;
+      errno = 0;
+      gpr_atm_no_barrier_store(&pargs->status, CANCELLED);
+    }
+  } else {
+    gpr_timespec deadline = gpr_now(GPR_CLOCK_REALTIME);
+    deadline =
+        gpr_time_add(deadline, gpr_time_from_millis(timeout, GPR_TIMESPAN));
+    gpr_cv_wait(pollcv, &g_cvfds.mu, deadline);
+    res = 0;
+  }
+
+  idx = 0;
+  for (i = 0; i < nfds; i++) {
+    if (fds[i].fd < 0 && (fds[i].events & POLLIN)) {
+      cvn = g_cvfds.cvfds[FD_TO_IDX(fds[i].fd)].cvs;
+      prev = NULL;
+      while (cvn->cv != pollcv) {
+        prev = cvn;
+        cvn = cvn->next;
+        GPR_ASSERT(cvn);
+      }
+      if (!prev) {
+        g_cvfds.cvfds[FD_TO_IDX(fds[i].fd)].cvs = cvn->next;
+      } else {
+        prev->next = cvn->next;
+      }
+      gpr_free(cvn);
+
+      if (g_cvfds.cvfds[FD_TO_IDX(fds[i].fd)].is_set) {
+        fds[i].revents = POLLIN;
+        if (res >= 0) res++;
+      }
+    } else if (fds[i].fd >= 0 &&
+               gpr_atm_no_barrier_load(&pargs->status) == COMPLETED) {
+      fds[i].revents = pargs->fds[idx].revents;
+      idx++;
+    }
+  }
+
+  if (pargs) {
+    decref_poll_args(pargs);
+  } else {
+    gpr_cv_destroy(pollcv);
+    gpr_free(pollcv);
+  }
+  gpr_mu_unlock(&g_cvfds.mu);
+
+  return res;
+}
+
+static void global_cv_fd_table_init() {
+  gpr_mu_init(&g_cvfds.mu);
+  gpr_mu_lock(&g_cvfds.mu);
+  gpr_cv_init(&g_cvfds.shutdown_complete);
+  g_cvfds.shutdown = 0;
+  g_cvfds.pollcount = 0;
+  g_cvfds.size = CV_DEFAULT_TABLE_SIZE;
+  g_cvfds.cvfds = gpr_malloc(sizeof(fd_node) * CV_DEFAULT_TABLE_SIZE);
+  g_cvfds.free_fds = NULL;
+  for (int i = 0; i < CV_DEFAULT_TABLE_SIZE; i++) {
+    g_cvfds.cvfds[i].is_set = 0;
+    g_cvfds.cvfds[i].cvs = NULL;
+    g_cvfds.cvfds[i].next_free = g_cvfds.free_fds;
+    g_cvfds.free_fds = &g_cvfds.cvfds[i];
+  }
+  // Override the poll function with one that supports cvfds
+  g_cvfds.poll = grpc_poll_function;
+  grpc_poll_function = &cvfd_poll;
+  gpr_mu_unlock(&g_cvfds.mu);
+}
+
+static void global_cv_fd_table_shutdown() {
+  gpr_mu_lock(&g_cvfds.mu);
+  g_cvfds.shutdown = 1;
+  // Attempt to wait for all abandoned poll() threads to terminate
+  // Not doing so will result in reported memory leaks
+  if (g_cvfds.pollcount > 0) {
+    int res = gpr_cv_wait(&g_cvfds.shutdown_complete, &g_cvfds.mu,
+                          gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                                       gpr_time_from_seconds(3, GPR_TIMESPAN)));
+    GPR_ASSERT(res == 0);
+  }
+  gpr_cv_destroy(&g_cvfds.shutdown_complete);
+  grpc_poll_function = g_cvfds.poll;
+  gpr_free(g_cvfds.cvfds);
+  gpr_mu_unlock(&g_cvfds.mu);
+  gpr_mu_destroy(&g_cvfds.mu);
+}
+
+/*******************************************************************************
  * event engine binding
  */
 
-static void shutdown_engine(void) { pollset_global_shutdown(); }
+static void shutdown_engine(void) {
+  pollset_global_shutdown();
+  if (grpc_cv_wakeup_fds_enabled()) {
+    global_cv_fd_table_shutdown();
+  }
+}
 
 static const grpc_event_engine_vtable vtable = {
     .pollset_size = sizeof(grpc_pollset),
@@ -1273,11 +1524,29 @@ static const grpc_event_engine_vtable vtable = {
 
     .kick_poller = kick_poller,
 
+    .workqueue_ref = workqueue_ref,
+    .workqueue_unref = workqueue_unref,
+    .workqueue_enqueue = workqueue_enqueue,
+
     .shutdown_engine = shutdown_engine,
 };
 
 const grpc_event_engine_vtable *grpc_init_poll_posix(void) {
+  if (!grpc_has_wakeup_fd()) {
+    return NULL;
+  }
+  if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) {
+    return NULL;
+  }
+  return &vtable;
+}
+
+const grpc_event_engine_vtable *grpc_init_poll_cv_posix(void) {
+  global_cv_fd_table_init();
+  grpc_enable_cv_wakeup_fds(1);
   if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) {
+    global_cv_fd_table_shutdown();
+    grpc_enable_cv_wakeup_fds(0);
     return NULL;
   }
   return &vtable;
diff --git a/src/core/lib/iomgr/ev_poll_posix.h b/src/core/lib/iomgr/ev_poll_posix.h
index 291736a2db..202ffca14c 100644
--- a/src/core/lib/iomgr/ev_poll_posix.h
+++ b/src/core/lib/iomgr/ev_poll_posix.h
@@ -37,5 +37,6 @@
 #include "src/core/lib/iomgr/ev_posix.h"
 
 const grpc_event_engine_vtable *grpc_init_poll_posix(void);
+const grpc_event_engine_vtable *grpc_init_poll_cv_posix(void);
 
 #endif /* GRPC_CORE_LIB_IOMGR_EV_POLL_POSIX_H */
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index 6536672685..9857b0bce9 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -66,6 +66,7 @@ typedef struct {
 static const event_engine_factory g_factories[] = {
     {"epoll", grpc_init_epoll_linux},
     {"poll", grpc_init_poll_posix},
+    {"poll-cv", grpc_init_poll_cv_posix},
     {"legacy", grpc_init_poll_and_epoll_posix},
 };
 
@@ -258,4 +259,27 @@ void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
 
 grpc_error *grpc_kick_poller(void) { return g_event_engine->kick_poller(); }
 
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
+                                   int line, const char *reason) {
+  return g_event_engine->workqueue_ref(workqueue, file, line, reason);
+}
+void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                          const char *file, int line, const char *reason) {
+  g_event_engine->workqueue_unref(exec_ctx, workqueue, file, line, reason);
+}
+#else
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
+  return g_event_engine->workqueue_ref(workqueue);
+}
+void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
+  g_event_engine->workqueue_unref(exec_ctx, workqueue);
+}
+#endif
+
+void grpc_workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            grpc_closure *closure, grpc_error *error) {
+  g_event_engine->workqueue_enqueue(exec_ctx, workqueue, closure, error);
+}
+
 #endif  // GPR_POSIX_SOCKET
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index c2aa1756ea..2fdef06838 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -40,6 +40,7 @@
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
+#include "src/core/lib/iomgr/workqueue.h"
 
 typedef struct grpc_fd grpc_fd;
 
@@ -95,6 +96,18 @@ typedef struct grpc_event_engine_vtable {
   grpc_error *(*kick_poller)(void);
 
   void (*shutdown_engine)(void);
+
+#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
+  grpc_workqueue *(*workqueue_ref)(grpc_workqueue *workqueue, const char *file,
+                                   int line, const char *reason);
+  void (*workqueue_unref)(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                          const char *file, int line, const char *reason);
+#else
+  grpc_workqueue *(*workqueue_ref)(grpc_workqueue *workqueue);
+  void (*workqueue_unref)(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue);
+#endif
+  void (*workqueue_enqueue)(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
+                            grpc_closure *closure, grpc_error *error);
 } grpc_event_engine_vtable;
 
 void grpc_event_engine_init(void);
diff --git a/src/core/lib/iomgr/exec_ctx.c b/src/core/lib/iomgr/exec_ctx.c
index ac7785ec13..604713e578 100644
--- a/src/core/lib/iomgr/exec_ctx.c
+++ b/src/core/lib/iomgr/exec_ctx.c
@@ -37,6 +37,7 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
 
+#include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 
@@ -60,18 +61,43 @@ bool grpc_always_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored) {
 bool grpc_exec_ctx_flush(grpc_exec_ctx *exec_ctx) {
   bool did_something = 0;
   GPR_TIMER_BEGIN("grpc_exec_ctx_flush", 0);
-  while (!grpc_closure_list_empty(exec_ctx->closure_list)) {
-    grpc_closure *c = exec_ctx->closure_list.head;
-    exec_ctx->closure_list.head = exec_ctx->closure_list.tail = NULL;
-    while (c != NULL) {
-      grpc_closure *next = c->next_data.next;
-      grpc_error *error = c->error;
-      did_something = true;
-      GPR_TIMER_BEGIN("grpc_exec_ctx_flush.cb", 0);
+  for (;;) {
+    if (!grpc_closure_list_empty(exec_ctx->closure_list)) {
+      grpc_closure *c = exec_ctx->closure_list.head;
+      exec_ctx->closure_list.head = exec_ctx->closure_list.tail = NULL;
+      while (c != NULL) {
+        grpc_closure *next = c->next_data.next;
+        did_something = true;
+        grpc_closure_run(exec_ctx, c, c->error_data.error);
+        c = next;
+      }
+    } else if (!grpc_combiner_continue_exec_ctx(exec_ctx)) {
+      break;
+    }
+  }
+  GPR_ASSERT(exec_ctx->active_combiner == NULL);
+  if (exec_ctx->stealing_from_workqueue != NULL) {
+    if (grpc_exec_ctx_ready_to_finish(exec_ctx)) {
+      grpc_workqueue_enqueue(exec_ctx, exec_ctx->stealing_from_workqueue,
+                             exec_ctx->stolen_closure,
+                             exec_ctx->stolen_closure->error_data.error);
+      GRPC_WORKQUEUE_UNREF(exec_ctx, exec_ctx->stealing_from_workqueue,
+                           "exec_ctx_sched");
+      exec_ctx->stealing_from_workqueue = NULL;
+      exec_ctx->stolen_closure = NULL;
+    } else {
+      grpc_closure *c = exec_ctx->stolen_closure;
+      GRPC_WORKQUEUE_UNREF(exec_ctx, exec_ctx->stealing_from_workqueue,
+                           "exec_ctx_sched");
+      exec_ctx->stealing_from_workqueue = NULL;
+      exec_ctx->stolen_closure = NULL;
+      grpc_error *error = c->error_data.error;
+      GPR_TIMER_BEGIN("grpc_exec_ctx_flush.stolen_cb", 0);
       c->cb(exec_ctx, c->cb_arg, error);
       GRPC_ERROR_UNREF(error);
-      GPR_TIMER_END("grpc_exec_ctx_flush.cb", 0);
-      c = next;
+      GPR_TIMER_END("grpc_exec_ctx_flush.stolen_cb", 0);
+      grpc_exec_ctx_flush(exec_ctx);
+      did_something = true;
     }
   }
   GPR_TIMER_END("grpc_exec_ctx_flush", 0);
@@ -86,12 +112,25 @@ void grpc_exec_ctx_finish(grpc_exec_ctx *exec_ctx) {
 void grpc_exec_ctx_sched(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                          grpc_error *error,
                          grpc_workqueue *offload_target_or_null) {
+  GPR_TIMER_BEGIN("grpc_exec_ctx_sched", 0);
   if (offload_target_or_null == NULL) {
     grpc_closure_list_append(&exec_ctx->closure_list, closure, error);
-  } else {
+  } else if (exec_ctx->stealing_from_workqueue == NULL) {
+    exec_ctx->stealing_from_workqueue = offload_target_or_null;
+    closure->error_data.error = error;
+    exec_ctx->stolen_closure = closure;
+  } else if (exec_ctx->stealing_from_workqueue != offload_target_or_null) {
     grpc_workqueue_enqueue(exec_ctx, offload_target_or_null, closure, error);
     GRPC_WORKQUEUE_UNREF(exec_ctx, offload_target_or_null, "exec_ctx_sched");
+  } else { /* stealing_from_workqueue == offload_target_or_null */
+    grpc_workqueue_enqueue(exec_ctx, offload_target_or_null,
+                           exec_ctx->stolen_closure,
+                           exec_ctx->stolen_closure->error_data.error);
+    closure->error_data.error = error;
+    exec_ctx->stolen_closure = closure;
+    GRPC_WORKQUEUE_UNREF(exec_ctx, offload_target_or_null, "exec_ctx_sched");
   }
+  GPR_TIMER_END("grpc_exec_ctx_sched", 0);
 }
 
 void grpc_exec_ctx_enqueue_list(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index 4d20ecf922..7e50cb9825 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -66,15 +66,33 @@ typedef struct grpc_combiner grpc_combiner;
 #ifndef GRPC_EXECUTION_CONTEXT_SANITIZER
 struct grpc_exec_ctx {
   grpc_closure_list closure_list;
+  /** The workqueue we're stealing work from.
+      As items are queued to the execution context, we try to steal one
+      workqueue item and execute it inline (assuming the exec_ctx is not
+      finished) - doing so does not invalidate the workqueue's contract, and
+      provides a small latency win in cases where we get a hit */
+  grpc_workqueue *stealing_from_workqueue;
+  /** The workqueue item that was stolen from the workqueue above. When new
+      items are scheduled to be offloaded to that workqueue, we need to update
+      this like a 1-deep fifo to maintain the invariant that workqueue items
+      queued by one thread are started in order */
+  grpc_closure *stolen_closure;
   /** currently active combiner: updated only via combiner.c */
   grpc_combiner *active_combiner;
+  /** last active combiner in the active combiner list */
+  grpc_combiner *last_combiner;
   bool cached_ready_to_finish;
   void *check_ready_to_finish_arg;
   bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
 };
 
+/* initializer for grpc_exec_ctx:
+   prefer to use GRPC_EXEC_CTX_INIT whenever possible */
 #define GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(finish_check, finish_check_arg) \
-  { GRPC_CLOSURE_LIST_INIT, NULL, false, finish_check_arg, finish_check }
+  {                                                                          \
+    GRPC_CLOSURE_LIST_INIT, NULL, NULL, NULL, NULL, false, finish_check_arg, \
+        finish_check                                                         \
+  }
 #else
 struct grpc_exec_ctx {
   bool cached_ready_to_finish;
@@ -85,8 +103,10 @@ struct grpc_exec_ctx {
   { false, finish_check_arg, finish_check }
 #endif
 
+/* initialize an execution context at the top level of an API call into grpc
+   (this is safe to use elsewhere, though possibly not as efficient) */
 #define GRPC_EXEC_CTX_INIT \
-  GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(grpc_never_ready_to_finish, NULL)
+  GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(grpc_always_ready_to_finish, NULL)
 
 /** Flush any work that has been enqueued onto this grpc_exec_ctx.
  *  Caller must guarantee that no interfering locks are held.
diff --git a/src/core/lib/iomgr/iomgr.c b/src/core/lib/iomgr/iomgr.c
index d67d388b8c..4fd83e0b22 100644
--- a/src/core/lib/iomgr/iomgr.c
+++ b/src/core/lib/iomgr/iomgr.c
@@ -112,6 +112,14 @@ void grpc_iomgr_shutdown(void) {
       continue;
     }
     if (g_root_object.next != &g_root_object) {
+      if (grpc_iomgr_abort_on_leaks()) {
+        gpr_log(GPR_DEBUG, "Failed to free %" PRIuPTR
+                           " iomgr objects before shutdown deadline: "
+                           "memory leaks are likely",
+                count_objects());
+        dump_objects("LEAKED");
+        abort();
+      }
       gpr_timespec short_deadline = gpr_time_add(
           gpr_now(GPR_CLOCK_REALTIME), gpr_time_from_millis(100, GPR_TIMESPAN));
       if (gpr_cv_wait(&g_rcv, &g_mu, short_deadline)) {
@@ -122,9 +130,6 @@ void grpc_iomgr_shutdown(void) {
                                "memory leaks are likely",
                     count_objects());
             dump_objects("LEAKED");
-            if (grpc_iomgr_abort_on_leaks()) {
-              abort();
-            }
           }
           break;
         }
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 92767721d5..00fd77679a 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -177,7 +177,7 @@ static void call_read_cb(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
 
   tcp->read_cb = NULL;
   tcp->incoming_buffer = NULL;
-  grpc_exec_ctx_sched(exec_ctx, cb, error, NULL);
+  grpc_closure_run(exec_ctx, cb, error);
 }
 
 #define MAX_READ_IOVEC 4
@@ -209,11 +209,11 @@ static void tcp_continue_read(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   msg.msg_controllen = 0;
   msg.msg_flags = 0;
 
-  GPR_TIMER_BEGIN("recvmsg", 1);
+  GPR_TIMER_BEGIN("recvmsg", 0);
   do {
     read_bytes = recvmsg(tcp->fd, &msg, 0);
   } while (read_bytes < 0 && errno == EINTR);
-  GPR_TIMER_END("recvmsg", 0);
+  GPR_TIMER_END("recvmsg", read_bytes >= 0);
 
   if (read_bytes < 0) {
     /* NB: After calling call_read_cb a parallel call of the read handler may
@@ -392,11 +392,8 @@ static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
       grpc_error_free_string(str);
     }
 
-    GPR_TIMER_BEGIN("tcp_handle_write.cb", 0);
-    cb->cb(exec_ctx, cb->cb_arg, error);
-    GPR_TIMER_END("tcp_handle_write.cb", 0);
+    grpc_closure_run(exec_ctx, cb, error);
     TCP_UNREF(exec_ctx, tcp, "write");
-    GRPC_ERROR_UNREF(error);
   }
 }
 
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.c b/src/core/lib/iomgr/wakeup_fd_cv.c
new file mode 100644
index 0000000000..b4165208ed
--- /dev/null
+++ b/src/core/lib/iomgr/wakeup_fd_cv.c
@@ -0,0 +1,118 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_WAKEUP_FD
+
+#include "src/core/lib/iomgr/wakeup_fd_cv.h"
+
+#include <errno.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/thd.h>
+#include <grpc/support/time.h>
+#include <grpc/support/useful.h>
+
+#define MAX_TABLE_RESIZE 256
+
+extern cv_fd_table g_cvfds;
+
+static grpc_error* cv_fd_init(grpc_wakeup_fd* fd_info) {
+  unsigned int i, newsize;
+  int idx;
+  gpr_mu_lock(&g_cvfds.mu);
+  if (!g_cvfds.free_fds) {
+    newsize = GPR_MIN(g_cvfds.size * 2, g_cvfds.size + MAX_TABLE_RESIZE);
+    g_cvfds.cvfds = gpr_realloc(g_cvfds.cvfds, sizeof(fd_node) * newsize);
+    for (i = g_cvfds.size; i < newsize; i++) {
+      g_cvfds.cvfds[i].is_set = 0;
+      g_cvfds.cvfds[i].cvs = NULL;
+      g_cvfds.cvfds[i].next_free = g_cvfds.free_fds;
+      g_cvfds.free_fds = &g_cvfds.cvfds[i];
+    }
+    g_cvfds.size = newsize;
+  }
+
+  idx = (int)(g_cvfds.free_fds - g_cvfds.cvfds);
+  g_cvfds.free_fds = g_cvfds.free_fds->next_free;
+  g_cvfds.cvfds[idx].cvs = NULL;
+  g_cvfds.cvfds[idx].is_set = 0;
+  fd_info->read_fd = IDX_TO_FD(idx);
+  fd_info->write_fd = -1;
+  gpr_mu_unlock(&g_cvfds.mu);
+  return GRPC_ERROR_NONE;
+}
+
+static grpc_error* cv_fd_wakeup(grpc_wakeup_fd* fd_info) {
+  cv_node* cvn;
+  gpr_mu_lock(&g_cvfds.mu);
+  g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)].is_set = 1;
+  cvn = g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)].cvs;
+  while (cvn) {
+    gpr_cv_signal(cvn->cv);
+    cvn = cvn->next;
+  }
+  gpr_mu_unlock(&g_cvfds.mu);
+  return GRPC_ERROR_NONE;
+}
+
+static grpc_error* cv_fd_consume(grpc_wakeup_fd* fd_info) {
+  gpr_mu_lock(&g_cvfds.mu);
+  g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)].is_set = 0;
+  gpr_mu_unlock(&g_cvfds.mu);
+  return GRPC_ERROR_NONE;
+}
+
+static void cv_fd_destroy(grpc_wakeup_fd* fd_info) {
+  if (fd_info->read_fd == 0) {
+    return;
+  }
+  gpr_mu_lock(&g_cvfds.mu);
+  // Assert that there are no active pollers
+  GPR_ASSERT(!g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)].cvs);
+  g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)].next_free = g_cvfds.free_fds;
+  g_cvfds.free_fds = &g_cvfds.cvfds[FD_TO_IDX(fd_info->read_fd)];
+  gpr_mu_unlock(&g_cvfds.mu);
+}
+
+static int cv_check_availability(void) { return 1; }
+
+const grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable = {
+    cv_fd_init, cv_fd_consume, cv_fd_wakeup, cv_fd_destroy,
+    cv_check_availability};
+
+#endif /* GPR_POSIX_WAKUP_FD */
diff --git a/src/core/lib/iomgr/wakeup_fd_cv.h b/src/core/lib/iomgr/wakeup_fd_cv.h
new file mode 100644
index 0000000000..ac16be1750
--- /dev/null
+++ b/src/core/lib/iomgr/wakeup_fd_cv.h
@@ -0,0 +1,80 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/*
+ * wakeup_fd_cv uses condition variables to implement wakeup fds.
+ *
+ * It is intended for use only in cases when eventfd() and pipe() are not
+ * available.  It can only be used with the "poll" engine.
+ *
+ * Implementation:
+ * A global table of cv wakeup fds is mantained.  A cv wakeup fd is a negative
+ * file descriptor.  poll() is then run in a background thread with only the
+ * real socket fds while we wait on a condition variable trigged by either the
+ * poll() completion or a wakeup_fd() call.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H
+#define GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H
+
+#include <grpc/support/sync.h>
+
+#include "src/core/lib/iomgr/ev_posix.h"
+
+#define FD_TO_IDX(fd) (-(fd)-1)
+#define IDX_TO_FD(idx) (-(idx)-1)
+
+typedef struct cv_node {
+  gpr_cv* cv;
+  struct cv_node* next;
+} cv_node;
+
+typedef struct fd_node {
+  int is_set;
+  cv_node* cvs;
+  struct fd_node* next_free;
+} fd_node;
+
+typedef struct cv_fd_table {
+  gpr_mu mu;
+  int pollcount;
+  int shutdown;
+  gpr_cv shutdown_complete;
+  fd_node* cvfds;
+  fd_node* free_fds;
+  unsigned int size;
+  grpc_poll_function_type poll;
+} cv_fd_table;
+
+#endif /* GRPC_CORE_LIB_IOMGR_WAKEUP_FD_CV_H */
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index 4e5dbdcb73..d0ea216aa0 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -47,11 +47,10 @@
 
 static grpc_error* pipe_init(grpc_wakeup_fd* fd_info) {
   int pipefd[2];
-  /* TODO(klempner): Make this nonfatal */
   int r = pipe(pipefd);
   if (0 != r) {
     gpr_log(GPR_ERROR, "pipe creation failed (%d): %s", errno, strerror(errno));
-    abort();
+    return GRPC_OS_ERROR(errno, "pipe");
   }
   grpc_error* err;
   err = grpc_set_socket_nonblocking(pipefd[0], 1);
@@ -95,8 +94,13 @@ static void pipe_destroy(grpc_wakeup_fd* fd_info) {
 }
 
 static int pipe_check_availability(void) {
-  /* Assume that pipes are always available. */
-  return 1;
+  grpc_wakeup_fd fd;
+  if (pipe_init(&fd) == GRPC_ERROR_NONE) {
+    pipe_destroy(&fd);
+    return 1;
+  } else {
+    return 0;
+  }
 }
 
 const grpc_wakeup_fd_vtable grpc_pipe_wakeup_fd_vtable = {
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.c b/src/core/lib/iomgr/wakeup_fd_posix.c
index 046208abc8..5c894bef37 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.c
+++ b/src/core/lib/iomgr/wakeup_fd_posix.c
@@ -36,37 +36,66 @@
 #ifdef GPR_POSIX_WAKEUP_FD
 
 #include <stddef.h>
+#include "src/core/lib/iomgr/wakeup_fd_cv.h"
 #include "src/core/lib/iomgr/wakeup_fd_pipe.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 
+extern grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable;
 static const grpc_wakeup_fd_vtable *wakeup_fd_vtable = NULL;
+
 int grpc_allow_specialized_wakeup_fd = 1;
+int grpc_allow_pipe_wakeup_fd = 1;
+
+int has_real_wakeup_fd = 1;
+int cv_wakeup_fds_enabled = 0;
 
 void grpc_wakeup_fd_global_init(void) {
   if (grpc_allow_specialized_wakeup_fd &&
       grpc_specialized_wakeup_fd_vtable.check_availability()) {
     wakeup_fd_vtable = &grpc_specialized_wakeup_fd_vtable;
-  } else {
+  } else if (grpc_allow_pipe_wakeup_fd &&
+             grpc_pipe_wakeup_fd_vtable.check_availability()) {
     wakeup_fd_vtable = &grpc_pipe_wakeup_fd_vtable;
+  } else {
+    has_real_wakeup_fd = 0;
   }
 }
 
 void grpc_wakeup_fd_global_destroy(void) { wakeup_fd_vtable = NULL; }
 
+int grpc_has_wakeup_fd(void) { return has_real_wakeup_fd; }
+
+int grpc_cv_wakeup_fds_enabled(void) { return cv_wakeup_fds_enabled; }
+
+void grpc_enable_cv_wakeup_fds(int enable) { cv_wakeup_fds_enabled = enable; }
+
 grpc_error *grpc_wakeup_fd_init(grpc_wakeup_fd *fd_info) {
+  if (cv_wakeup_fds_enabled) {
+    return grpc_cv_wakeup_fd_vtable.init(fd_info);
+  }
   return wakeup_fd_vtable->init(fd_info);
 }
 
 grpc_error *grpc_wakeup_fd_consume_wakeup(grpc_wakeup_fd *fd_info) {
+  if (cv_wakeup_fds_enabled) {
+    return grpc_cv_wakeup_fd_vtable.consume(fd_info);
+  }
   return wakeup_fd_vtable->consume(fd_info);
 }
 
 grpc_error *grpc_wakeup_fd_wakeup(grpc_wakeup_fd *fd_info) {
+  if (cv_wakeup_fds_enabled) {
+    return grpc_cv_wakeup_fd_vtable.wakeup(fd_info);
+  }
   return wakeup_fd_vtable->wakeup(fd_info);
 }
 
 void grpc_wakeup_fd_destroy(grpc_wakeup_fd *fd_info) {
-  wakeup_fd_vtable->destroy(fd_info);
+  if (cv_wakeup_fds_enabled) {
+    grpc_cv_wakeup_fd_vtable.destroy(fd_info);
+  } else {
+    wakeup_fd_vtable->destroy(fd_info);
+  }
 }
 
 #endif /* GPR_POSIX_WAKEUP_FD */
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.h b/src/core/lib/iomgr/wakeup_fd_posix.h
index e269f242d8..71d32d97ba 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.h
+++ b/src/core/lib/iomgr/wakeup_fd_posix.h
@@ -71,6 +71,10 @@ void grpc_wakeup_fd_global_destroy(void);
  * purposes only.*/
 void grpc_wakeup_fd_global_init_force_fallback(void);
 
+int grpc_has_wakeup_fd(void);
+int grpc_cv_wakeup_fds_enabled(void);
+void grpc_enable_cv_wakeup_fds(int enable);
+
 typedef struct grpc_wakeup_fd grpc_wakeup_fd;
 
 typedef struct grpc_wakeup_fd_vtable {
@@ -88,6 +92,7 @@ struct grpc_wakeup_fd {
 };
 
 extern int grpc_allow_specialized_wakeup_fd;
+extern int grpc_allow_pipe_wakeup_fd;
 
 #define GRPC_WAKEUP_FD_GET_READ_FD(fd_info) ((fd_info)->read_fd)
 
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
index b2805dc66c..5b96d1d851 100644
--- a/src/core/lib/iomgr/workqueue.h
+++ b/src/core/lib/iomgr/workqueue.h
@@ -40,10 +40,6 @@
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
-#ifdef GPR_POSIX_SOCKET
-#include "src/core/lib/iomgr/workqueue_posix.h"
-#endif
-
 #ifdef GPR_WINDOWS
 #include "src/core/lib/iomgr/workqueue_windows.h"
 #endif
@@ -58,20 +54,20 @@
    string will be printed alongside the refcount. When it is not defined, the
    string will be discarded at compilation time. */
 
-//#define GRPC_WORKQUEUE_REFCOUNT_DEBUG
+/*#define GRPC_WORKQUEUE_REFCOUNT_DEBUG*/
 #ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
 #define GRPC_WORKQUEUE_REF(p, r) \
-  (grpc_workqueue_ref((p), __FILE__, __LINE__, (r)), (p))
+  grpc_workqueue_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_WORKQUEUE_UNREF(exec_ctx, p, r) \
   grpc_workqueue_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
-void grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file, int line,
-                        const char *reason);
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
+                                   int line, const char *reason);
 void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
                           const char *file, int line, const char *reason);
 #else
-#define GRPC_WORKQUEUE_REF(p, r) (grpc_workqueue_ref((p)), (p))
+#define GRPC_WORKQUEUE_REF(p, r) grpc_workqueue_ref((p))
 #define GRPC_WORKQUEUE_UNREF(cl, p, r) grpc_workqueue_unref((cl), (p))
-void grpc_workqueue_ref(grpc_workqueue *workqueue);
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue);
 void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue);
 #endif
 
diff --git a/src/core/lib/iomgr/workqueue_posix.c b/src/core/lib/iomgr/workqueue_posix.c
deleted file mode 100644
index ecfea68f56..0000000000
--- a/src/core/lib/iomgr/workqueue_posix.c
+++ /dev/null
@@ -1,196 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include <grpc/support/port_platform.h>
-
-#ifdef GPR_POSIX_SOCKET
-
-#include "src/core/lib/iomgr/workqueue.h"
-
-#include <stdio.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/ev_posix.h"
-#include "src/core/lib/profiling/timers.h"
-
-static void on_readable(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
-
-grpc_error *grpc_workqueue_create(grpc_exec_ctx *exec_ctx,
-                                  grpc_workqueue **workqueue) {
-  char name[32];
-  *workqueue = gpr_malloc(sizeof(grpc_workqueue));
-  gpr_ref_init(&(*workqueue)->refs, 1);
-  gpr_atm_no_barrier_store(&(*workqueue)->state, 1);
-  grpc_error *err = grpc_wakeup_fd_init(&(*workqueue)->wakeup_fd);
-  if (err != GRPC_ERROR_NONE) {
-    gpr_free(*workqueue);
-    return err;
-  }
-  sprintf(name, "workqueue:%p", (void *)(*workqueue));
-  (*workqueue)->wakeup_read_fd = grpc_fd_create(
-      GRPC_WAKEUP_FD_GET_READ_FD(&(*workqueue)->wakeup_fd), name);
-  gpr_mpscq_init(&(*workqueue)->queue);
-  grpc_closure_init(&(*workqueue)->read_closure, on_readable, *workqueue);
-  grpc_fd_notify_on_read(exec_ctx, (*workqueue)->wakeup_read_fd,
-                         &(*workqueue)->read_closure);
-  return GRPC_ERROR_NONE;
-}
-
-static void workqueue_destroy(grpc_exec_ctx *exec_ctx,
-                              grpc_workqueue *workqueue) {
-  grpc_fd_shutdown(exec_ctx, workqueue->wakeup_read_fd);
-}
-
-static void workqueue_orphan(grpc_exec_ctx *exec_ctx,
-                             grpc_workqueue *workqueue) {
-  if (gpr_atm_full_fetch_add(&workqueue->state, -1) == 1) {
-    workqueue_destroy(exec_ctx, workqueue);
-  }
-}
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-void grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file, int line,
-                        const char *reason) {
-  if (workqueue == NULL) return;
-  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "WORKQUEUE:%p   ref %d -> %d %s",
-          workqueue, (int)workqueue->refs.count, (int)workqueue->refs.count + 1,
-          reason);
-  gpr_ref(&workqueue->refs);
-}
-#else
-void grpc_workqueue_ref(grpc_workqueue *workqueue) {
-  if (workqueue == NULL) return;
-  gpr_ref(&workqueue->refs);
-}
-#endif
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                          const char *file, int line, const char *reason) {
-  if (workqueue == NULL) return;
-  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "WORKQUEUE:%p unref %d -> %d %s",
-          workqueue, (int)workqueue->refs.count, (int)workqueue->refs.count - 1,
-          reason);
-  if (gpr_unref(&workqueue->refs)) {
-    workqueue_orphan(exec_ctx, workqueue);
-  }
-}
-#else
-void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
-  if (workqueue == NULL) return;
-  if (gpr_unref(&workqueue->refs)) {
-    workqueue_orphan(exec_ctx, workqueue);
-  }
-}
-#endif
-
-static void drain(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
-  abort();
-}
-
-static void wakeup(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {
-  GPR_TIMER_MARK("workqueue.wakeup", 0);
-  grpc_error *err = grpc_wakeup_fd_wakeup(&workqueue->wakeup_fd);
-  if (!GRPC_LOG_IF_ERROR("wakeupfd_wakeup", err)) {
-    drain(exec_ctx, workqueue);
-  }
-}
-
-static void on_readable(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.on_readable", 0);
-
-  grpc_workqueue *workqueue = arg;
-
-  if (error != GRPC_ERROR_NONE) {
-    /* HACK: let wakeup_fd code know that we stole the fd */
-    workqueue->wakeup_fd.read_fd = 0;
-    grpc_wakeup_fd_destroy(&workqueue->wakeup_fd);
-    grpc_fd_orphan(exec_ctx, workqueue->wakeup_read_fd, NULL, NULL, "destroy");
-    GPR_ASSERT(gpr_atm_no_barrier_load(&workqueue->state) == 0);
-    gpr_free(workqueue);
-  } else {
-    error = grpc_wakeup_fd_consume_wakeup(&workqueue->wakeup_fd);
-    gpr_mpscq_node *n = gpr_mpscq_pop(&workqueue->queue);
-    if (error == GRPC_ERROR_NONE) {
-      grpc_fd_notify_on_read(exec_ctx, workqueue->wakeup_read_fd,
-                             &workqueue->read_closure);
-    } else {
-      /* recurse to get error handling */
-      on_readable(exec_ctx, arg, error);
-    }
-    if (n == NULL) {
-      /* try again - queue in an inconsistant state */
-      wakeup(exec_ctx, workqueue);
-    } else {
-      switch (gpr_atm_full_fetch_add(&workqueue->state, -2)) {
-        case 3:  // had one count, one unorphaned --> done, unorphaned
-          break;
-        case 2:  // had one count, one orphaned --> done, orphaned
-          workqueue_destroy(exec_ctx, workqueue);
-          break;
-        case 1:
-        case 0:
-          // these values are illegal - representing an already done or
-          // deleted workqueue
-          GPR_UNREACHABLE_CODE(break);
-        default:
-          // schedule a wakeup since there's more to do
-          wakeup(exec_ctx, workqueue);
-      }
-      grpc_closure *cl = (grpc_closure *)n;
-      grpc_error *clerr = cl->error;
-      cl->cb(exec_ctx, cl->cb_arg, clerr);
-      GRPC_ERROR_UNREF(clerr);
-    }
-  }
-
-  GPR_TIMER_END("workqueue.on_readable", 0);
-}
-
-void grpc_workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            grpc_closure *closure, grpc_error *error) {
-  GPR_TIMER_BEGIN("workqueue.enqueue", 0);
-  gpr_atm last = gpr_atm_full_fetch_add(&workqueue->state, 2);
-  GPR_ASSERT(last & 1);
-  closure->error = error;
-  gpr_mpscq_push(&workqueue->queue, &closure->next_data.atm_next);
-  if (last == 1) {
-    wakeup(exec_ctx, workqueue);
-  }
-  GPR_TIMER_END("workqueue.enqueue", 0);
-}
-
-#endif /* GPR_POSIX_SOCKET */
diff --git a/src/core/lib/iomgr/workqueue_windows.c b/src/core/lib/iomgr/workqueue_windows.c
index ee81dc248e..5c93d3c59e 100644
--- a/src/core/lib/iomgr/workqueue_windows.c
+++ b/src/core/lib/iomgr/workqueue_windows.c
@@ -43,12 +43,16 @@
 // workqueues.
 
 #ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-void grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file, int line,
-                        const char *reason) {}
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue, const char *file,
+                                   int line, const char *reason) {
+  return workqueue;
+}
 void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
                           const char *file, int line, const char *reason) {}
 #else
-void grpc_workqueue_ref(grpc_workqueue *workqueue) {}
+grpc_workqueue *grpc_workqueue_ref(grpc_workqueue *workqueue) {
+  return workqueue;
+}
 void grpc_workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue) {}
 #endif
 
diff --git a/src/core/lib/profiling/basic_timers.c b/src/core/lib/profiling/basic_timers.c
index 51813d0461..bdf9af2339 100644
--- a/src/core/lib/profiling/basic_timers.c
+++ b/src/core/lib/profiling/basic_timers.c
@@ -83,6 +83,7 @@ static int g_shutdown;
 static gpr_thd_id g_writing_thread;
 static __thread int g_thread_id;
 static int g_next_thread_id;
+static int g_writing_enabled = 1;
 
 static int timer_log_push_back(gpr_timer_log_list *list, gpr_timer_log *log) {
   if (list->head == NULL) {
@@ -177,7 +178,7 @@ static void flush_logs(gpr_timer_log_list *list) {
   }
 }
 
-static void finish_writing() {
+static void finish_writing(void) {
   pthread_mutex_lock(&g_mu);
   g_shutdown = 1;
   pthread_cond_signal(&g_cv);
@@ -230,6 +231,10 @@ static void gpr_timers_log_add(const char *tagstr, marker_type type,
                                int important, const char *file, int line) {
   gpr_timer_entry *entry;
 
+  if (!g_writing_enabled) {
+    return;
+  }
+
   if (g_thread_log == NULL || g_thread_log->num_entries == MAX_COUNT) {
     rotate_log();
   }
@@ -261,6 +266,8 @@ void gpr_timer_end(const char *tagstr, int important, const char *file,
   gpr_timers_log_add(tagstr, END, important, file, line);
 }
 
+void gpr_timer_set_enabled(int enabled) { g_writing_enabled = enabled; }
+
 /* Basic profiler specific API functions. */
 void gpr_timers_global_init(void) {}
 
@@ -272,4 +279,6 @@ void gpr_timers_global_init(void) {}
 void gpr_timers_global_destroy(void) {}
 
 void gpr_timers_set_log_filename(const char *filename) {}
+
+void gpr_timer_set_enabled(int enabled) {}
 #endif /* GRPC_BASIC_PROFILER */
diff --git a/src/core/lib/profiling/timers.h b/src/core/lib/profiling/timers.h
index c8567e8137..621cdbf656 100644
--- a/src/core/lib/profiling/timers.h
+++ b/src/core/lib/profiling/timers.h
@@ -50,6 +50,8 @@ void gpr_timer_end(const char *tagstr, int important, const char *file,
 
 void gpr_timers_set_log_filename(const char *filename);
 
+void gpr_timer_set_enabled(int enabled);
+
 #if !(defined(GRPC_STAP_PROFILER) + defined(GRPC_BASIC_PROFILER))
 /* No profiling. No-op all the things. */
 #define GPR_TIMER_MARK(tag, important) \
diff --git a/src/core/lib/support/log.c b/src/core/lib/support/log.c
index 899f1218b6..af1651dae5 100644
--- a/src/core/lib/support/log.c
+++ b/src/core/lib/support/log.c
@@ -60,8 +60,9 @@ const char *gpr_log_severity_string(gpr_log_severity severity) {
 
 void gpr_log_message(const char *file, int line, gpr_log_severity severity,
                      const char *message) {
-  if ((gpr_atm)severity < gpr_atm_no_barrier_load(&g_min_severity_to_print))
+  if ((gpr_atm)severity < gpr_atm_no_barrier_load(&g_min_severity_to_print)) {
     return;
+  }
 
   gpr_log_func_args lfargs;
   memset(&lfargs, 0, sizeof(lfargs));
@@ -82,11 +83,11 @@ void gpr_log_verbosity_init() {
 
   gpr_atm min_severity_to_print = GPR_LOG_SEVERITY_ERROR;
   if (verbosity != NULL) {
-    if (strcmp(verbosity, "DEBUG") == 0) {
+    if (gpr_stricmp(verbosity, "DEBUG") == 0) {
       min_severity_to_print = (gpr_atm)GPR_LOG_SEVERITY_DEBUG;
-    } else if (strcmp(verbosity, "INFO") == 0) {
+    } else if (gpr_stricmp(verbosity, "INFO") == 0) {
       min_severity_to_print = (gpr_atm)GPR_LOG_SEVERITY_INFO;
-    } else if (strcmp(verbosity, "ERROR") == 0) {
+    } else if (gpr_stricmp(verbosity, "ERROR") == 0) {
       min_severity_to_print = (gpr_atm)GPR_LOG_SEVERITY_ERROR;
     }
     gpr_free(verbosity);
diff --git a/src/core/lib/support/string.c b/src/core/lib/support/string.c
index 30c1e67647..d17fb9da4b 100644
--- a/src/core/lib/support/string.c
+++ b/src/core/lib/support/string.c
@@ -304,3 +304,14 @@ void gpr_strvec_add(gpr_strvec *sv, char *str) {
 char *gpr_strvec_flatten(gpr_strvec *sv, size_t *final_length) {
   return gpr_strjoin((const char **)sv->strs, sv->count, final_length);
 }
+
+int gpr_stricmp(const char *a, const char *b) {
+  int ca, cb;
+  do {
+    ca = tolower(*a);
+    cb = tolower(*b);
+    ++a;
+    ++b;
+  } while (ca == cb && ca && cb);
+  return ca - cb;
+}
diff --git a/src/core/lib/support/string.h b/src/core/lib/support/string.h
index 2b6bb3eec6..9a94e9471c 100644
--- a/src/core/lib/support/string.h
+++ b/src/core/lib/support/string.h
@@ -118,6 +118,10 @@ void gpr_strvec_add(gpr_strvec *strs, char *add);
    total_length as per gpr_strjoin */
 char *gpr_strvec_flatten(gpr_strvec *strs, size_t *total_length);
 
+/** Case insensitive string comparison... return <0 if lower(a)<lower(b), ==0 if
+    lower(a)==lower(b), >0 if lower(a)>lower(b) */
+int gpr_stricmp(const char *a, const char *b);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index b0f66f4f61..c4effa9a05 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -223,33 +223,33 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                   grpc_error *error);
 
-grpc_call *grpc_call_create(
-    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
-    grpc_completion_queue *cq, grpc_pollset_set *pollset_set_alternative,
-    const void *server_transport_data, grpc_mdelem **add_initial_metadata,
-    size_t add_initial_metadata_count, gpr_timespec send_deadline) {
+grpc_error *grpc_call_create(const grpc_call_create_args *args,
+                             grpc_call **out_call) {
   size_t i, j;
-  grpc_channel_stack *channel_stack = grpc_channel_get_channel_stack(channel);
+  grpc_channel_stack *channel_stack =
+      grpc_channel_get_channel_stack(args->channel);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_call *call;
   GPR_TIMER_BEGIN("grpc_call_create", 0);
   call = gpr_malloc(sizeof(grpc_call) + channel_stack->call_stack_size);
+  *out_call = call;
   memset(call, 0, sizeof(grpc_call));
   gpr_mu_init(&call->mu);
-  call->channel = channel;
-  call->cq = cq;
-  call->parent = parent_call;
+  call->channel = args->channel;
+  call->cq = args->cq;
+  call->parent = args->parent_call;
   /* Always support no compression */
   GPR_BITSET(&call->encodings_accepted_by_peer, GRPC_COMPRESS_NONE);
-  call->is_client = server_transport_data == NULL;
+  call->is_client = args->server_transport_data == NULL;
   if (call->is_client) {
-    GPR_ASSERT(add_initial_metadata_count < MAX_SEND_EXTRA_METADATA_COUNT);
-    for (i = 0; i < add_initial_metadata_count; i++) {
-      call->send_extra_metadata[i].md = add_initial_metadata[i];
+    GPR_ASSERT(args->add_initial_metadata_count <
+               MAX_SEND_EXTRA_METADATA_COUNT);
+    for (i = 0; i < args->add_initial_metadata_count; i++) {
+      call->send_extra_metadata[i].md = args->add_initial_metadata[i];
     }
-    call->send_extra_metadata_count = (int)add_initial_metadata_count;
+    call->send_extra_metadata_count = (int)args->add_initial_metadata_count;
   } else {
-    GPR_ASSERT(add_initial_metadata_count == 0);
+    GPR_ASSERT(args->add_initial_metadata_count == 0);
     call->send_extra_metadata_count = 0;
   }
   for (i = 0; i < 2; i++) {
@@ -257,75 +257,75 @@ grpc_call *grpc_call_create(
       call->metadata_batch[i][j].deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
     }
   }
-  send_deadline = gpr_convert_clock_type(send_deadline, GPR_CLOCK_MONOTONIC);
+  gpr_timespec send_deadline =
+      gpr_convert_clock_type(args->send_deadline, GPR_CLOCK_MONOTONIC);
 
-  if (parent_call != NULL) {
-    GRPC_CALL_INTERNAL_REF(parent_call, "child");
+  if (args->parent_call != NULL) {
+    GRPC_CALL_INTERNAL_REF(args->parent_call, "child");
     GPR_ASSERT(call->is_client);
-    GPR_ASSERT(!parent_call->is_client);
+    GPR_ASSERT(!args->parent_call->is_client);
 
-    gpr_mu_lock(&parent_call->mu);
+    gpr_mu_lock(&args->parent_call->mu);
 
-    if (propagation_mask & GRPC_PROPAGATE_DEADLINE) {
+    if (args->propagation_mask & GRPC_PROPAGATE_DEADLINE) {
       send_deadline = gpr_time_min(
           gpr_convert_clock_type(send_deadline,
-                                 parent_call->send_deadline.clock_type),
-          parent_call->send_deadline);
+                                 args->parent_call->send_deadline.clock_type),
+          args->parent_call->send_deadline);
     }
     /* for now GRPC_PROPAGATE_TRACING_CONTEXT *MUST* be passed with
      * GRPC_PROPAGATE_STATS_CONTEXT */
     /* TODO(ctiller): This should change to use the appropriate census start_op
      * call. */
-    if (propagation_mask & GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT) {
-      GPR_ASSERT(propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
-      grpc_call_context_set(call, GRPC_CONTEXT_TRACING,
-                            parent_call->context[GRPC_CONTEXT_TRACING].value,
-                            NULL);
+    if (args->propagation_mask & GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT) {
+      GPR_ASSERT(args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
+      grpc_call_context_set(
+          call, GRPC_CONTEXT_TRACING,
+          args->parent_call->context[GRPC_CONTEXT_TRACING].value, NULL);
     } else {
-      GPR_ASSERT(propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
+      GPR_ASSERT(args->propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
     }
-    if (propagation_mask & GRPC_PROPAGATE_CANCELLATION) {
+    if (args->propagation_mask & GRPC_PROPAGATE_CANCELLATION) {
       call->cancellation_is_inherited = 1;
     }
 
-    if (parent_call->first_child == NULL) {
-      parent_call->first_child = call;
+    if (args->parent_call->first_child == NULL) {
+      args->parent_call->first_child = call;
       call->sibling_next = call->sibling_prev = call;
     } else {
-      call->sibling_next = parent_call->first_child;
-      call->sibling_prev = parent_call->first_child->sibling_prev;
+      call->sibling_next = args->parent_call->first_child;
+      call->sibling_prev = args->parent_call->first_child->sibling_prev;
       call->sibling_next->sibling_prev = call->sibling_prev->sibling_next =
           call;
     }
 
-    gpr_mu_unlock(&parent_call->mu);
+    gpr_mu_unlock(&args->parent_call->mu);
   }
 
   call->send_deadline = send_deadline;
 
-  GRPC_CHANNEL_INTERNAL_REF(channel, "call");
+  GRPC_CHANNEL_INTERNAL_REF(args->channel, "call");
   /* initial refcount dropped by grpc_call_destroy */
   grpc_error *error = grpc_call_stack_init(
       &exec_ctx, channel_stack, 1, destroy_call, call, call->context,
-      server_transport_data, send_deadline, CALL_STACK_FROM_CALL(call));
+      args->server_transport_data, send_deadline, CALL_STACK_FROM_CALL(call));
   if (error != GRPC_ERROR_NONE) {
     grpc_status_code status;
     const char *error_str;
     grpc_error_get_status(error, &status, &error_str);
     close_with_status(&exec_ctx, call, status, error_str);
-    GRPC_ERROR_UNREF(error);
   }
-  if (cq != NULL) {
+  if (args->cq != NULL) {
     GPR_ASSERT(
-        pollset_set_alternative == NULL &&
+        args->pollset_set_alternative == NULL &&
         "Only one of 'cq' and 'pollset_set_alternative' should be non-NULL.");
-    GRPC_CQ_INTERNAL_REF(cq, "bind");
+    GRPC_CQ_INTERNAL_REF(args->cq, "bind");
     call->pollent =
-        grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq));
+        grpc_polling_entity_create_from_pollset(grpc_cq_pollset(args->cq));
   }
-  if (pollset_set_alternative != NULL) {
-    call->pollent =
-        grpc_polling_entity_create_from_pollset_set(pollset_set_alternative);
+  if (args->pollset_set_alternative != NULL) {
+    call->pollent = grpc_polling_entity_create_from_pollset_set(
+        args->pollset_set_alternative);
   }
   if (!grpc_polling_entity_is_empty(&call->pollent)) {
     grpc_call_stack_set_pollset_or_pollset_set(
@@ -334,7 +334,7 @@ grpc_call *grpc_call_create(
 
   grpc_exec_ctx_finish(&exec_ctx);
   GPR_TIMER_END("grpc_call_create", 0);
-  return call;
+  return error;
 }
 
 void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
@@ -1038,9 +1038,14 @@ static void finish_batch_completion(grpc_exec_ctx *exec_ctx, void *user_data,
 static void post_batch_completion(grpc_exec_ctx *exec_ctx,
                                   batch_control *bctl) {
   grpc_call *call = bctl->call;
+  grpc_error *error = bctl->error;
+  if (bctl->recv_final_op) {
+    GRPC_ERROR_UNREF(error);
+    error = GRPC_ERROR_NONE;
+  }
   if (bctl->is_notify_tag_closure) {
     /* unrefs bctl->error */
-    grpc_exec_ctx_sched(exec_ctx, bctl->notify_tag, bctl->error, NULL);
+    grpc_closure_run(exec_ctx, bctl->notify_tag, error);
     gpr_mu_lock(&call->mu);
     bctl->call->used_batches =
         (uint8_t)(bctl->call->used_batches &
@@ -1049,7 +1054,7 @@ static void post_batch_completion(grpc_exec_ctx *exec_ctx,
     GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "completion");
   } else {
     /* unrefs bctl->error */
-    grpc_cq_end_op(exec_ctx, bctl->call->cq, bctl->notify_tag, bctl->error,
+    grpc_cq_end_op(exec_ctx, bctl->call->cq, bctl->notify_tag, error,
                    finish_batch_completion, bctl, &bctl->cq_completion);
   }
 }
@@ -1198,6 +1203,14 @@ static void validate_filtered_metadata(grpc_exec_ctx *exec_ctx,
   }
 }
 
+static void add_batch_error(batch_control *bctl, grpc_error *error) {
+  if (error == GRPC_ERROR_NONE) return;
+  if (bctl->error == GRPC_ERROR_NONE) {
+    bctl->error = GRPC_ERROR_CREATE("Call batch operation failed");
+  }
+  bctl->error = grpc_error_add_child(bctl->error, error);
+}
+
 static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
                                              void *bctlp, grpc_error *error) {
   batch_control *bctl = bctlp;
@@ -1205,9 +1218,8 @@ static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
 
   gpr_mu_lock(&call->mu);
 
-  if (error != GRPC_ERROR_NONE) {
-    bctl->error = GRPC_ERROR_REF(error);
-  } else {
+  add_batch_error(bctl, GRPC_ERROR_REF(error));
+  if (error == GRPC_ERROR_NONE) {
     grpc_metadata_batch *md =
         &call->metadata_batch[1 /* is_receiving */][0 /* is_trailing */];
     grpc_metadata_batch_filter(md, recv_initial_filter, call);
@@ -1304,8 +1316,7 @@ static void finish_batch(grpc_exec_ctx *exec_ctx, void *bctlp,
     GRPC_ERROR_UNREF(error);
     error = GRPC_ERROR_NONE;
   }
-  GRPC_ERROR_UNREF(bctl->error);
-  bctl->error = GRPC_ERROR_REF(error);
+  add_batch_error(bctl, GRPC_ERROR_REF(error));
   gpr_mu_unlock(&call->mu);
   if (gpr_unref(&bctl->steps_to_complete)) {
     post_batch_completion(exec_ctx, bctl);
@@ -1341,6 +1352,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
 
   grpc_transport_stream_op *stream_op = &bctl->op;
   memset(stream_op, 0, sizeof(*stream_op));
+  stream_op->covered_by_poller = true;
 
   if (nops == 0) {
     GRPC_CALL_INTERNAL_REF(call, "completion");
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index 3a78fe3aa3..18af41b7fb 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -49,15 +49,29 @@ typedef void (*grpc_ioreq_completion_func)(grpc_exec_ctx *exec_ctx,
                                            grpc_call *call, int success,
                                            void *user_data);
 
-grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
-                            uint32_t propagation_mask,
-                            grpc_completion_queue *cq,
-                            /* if not NULL, it'll be used in lieu of \a cq */
-                            grpc_pollset_set *pollset_set_alternative,
-                            const void *server_transport_data,
-                            grpc_mdelem **add_initial_metadata,
-                            size_t add_initial_metadata_count,
-                            gpr_timespec send_deadline);
+typedef struct grpc_call_create_args {
+  grpc_channel *channel;
+
+  grpc_call *parent_call;
+  uint32_t propagation_mask;
+
+  grpc_completion_queue *cq;
+  /* if not NULL, it'll be used in lieu of cq */
+  grpc_pollset_set *pollset_set_alternative;
+
+  const void *server_transport_data;
+
+  grpc_mdelem **add_initial_metadata;
+  size_t add_initial_metadata_count;
+
+  gpr_timespec send_deadline;
+} grpc_call_create_args;
+
+/* Create a new call based on \a args.
+   Regardless of success or failure, always returns a valid new call into *call
+   */
+grpc_error *grpc_call_create(const grpc_call_create_args *args,
+                             grpc_call **call);
 
 void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
                                     grpc_completion_queue *cq);
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index 6adb70a987..92d783b78d 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -193,9 +193,21 @@ static grpc_call *grpc_channel_create_call_internal(
     send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
   }
 
-  return grpc_call_create(channel, parent_call, propagation_mask, cq,
-                          pollset_set_alternative, NULL, send_metadata,
-                          num_metadata, deadline);
+  grpc_call_create_args args;
+  memset(&args, 0, sizeof(args));
+  args.channel = channel;
+  args.parent_call = parent_call;
+  args.propagation_mask = propagation_mask;
+  args.cq = cq;
+  args.pollset_set_alternative = pollset_set_alternative;
+  args.server_transport_data = NULL;
+  args.add_initial_metadata = send_metadata;
+  args.add_initial_metadata_count = num_metadata;
+  args.send_deadline = deadline;
+
+  grpc_call *call;
+  GRPC_LOG_IF_ERROR("call_create", grpc_call_create(&args, &call));
+  return call;
 }
 
 grpc_call *grpc_channel_create_call(grpc_channel *channel,
diff --git a/src/core/lib/surface/completion_queue.c b/src/core/lib/surface/completion_queue.c
index 5978884db8..4e0feb56ac 100644
--- a/src/core/lib/surface/completion_queue.c
+++ b/src/core/lib/surface/completion_queue.c
@@ -39,6 +39,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/atm.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
 #include "src/core/lib/iomgr/pollset.h"
@@ -50,6 +51,9 @@
 #include "src/core/lib/surface/event_string.h"
 
 int grpc_trace_operation_failures;
+#ifndef NDEBUG
+int grpc_trace_pending_tags;
+#endif
 
 typedef struct {
   grpc_pollset_worker **worker;
@@ -67,6 +71,9 @@ struct grpc_completion_queue {
   gpr_refcount pending_events;
   /** Once owning_refs drops to zero, we will destroy the cq */
   gpr_refcount owning_refs;
+  /** counter of how many things have ever been queued on this completion queue
+      useful for avoiding locks to check the queue */
+  gpr_atm things_queued_ever;
   /** 0 initially, 1 once we've begun shutting down */
   int shutdown;
   int shutdown_called;
@@ -121,15 +128,6 @@ void grpc_cq_global_shutdown(void) {
   }
 }
 
-struct grpc_cq_alarm {
-  grpc_timer alarm;
-  grpc_cq_completion completion;
-  /** completion queue where events about this alarm will be posted */
-  grpc_completion_queue *cq;
-  /** user supplied tag */
-  void *tag;
-};
-
 grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   grpc_completion_queue *cc;
   GPR_ASSERT(!reserved);
@@ -166,6 +164,7 @@ grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   cc->is_server_cq = 0;
   cc->is_non_listening_server_cq = 0;
   cc->num_pluckers = 0;
+  gpr_atm_no_barrier_store(&cc->things_queued_ever, 0);
 #ifndef NDEBUG
   cc->outstanding_tag_count = 0;
 #endif
@@ -276,6 +275,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
   GPR_ASSERT(found);
 #endif
   shutdown = gpr_unref(&cc->pending_events);
+  gpr_atm_no_barrier_fetch_add(&cc->things_queued_ever, 1);
   if (!shutdown) {
     cc->completed_tail->next =
         ((uintptr_t)storage) | (1u & (uintptr_t)cc->completed_tail->next);
@@ -313,13 +313,66 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
   GRPC_ERROR_UNREF(error);
 }
 
+typedef struct {
+  gpr_atm last_seen_things_queued_ever;
+  grpc_completion_queue *cq;
+  gpr_timespec deadline;
+  grpc_cq_completion *stolen_completion;
+  void *tag; /* for pluck */
+  bool first_loop;
+} cq_is_finished_arg;
+
+static bool cq_is_next_finished(grpc_exec_ctx *exec_ctx, void *arg) {
+  cq_is_finished_arg *a = arg;
+  grpc_completion_queue *cq = a->cq;
+  GPR_ASSERT(a->stolen_completion == NULL);
+  gpr_atm current_last_seen_things_queued_ever =
+      gpr_atm_no_barrier_load(&cq->things_queued_ever);
+  if (current_last_seen_things_queued_ever != a->last_seen_things_queued_ever) {
+    gpr_mu_lock(cq->mu);
+    a->last_seen_things_queued_ever =
+        gpr_atm_no_barrier_load(&cq->things_queued_ever);
+    if (cq->completed_tail != &cq->completed_head) {
+      a->stolen_completion = (grpc_cq_completion *)cq->completed_head.next;
+      cq->completed_head.next = a->stolen_completion->next & ~(uintptr_t)1;
+      if (a->stolen_completion == cq->completed_tail) {
+        cq->completed_tail = &cq->completed_head;
+      }
+      gpr_mu_unlock(cq->mu);
+      return true;
+    }
+    gpr_mu_unlock(cq->mu);
+  }
+  return !a->first_loop &&
+         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+}
+
+#ifndef NDEBUG
+static void dump_pending_tags(grpc_completion_queue *cc) {
+  if (!grpc_trace_pending_tags) return;
+
+  gpr_strvec v;
+  gpr_strvec_init(&v);
+  gpr_strvec_add(&v, gpr_strdup("PENDING TAGS:"));
+  for (size_t i = 0; i < cc->outstanding_tag_count; i++) {
+    char *s;
+    gpr_asprintf(&s, " %p", cc->outstanding_tags[i]);
+    gpr_strvec_add(&v, s);
+  }
+  char *out = gpr_strvec_flatten(&v, NULL);
+  gpr_strvec_destroy(&v);
+  gpr_log(GPR_DEBUG, "%s", out);
+  gpr_free(out);
+}
+#else
+static void dump_pending_tags(grpc_completion_queue *cc) {}
+#endif
+
 grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
   grpc_pollset_worker *worker = NULL;
-  int first_loop = 1;
   gpr_timespec now;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   GPR_TIMER_BEGIN("grpc_completion_queue_next", 0);
 
@@ -333,11 +386,33 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
           reserved));
   GPR_ASSERT(!reserved);
 
+  dump_pending_tags(cc);
+
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 
   GRPC_CQ_INTERNAL_REF(cc, "next");
   gpr_mu_lock(cc->mu);
+  cq_is_finished_arg is_finished_arg = {
+      .last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cc->things_queued_ever),
+      .cq = cc,
+      .deadline = deadline,
+      .stolen_completion = NULL,
+      .tag = NULL,
+      .first_loop = true};
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
+      cq_is_next_finished, &is_finished_arg);
   for (;;) {
+    if (is_finished_arg.stolen_completion != NULL) {
+      gpr_mu_unlock(cc->mu);
+      grpc_cq_completion *c = is_finished_arg.stolen_completion;
+      is_finished_arg.stolen_completion = NULL;
+      ret.type = GRPC_OP_COMPLETE;
+      ret.success = c->next & 1u;
+      ret.tag = c->tag;
+      c->done(&exec_ctx, c->done_arg, c);
+      break;
+    }
     if (cc->completed_tail != &cc->completed_head) {
       grpc_cq_completion *c = (grpc_cq_completion *)cc->completed_head.next;
       cc->completed_head.next = c->next & ~(uintptr_t)1;
@@ -358,13 +433,13 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
       break;
     }
     now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
       gpr_mu_unlock(cc->mu);
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
+      dump_pending_tags(cc);
       break;
     }
-    first_loop = 0;
     /* Check alarms - these are a global resource so we just ping
        each time through on every pollset.
        May update deadline to ensure timely wakeups.
@@ -387,13 +462,16 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
         GRPC_ERROR_UNREF(err);
         memset(&ret, 0, sizeof(ret));
         ret.type = GRPC_QUEUE_TIMEOUT;
+        dump_pending_tags(cc);
         break;
       }
     }
+    is_finished_arg.first_loop = false;
   }
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
   GRPC_CQ_INTERNAL_UNREF(cc, "next");
   grpc_exec_ctx_finish(&exec_ctx);
+  GPR_ASSERT(is_finished_arg.stolen_completion == NULL);
 
   GPR_TIMER_END("grpc_completion_queue_next", 0);
 
@@ -424,6 +502,37 @@ static void del_plucker(grpc_completion_queue *cc, void *tag,
   GPR_UNREACHABLE_CODE(return );
 }
 
+static bool cq_is_pluck_finished(grpc_exec_ctx *exec_ctx, void *arg) {
+  cq_is_finished_arg *a = arg;
+  grpc_completion_queue *cq = a->cq;
+  GPR_ASSERT(a->stolen_completion == NULL);
+  gpr_atm current_last_seen_things_queued_ever =
+      gpr_atm_no_barrier_load(&cq->things_queued_ever);
+  if (current_last_seen_things_queued_ever != a->last_seen_things_queued_ever) {
+    gpr_mu_lock(cq->mu);
+    a->last_seen_things_queued_ever =
+        gpr_atm_no_barrier_load(&cq->things_queued_ever);
+    grpc_cq_completion *c;
+    grpc_cq_completion *prev = &cq->completed_head;
+    while ((c = (grpc_cq_completion *)(prev->next & ~(uintptr_t)1)) !=
+           &cq->completed_head) {
+      if (c->tag == a->tag) {
+        prev->next = (prev->next & (uintptr_t)1) | (c->next & ~(uintptr_t)1);
+        if (c == cq->completed_tail) {
+          cq->completed_tail = prev;
+        }
+        gpr_mu_unlock(cq->mu);
+        a->stolen_completion = c;
+        return true;
+      }
+      prev = c;
+    }
+    gpr_mu_unlock(cq->mu);
+  }
+  return !a->first_loop &&
+         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+}
+
 grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
                                        gpr_timespec deadline, void *reserved) {
   grpc_event ret;
@@ -431,8 +540,6 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   grpc_cq_completion *prev;
   grpc_pollset_worker *worker = NULL;
   gpr_timespec now;
-  int first_loop = 1;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
   GPR_TIMER_BEGIN("grpc_completion_queue_pluck", 0);
 
@@ -448,11 +555,33 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   }
   GPR_ASSERT(!reserved);
 
+  dump_pending_tags(cc);
+
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
 
   GRPC_CQ_INTERNAL_REF(cc, "pluck");
   gpr_mu_lock(cc->mu);
+  cq_is_finished_arg is_finished_arg = {
+      .last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cc->things_queued_ever),
+      .cq = cc,
+      .deadline = deadline,
+      .stolen_completion = NULL,
+      .tag = tag,
+      .first_loop = true};
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
+      cq_is_pluck_finished, &is_finished_arg);
   for (;;) {
+    if (is_finished_arg.stolen_completion != NULL) {
+      gpr_mu_unlock(cc->mu);
+      c = is_finished_arg.stolen_completion;
+      is_finished_arg.stolen_completion = NULL;
+      ret.type = GRPC_OP_COMPLETE;
+      ret.success = c->next & 1u;
+      ret.tag = c->tag;
+      c->done(&exec_ctx, c->done_arg, c);
+      break;
+    }
     prev = &cc->completed_head;
     while ((c = (grpc_cq_completion *)(prev->next & ~(uintptr_t)1)) !=
            &cc->completed_head) {
@@ -485,17 +614,18 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       memset(&ret, 0, sizeof(ret));
       /* TODO(ctiller): should we use a different result here */
       ret.type = GRPC_QUEUE_TIMEOUT;
+      dump_pending_tags(cc);
       break;
     }
     now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
       del_plucker(cc, tag, &worker);
       gpr_mu_unlock(cc->mu);
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
+      dump_pending_tags(cc);
       break;
     }
-    first_loop = 0;
     /* Check alarms - these are a global resource so we just ping
        each time through on every pollset.
        May update deadline to ensure timely wakeups.
@@ -518,15 +648,18 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
         GRPC_ERROR_UNREF(err);
         memset(&ret, 0, sizeof(ret));
         ret.type = GRPC_QUEUE_TIMEOUT;
+        dump_pending_tags(cc);
         break;
       }
     }
+    is_finished_arg.first_loop = false;
     del_plucker(cc, tag, &worker);
   }
 done:
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
   GRPC_CQ_INTERNAL_UNREF(cc, "pluck");
   grpc_exec_ctx_finish(&exec_ctx);
+  GPR_ASSERT(is_finished_arg.stolen_completion == NULL);
 
   GPR_TIMER_END("grpc_completion_queue_pluck", 0);
 
diff --git a/src/core/lib/surface/completion_queue.h b/src/core/lib/surface/completion_queue.h
index 4dbf3aae63..c1cafba5f2 100644
--- a/src/core/lib/surface/completion_queue.h
+++ b/src/core/lib/surface/completion_queue.h
@@ -44,6 +44,9 @@
 extern int grpc_cq_pluck_trace;
 extern int grpc_cq_event_timeout_trace;
 extern int grpc_trace_operation_failures;
+#ifndef NDEBUG
+extern int grpc_trace_pending_tags;
+#endif
 
 typedef struct grpc_cq_completion {
   /** user supplied tag */
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index 289f4ce8e8..8ca0643ba7 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -184,12 +184,16 @@ void grpc_init(void) {
     grpc_register_tracer("compression", &grpc_compression_trace);
     grpc_register_tracer("queue_pluck", &grpc_cq_pluck_trace);
     grpc_register_tracer("combiner", &grpc_combiner_trace);
+    grpc_register_tracer("server_channel", &grpc_server_channel_trace);
     // Default pluck trace to 1
     grpc_cq_pluck_trace = 1;
     grpc_register_tracer("queue_timeout", &grpc_cq_event_timeout_trace);
     // Default timeout trace to 1
     grpc_cq_event_timeout_trace = 1;
     grpc_register_tracer("op_failure", &grpc_trace_operation_failures);
+#ifndef NDEBUG
+    grpc_register_tracer("pending_tags", &grpc_trace_pending_tags);
+#endif
     grpc_security_pre_init();
     grpc_iomgr_init();
     grpc_executor_init();
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 7300d79b9f..3a90308058 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -71,6 +71,8 @@ typedef struct registered_method registered_method;
 
 typedef enum { BATCH_CALL, REGISTERED_CALL } requested_call_type;
 
+int grpc_server_channel_trace = 0;
+
 typedef struct requested_call {
   requested_call_type type;
   size_t cq_idx;
@@ -280,6 +282,7 @@ static void send_shutdown(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
   grpc_channel_element *elem;
 
   op->send_goaway = send_goaway;
+  op->set_accept_stream = true;
   sc->slice = gpr_slice_from_copied_string("Server shutdown");
   op->goaway_message = &sc->slice;
   op->goaway_status = GRPC_STATUS_OK;
@@ -439,6 +442,13 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand,
   chand->finish_destroy_channel_closure.cb = finish_destroy_channel;
   chand->finish_destroy_channel_closure.cb_arg = chand;
 
+  if (grpc_server_channel_trace && error != GRPC_ERROR_NONE) {
+    const char *msg = grpc_error_string(error);
+    gpr_log(GPR_INFO, "Disconnected client: %s", msg);
+    grpc_error_free_string(msg);
+  }
+  GRPC_ERROR_UNREF(error);
+
   grpc_transport_op *op =
       grpc_make_transport_op(&chand->finish_destroy_channel_closure);
   op->set_accept_stream = true;
@@ -446,13 +456,6 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand,
                        grpc_channel_stack_element(
                            grpc_channel_get_channel_stack(chand->channel), 0),
                        op);
-
-  if (error != GRPC_ERROR_NONE) {
-    const char *msg = grpc_error_string(error);
-    gpr_log(GPR_INFO, "Disconnected client: %s", msg);
-    grpc_error_free_string(msg);
-  }
-  GRPC_ERROR_UNREF(error);
 }
 
 static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
@@ -773,8 +776,7 @@ static void server_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
         GRPC_ERROR_CREATE_REFERENCING("Missing :authority or :path", &error, 1);
   }
 
-  grpc_exec_ctx_sched(exec_ctx, calld->on_done_recv_initial_metadata, error,
-                      NULL);
+  grpc_closure_run(exec_ctx, calld->on_done_recv_initial_metadata, error);
 }
 
 static void server_mutate_op(grpc_call_element *elem,
@@ -829,11 +831,20 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
                           const void *transport_server_data) {
   channel_data *chand = cd;
   /* create a call */
-  grpc_call *call = grpc_call_create(chand->channel, NULL, 0, NULL, NULL,
-                                     transport_server_data, NULL, 0,
-                                     gpr_inf_future(GPR_CLOCK_MONOTONIC));
+  grpc_call_create_args args;
+  memset(&args, 0, sizeof(args));
+  args.channel = chand->channel;
+  args.server_transport_data = transport_server_data;
+  args.send_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  grpc_call *call;
+  grpc_error *error = grpc_call_create(&args, &call);
   grpc_call_element *elem =
       grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
+  if (error != GRPC_ERROR_NONE) {
+    got_initial_metadata(exec_ctx, elem, error);
+    GRPC_ERROR_UNREF(error);
+    return;
+  }
   call_data *calld = elem->call_data;
   grpc_op op;
   memset(&op, 0, sizeof(op));
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
index 551a40a4ff..a85d9f4964 100644
--- a/src/core/lib/surface/server.h
+++ b/src/core/lib/surface/server.h
@@ -40,6 +40,9 @@
 
 extern const grpc_channel_filter grpc_server_top_filter;
 
+/** Lightweight tracing of server channel state */
+extern int grpc_server_channel_trace;
+
 /* Add a listener to the server: when the server starts, it will call start,
    and when it shuts down, it will call destroy */
 void grpc_server_add_listener(
diff --git a/src/core/lib/transport/connectivity_state.c b/src/core/lib/transport/connectivity_state.c
index 68d05e3a85..fdb5307814 100644
--- a/src/core/lib/transport/connectivity_state.c
+++ b/src/core/lib/transport/connectivity_state.c
@@ -180,7 +180,8 @@ void grpc_connectivity_state_set(grpc_exec_ctx *exec_ctx,
     *w->current = tracker->current_state;
     tracker->watchers = w->next;
     if (grpc_connectivity_state_trace) {
-      gpr_log(GPR_DEBUG, "NOTIFY: %p", w->notify);
+      gpr_log(GPR_DEBUG, "NOTIFY: %p %s: %p", tracker, tracker->name,
+              w->notify);
     }
     grpc_exec_ctx_sched(exec_ctx, w->notify,
                         GRPC_ERROR_REF(tracker->current_error), NULL);
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index 5e0352a467..f019ef156a 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -126,9 +126,9 @@ const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
     "if-range",
     "if-unmodified-since",
     "last-modified",
+    "lb-cost",
+    "lb-token",
     "link",
-    "load-reporting-initial",
-    "load-reporting-trailing",
     "location",
     "max-forwards",
     ":method",
diff --git a/src/core/lib/transport/static_metadata.h b/src/core/lib/transport/static_metadata.h
index 5b9ee1a60a..e0a8196419 100644
--- a/src/core/lib/transport/static_metadata.h
+++ b/src/core/lib/transport/static_metadata.h
@@ -175,12 +175,12 @@ extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 #define GRPC_MDSTR_IF_UNMODIFIED_SINCE (&grpc_static_mdstr_table[62])
 /* "last-modified" */
 #define GRPC_MDSTR_LAST_MODIFIED (&grpc_static_mdstr_table[63])
+/* "lb-cost" */
+#define GRPC_MDSTR_LB_COST (&grpc_static_mdstr_table[64])
+/* "lb-token" */
+#define GRPC_MDSTR_LB_TOKEN (&grpc_static_mdstr_table[65])
 /* "link" */
-#define GRPC_MDSTR_LINK (&grpc_static_mdstr_table[64])
-/* "load-reporting-initial" */
-#define GRPC_MDSTR_LOAD_REPORTING_INITIAL (&grpc_static_mdstr_table[65])
-/* "load-reporting-trailing" */
-#define GRPC_MDSTR_LOAD_REPORTING_TRAILING (&grpc_static_mdstr_table[66])
+#define GRPC_MDSTR_LINK (&grpc_static_mdstr_table[66])
 /* "location" */
 #define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[67])
 /* "max-forwards" */
@@ -337,13 +337,12 @@ extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
 #define GRPC_MDELEM_IF_UNMODIFIED_SINCE_EMPTY (&grpc_static_mdelem_table[44])
 /* "last-modified": "" */
 #define GRPC_MDELEM_LAST_MODIFIED_EMPTY (&grpc_static_mdelem_table[45])
+/* "lb-cost": "" */
+#define GRPC_MDELEM_LB_COST_EMPTY (&grpc_static_mdelem_table[46])
+/* "lb-token": "" */
+#define GRPC_MDELEM_LB_TOKEN_EMPTY (&grpc_static_mdelem_table[47])
 /* "link": "" */
-#define GRPC_MDELEM_LINK_EMPTY (&grpc_static_mdelem_table[46])
-/* "load-reporting-initial": "" */
-#define GRPC_MDELEM_LOAD_REPORTING_INITIAL_EMPTY (&grpc_static_mdelem_table[47])
-/* "load-reporting-trailing": "" */
-#define GRPC_MDELEM_LOAD_REPORTING_TRAILING_EMPTY \
-  (&grpc_static_mdelem_table[48])
+#define GRPC_MDELEM_LINK_EMPTY (&grpc_static_mdelem_table[48])
 /* "location": "" */
 #define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[49])
 /* "max-forwards": "" */
diff --git a/src/core/lib/transport/transport.c b/src/core/lib/transport/transport.c
index 82fc605218..75aec7a5b4 100644
--- a/src/core/lib/transport/transport.c
+++ b/src/core/lib/transport/transport.c
@@ -46,8 +46,9 @@
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 void grpc_stream_ref(grpc_stream_refcount *refcount, const char *reason) {
   gpr_atm val = gpr_atm_no_barrier_load(&refcount->refs.count);
-  gpr_log(GPR_DEBUG, "%s %p:%p   REF %d->%d %s", refcount->object_type,
-          refcount, refcount->destroy.cb_arg, (int)val, (int)val + 1, reason);
+  gpr_log(GPR_DEBUG, "%s %p:%p   REF %" PRIdPTR "->%" PRIdPTR " %s",
+          refcount->object_type, refcount, refcount->destroy.cb_arg, val,
+          val + 1, reason);
 #else
 void grpc_stream_ref(grpc_stream_refcount *refcount) {
 #endif
@@ -58,8 +59,9 @@ void grpc_stream_ref(grpc_stream_refcount *refcount) {
 void grpc_stream_unref(grpc_exec_ctx *exec_ctx, grpc_stream_refcount *refcount,
                        const char *reason) {
   gpr_atm val = gpr_atm_no_barrier_load(&refcount->refs.count);
-  gpr_log(GPR_DEBUG, "%s %p:%p UNREF %d->%d %s", refcount->object_type,
-          refcount, refcount->destroy.cb_arg, (int)val, (int)val - 1, reason);
+  gpr_log(GPR_DEBUG, "%s %p:%p UNREF %" PRIdPTR "->%" PRIdPTR " %s",
+          refcount->object_type, refcount, refcount->destroy.cb_arg, val,
+          val - 1, reason);
 #else
 void grpc_stream_unref(grpc_exec_ctx *exec_ctx,
                        grpc_stream_refcount *refcount) {
@@ -274,3 +276,28 @@ grpc_transport_op *grpc_make_transport_op(grpc_closure *on_complete) {
   op->op.on_consumed = &op->outer_on_complete;
   return &op->op;
 }
+
+typedef struct {
+  grpc_closure outer_on_complete;
+  grpc_closure *inner_on_complete;
+  grpc_transport_stream_op op;
+} made_transport_stream_op;
+
+static void destroy_made_transport_stream_op(grpc_exec_ctx *exec_ctx, void *arg,
+                                             grpc_error *error) {
+  made_transport_stream_op *op = arg;
+  grpc_exec_ctx_sched(exec_ctx, op->inner_on_complete, GRPC_ERROR_REF(error),
+                      NULL);
+  gpr_free(op);
+}
+
+grpc_transport_stream_op *grpc_make_transport_stream_op(
+    grpc_closure *on_complete) {
+  made_transport_stream_op *op = gpr_malloc(sizeof(*op));
+  grpc_closure_init(&op->outer_on_complete, destroy_made_transport_stream_op,
+                    op);
+  op->inner_on_complete = on_complete;
+  memset(&op->op, 0, sizeof(op->op));
+  op->op.on_complete = &op->outer_on_complete;
+  return &op->op;
+}
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 8dc393fd61..50253ebad1 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -113,6 +113,10 @@ typedef struct grpc_transport_stream_op {
       have been completed. */
   grpc_closure *on_complete;
 
+  /** Is the completion of this op covered by a poller (if false: the op should
+      complete independently of some pollset being polled) */
+  bool covered_by_poller;
+
   /** Send initial metadata to the peer, from the provided metadata batch.
       idempotent_request MUST be set if this is non-null */
   grpc_metadata_batch *send_initial_metadata;
@@ -252,6 +256,7 @@ void grpc_transport_stream_op_add_close(grpc_transport_stream_op *op,
                                         gpr_slice *optional_message);
 
 char *grpc_transport_stream_op_string(grpc_transport_stream_op *op);
+char *grpc_transport_op_string(grpc_transport_op *op);
 
 /* Send a batch of operations on a transport
 
@@ -293,6 +298,10 @@ char *grpc_transport_get_peer(grpc_exec_ctx *exec_ctx,
 /* Allocate a grpc_transport_op, and preconfigure the on_consumed closure to
    \a on_consumed and then delete the returned transport op */
 grpc_transport_op *grpc_make_transport_op(grpc_closure *on_consumed);
+/* Allocate a grpc_transport_stream_op, and preconfigure the on_consumed closure
+   to \a on_consumed and then delete the returned transport op */
+grpc_transport_stream_op *grpc_make_transport_stream_op(
+    grpc_closure *on_consumed);
 
 #ifdef __cplusplus
 }
diff --git a/src/core/lib/transport/transport_op_string.c b/src/core/lib/transport/transport_op_string.c
index 138591db2a..533ec52077 100644
--- a/src/core/lib/transport/transport_op_string.c
+++ b/src/core/lib/transport/transport_op_string.c
@@ -41,6 +41,7 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 #include "src/core/lib/support/string.h"
+#include "src/core/lib/transport/connectivity_state.h"
 
 /* These routines are here to facilitate debugging - they produce string
    representations of various transport data structures */
@@ -72,56 +73,51 @@ static void put_metadata_list(gpr_strvec *b, grpc_metadata_batch md) {
 char *grpc_transport_stream_op_string(grpc_transport_stream_op *op) {
   char *tmp;
   char *out;
-  int first = 1;
 
   gpr_strvec b;
   gpr_strvec_init(&b);
 
+  gpr_strvec_add(
+      &b, gpr_strdup(op->covered_by_poller ? "[COVERED]" : "[UNCOVERED]"));
+
   if (op->send_initial_metadata != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_strvec_add(&b, gpr_strdup("SEND_INITIAL_METADATA{"));
     put_metadata_list(&b, *op->send_initial_metadata);
     gpr_strvec_add(&b, gpr_strdup("}"));
   }
 
   if (op->send_message != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_asprintf(&tmp, "SEND_MESSAGE:flags=0x%08x:len=%d",
                  op->send_message->flags, op->send_message->length);
     gpr_strvec_add(&b, tmp);
   }
 
   if (op->send_trailing_metadata != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_strvec_add(&b, gpr_strdup("SEND_TRAILING_METADATA{"));
     put_metadata_list(&b, *op->send_trailing_metadata);
     gpr_strvec_add(&b, gpr_strdup("}"));
   }
 
   if (op->recv_initial_metadata != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_strvec_add(&b, gpr_strdup("RECV_INITIAL_METADATA"));
   }
 
   if (op->recv_message != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_strvec_add(&b, gpr_strdup("RECV_MESSAGE"));
   }
 
   if (op->recv_trailing_metadata != NULL) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     gpr_strvec_add(&b, gpr_strdup("RECV_TRAILING_METADATA"));
   }
 
   if (op->cancel_error != GRPC_ERROR_NONE) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     const char *msg = grpc_error_string(op->cancel_error);
     gpr_asprintf(&tmp, "CANCEL:%s", msg);
     grpc_error_free_string(msg);
@@ -129,8 +125,7 @@ char *grpc_transport_stream_op_string(grpc_transport_stream_op *op) {
   }
 
   if (op->close_error != GRPC_ERROR_NONE) {
-    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = 0;
+    gpr_strvec_add(&b, gpr_strdup(" "));
     const char *msg = grpc_error_string(op->close_error);
     gpr_asprintf(&tmp, "CLOSE:%s", msg);
     grpc_error_free_string(msg);
@@ -143,6 +138,82 @@ char *grpc_transport_stream_op_string(grpc_transport_stream_op *op) {
   return out;
 }
 
+char *grpc_transport_op_string(grpc_transport_op *op) {
+  char *tmp;
+  char *out;
+  bool first = true;
+
+  gpr_strvec b;
+  gpr_strvec_init(&b);
+
+  if (op->on_connectivity_state_change != NULL) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    if (op->connectivity_state != NULL) {
+      gpr_asprintf(&tmp, "ON_CONNECTIVITY_STATE_CHANGE:p=%p:from=%s",
+                   op->on_connectivity_state_change,
+                   grpc_connectivity_state_name(*op->connectivity_state));
+      gpr_strvec_add(&b, tmp);
+    } else {
+      gpr_asprintf(&tmp, "ON_CONNECTIVITY_STATE_CHANGE:p=%p:unsubscribe",
+                   op->on_connectivity_state_change);
+      gpr_strvec_add(&b, tmp);
+    }
+  }
+
+  if (op->disconnect_with_error != GRPC_ERROR_NONE) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    const char *err = grpc_error_string(op->disconnect_with_error);
+    gpr_asprintf(&tmp, "DISCONNECT:%s", err);
+    gpr_strvec_add(&b, tmp);
+    grpc_error_free_string(err);
+  }
+
+  if (op->send_goaway) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    char *msg = op->goaway_message == NULL
+                    ? "null"
+                    : gpr_dump_slice(*op->goaway_message,
+                                     GPR_DUMP_ASCII | GPR_DUMP_HEX);
+    gpr_asprintf(&tmp, "SEND_GOAWAY:status=%d:msg=%s", op->goaway_status, msg);
+    if (op->goaway_message != NULL) gpr_free(msg);
+    gpr_strvec_add(&b, tmp);
+  }
+
+  if (op->set_accept_stream) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    gpr_asprintf(&tmp, "SET_ACCEPT_STREAM:%p(%p,...)", op->set_accept_stream_fn,
+                 op->set_accept_stream_user_data);
+    gpr_strvec_add(&b, tmp);
+  }
+
+  if (op->bind_pollset != NULL) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    gpr_strvec_add(&b, gpr_strdup("BIND_POLLSET"));
+  }
+
+  if (op->bind_pollset_set != NULL) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    gpr_strvec_add(&b, gpr_strdup("BIND_POLLSET_SET"));
+  }
+
+  if (op->send_ping != NULL) {
+    if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
+    first = false;
+    gpr_strvec_add(&b, gpr_strdup("SEND_PING"));
+  }
+
+  out = gpr_strvec_flatten(&b, NULL);
+  gpr_strvec_destroy(&b);
+
+  return out;
+}
+
 void grpc_call_log_op(char *file, int line, gpr_log_severity severity,
                       grpc_call_element *elem, grpc_transport_stream_op *op) {
   char *str = grpc_transport_stream_op_string(op);
diff --git a/src/core/lib/iomgr/workqueue_posix.h b/src/cpp/test/server_context_test_spouse.cc
index 03ee21cef7..b93152eea0 100644
--- a/src/core/lib/iomgr/workqueue_posix.h
+++ b/src/cpp/test/server_context_test_spouse.cc
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,31 +31,22 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_IOMGR_WORKQUEUE_POSIX_H
-#define GRPC_CORE_LIB_IOMGR_WORKQUEUE_POSIX_H
-
-#include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/support/mpscq.h"
-
-struct grpc_fd;
-
-struct grpc_workqueue {
-  gpr_refcount refs;
-  gpr_mpscq queue;
-  // state is:
-  // lower bit - zero if orphaned
-  // other bits - number of items enqueued
-  gpr_atm state;
-
-  grpc_wakeup_fd wakeup_fd;
-  struct grpc_fd *wakeup_read_fd;
-
-  grpc_closure read_closure;
-};
-
-/** Create a work queue. Returns an error if creation fails. If creation
-    succeeds, sets *workqueue to point to it. */
-grpc_error *grpc_workqueue_create(grpc_exec_ctx *exec_ctx,
-                                  grpc_workqueue **workqueue);
-
-#endif /* GRPC_CORE_LIB_IOMGR_WORKQUEUE_POSIX_H */
+#include <grpc++/test/server_context_test_spouse.h>
+
+namespace grpc {
+namespace testing {
+
+void ServerContextTestSpouse::AddClientMetadata(const grpc::string& key,
+                                                const grpc::string& value) {
+  client_metadata_storage_.insert(
+      std::pair<grpc::string, grpc::string>(key, value));
+  ctx_->client_metadata_.clear();
+  for (auto iter = client_metadata_storage_.begin();
+       iter != client_metadata_storage_.end(); ++iter) {
+    ctx_->client_metadata_.insert(std::pair<grpc::string_ref, grpc::string_ref>(
+        iter->first.c_str(), iter->second.c_str()));
+  }
+}
+
+}  // namespace testing
+}  // namespace grpc
diff --git a/src/csharp/Grpc.Examples/Math.cs b/src/csharp/Grpc.Examples/Math.cs
index a17228c8c5..fae4fd3c26 100644
--- a/src/csharp/Grpc.Examples/Math.cs
+++ b/src/csharp/Grpc.Examples/Math.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Math {
 
   /// <summary>Holder for reflection information generated from math.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class MathReflection {
 
     #region Descriptor
@@ -46,30 +45,35 @@ namespace Math {
 
   }
   #region Messages
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class DivArgs : pb::IMessage<DivArgs> {
     private static readonly pb::MessageParser<DivArgs> _parser = new pb::MessageParser<DivArgs>(() => new DivArgs());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<DivArgs> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Math.MathReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivArgs() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivArgs(DivArgs other) : this() {
       dividend_ = other.dividend_;
       divisor_ = other.divisor_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivArgs Clone() {
       return new DivArgs(this);
     }
@@ -77,6 +81,7 @@ namespace Math {
     /// <summary>Field number for the "dividend" field.</summary>
     public const int DividendFieldNumber = 1;
     private long dividend_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Dividend {
       get { return dividend_; }
       set {
@@ -87,6 +92,7 @@ namespace Math {
     /// <summary>Field number for the "divisor" field.</summary>
     public const int DivisorFieldNumber = 2;
     private long divisor_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Divisor {
       get { return divisor_; }
       set {
@@ -94,10 +100,12 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as DivArgs);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(DivArgs other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -110,6 +118,7 @@ namespace Math {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Dividend != 0L) hash ^= Dividend.GetHashCode();
@@ -117,10 +126,12 @@ namespace Math {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Dividend != 0L) {
         output.WriteRawTag(8);
@@ -132,6 +143,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Dividend != 0L) {
@@ -143,6 +155,7 @@ namespace Math {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(DivArgs other) {
       if (other == null) {
         return;
@@ -155,6 +168,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -176,30 +190,35 @@ namespace Math {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class DivReply : pb::IMessage<DivReply> {
     private static readonly pb::MessageParser<DivReply> _parser = new pb::MessageParser<DivReply>(() => new DivReply());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<DivReply> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Math.MathReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivReply() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivReply(DivReply other) : this() {
       quotient_ = other.quotient_;
       remainder_ = other.remainder_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public DivReply Clone() {
       return new DivReply(this);
     }
@@ -207,6 +226,7 @@ namespace Math {
     /// <summary>Field number for the "quotient" field.</summary>
     public const int QuotientFieldNumber = 1;
     private long quotient_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Quotient {
       get { return quotient_; }
       set {
@@ -217,6 +237,7 @@ namespace Math {
     /// <summary>Field number for the "remainder" field.</summary>
     public const int RemainderFieldNumber = 2;
     private long remainder_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Remainder {
       get { return remainder_; }
       set {
@@ -224,10 +245,12 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as DivReply);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(DivReply other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -240,6 +263,7 @@ namespace Math {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Quotient != 0L) hash ^= Quotient.GetHashCode();
@@ -247,10 +271,12 @@ namespace Math {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Quotient != 0L) {
         output.WriteRawTag(8);
@@ -262,6 +288,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Quotient != 0L) {
@@ -273,6 +300,7 @@ namespace Math {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(DivReply other) {
       if (other == null) {
         return;
@@ -285,6 +313,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -306,29 +335,34 @@ namespace Math {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class FibArgs : pb::IMessage<FibArgs> {
     private static readonly pb::MessageParser<FibArgs> _parser = new pb::MessageParser<FibArgs>(() => new FibArgs());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<FibArgs> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Math.MathReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibArgs() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibArgs(FibArgs other) : this() {
       limit_ = other.limit_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibArgs Clone() {
       return new FibArgs(this);
     }
@@ -336,6 +370,7 @@ namespace Math {
     /// <summary>Field number for the "limit" field.</summary>
     public const int LimitFieldNumber = 1;
     private long limit_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Limit {
       get { return limit_; }
       set {
@@ -343,10 +378,12 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as FibArgs);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(FibArgs other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -358,16 +395,19 @@ namespace Math {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Limit != 0L) hash ^= Limit.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Limit != 0L) {
         output.WriteRawTag(8);
@@ -375,6 +415,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Limit != 0L) {
@@ -383,6 +424,7 @@ namespace Math {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(FibArgs other) {
       if (other == null) {
         return;
@@ -392,6 +434,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -409,29 +452,34 @@ namespace Math {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Num : pb::IMessage<Num> {
     private static readonly pb::MessageParser<Num> _parser = new pb::MessageParser<Num>(() => new Num());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Num> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Math.MathReflection.Descriptor.MessageTypes[3]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Num() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Num(Num other) : this() {
       num_ = other.num_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Num Clone() {
       return new Num(this);
     }
@@ -439,6 +487,7 @@ namespace Math {
     /// <summary>Field number for the "num" field.</summary>
     public const int Num_FieldNumber = 1;
     private long num_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Num_ {
       get { return num_; }
       set {
@@ -446,10 +495,12 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Num);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Num other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -461,16 +512,19 @@ namespace Math {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Num_ != 0L) hash ^= Num_.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Num_ != 0L) {
         output.WriteRawTag(8);
@@ -478,6 +532,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Num_ != 0L) {
@@ -486,6 +541,7 @@ namespace Math {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Num other) {
       if (other == null) {
         return;
@@ -495,6 +551,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -512,29 +569,34 @@ namespace Math {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class FibReply : pb::IMessage<FibReply> {
     private static readonly pb::MessageParser<FibReply> _parser = new pb::MessageParser<FibReply>(() => new FibReply());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<FibReply> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Math.MathReflection.Descriptor.MessageTypes[4]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibReply() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibReply(FibReply other) : this() {
       count_ = other.count_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public FibReply Clone() {
       return new FibReply(this);
     }
@@ -542,6 +604,7 @@ namespace Math {
     /// <summary>Field number for the "count" field.</summary>
     public const int CountFieldNumber = 1;
     private long count_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long Count {
       get { return count_; }
       set {
@@ -549,10 +612,12 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as FibReply);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(FibReply other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -564,16 +629,19 @@ namespace Math {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Count != 0L) hash ^= Count.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Count != 0L) {
         output.WriteRawTag(8);
@@ -581,6 +649,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Count != 0L) {
@@ -589,6 +658,7 @@ namespace Math {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(FibReply other) {
       if (other == null) {
         return;
@@ -598,6 +668,7 @@ namespace Math {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.Examples/MathGrpc.cs b/src/csharp/Grpc.Examples/MathGrpc.cs
index 25abc51419..d6ba61e7dc 100644
--- a/src/csharp/Grpc.Examples/MathGrpc.cs
+++ b/src/csharp/Grpc.Examples/MathGrpc.cs
@@ -234,6 +234,7 @@ namespace Math {
       {
         return CallInvoker.AsyncClientStreamingCall(__Method_Sum, null, options);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override MathClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new MathClient(configuration);
diff --git a/src/csharp/Grpc.HealthCheck/Health.cs b/src/csharp/Grpc.HealthCheck/Health.cs
index 100ad187d7..b8e2e2274c 100644
--- a/src/csharp/Grpc.HealthCheck/Health.cs
+++ b/src/csharp/Grpc.HealthCheck/Health.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Health.V1 {
 
   /// <summary>Holder for reflection information generated from health.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class HealthReflection {
 
     #region Descriptor
@@ -42,29 +41,34 @@ namespace Grpc.Health.V1 {
 
   }
   #region Messages
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class HealthCheckRequest : pb::IMessage<HealthCheckRequest> {
     private static readonly pb::MessageParser<HealthCheckRequest> _parser = new pb::MessageParser<HealthCheckRequest>(() => new HealthCheckRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HealthCheckRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Health.V1.HealthReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckRequest(HealthCheckRequest other) : this() {
       service_ = other.service_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckRequest Clone() {
       return new HealthCheckRequest(this);
     }
@@ -72,6 +76,7 @@ namespace Grpc.Health.V1 {
     /// <summary>Field number for the "service" field.</summary>
     public const int ServiceFieldNumber = 1;
     private string service_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Service {
       get { return service_; }
       set {
@@ -79,10 +84,12 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as HealthCheckRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(HealthCheckRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -94,16 +101,19 @@ namespace Grpc.Health.V1 {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Service.Length != 0) hash ^= Service.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Service.Length != 0) {
         output.WriteRawTag(10);
@@ -111,6 +121,7 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Service.Length != 0) {
@@ -119,6 +130,7 @@ namespace Grpc.Health.V1 {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(HealthCheckRequest other) {
       if (other == null) {
         return;
@@ -128,6 +140,7 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -145,29 +158,34 @@ namespace Grpc.Health.V1 {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class HealthCheckResponse : pb::IMessage<HealthCheckResponse> {
     private static readonly pb::MessageParser<HealthCheckResponse> _parser = new pb::MessageParser<HealthCheckResponse>(() => new HealthCheckResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HealthCheckResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Health.V1.HealthReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckResponse(HealthCheckResponse other) : this() {
       status_ = other.status_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HealthCheckResponse Clone() {
       return new HealthCheckResponse(this);
     }
@@ -175,6 +193,7 @@ namespace Grpc.Health.V1 {
     /// <summary>Field number for the "status" field.</summary>
     public const int StatusFieldNumber = 1;
     private global::Grpc.Health.V1.HealthCheckResponse.Types.ServingStatus status_ = 0;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Health.V1.HealthCheckResponse.Types.ServingStatus Status {
       get { return status_; }
       set {
@@ -182,10 +201,12 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as HealthCheckResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(HealthCheckResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -197,16 +218,19 @@ namespace Grpc.Health.V1 {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Status != 0) hash ^= Status.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Status != 0) {
         output.WriteRawTag(8);
@@ -214,6 +238,7 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Status != 0) {
@@ -222,6 +247,7 @@ namespace Grpc.Health.V1 {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(HealthCheckResponse other) {
       if (other == null) {
         return;
@@ -231,6 +257,7 @@ namespace Grpc.Health.V1 {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -248,7 +275,7 @@ namespace Grpc.Health.V1 {
 
     #region Nested types
     /// <summary>Container for nested types declared in the HealthCheckResponse message type.</summary>
-    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static partial class Types {
       public enum ServingStatus {
         [pbr::OriginalName("UNKNOWN")] Unknown = 0,
diff --git a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
index 43eea0f22f..b2a35a79be 100644
--- a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
+++ b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
@@ -107,6 +107,7 @@ namespace Grpc.Health.V1 {
       {
         return CallInvoker.AsyncUnaryCall(__Method_Check, null, options, request);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override HealthClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new HealthClient(configuration);
diff --git a/src/csharp/Grpc.IntegrationTesting/Control.cs b/src/csharp/Grpc.IntegrationTesting/Control.cs
index 412f800ff9..7928b51ba5 100644
--- a/src/csharp/Grpc.IntegrationTesting/Control.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Control.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/control.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class ControlReflection {
 
     #region Descriptor
@@ -71,18 +70,19 @@ namespace Grpc.Testing {
             "ASgBEhoKEmNsaWVudF9zeXN0ZW1fdGltZRgFIAEoARIYChBjbGllbnRfdXNl",
             "cl90aW1lGAYgASgBEhIKCmxhdGVuY3lfNTAYByABKAESEgoKbGF0ZW5jeV85",
             "MBgIIAEoARISCgpsYXRlbmN5Xzk1GAkgASgBEhIKCmxhdGVuY3lfOTkYCiAB",
-            "KAESEwoLbGF0ZW5jeV85OTkYCyABKAEimAIKDlNjZW5hcmlvUmVzdWx0EigK",
+            "KAESEwoLbGF0ZW5jeV85OTkYCyABKAEiyAIKDlNjZW5hcmlvUmVzdWx0EigK",
             "CHNjZW5hcmlvGAEgASgLMhYuZ3JwYy50ZXN0aW5nLlNjZW5hcmlvEi4KCWxh",
             "dGVuY2llcxgCIAEoCzIbLmdycGMudGVzdGluZy5IaXN0b2dyYW1EYXRhEi8K",
             "DGNsaWVudF9zdGF0cxgDIAMoCzIZLmdycGMudGVzdGluZy5DbGllbnRTdGF0",
             "cxIvCgxzZXJ2ZXJfc3RhdHMYBCADKAsyGS5ncnBjLnRlc3RpbmcuU2VydmVy",
             "U3RhdHMSFAoMc2VydmVyX2NvcmVzGAUgAygFEjQKB3N1bW1hcnkYBiABKAsy",
-            "Iy5ncnBjLnRlc3RpbmcuU2NlbmFyaW9SZXN1bHRTdW1tYXJ5KkEKCkNsaWVu",
-            "dFR5cGUSDwoLU1lOQ19DTElFTlQQABIQCgxBU1lOQ19DTElFTlQQARIQCgxP",
-            "VEhFUl9DTElFTlQQAipbCgpTZXJ2ZXJUeXBlEg8KC1NZTkNfU0VSVkVSEAAS",
-            "EAoMQVNZTkNfU0VSVkVSEAESGAoUQVNZTkNfR0VORVJJQ19TRVJWRVIQAhIQ",
-            "CgxPVEhFUl9TRVJWRVIQAyojCgdScGNUeXBlEgkKBVVOQVJZEAASDQoJU1RS",
-            "RUFNSU5HEAFiBnByb3RvMw=="));
+            "Iy5ncnBjLnRlc3RpbmcuU2NlbmFyaW9SZXN1bHRTdW1tYXJ5EhYKDmNsaWVu",
+            "dF9zdWNjZXNzGAcgAygIEhYKDnNlcnZlcl9zdWNjZXNzGAggAygIKkEKCkNs",
+            "aWVudFR5cGUSDwoLU1lOQ19DTElFTlQQABIQCgxBU1lOQ19DTElFTlQQARIQ",
+            "CgxPVEhFUl9DTElFTlQQAipbCgpTZXJ2ZXJUeXBlEg8KC1NZTkNfU0VSVkVS",
+            "EAASEAoMQVNZTkNfU0VSVkVSEAESGAoUQVNZTkNfR0VORVJJQ19TRVJWRVIQ",
+            "AhIQCgxPVEhFUl9TRVJWRVIQAyojCgdScGNUeXBlEgkKBVVOQVJZEAASDQoJ",
+            "U1RSRUFNSU5HEAFiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { global::Grpc.Testing.PayloadsReflection.Descriptor, global::Grpc.Testing.StatsReflection.Descriptor, },
           new pbr::GeneratedClrTypeInfo(new[] {typeof(global::Grpc.Testing.ClientType), typeof(global::Grpc.Testing.ServerType), typeof(global::Grpc.Testing.RpcType), }, new pbr::GeneratedClrTypeInfo[] {
@@ -103,7 +103,7 @@ namespace Grpc.Testing {
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.Scenario), global::Grpc.Testing.Scenario.Parser, new[]{ "Name", "ClientConfig", "NumClients", "ServerConfig", "NumServers", "WarmupSeconds", "BenchmarkSeconds", "SpawnLocalWorkerCount" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.Scenarios), global::Grpc.Testing.Scenarios.Parser, new[]{ "Scenarios_" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ScenarioResultSummary), global::Grpc.Testing.ScenarioResultSummary.Parser, new[]{ "Qps", "QpsPerServerCore", "ServerSystemTime", "ServerUserTime", "ClientSystemTime", "ClientUserTime", "Latency50", "Latency90", "Latency95", "Latency99", "Latency999" }, null, null, null),
-            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ScenarioResult), global::Grpc.Testing.ScenarioResult.Parser, new[]{ "Scenario", "Latencies", "ClientStats", "ServerStats", "ServerCores", "Summary" }, null, null, null)
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ScenarioResult), global::Grpc.Testing.ScenarioResult.Parser, new[]{ "Scenario", "Latencies", "ClientStats", "ServerStats", "ServerCores", "Summary", "ClientSuccess", "ServerSuccess" }, null, null, null)
           }));
     }
     #endregion
@@ -145,29 +145,34 @@ namespace Grpc.Testing {
   ///  Parameters of poisson process distribution, which is a good representation
   ///  of activity coming in from independent identical stationary sources.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class PoissonParams : pb::IMessage<PoissonParams> {
     private static readonly pb::MessageParser<PoissonParams> _parser = new pb::MessageParser<PoissonParams>(() => new PoissonParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<PoissonParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PoissonParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PoissonParams(PoissonParams other) : this() {
       offeredLoad_ = other.offeredLoad_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PoissonParams Clone() {
       return new PoissonParams(this);
     }
@@ -178,6 +183,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  The rate of arrivals (a.k.a. lambda parameter of the exp distribution).
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double OfferedLoad {
       get { return offeredLoad_; }
       set {
@@ -185,10 +191,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as PoissonParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(PoissonParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -200,16 +208,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (OfferedLoad != 0D) hash ^= OfferedLoad.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (OfferedLoad != 0D) {
         output.WriteRawTag(9);
@@ -217,6 +228,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (OfferedLoad != 0D) {
@@ -225,6 +237,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(PoissonParams other) {
       if (other == null) {
         return;
@@ -234,6 +247,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -255,36 +269,43 @@ namespace Grpc.Testing {
   ///  Once an RPC finishes, immediately start a new one.
   ///  No configuration parameters needed.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ClosedLoopParams : pb::IMessage<ClosedLoopParams> {
     private static readonly pb::MessageParser<ClosedLoopParams> _parser = new pb::MessageParser<ClosedLoopParams>(() => new ClosedLoopParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClosedLoopParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClosedLoopParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClosedLoopParams(ClosedLoopParams other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClosedLoopParams Clone() {
       return new ClosedLoopParams(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClosedLoopParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ClosedLoopParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -295,29 +316,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ClosedLoopParams other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -331,25 +358,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class LoadParams : pb::IMessage<LoadParams> {
     private static readonly pb::MessageParser<LoadParams> _parser = new pb::MessageParser<LoadParams>(() => new LoadParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<LoadParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public LoadParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public LoadParams(LoadParams other) : this() {
       switch (other.LoadCase) {
         case LoadOneofCase.ClosedLoop:
@@ -362,12 +393,14 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public LoadParams Clone() {
       return new LoadParams(this);
     }
 
     /// <summary>Field number for the "closed_loop" field.</summary>
     public const int ClosedLoopFieldNumber = 1;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ClosedLoopParams ClosedLoop {
       get { return loadCase_ == LoadOneofCase.ClosedLoop ? (global::Grpc.Testing.ClosedLoopParams) load_ : null; }
       set {
@@ -378,6 +411,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "poisson" field.</summary>
     public const int PoissonFieldNumber = 2;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PoissonParams Poisson {
       get { return loadCase_ == LoadOneofCase.Poisson ? (global::Grpc.Testing.PoissonParams) load_ : null; }
       set {
@@ -394,19 +428,23 @@ namespace Grpc.Testing {
       Poisson = 2,
     }
     private LoadOneofCase loadCase_ = LoadOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public LoadOneofCase LoadCase {
       get { return loadCase_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void ClearLoad() {
       loadCase_ = LoadOneofCase.None;
       load_ = null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as LoadParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(LoadParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -420,6 +458,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (loadCase_ == LoadOneofCase.ClosedLoop) hash ^= ClosedLoop.GetHashCode();
@@ -428,10 +467,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (loadCase_ == LoadOneofCase.ClosedLoop) {
         output.WriteRawTag(10);
@@ -443,6 +484,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (loadCase_ == LoadOneofCase.ClosedLoop) {
@@ -454,6 +496,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(LoadParams other) {
       if (other == null) {
         return;
@@ -469,6 +512,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -503,30 +547,35 @@ namespace Grpc.Testing {
   /// <summary>
   ///  presence of SecurityParams implies use of TLS
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class SecurityParams : pb::IMessage<SecurityParams> {
     private static readonly pb::MessageParser<SecurityParams> _parser = new pb::MessageParser<SecurityParams>(() => new SecurityParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SecurityParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[3]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SecurityParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SecurityParams(SecurityParams other) : this() {
       useTestCa_ = other.useTestCa_;
       serverHostOverride_ = other.serverHostOverride_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SecurityParams Clone() {
       return new SecurityParams(this);
     }
@@ -534,6 +583,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "use_test_ca" field.</summary>
     public const int UseTestCaFieldNumber = 1;
     private bool useTestCa_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool UseTestCa {
       get { return useTestCa_; }
       set {
@@ -544,6 +594,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "server_host_override" field.</summary>
     public const int ServerHostOverrideFieldNumber = 2;
     private string serverHostOverride_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string ServerHostOverride {
       get { return serverHostOverride_; }
       set {
@@ -551,10 +602,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as SecurityParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(SecurityParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -567,6 +620,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (UseTestCa != false) hash ^= UseTestCa.GetHashCode();
@@ -574,10 +628,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (UseTestCa != false) {
         output.WriteRawTag(8);
@@ -589,6 +645,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (UseTestCa != false) {
@@ -600,6 +657,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(SecurityParams other) {
       if (other == null) {
         return;
@@ -612,6 +670,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -633,25 +692,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ClientConfig : pb::IMessage<ClientConfig> {
     private static readonly pb::MessageParser<ClientConfig> _parser = new pb::MessageParser<ClientConfig>(() => new ClientConfig());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientConfig> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[4]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientConfig() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientConfig(ClientConfig other) : this() {
       serverTargets_ = other.serverTargets_.Clone();
       clientType_ = other.clientType_;
@@ -668,6 +731,7 @@ namespace Grpc.Testing {
       otherClientApi_ = other.otherClientApi_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientConfig Clone() {
       return new ClientConfig(this);
     }
@@ -680,6 +744,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  List of targets to connect to. At least one target needs to be specified.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<string> ServerTargets {
       get { return serverTargets_; }
     }
@@ -687,6 +752,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "client_type" field.</summary>
     public const int ClientTypeFieldNumber = 2;
     private global::Grpc.Testing.ClientType clientType_ = 0;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ClientType ClientType {
       get { return clientType_; }
       set {
@@ -697,6 +763,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "security_params" field.</summary>
     public const int SecurityParamsFieldNumber = 3;
     private global::Grpc.Testing.SecurityParams securityParams_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.SecurityParams SecurityParams {
       get { return securityParams_; }
       set {
@@ -711,6 +778,7 @@ namespace Grpc.Testing {
     ///  How many concurrent RPCs to start for each channel.
     ///  For synchronous client, use a separate thread for each outstanding RPC.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int OutstandingRpcsPerChannel {
       get { return outstandingRpcsPerChannel_; }
       set {
@@ -725,6 +793,7 @@ namespace Grpc.Testing {
     ///  Number of independent client channels to create.
     ///  i-th channel will connect to server_target[i % server_targets.size()]
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int ClientChannels {
       get { return clientChannels_; }
       set {
@@ -738,6 +807,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Only for async client. Number of threads to use to start/manage RPCs.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int AsyncClientThreads {
       get { return asyncClientThreads_; }
       set {
@@ -748,6 +818,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "rpc_type" field.</summary>
     public const int RpcTypeFieldNumber = 8;
     private global::Grpc.Testing.RpcType rpcType_ = 0;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.RpcType RpcType {
       get { return rpcType_; }
       set {
@@ -761,6 +832,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  The requested load for the entire client (aggregated over all the threads).
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.LoadParams LoadParams {
       get { return loadParams_; }
       set {
@@ -771,6 +843,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "payload_config" field.</summary>
     public const int PayloadConfigFieldNumber = 11;
     private global::Grpc.Testing.PayloadConfig payloadConfig_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PayloadConfig PayloadConfig {
       get { return payloadConfig_; }
       set {
@@ -781,6 +854,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "histogram_params" field.</summary>
     public const int HistogramParamsFieldNumber = 12;
     private global::Grpc.Testing.HistogramParams histogramParams_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.HistogramParams HistogramParams {
       get { return histogramParams_; }
       set {
@@ -796,6 +870,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Specify the cores we should run the client on, if desired
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<int> CoreList {
       get { return coreList_; }
     }
@@ -803,6 +878,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "core_limit" field.</summary>
     public const int CoreLimitFieldNumber = 14;
     private int coreLimit_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CoreLimit {
       get { return coreLimit_; }
       set {
@@ -816,6 +892,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  If we use an OTHER_CLIENT client_type, this string gives more detail
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string OtherClientApi {
       get { return otherClientApi_; }
       set {
@@ -823,10 +900,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClientConfig);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ClientConfig other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -850,6 +929,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= serverTargets_.GetHashCode();
@@ -868,10 +948,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       serverTargets_.WriteTo(output, _repeated_serverTargets_codec);
       if (ClientType != 0) {
@@ -921,6 +1003,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += serverTargets_.CalculateSize(_repeated_serverTargets_codec);
@@ -961,6 +1044,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ClientConfig other) {
       if (other == null) {
         return;
@@ -1014,6 +1098,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1092,29 +1177,34 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ClientStatus : pb::IMessage<ClientStatus> {
     private static readonly pb::MessageParser<ClientStatus> _parser = new pb::MessageParser<ClientStatus>(() => new ClientStatus());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientStatus> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[5]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStatus() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStatus(ClientStatus other) : this() {
       Stats = other.stats_ != null ? other.Stats.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStatus Clone() {
       return new ClientStatus(this);
     }
@@ -1122,6 +1212,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "stats" field.</summary>
     public const int StatsFieldNumber = 1;
     private global::Grpc.Testing.ClientStats stats_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ClientStats Stats {
       get { return stats_; }
       set {
@@ -1129,10 +1220,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClientStatus);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ClientStatus other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1144,16 +1237,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (stats_ != null) hash ^= Stats.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (stats_ != null) {
         output.WriteRawTag(10);
@@ -1161,6 +1257,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (stats_ != null) {
@@ -1169,6 +1266,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ClientStatus other) {
       if (other == null) {
         return;
@@ -1181,6 +1279,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1204,29 +1303,34 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Request current stats
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Mark : pb::IMessage<Mark> {
     private static readonly pb::MessageParser<Mark> _parser = new pb::MessageParser<Mark>(() => new Mark());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Mark> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[6]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Mark() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Mark(Mark other) : this() {
       reset_ = other.reset_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Mark Clone() {
       return new Mark(this);
     }
@@ -1237,6 +1341,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  if true, the stats will be reset after taking their snapshot.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Reset {
       get { return reset_; }
       set {
@@ -1244,10 +1349,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Mark);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Mark other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1259,16 +1366,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Reset != false) hash ^= Reset.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Reset != false) {
         output.WriteRawTag(8);
@@ -1276,6 +1386,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Reset != false) {
@@ -1284,6 +1395,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Mark other) {
       if (other == null) {
         return;
@@ -1293,6 +1405,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1310,25 +1423,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ClientArgs : pb::IMessage<ClientArgs> {
     private static readonly pb::MessageParser<ClientArgs> _parser = new pb::MessageParser<ClientArgs>(() => new ClientArgs());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientArgs> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[7]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientArgs() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientArgs(ClientArgs other) : this() {
       switch (other.ArgtypeCase) {
         case ArgtypeOneofCase.Setup:
@@ -1341,12 +1458,14 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientArgs Clone() {
       return new ClientArgs(this);
     }
 
     /// <summary>Field number for the "setup" field.</summary>
     public const int SetupFieldNumber = 1;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ClientConfig Setup {
       get { return argtypeCase_ == ArgtypeOneofCase.Setup ? (global::Grpc.Testing.ClientConfig) argtype_ : null; }
       set {
@@ -1357,6 +1476,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "mark" field.</summary>
     public const int MarkFieldNumber = 2;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Mark Mark {
       get { return argtypeCase_ == ArgtypeOneofCase.Mark ? (global::Grpc.Testing.Mark) argtype_ : null; }
       set {
@@ -1373,19 +1493,23 @@ namespace Grpc.Testing {
       Mark = 2,
     }
     private ArgtypeOneofCase argtypeCase_ = ArgtypeOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ArgtypeOneofCase ArgtypeCase {
       get { return argtypeCase_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void ClearArgtype() {
       argtypeCase_ = ArgtypeOneofCase.None;
       argtype_ = null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClientArgs);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ClientArgs other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1399,6 +1523,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (argtypeCase_ == ArgtypeOneofCase.Setup) hash ^= Setup.GetHashCode();
@@ -1407,10 +1532,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (argtypeCase_ == ArgtypeOneofCase.Setup) {
         output.WriteRawTag(10);
@@ -1422,6 +1549,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (argtypeCase_ == ArgtypeOneofCase.Setup) {
@@ -1433,6 +1561,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ClientArgs other) {
       if (other == null) {
         return;
@@ -1448,6 +1577,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1479,25 +1609,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ServerConfig : pb::IMessage<ServerConfig> {
     private static readonly pb::MessageParser<ServerConfig> _parser = new pb::MessageParser<ServerConfig>(() => new ServerConfig());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerConfig> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[8]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerConfig() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerConfig(ServerConfig other) : this() {
       serverType_ = other.serverType_;
       SecurityParams = other.securityParams_ != null ? other.SecurityParams.Clone() : null;
@@ -1509,6 +1643,7 @@ namespace Grpc.Testing {
       otherServerApi_ = other.otherServerApi_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerConfig Clone() {
       return new ServerConfig(this);
     }
@@ -1516,6 +1651,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "server_type" field.</summary>
     public const int ServerTypeFieldNumber = 1;
     private global::Grpc.Testing.ServerType serverType_ = 0;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ServerType ServerType {
       get { return serverType_; }
       set {
@@ -1526,6 +1662,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "security_params" field.</summary>
     public const int SecurityParamsFieldNumber = 2;
     private global::Grpc.Testing.SecurityParams securityParams_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.SecurityParams SecurityParams {
       get { return securityParams_; }
       set {
@@ -1539,6 +1676,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Port on which to listen. Zero means pick unused port.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Port {
       get { return port_; }
       set {
@@ -1552,6 +1690,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Only for async server. Number of threads used to serve the requests.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int AsyncServerThreads {
       get { return asyncServerThreads_; }
       set {
@@ -1565,6 +1704,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Specify the number of cores to limit server to, if desired
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CoreLimit {
       get { return coreLimit_; }
       set {
@@ -1578,6 +1718,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  payload config, used in generic server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PayloadConfig PayloadConfig {
       get { return payloadConfig_; }
       set {
@@ -1593,6 +1734,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Specify the cores we should run the server on, if desired
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<int> CoreList {
       get { return coreList_; }
     }
@@ -1603,6 +1745,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  If we use an OTHER_SERVER client_type, this string gives more detail
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string OtherServerApi {
       get { return otherServerApi_; }
       set {
@@ -1610,10 +1753,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ServerConfig);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ServerConfig other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1632,6 +1777,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (ServerType != 0) hash ^= ServerType.GetHashCode();
@@ -1645,10 +1791,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (ServerType != 0) {
         output.WriteRawTag(8);
@@ -1681,6 +1829,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (ServerType != 0) {
@@ -1708,6 +1857,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ServerConfig other) {
       if (other == null) {
         return;
@@ -1742,6 +1892,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1794,25 +1945,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ServerArgs : pb::IMessage<ServerArgs> {
     private static readonly pb::MessageParser<ServerArgs> _parser = new pb::MessageParser<ServerArgs>(() => new ServerArgs());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerArgs> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[9]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerArgs() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerArgs(ServerArgs other) : this() {
       switch (other.ArgtypeCase) {
         case ArgtypeOneofCase.Setup:
@@ -1825,12 +1980,14 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerArgs Clone() {
       return new ServerArgs(this);
     }
 
     /// <summary>Field number for the "setup" field.</summary>
     public const int SetupFieldNumber = 1;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ServerConfig Setup {
       get { return argtypeCase_ == ArgtypeOneofCase.Setup ? (global::Grpc.Testing.ServerConfig) argtype_ : null; }
       set {
@@ -1841,6 +1998,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "mark" field.</summary>
     public const int MarkFieldNumber = 2;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Mark Mark {
       get { return argtypeCase_ == ArgtypeOneofCase.Mark ? (global::Grpc.Testing.Mark) argtype_ : null; }
       set {
@@ -1857,19 +2015,23 @@ namespace Grpc.Testing {
       Mark = 2,
     }
     private ArgtypeOneofCase argtypeCase_ = ArgtypeOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ArgtypeOneofCase ArgtypeCase {
       get { return argtypeCase_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void ClearArgtype() {
       argtypeCase_ = ArgtypeOneofCase.None;
       argtype_ = null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ServerArgs);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ServerArgs other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1883,6 +2045,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (argtypeCase_ == ArgtypeOneofCase.Setup) hash ^= Setup.GetHashCode();
@@ -1891,10 +2054,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (argtypeCase_ == ArgtypeOneofCase.Setup) {
         output.WriteRawTag(10);
@@ -1906,6 +2071,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (argtypeCase_ == ArgtypeOneofCase.Setup) {
@@ -1917,6 +2083,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ServerArgs other) {
       if (other == null) {
         return;
@@ -1932,6 +2099,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1963,31 +2131,36 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ServerStatus : pb::IMessage<ServerStatus> {
     private static readonly pb::MessageParser<ServerStatus> _parser = new pb::MessageParser<ServerStatus>(() => new ServerStatus());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerStatus> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[10]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStatus() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStatus(ServerStatus other) : this() {
       Stats = other.stats_ != null ? other.Stats.Clone() : null;
       port_ = other.port_;
       cores_ = other.cores_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStatus Clone() {
       return new ServerStatus(this);
     }
@@ -1995,6 +2168,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "stats" field.</summary>
     public const int StatsFieldNumber = 1;
     private global::Grpc.Testing.ServerStats stats_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ServerStats Stats {
       get { return stats_; }
       set {
@@ -2008,6 +2182,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  the port bound by the server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Port {
       get { return port_; }
       set {
@@ -2021,6 +2196,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of cores available to the server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Cores {
       get { return cores_; }
       set {
@@ -2028,10 +2204,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ServerStatus);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ServerStatus other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2045,6 +2223,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (stats_ != null) hash ^= Stats.GetHashCode();
@@ -2053,10 +2232,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (stats_ != null) {
         output.WriteRawTag(10);
@@ -2072,6 +2253,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (stats_ != null) {
@@ -2086,6 +2268,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ServerStatus other) {
       if (other == null) {
         return;
@@ -2104,6 +2287,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2132,36 +2316,43 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class CoreRequest : pb::IMessage<CoreRequest> {
     private static readonly pb::MessageParser<CoreRequest> _parser = new pb::MessageParser<CoreRequest>(() => new CoreRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<CoreRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[11]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreRequest(CoreRequest other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreRequest Clone() {
       return new CoreRequest(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as CoreRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(CoreRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2172,29 +2363,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(CoreRequest other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2208,29 +2405,34 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class CoreResponse : pb::IMessage<CoreResponse> {
     private static readonly pb::MessageParser<CoreResponse> _parser = new pb::MessageParser<CoreResponse>(() => new CoreResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<CoreResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[12]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreResponse(CoreResponse other) : this() {
       cores_ = other.cores_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public CoreResponse Clone() {
       return new CoreResponse(this);
     }
@@ -2241,6 +2443,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of cores available on the server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Cores {
       get { return cores_; }
       set {
@@ -2248,10 +2451,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as CoreResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(CoreResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2263,16 +2468,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Cores != 0) hash ^= Cores.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Cores != 0) {
         output.WriteRawTag(8);
@@ -2280,6 +2488,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Cores != 0) {
@@ -2288,6 +2497,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(CoreResponse other) {
       if (other == null) {
         return;
@@ -2297,6 +2507,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2314,36 +2525,43 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Void : pb::IMessage<Void> {
     private static readonly pb::MessageParser<Void> _parser = new pb::MessageParser<Void>(() => new Void());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Void> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[13]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Void() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Void(Void other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Void Clone() {
       return new Void(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Void);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Void other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2354,29 +2572,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Void other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2393,25 +2617,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  A single performance scenario: input to qps_json_driver
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Scenario : pb::IMessage<Scenario> {
     private static readonly pb::MessageParser<Scenario> _parser = new pb::MessageParser<Scenario>(() => new Scenario());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Scenario> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[14]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenario() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenario(Scenario other) : this() {
       name_ = other.name_;
       ClientConfig = other.clientConfig_ != null ? other.ClientConfig.Clone() : null;
@@ -2423,6 +2651,7 @@ namespace Grpc.Testing {
       spawnLocalWorkerCount_ = other.spawnLocalWorkerCount_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenario Clone() {
       return new Scenario(this);
     }
@@ -2433,6 +2662,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Human readable name for this scenario
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Name {
       get { return name_; }
       set {
@@ -2446,6 +2676,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Client configuration
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ClientConfig ClientConfig {
       get { return clientConfig_; }
       set {
@@ -2459,6 +2690,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of clients to start for the test
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int NumClients {
       get { return numClients_; }
       set {
@@ -2472,6 +2704,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Server configuration
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ServerConfig ServerConfig {
       get { return serverConfig_; }
       set {
@@ -2485,6 +2718,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of servers to start for the test
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int NumServers {
       get { return numServers_; }
       set {
@@ -2498,6 +2732,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Warmup period, in seconds
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int WarmupSeconds {
       get { return warmupSeconds_; }
       set {
@@ -2511,6 +2746,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Benchmark time, in seconds
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int BenchmarkSeconds {
       get { return benchmarkSeconds_; }
       set {
@@ -2524,6 +2760,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of workers to spawn locally (usually zero)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int SpawnLocalWorkerCount {
       get { return spawnLocalWorkerCount_; }
       set {
@@ -2531,10 +2768,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Scenario);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Scenario other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2553,6 +2792,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
@@ -2566,10 +2806,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -2605,6 +2847,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Name.Length != 0) {
@@ -2634,6 +2877,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Scenario other) {
       if (other == null) {
         return;
@@ -2670,6 +2914,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2724,29 +2969,34 @@ namespace Grpc.Testing {
   /// <summary>
   ///  A set of scenarios to be run with qps_json_driver
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Scenarios : pb::IMessage<Scenarios> {
     private static readonly pb::MessageParser<Scenarios> _parser = new pb::MessageParser<Scenarios>(() => new Scenarios());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Scenarios> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[15]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenarios() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenarios(Scenarios other) : this() {
       scenarios_ = other.scenarios_.Clone();
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Scenarios Clone() {
       return new Scenarios(this);
     }
@@ -2756,14 +3006,17 @@ namespace Grpc.Testing {
     private static readonly pb::FieldCodec<global::Grpc.Testing.Scenario> _repeated_scenarios_codec
         = pb::FieldCodec.ForMessage(10, global::Grpc.Testing.Scenario.Parser);
     private readonly pbc::RepeatedField<global::Grpc.Testing.Scenario> scenarios_ = new pbc::RepeatedField<global::Grpc.Testing.Scenario>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<global::Grpc.Testing.Scenario> Scenarios_ {
       get { return scenarios_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Scenarios);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Scenarios other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -2775,26 +3028,31 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= scenarios_.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       scenarios_.WriteTo(output, _repeated_scenarios_codec);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += scenarios_.CalculateSize(_repeated_scenarios_codec);
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Scenarios other) {
       if (other == null) {
         return;
@@ -2802,6 +3060,7 @@ namespace Grpc.Testing {
       scenarios_.Add(other.scenarios_);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -2823,25 +3082,29 @@ namespace Grpc.Testing {
   ///  Basic summary that can be computed from ClientStats and ServerStats
   ///  once the scenario has finished.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ScenarioResultSummary : pb::IMessage<ScenarioResultSummary> {
     private static readonly pb::MessageParser<ScenarioResultSummary> _parser = new pb::MessageParser<ScenarioResultSummary>(() => new ScenarioResultSummary());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ScenarioResultSummary> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[16]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResultSummary() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResultSummary(ScenarioResultSummary other) : this() {
       qps_ = other.qps_;
       qpsPerServerCore_ = other.qpsPerServerCore_;
@@ -2856,6 +3119,7 @@ namespace Grpc.Testing {
       latency999_ = other.latency999_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResultSummary Clone() {
       return new ScenarioResultSummary(this);
     }
@@ -2866,6 +3130,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Total number of operations per second over all clients.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Qps {
       get { return qps_; }
       set {
@@ -2879,6 +3144,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  QPS per one server core.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double QpsPerServerCore {
       get { return qpsPerServerCore_; }
       set {
@@ -2892,6 +3158,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  server load based on system_time (0.85 => 85%)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double ServerSystemTime {
       get { return serverSystemTime_; }
       set {
@@ -2905,6 +3172,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  server load based on user_time (0.85 => 85%)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double ServerUserTime {
       get { return serverUserTime_; }
       set {
@@ -2918,6 +3186,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  client load based on system_time (0.85 => 85%)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double ClientSystemTime {
       get { return clientSystemTime_; }
       set {
@@ -2931,6 +3200,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  client load based on user_time (0.85 => 85%)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double ClientUserTime {
       get { return clientUserTime_; }
       set {
@@ -2944,6 +3214,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  X% latency percentiles (in nanoseconds)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Latency50 {
       get { return latency50_; }
       set {
@@ -2954,6 +3225,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "latency_90" field.</summary>
     public const int Latency90FieldNumber = 8;
     private double latency90_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Latency90 {
       get { return latency90_; }
       set {
@@ -2964,6 +3236,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "latency_95" field.</summary>
     public const int Latency95FieldNumber = 9;
     private double latency95_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Latency95 {
       get { return latency95_; }
       set {
@@ -2974,6 +3247,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "latency_99" field.</summary>
     public const int Latency99FieldNumber = 10;
     private double latency99_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Latency99 {
       get { return latency99_; }
       set {
@@ -2984,6 +3258,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "latency_999" field.</summary>
     public const int Latency999FieldNumber = 11;
     private double latency999_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Latency999 {
       get { return latency999_; }
       set {
@@ -2991,10 +3266,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ScenarioResultSummary);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ScenarioResultSummary other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -3016,6 +3293,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Qps != 0D) hash ^= Qps.GetHashCode();
@@ -3032,10 +3310,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Qps != 0D) {
         output.WriteRawTag(9);
@@ -3083,6 +3363,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Qps != 0D) {
@@ -3121,6 +3402,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ScenarioResultSummary other) {
       if (other == null) {
         return;
@@ -3160,6 +3442,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -3220,25 +3503,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Results of a single benchmark scenario.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ScenarioResult : pb::IMessage<ScenarioResult> {
     private static readonly pb::MessageParser<ScenarioResult> _parser = new pb::MessageParser<ScenarioResult>(() => new ScenarioResult());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ScenarioResult> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.ControlReflection.Descriptor.MessageTypes[17]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResult() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResult(ScenarioResult other) : this() {
       Scenario = other.scenario_ != null ? other.Scenario.Clone() : null;
       Latencies = other.latencies_ != null ? other.Latencies.Clone() : null;
@@ -3246,8 +3533,11 @@ namespace Grpc.Testing {
       serverStats_ = other.serverStats_.Clone();
       serverCores_ = other.serverCores_.Clone();
       Summary = other.summary_ != null ? other.Summary.Clone() : null;
+      clientSuccess_ = other.clientSuccess_.Clone();
+      serverSuccess_ = other.serverSuccess_.Clone();
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ScenarioResult Clone() {
       return new ScenarioResult(this);
     }
@@ -3258,6 +3548,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Inputs used to run the scenario.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Scenario Scenario {
       get { return scenario_; }
       set {
@@ -3271,6 +3562,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Histograms from all clients merged into one histogram.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.HistogramData Latencies {
       get { return latencies_; }
       set {
@@ -3286,6 +3578,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Client stats for each client
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<global::Grpc.Testing.ClientStats> ClientStats {
       get { return clientStats_; }
     }
@@ -3298,6 +3591,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Server stats for each server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<global::Grpc.Testing.ServerStats> ServerStats {
       get { return serverStats_; }
     }
@@ -3310,6 +3604,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Number of cores available to each server
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<int> ServerCores {
       get { return serverCores_; }
     }
@@ -3320,6 +3615,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  An after-the-fact computed summary
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ScenarioResultSummary Summary {
       get { return summary_; }
       set {
@@ -3327,10 +3623,35 @@ namespace Grpc.Testing {
       }
     }
 
+    /// <summary>Field number for the "client_success" field.</summary>
+    public const int ClientSuccessFieldNumber = 7;
+    private static readonly pb::FieldCodec<bool> _repeated_clientSuccess_codec
+        = pb::FieldCodec.ForBool(58);
+    private readonly pbc::RepeatedField<bool> clientSuccess_ = new pbc::RepeatedField<bool>();
+    /// <summary>
+    ///  Information on success or failure of each worker
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public pbc::RepeatedField<bool> ClientSuccess {
+      get { return clientSuccess_; }
+    }
+
+    /// <summary>Field number for the "server_success" field.</summary>
+    public const int ServerSuccessFieldNumber = 8;
+    private static readonly pb::FieldCodec<bool> _repeated_serverSuccess_codec
+        = pb::FieldCodec.ForBool(66);
+    private readonly pbc::RepeatedField<bool> serverSuccess_ = new pbc::RepeatedField<bool>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public pbc::RepeatedField<bool> ServerSuccess {
+      get { return serverSuccess_; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ScenarioResult);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ScenarioResult other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -3344,9 +3665,12 @@ namespace Grpc.Testing {
       if(!serverStats_.Equals(other.serverStats_)) return false;
       if(!serverCores_.Equals(other.serverCores_)) return false;
       if (!object.Equals(Summary, other.Summary)) return false;
+      if(!clientSuccess_.Equals(other.clientSuccess_)) return false;
+      if(!serverSuccess_.Equals(other.serverSuccess_)) return false;
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (scenario_ != null) hash ^= Scenario.GetHashCode();
@@ -3355,13 +3679,17 @@ namespace Grpc.Testing {
       hash ^= serverStats_.GetHashCode();
       hash ^= serverCores_.GetHashCode();
       if (summary_ != null) hash ^= Summary.GetHashCode();
+      hash ^= clientSuccess_.GetHashCode();
+      hash ^= serverSuccess_.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (scenario_ != null) {
         output.WriteRawTag(10);
@@ -3378,8 +3706,11 @@ namespace Grpc.Testing {
         output.WriteRawTag(50);
         output.WriteMessage(Summary);
       }
+      clientSuccess_.WriteTo(output, _repeated_clientSuccess_codec);
+      serverSuccess_.WriteTo(output, _repeated_serverSuccess_codec);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (scenario_ != null) {
@@ -3394,9 +3725,12 @@ namespace Grpc.Testing {
       if (summary_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(Summary);
       }
+      size += clientSuccess_.CalculateSize(_repeated_clientSuccess_codec);
+      size += serverSuccess_.CalculateSize(_repeated_serverSuccess_codec);
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ScenarioResult other) {
       if (other == null) {
         return;
@@ -3422,8 +3756,11 @@ namespace Grpc.Testing {
         }
         Summary.MergeFrom(other.Summary);
       }
+      clientSuccess_.Add(other.clientSuccess_);
+      serverSuccess_.Add(other.serverSuccess_);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -3465,6 +3802,16 @@ namespace Grpc.Testing {
             input.ReadMessage(summary_);
             break;
           }
+          case 58:
+          case 56: {
+            clientSuccess_.AddEntriesFrom(input, _repeated_clientSuccess_codec);
+            break;
+          }
+          case 66:
+          case 64: {
+            serverSuccess_.AddEntriesFrom(input, _repeated_serverSuccess_codec);
+            break;
+          }
         }
       }
     }
diff --git a/src/csharp/Grpc.IntegrationTesting/Empty.cs b/src/csharp/Grpc.IntegrationTesting/Empty.cs
index cf1c23fb0f..3017e664b9 100644
--- a/src/csharp/Grpc.IntegrationTesting/Empty.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Empty.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/empty.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class EmptyReflection {
 
     #region Descriptor
@@ -44,36 +43,43 @@ namespace Grpc.Testing {
   ///      rpc Bar (grpc.testing.Empty) returns (grpc.testing.Empty) { };
   ///    };
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Empty : pb::IMessage<Empty> {
     private static readonly pb::MessageParser<Empty> _parser = new pb::MessageParser<Empty>(() => new Empty());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Empty> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.EmptyReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Empty() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Empty(Empty other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Empty Clone() {
       return new Empty(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Empty);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Empty other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -84,29 +90,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Empty other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
index 79fd18b6d5..cb926328e0 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
@@ -520,12 +520,12 @@ namespace Grpc.IntegrationTesting
                 };
 
                 var call = client.FullDuplexCall(headers: CreateTestMetadata());
-                var responseHeaders = await call.ResponseHeadersAsync;
 
                 await call.RequestStream.WriteAsync(request);
                 await call.RequestStream.CompleteAsync();
                 await call.ResponseStream.ToListAsync();
 
+                var responseHeaders = await call.ResponseHeadersAsync;
                 var responseTrailers = call.GetTrailers();
 
                 Assert.AreEqual("test_initial_metadata_value", responseHeaders.First((entry) => entry.Key == "x-grpc-test-echo-initial").Value);
diff --git a/src/csharp/Grpc.IntegrationTesting/Messages.cs b/src/csharp/Grpc.IntegrationTesting/Messages.cs
index 1240db128b..369fe738d6 100644
--- a/src/csharp/Grpc.IntegrationTesting/Messages.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Messages.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/messages.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class MessagesReflection {
 
     #region Descriptor
@@ -94,29 +93,34 @@ namespace Grpc.Testing {
   ///  https://github.com/grpc/grpc/issues/6980 has been fixed.
   ///  import "google/protobuf/wrappers.proto";
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class BoolValue : pb::IMessage<BoolValue> {
     private static readonly pb::MessageParser<BoolValue> _parser = new pb::MessageParser<BoolValue>(() => new BoolValue());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<BoolValue> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public BoolValue() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public BoolValue(BoolValue other) : this() {
       value_ = other.value_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public BoolValue Clone() {
       return new BoolValue(this);
     }
@@ -127,6 +131,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  The bool value.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Value {
       get { return value_; }
       set {
@@ -134,10 +139,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as BoolValue);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(BoolValue other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -149,16 +156,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Value != false) hash ^= Value.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Value != false) {
         output.WriteRawTag(8);
@@ -166,6 +176,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Value != false) {
@@ -174,6 +185,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(BoolValue other) {
       if (other == null) {
         return;
@@ -183,6 +195,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -203,30 +216,35 @@ namespace Grpc.Testing {
   /// <summary>
   ///  A block of data, to simply increase gRPC message size.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class Payload : pb::IMessage<Payload> {
     private static readonly pb::MessageParser<Payload> _parser = new pb::MessageParser<Payload>(() => new Payload());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<Payload> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Payload() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Payload(Payload other) : this() {
       type_ = other.type_;
       body_ = other.body_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public Payload Clone() {
       return new Payload(this);
     }
@@ -238,6 +256,7 @@ namespace Grpc.Testing {
     ///  DEPRECATED, don't use. To be removed shortly.
     ///  The type of data in body.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PayloadType Type {
       get { return type_; }
       set {
@@ -251,6 +270,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Primary contents of payload.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pb::ByteString Body {
       get { return body_; }
       set {
@@ -258,10 +278,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as Payload);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(Payload other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -274,6 +296,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Type != 0) hash ^= Type.GetHashCode();
@@ -281,10 +304,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Type != 0) {
         output.WriteRawTag(8);
@@ -296,6 +321,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Type != 0) {
@@ -307,6 +333,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(Payload other) {
       if (other == null) {
         return;
@@ -319,6 +346,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -344,30 +372,35 @@ namespace Grpc.Testing {
   ///  A protobuf representation for grpc status. This is used by test
   ///  clients to specify a status that the server should attempt to return.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class EchoStatus : pb::IMessage<EchoStatus> {
     private static readonly pb::MessageParser<EchoStatus> _parser = new pb::MessageParser<EchoStatus>(() => new EchoStatus());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EchoStatus> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EchoStatus() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EchoStatus(EchoStatus other) : this() {
       code_ = other.code_;
       message_ = other.message_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EchoStatus Clone() {
       return new EchoStatus(this);
     }
@@ -375,6 +408,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "code" field.</summary>
     public const int CodeFieldNumber = 1;
     private int code_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Code {
       get { return code_; }
       set {
@@ -385,6 +419,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "message" field.</summary>
     public const int MessageFieldNumber = 2;
     private string message_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Message {
       get { return message_; }
       set {
@@ -392,10 +427,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as EchoStatus);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(EchoStatus other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -408,6 +445,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Code != 0) hash ^= Code.GetHashCode();
@@ -415,10 +453,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Code != 0) {
         output.WriteRawTag(8);
@@ -430,6 +470,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Code != 0) {
@@ -441,6 +482,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(EchoStatus other) {
       if (other == null) {
         return;
@@ -453,6 +495,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -477,25 +520,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Unary request.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class SimpleRequest : pb::IMessage<SimpleRequest> {
     private static readonly pb::MessageParser<SimpleRequest> _parser = new pb::MessageParser<SimpleRequest>(() => new SimpleRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[3]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleRequest(SimpleRequest other) : this() {
       responseType_ = other.responseType_;
       responseSize_ = other.responseSize_;
@@ -507,6 +554,7 @@ namespace Grpc.Testing {
       ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleRequest Clone() {
       return new SimpleRequest(this);
     }
@@ -519,6 +567,7 @@ namespace Grpc.Testing {
     ///  Desired payload type in the response from the server.
     ///  If response_type is RANDOM, server randomly chooses one from other formats.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PayloadType ResponseType {
       get { return responseType_; }
       set {
@@ -532,6 +581,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Desired payload size in the response from the server.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int ResponseSize {
       get { return responseSize_; }
       set {
@@ -545,6 +595,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Optional input payload sent along with the request.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Payload Payload {
       get { return payload_; }
       set {
@@ -558,6 +609,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Whether SimpleResponse should include username.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool FillUsername {
       get { return fillUsername_; }
       set {
@@ -571,6 +623,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Whether SimpleResponse should include OAuth scope.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool FillOauthScope {
       get { return fillOauthScope_; }
       set {
@@ -587,6 +640,7 @@ namespace Grpc.Testing {
     ///  implement the full compression tests by introspecting the call to verify
     ///  the response's compression status.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.BoolValue ResponseCompressed {
       get { return responseCompressed_; }
       set {
@@ -600,6 +654,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Whether server should return a given status
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.EchoStatus ResponseStatus {
       get { return responseStatus_; }
       set {
@@ -613,6 +668,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Whether the server should expect this request to be compressed.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.BoolValue ExpectCompressed {
       get { return expectCompressed_; }
       set {
@@ -620,10 +676,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as SimpleRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(SimpleRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -642,6 +700,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (ResponseType != 0) hash ^= ResponseType.GetHashCode();
@@ -655,10 +714,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (ResponseType != 0) {
         output.WriteRawTag(8);
@@ -694,6 +755,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (ResponseType != 0) {
@@ -723,6 +785,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(SimpleRequest other) {
       if (other == null) {
         return;
@@ -765,6 +828,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -825,31 +889,36 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Unary response, as configured by the request.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class SimpleResponse : pb::IMessage<SimpleResponse> {
     private static readonly pb::MessageParser<SimpleResponse> _parser = new pb::MessageParser<SimpleResponse>(() => new SimpleResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[4]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleResponse(SimpleResponse other) : this() {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
       username_ = other.username_;
       oauthScope_ = other.oauthScope_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleResponse Clone() {
       return new SimpleResponse(this);
     }
@@ -860,6 +929,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Payload to increase message size.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Payload Payload {
       get { return payload_; }
       set {
@@ -874,6 +944,7 @@ namespace Grpc.Testing {
     ///  The user the request came from, for verifying authentication was
     ///  successful when the client expected it.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Username {
       get { return username_; }
       set {
@@ -887,6 +958,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  OAuth scope.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string OauthScope {
       get { return oauthScope_; }
       set {
@@ -894,10 +966,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as SimpleResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(SimpleResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -911,6 +985,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (payload_ != null) hash ^= Payload.GetHashCode();
@@ -919,10 +994,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (payload_ != null) {
         output.WriteRawTag(10);
@@ -938,6 +1015,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (payload_ != null) {
@@ -952,6 +1030,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(SimpleResponse other) {
       if (other == null) {
         return;
@@ -970,6 +1049,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1001,30 +1081,35 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Client-streaming request.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class StreamingInputCallRequest : pb::IMessage<StreamingInputCallRequest> {
     private static readonly pb::MessageParser<StreamingInputCallRequest> _parser = new pb::MessageParser<StreamingInputCallRequest>(() => new StreamingInputCallRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingInputCallRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[5]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallRequest(StreamingInputCallRequest other) : this() {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
       ExpectCompressed = other.expectCompressed_ != null ? other.ExpectCompressed.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallRequest Clone() {
       return new StreamingInputCallRequest(this);
     }
@@ -1035,6 +1120,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Optional input payload sent along with the request.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Payload Payload {
       get { return payload_; }
       set {
@@ -1051,6 +1137,7 @@ namespace Grpc.Testing {
     ///  implement the full compression tests by introspecting the call to verify
     ///  the request's compression status.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.BoolValue ExpectCompressed {
       get { return expectCompressed_; }
       set {
@@ -1058,10 +1145,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as StreamingInputCallRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(StreamingInputCallRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1074,6 +1163,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (payload_ != null) hash ^= Payload.GetHashCode();
@@ -1081,10 +1171,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (payload_ != null) {
         output.WriteRawTag(10);
@@ -1096,6 +1188,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (payload_ != null) {
@@ -1107,6 +1200,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(StreamingInputCallRequest other) {
       if (other == null) {
         return;
@@ -1125,6 +1219,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1155,29 +1250,34 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Client-streaming response.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class StreamingInputCallResponse : pb::IMessage<StreamingInputCallResponse> {
     private static readonly pb::MessageParser<StreamingInputCallResponse> _parser = new pb::MessageParser<StreamingInputCallResponse>(() => new StreamingInputCallResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingInputCallResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[6]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallResponse(StreamingInputCallResponse other) : this() {
       aggregatedPayloadSize_ = other.aggregatedPayloadSize_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingInputCallResponse Clone() {
       return new StreamingInputCallResponse(this);
     }
@@ -1188,6 +1288,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Aggregated size of payloads received from the client.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int AggregatedPayloadSize {
       get { return aggregatedPayloadSize_; }
       set {
@@ -1195,10 +1296,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as StreamingInputCallResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(StreamingInputCallResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1210,16 +1313,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (AggregatedPayloadSize != 0) hash ^= AggregatedPayloadSize.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (AggregatedPayloadSize != 0) {
         output.WriteRawTag(8);
@@ -1227,6 +1333,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (AggregatedPayloadSize != 0) {
@@ -1235,6 +1342,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(StreamingInputCallResponse other) {
       if (other == null) {
         return;
@@ -1244,6 +1352,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1264,31 +1373,36 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Configuration for a particular response.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ResponseParameters : pb::IMessage<ResponseParameters> {
     private static readonly pb::MessageParser<ResponseParameters> _parser = new pb::MessageParser<ResponseParameters>(() => new ResponseParameters());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ResponseParameters> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[7]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ResponseParameters() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ResponseParameters(ResponseParameters other) : this() {
       size_ = other.size_;
       intervalUs_ = other.intervalUs_;
       Compressed = other.compressed_ != null ? other.Compressed.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ResponseParameters Clone() {
       return new ResponseParameters(this);
     }
@@ -1299,6 +1413,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Desired payload sizes in responses from the server.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int Size {
       get { return size_; }
       set {
@@ -1313,6 +1428,7 @@ namespace Grpc.Testing {
     ///  Desired interval between consecutive responses in the response stream in
     ///  microseconds.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int IntervalUs {
       get { return intervalUs_; }
       set {
@@ -1329,6 +1445,7 @@ namespace Grpc.Testing {
     ///  implement the full compression tests by introspecting the call to verify
     ///  the response's compression status.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.BoolValue Compressed {
       get { return compressed_; }
       set {
@@ -1336,10 +1453,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ResponseParameters);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ResponseParameters other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1353,6 +1472,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Size != 0) hash ^= Size.GetHashCode();
@@ -1361,10 +1481,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Size != 0) {
         output.WriteRawTag(8);
@@ -1380,6 +1502,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Size != 0) {
@@ -1394,6 +1517,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ResponseParameters other) {
       if (other == null) {
         return;
@@ -1412,6 +1536,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1443,25 +1568,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Server-streaming request.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class StreamingOutputCallRequest : pb::IMessage<StreamingOutputCallRequest> {
     private static readonly pb::MessageParser<StreamingOutputCallRequest> _parser = new pb::MessageParser<StreamingOutputCallRequest>(() => new StreamingOutputCallRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingOutputCallRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[8]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallRequest(StreamingOutputCallRequest other) : this() {
       responseType_ = other.responseType_;
       responseParameters_ = other.responseParameters_.Clone();
@@ -1469,6 +1598,7 @@ namespace Grpc.Testing {
       ResponseStatus = other.responseStatus_ != null ? other.ResponseStatus.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallRequest Clone() {
       return new StreamingOutputCallRequest(this);
     }
@@ -1483,6 +1613,7 @@ namespace Grpc.Testing {
     ///  might be of different types. This is to simulate a mixed type of payload
     ///  stream.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.PayloadType ResponseType {
       get { return responseType_; }
       set {
@@ -1498,6 +1629,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Configuration for each expected response message.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<global::Grpc.Testing.ResponseParameters> ResponseParameters {
       get { return responseParameters_; }
     }
@@ -1508,6 +1640,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Optional input payload sent along with the request.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Payload Payload {
       get { return payload_; }
       set {
@@ -1521,6 +1654,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Whether server should return a given status
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.EchoStatus ResponseStatus {
       get { return responseStatus_; }
       set {
@@ -1528,10 +1662,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as StreamingOutputCallRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(StreamingOutputCallRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1546,6 +1682,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (ResponseType != 0) hash ^= ResponseType.GetHashCode();
@@ -1555,10 +1692,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (ResponseType != 0) {
         output.WriteRawTag(8);
@@ -1575,6 +1714,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (ResponseType != 0) {
@@ -1590,6 +1730,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(StreamingOutputCallRequest other) {
       if (other == null) {
         return;
@@ -1612,6 +1753,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1650,29 +1792,34 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Server-streaming response, as configured by the request and parameters.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class StreamingOutputCallResponse : pb::IMessage<StreamingOutputCallResponse> {
     private static readonly pb::MessageParser<StreamingOutputCallResponse> _parser = new pb::MessageParser<StreamingOutputCallResponse>(() => new StreamingOutputCallResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<StreamingOutputCallResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[9]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallResponse(StreamingOutputCallResponse other) : this() {
       Payload = other.payload_ != null ? other.Payload.Clone() : null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public StreamingOutputCallResponse Clone() {
       return new StreamingOutputCallResponse(this);
     }
@@ -1683,6 +1830,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Payload to increase response size.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.Payload Payload {
       get { return payload_; }
       set {
@@ -1690,10 +1838,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as StreamingOutputCallResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(StreamingOutputCallResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1705,16 +1855,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (payload_ != null) hash ^= Payload.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (payload_ != null) {
         output.WriteRawTag(10);
@@ -1722,6 +1875,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (payload_ != null) {
@@ -1730,6 +1884,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(StreamingOutputCallResponse other) {
       if (other == null) {
         return;
@@ -1742,6 +1897,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1766,29 +1922,34 @@ namespace Grpc.Testing {
   ///  For reconnect interop test only.
   ///  Client tells server what reconnection parameters it used.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ReconnectParams : pb::IMessage<ReconnectParams> {
     private static readonly pb::MessageParser<ReconnectParams> _parser = new pb::MessageParser<ReconnectParams>(() => new ReconnectParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ReconnectParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[10]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectParams(ReconnectParams other) : this() {
       maxReconnectBackoffMs_ = other.maxReconnectBackoffMs_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectParams Clone() {
       return new ReconnectParams(this);
     }
@@ -1796,6 +1957,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "max_reconnect_backoff_ms" field.</summary>
     public const int MaxReconnectBackoffMsFieldNumber = 1;
     private int maxReconnectBackoffMs_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int MaxReconnectBackoffMs {
       get { return maxReconnectBackoffMs_; }
       set {
@@ -1803,10 +1965,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ReconnectParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ReconnectParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1818,16 +1982,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (MaxReconnectBackoffMs != 0) hash ^= MaxReconnectBackoffMs.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (MaxReconnectBackoffMs != 0) {
         output.WriteRawTag(8);
@@ -1835,6 +2002,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (MaxReconnectBackoffMs != 0) {
@@ -1843,6 +2011,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ReconnectParams other) {
       if (other == null) {
         return;
@@ -1852,6 +2021,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -1874,30 +2044,35 @@ namespace Grpc.Testing {
   ///  Server tells client whether its reconnects are following the spec and the
   ///  reconnect backoffs it saw.
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ReconnectInfo : pb::IMessage<ReconnectInfo> {
     private static readonly pb::MessageParser<ReconnectInfo> _parser = new pb::MessageParser<ReconnectInfo>(() => new ReconnectInfo());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ReconnectInfo> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MessagesReflection.Descriptor.MessageTypes[11]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectInfo() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectInfo(ReconnectInfo other) : this() {
       passed_ = other.passed_;
       backoffMs_ = other.backoffMs_.Clone();
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ReconnectInfo Clone() {
       return new ReconnectInfo(this);
     }
@@ -1905,6 +2080,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "passed" field.</summary>
     public const int PassedFieldNumber = 1;
     private bool passed_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Passed {
       get { return passed_; }
       set {
@@ -1917,14 +2093,17 @@ namespace Grpc.Testing {
     private static readonly pb::FieldCodec<int> _repeated_backoffMs_codec
         = pb::FieldCodec.ForInt32(18);
     private readonly pbc::RepeatedField<int> backoffMs_ = new pbc::RepeatedField<int>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<int> BackoffMs {
       get { return backoffMs_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ReconnectInfo);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ReconnectInfo other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -1937,6 +2116,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Passed != false) hash ^= Passed.GetHashCode();
@@ -1944,10 +2124,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Passed != false) {
         output.WriteRawTag(8);
@@ -1956,6 +2138,7 @@ namespace Grpc.Testing {
       backoffMs_.WriteTo(output, _repeated_backoffMs_codec);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Passed != false) {
@@ -1965,6 +2148,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ReconnectInfo other) {
       if (other == null) {
         return;
@@ -1975,6 +2159,7 @@ namespace Grpc.Testing {
       backoffMs_.Add(other.backoffMs_);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.IntegrationTesting/Metrics.cs b/src/csharp/Grpc.IntegrationTesting/Metrics.cs
index 8f31fbc2a9..4de1847e5f 100644
--- a/src/csharp/Grpc.IntegrationTesting/Metrics.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Metrics.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/metrics.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class MetricsReflection {
 
     #region Descriptor
@@ -47,25 +46,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Reponse message containing the gauge name and value
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class GaugeResponse : pb::IMessage<GaugeResponse> {
     private static readonly pb::MessageParser<GaugeResponse> _parser = new pb::MessageParser<GaugeResponse>(() => new GaugeResponse());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<GaugeResponse> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MetricsReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeResponse() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeResponse(GaugeResponse other) : this() {
       name_ = other.name_;
       switch (other.ValueCase) {
@@ -82,6 +85,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeResponse Clone() {
       return new GaugeResponse(this);
     }
@@ -89,6 +93,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "name" field.</summary>
     public const int NameFieldNumber = 1;
     private string name_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Name {
       get { return name_; }
       set {
@@ -98,6 +103,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "long_value" field.</summary>
     public const int LongValueFieldNumber = 2;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public long LongValue {
       get { return valueCase_ == ValueOneofCase.LongValue ? (long) value_ : 0L; }
       set {
@@ -108,6 +114,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "double_value" field.</summary>
     public const int DoubleValueFieldNumber = 3;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double DoubleValue {
       get { return valueCase_ == ValueOneofCase.DoubleValue ? (double) value_ : 0D; }
       set {
@@ -118,6 +125,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "string_value" field.</summary>
     public const int StringValueFieldNumber = 4;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string StringValue {
       get { return valueCase_ == ValueOneofCase.StringValue ? (string) value_ : ""; }
       set {
@@ -135,19 +143,23 @@ namespace Grpc.Testing {
       StringValue = 4,
     }
     private ValueOneofCase valueCase_ = ValueOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ValueOneofCase ValueCase {
       get { return valueCase_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void ClearValue() {
       valueCase_ = ValueOneofCase.None;
       value_ = null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as GaugeResponse);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(GaugeResponse other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -163,6 +175,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
@@ -173,10 +186,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -196,6 +211,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Name.Length != 0) {
@@ -213,6 +229,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(GaugeResponse other) {
       if (other == null) {
         return;
@@ -234,6 +251,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -266,29 +284,34 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Request message containing the gauge name
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class GaugeRequest : pb::IMessage<GaugeRequest> {
     private static readonly pb::MessageParser<GaugeRequest> _parser = new pb::MessageParser<GaugeRequest>(() => new GaugeRequest());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<GaugeRequest> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MetricsReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeRequest() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeRequest(GaugeRequest other) : this() {
       name_ = other.name_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public GaugeRequest Clone() {
       return new GaugeRequest(this);
     }
@@ -296,6 +319,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "name" field.</summary>
     public const int NameFieldNumber = 1;
     private string name_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public string Name {
       get { return name_; }
       set {
@@ -303,10 +327,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as GaugeRequest);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(GaugeRequest other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -318,16 +344,19 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -335,6 +364,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Name.Length != 0) {
@@ -343,6 +373,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(GaugeRequest other) {
       if (other == null) {
         return;
@@ -352,6 +383,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -369,36 +401,43 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class EmptyMessage : pb::IMessage<EmptyMessage> {
     private static readonly pb::MessageParser<EmptyMessage> _parser = new pb::MessageParser<EmptyMessage>(() => new EmptyMessage());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<EmptyMessage> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.MetricsReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EmptyMessage() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EmptyMessage(EmptyMessage other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public EmptyMessage Clone() {
       return new EmptyMessage(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as EmptyMessage);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(EmptyMessage other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -409,29 +448,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(EmptyMessage other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
index 040798e3c2..bcd7e3c040 100644
--- a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
@@ -161,6 +161,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncUnaryCall(__Method_GetGauge, null, options, request);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override MetricsServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new MetricsServiceClient(configuration);
diff --git a/src/csharp/Grpc.IntegrationTesting/Payloads.cs b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
index 3ad7a44f4b..7aef35cda3 100644
--- a/src/csharp/Grpc.IntegrationTesting/Payloads.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/payloads.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class PayloadsReflection {
 
     #region Descriptor
@@ -45,30 +44,35 @@ namespace Grpc.Testing {
 
   }
   #region Messages
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ByteBufferParams : pb::IMessage<ByteBufferParams> {
     private static readonly pb::MessageParser<ByteBufferParams> _parser = new pb::MessageParser<ByteBufferParams>(() => new ByteBufferParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ByteBufferParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.PayloadsReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ByteBufferParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ByteBufferParams(ByteBufferParams other) : this() {
       reqSize_ = other.reqSize_;
       respSize_ = other.respSize_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ByteBufferParams Clone() {
       return new ByteBufferParams(this);
     }
@@ -76,6 +80,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "req_size" field.</summary>
     public const int ReqSizeFieldNumber = 1;
     private int reqSize_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int ReqSize {
       get { return reqSize_; }
       set {
@@ -86,6 +91,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "resp_size" field.</summary>
     public const int RespSizeFieldNumber = 2;
     private int respSize_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int RespSize {
       get { return respSize_; }
       set {
@@ -93,10 +99,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ByteBufferParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ByteBufferParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -109,6 +117,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (ReqSize != 0) hash ^= ReqSize.GetHashCode();
@@ -116,10 +125,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (ReqSize != 0) {
         output.WriteRawTag(8);
@@ -131,6 +142,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (ReqSize != 0) {
@@ -142,6 +154,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ByteBufferParams other) {
       if (other == null) {
         return;
@@ -154,6 +167,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -175,30 +189,35 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class SimpleProtoParams : pb::IMessage<SimpleProtoParams> {
     private static readonly pb::MessageParser<SimpleProtoParams> _parser = new pb::MessageParser<SimpleProtoParams>(() => new SimpleProtoParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<SimpleProtoParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.PayloadsReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleProtoParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleProtoParams(SimpleProtoParams other) : this() {
       reqSize_ = other.reqSize_;
       respSize_ = other.respSize_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public SimpleProtoParams Clone() {
       return new SimpleProtoParams(this);
     }
@@ -206,6 +225,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "req_size" field.</summary>
     public const int ReqSizeFieldNumber = 1;
     private int reqSize_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int ReqSize {
       get { return reqSize_; }
       set {
@@ -216,6 +236,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "resp_size" field.</summary>
     public const int RespSizeFieldNumber = 2;
     private int respSize_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int RespSize {
       get { return respSize_; }
       set {
@@ -223,10 +244,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as SimpleProtoParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(SimpleProtoParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -239,6 +262,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (ReqSize != 0) hash ^= ReqSize.GetHashCode();
@@ -246,10 +270,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (ReqSize != 0) {
         output.WriteRawTag(8);
@@ -261,6 +287,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (ReqSize != 0) {
@@ -272,6 +299,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(SimpleProtoParams other) {
       if (other == null) {
         return;
@@ -284,6 +312,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -309,36 +338,43 @@ namespace Grpc.Testing {
   ///  TODO (vpai): Fill this in once the details of complex, representative
   ///               protos are decided
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ComplexProtoParams : pb::IMessage<ComplexProtoParams> {
     private static readonly pb::MessageParser<ComplexProtoParams> _parser = new pb::MessageParser<ComplexProtoParams>(() => new ComplexProtoParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ComplexProtoParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.PayloadsReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ComplexProtoParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ComplexProtoParams(ComplexProtoParams other) : this() {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ComplexProtoParams Clone() {
       return new ComplexProtoParams(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ComplexProtoParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ComplexProtoParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -349,29 +385,35 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ComplexProtoParams other) {
       if (other == null) {
         return;
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -385,25 +427,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class PayloadConfig : pb::IMessage<PayloadConfig> {
     private static readonly pb::MessageParser<PayloadConfig> _parser = new pb::MessageParser<PayloadConfig>(() => new PayloadConfig());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<PayloadConfig> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.PayloadsReflection.Descriptor.MessageTypes[3]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PayloadConfig() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PayloadConfig(PayloadConfig other) : this() {
       switch (other.PayloadCase) {
         case PayloadOneofCase.BytebufParams:
@@ -419,12 +465,14 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PayloadConfig Clone() {
       return new PayloadConfig(this);
     }
 
     /// <summary>Field number for the "bytebuf_params" field.</summary>
     public const int BytebufParamsFieldNumber = 1;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ByteBufferParams BytebufParams {
       get { return payloadCase_ == PayloadOneofCase.BytebufParams ? (global::Grpc.Testing.ByteBufferParams) payload_ : null; }
       set {
@@ -435,6 +483,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "simple_params" field.</summary>
     public const int SimpleParamsFieldNumber = 2;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.SimpleProtoParams SimpleParams {
       get { return payloadCase_ == PayloadOneofCase.SimpleParams ? (global::Grpc.Testing.SimpleProtoParams) payload_ : null; }
       set {
@@ -445,6 +494,7 @@ namespace Grpc.Testing {
 
     /// <summary>Field number for the "complex_params" field.</summary>
     public const int ComplexParamsFieldNumber = 3;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.ComplexProtoParams ComplexParams {
       get { return payloadCase_ == PayloadOneofCase.ComplexParams ? (global::Grpc.Testing.ComplexProtoParams) payload_ : null; }
       set {
@@ -462,19 +512,23 @@ namespace Grpc.Testing {
       ComplexParams = 3,
     }
     private PayloadOneofCase payloadCase_ = PayloadOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public PayloadOneofCase PayloadCase {
       get { return payloadCase_; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void ClearPayload() {
       payloadCase_ = PayloadOneofCase.None;
       payload_ = null;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as PayloadConfig);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(PayloadConfig other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -489,6 +543,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (payloadCase_ == PayloadOneofCase.BytebufParams) hash ^= BytebufParams.GetHashCode();
@@ -498,10 +553,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (payloadCase_ == PayloadOneofCase.BytebufParams) {
         output.WriteRawTag(10);
@@ -517,6 +574,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (payloadCase_ == PayloadOneofCase.BytebufParams) {
@@ -531,6 +589,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(PayloadConfig other) {
       if (other == null) {
         return;
@@ -549,6 +608,7 @@ namespace Grpc.Testing {
 
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.IntegrationTesting/Services.cs b/src/csharp/Grpc.IntegrationTesting/Services.cs
index e10b45c9a2..bf36a0253b 100644
--- a/src/csharp/Grpc.IntegrationTesting/Services.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Services.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/services.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class ServicesReflection {
 
     #region Descriptor
diff --git a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
index e205dea93e..848dd04fa7 100644
--- a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
@@ -161,6 +161,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncDuplexStreamingCall(__Method_StreamingCall, null, options);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override BenchmarkServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new BenchmarkServiceClient(configuration);
@@ -396,6 +397,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncUnaryCall(__Method_QuitWorker, null, options, request);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override WorkerServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new WorkerServiceClient(configuration);
diff --git a/src/csharp/Grpc.IntegrationTesting/Stats.cs b/src/csharp/Grpc.IntegrationTesting/Stats.cs
index 304d676113..0ae77cfb92 100644
--- a/src/csharp/Grpc.IntegrationTesting/Stats.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Stats.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/stats.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class StatsReflection {
 
     #region Descriptor
@@ -46,31 +45,36 @@ namespace Grpc.Testing {
 
   }
   #region Messages
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ServerStats : pb::IMessage<ServerStats> {
     private static readonly pb::MessageParser<ServerStats> _parser = new pb::MessageParser<ServerStats>(() => new ServerStats());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ServerStats> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.StatsReflection.Descriptor.MessageTypes[0]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStats() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStats(ServerStats other) : this() {
       timeElapsed_ = other.timeElapsed_;
       timeUser_ = other.timeUser_;
       timeSystem_ = other.timeSystem_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ServerStats Clone() {
       return new ServerStats(this);
     }
@@ -81,6 +85,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  wall clock time change in seconds since last reset
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeElapsed {
       get { return timeElapsed_; }
       set {
@@ -94,6 +99,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  change in user time (in seconds) used by the server since last reset
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeUser {
       get { return timeUser_; }
       set {
@@ -108,6 +114,7 @@ namespace Grpc.Testing {
     ///  change in server time (in seconds) used by the server process and all
     ///  threads since last reset
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeSystem {
       get { return timeSystem_; }
       set {
@@ -115,10 +122,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ServerStats);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ServerStats other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -132,6 +141,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (TimeElapsed != 0D) hash ^= TimeElapsed.GetHashCode();
@@ -140,10 +150,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (TimeElapsed != 0D) {
         output.WriteRawTag(9);
@@ -159,6 +171,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (TimeElapsed != 0D) {
@@ -173,6 +186,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ServerStats other) {
       if (other == null) {
         return;
@@ -188,6 +202,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -216,30 +231,35 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Histogram params based on grpc/support/histogram.c
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class HistogramParams : pb::IMessage<HistogramParams> {
     private static readonly pb::MessageParser<HistogramParams> _parser = new pb::MessageParser<HistogramParams>(() => new HistogramParams());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HistogramParams> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.StatsReflection.Descriptor.MessageTypes[1]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramParams() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramParams(HistogramParams other) : this() {
       resolution_ = other.resolution_;
       maxPossible_ = other.maxPossible_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramParams Clone() {
       return new HistogramParams(this);
     }
@@ -250,6 +270,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  first bucket is [0, 1 + resolution)
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Resolution {
       get { return resolution_; }
       set {
@@ -263,6 +284,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  use enough buckets to allow this value
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double MaxPossible {
       get { return maxPossible_; }
       set {
@@ -270,10 +292,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as HistogramParams);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(HistogramParams other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -286,6 +310,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (Resolution != 0D) hash ^= Resolution.GetHashCode();
@@ -293,10 +318,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (Resolution != 0D) {
         output.WriteRawTag(9);
@@ -308,6 +335,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (Resolution != 0D) {
@@ -319,6 +347,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(HistogramParams other) {
       if (other == null) {
         return;
@@ -331,6 +360,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -355,25 +385,29 @@ namespace Grpc.Testing {
   /// <summary>
   ///  Histogram data based on grpc/support/histogram.c
   /// </summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class HistogramData : pb::IMessage<HistogramData> {
     private static readonly pb::MessageParser<HistogramData> _parser = new pb::MessageParser<HistogramData>(() => new HistogramData());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<HistogramData> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.StatsReflection.Descriptor.MessageTypes[2]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramData() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramData(HistogramData other) : this() {
       bucket_ = other.bucket_.Clone();
       minSeen_ = other.minSeen_;
@@ -383,6 +417,7 @@ namespace Grpc.Testing {
       count_ = other.count_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public HistogramData Clone() {
       return new HistogramData(this);
     }
@@ -392,6 +427,7 @@ namespace Grpc.Testing {
     private static readonly pb::FieldCodec<uint> _repeated_bucket_codec
         = pb::FieldCodec.ForUInt32(10);
     private readonly pbc::RepeatedField<uint> bucket_ = new pbc::RepeatedField<uint>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public pbc::RepeatedField<uint> Bucket {
       get { return bucket_; }
     }
@@ -399,6 +435,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "min_seen" field.</summary>
     public const int MinSeenFieldNumber = 2;
     private double minSeen_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double MinSeen {
       get { return minSeen_; }
       set {
@@ -409,6 +446,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "max_seen" field.</summary>
     public const int MaxSeenFieldNumber = 3;
     private double maxSeen_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double MaxSeen {
       get { return maxSeen_; }
       set {
@@ -419,6 +457,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "sum" field.</summary>
     public const int SumFieldNumber = 4;
     private double sum_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Sum {
       get { return sum_; }
       set {
@@ -429,6 +468,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "sum_of_squares" field.</summary>
     public const int SumOfSquaresFieldNumber = 5;
     private double sumOfSquares_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double SumOfSquares {
       get { return sumOfSquares_; }
       set {
@@ -439,6 +479,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "count" field.</summary>
     public const int CountFieldNumber = 6;
     private double count_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double Count {
       get { return count_; }
       set {
@@ -446,10 +487,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as HistogramData);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(HistogramData other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -466,6 +509,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       hash ^= bucket_.GetHashCode();
@@ -477,10 +521,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       bucket_.WriteTo(output, _repeated_bucket_codec);
       if (MinSeen != 0D) {
@@ -505,6 +551,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       size += bucket_.CalculateSize(_repeated_bucket_codec);
@@ -526,6 +573,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(HistogramData other) {
       if (other == null) {
         return;
@@ -548,6 +596,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
@@ -586,25 +635,29 @@ namespace Grpc.Testing {
 
   }
 
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class ClientStats : pb::IMessage<ClientStats> {
     private static readonly pb::MessageParser<ClientStats> _parser = new pb::MessageParser<ClientStats>(() => new ClientStats());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<ClientStats> Parser { get { return _parser; } }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pbr::MessageDescriptor Descriptor {
       get { return global::Grpc.Testing.StatsReflection.Descriptor.MessageTypes[3]; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     pbr::MessageDescriptor pb::IMessage.Descriptor {
       get { return Descriptor; }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStats() {
       OnConstruction();
     }
 
     partial void OnConstruction();
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStats(ClientStats other) : this() {
       Latencies = other.latencies_ != null ? other.Latencies.Clone() : null;
       timeElapsed_ = other.timeElapsed_;
@@ -612,6 +665,7 @@ namespace Grpc.Testing {
       timeSystem_ = other.timeSystem_;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public ClientStats Clone() {
       return new ClientStats(this);
     }
@@ -622,6 +676,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  Latency histogram. Data points are in nanoseconds.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public global::Grpc.Testing.HistogramData Latencies {
       get { return latencies_; }
       set {
@@ -635,6 +690,7 @@ namespace Grpc.Testing {
     /// <summary>
     ///  See ServerStats for details.
     /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeElapsed {
       get { return timeElapsed_; }
       set {
@@ -645,6 +701,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "time_user" field.</summary>
     public const int TimeUserFieldNumber = 3;
     private double timeUser_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeUser {
       get { return timeUser_; }
       set {
@@ -655,6 +712,7 @@ namespace Grpc.Testing {
     /// <summary>Field number for the "time_system" field.</summary>
     public const int TimeSystemFieldNumber = 4;
     private double timeSystem_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public double TimeSystem {
       get { return timeSystem_; }
       set {
@@ -662,10 +720,12 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClientStats);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public bool Equals(ClientStats other) {
       if (ReferenceEquals(other, null)) {
         return false;
@@ -680,6 +740,7 @@ namespace Grpc.Testing {
       return true;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override int GetHashCode() {
       int hash = 1;
       if (latencies_ != null) hash ^= Latencies.GetHashCode();
@@ -689,10 +750,12 @@ namespace Grpc.Testing {
       return hash;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override string ToString() {
       return pb::JsonFormatter.ToDiagnosticString(this);
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void WriteTo(pb::CodedOutputStream output) {
       if (latencies_ != null) {
         output.WriteRawTag(10);
@@ -712,6 +775,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public int CalculateSize() {
       int size = 0;
       if (latencies_ != null) {
@@ -729,6 +793,7 @@ namespace Grpc.Testing {
       return size;
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(ClientStats other) {
       if (other == null) {
         return;
@@ -750,6 +815,7 @@ namespace Grpc.Testing {
       }
     }
 
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public void MergeFrom(pb::CodedInputStream input) {
       uint tag;
       while ((tag = input.ReadTag()) != 0) {
diff --git a/src/csharp/Grpc.IntegrationTesting/Test.cs b/src/csharp/Grpc.IntegrationTesting/Test.cs
index 9258dc185d..88c2b8a921 100644
--- a/src/csharp/Grpc.IntegrationTesting/Test.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Test.cs
@@ -10,7 +10,6 @@ using scg = global::System.Collections.Generic;
 namespace Grpc.Testing {
 
   /// <summary>Holder for reflection information generated from src/proto/grpc/testing/test.proto</summary>
-  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public static partial class TestReflection {
 
     #region Descriptor
diff --git a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
index 3e149da3e0..61f2ed4015 100644
--- a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
@@ -314,6 +314,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncDuplexStreamingCall(__Method_HalfDuplexCall, null, options);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override TestServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new TestServiceClient(configuration);
@@ -420,6 +421,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncUnaryCall(__Method_UnimplementedCall, null, options, request);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override UnimplementedServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new UnimplementedServiceClient(configuration);
@@ -535,6 +537,7 @@ namespace Grpc.Testing {
       {
         return CallInvoker.AsyncUnaryCall(__Method_Stop, null, options, request);
       }
+      /// <summary>Creates a new instance of client from given <c>ClientBaseConfiguration</c>.</summary>
       protected override ReconnectServiceClient NewInstance(ClientBaseConfiguration configuration)
       {
         return new ReconnectServiceClient(configuration);
diff --git a/src/objective-c/tests/InteropTests.m b/src/objective-c/tests/InteropTests.m
index 44f22c9e85..9804734d6a 100644
--- a/src/objective-c/tests/InteropTests.m
+++ b/src/objective-c/tests/InteropTests.m
@@ -92,20 +92,21 @@
   return 0;
 }
 
++ (void)setUp {
+#ifdef GRPC_COMPILE_WITH_CRONET
+  // Cronet setup
+  [Cronet setHttp2Enabled:YES];
+  [Cronet start];
+  [GRPCCall useCronetWithEngine:[Cronet getGlobalEngine]];
+#endif
+}
+
 - (void)setUp {
   self.continueAfterFailure = NO;
 
   [GRPCCall resetHostSettings];
 
   _service = self.class.host ? [RMTTestService serviceWithHost:self.class.host] : nil;
-#ifdef GRPC_COMPILE_WITH_CRONET
-  if (cronetEngine == NULL) {
-    // Cronet setup
-    [Cronet setHttp2Enabled:YES];
-    [Cronet start];
-    [GRPCCall useCronetWithEngine:[Cronet getGlobalEngine]];
-  }
-#endif
 }
 
 - (void)testEmptyUnaryRPC {
diff --git a/src/php/tests/interop/interop_client.php b/src/php/tests/interop/interop_client.php
index 124d324913..72012a49d0 100755
--- a/src/php/tests/interop/interop_client.php
+++ b/src/php/tests/interop/interop_client.php
@@ -477,9 +477,11 @@ function statusCodeAndMessage($stub)
     list($result, $status) = $call->wait();
 
     hardAssert($status->code === 2,
-               'Received unexpected status code');
+               'Received unexpected UnaryCall status code: ' .
+               $status->code);
     hardAssert($status->details === 'test status message',
-               'Received unexpected status details');
+               'Received unexpected UnaryCall status details: ' .
+               $status->details);
 
     $streaming_call = $stub->FullDuplexCall();
 
@@ -487,12 +489,15 @@ function statusCodeAndMessage($stub)
     $streaming_request->setResponseStatus($echo_status);
     $streaming_call->write($streaming_request);
     $streaming_call->writesDone();
+    $result = $streaming_call->read();
 
     $status = $streaming_call->getStatus();
     hardAssert($status->code === 2,
-               'Received unexpected status code');
+               'Received unexpected FullDuplexCall status code: ' .
+               $status->code);
     hardAssert($status->details === 'test status message',
-               'Received unexpected status details');
+               'Received unexpected FullDuplexCall status details: ' .
+               $status->details);
 }
 
 function unimplementedMethod($stub)
diff --git a/src/proto/grpc/testing/test.proto b/src/proto/grpc/testing/test.proto
index b52c4cbad6..d6ef58ab12 100644
--- a/src/proto/grpc/testing/test.proto
+++ b/src/proto/grpc/testing/test.proto
@@ -74,6 +74,10 @@ service TestService {
   // first request.
   rpc HalfDuplexCall(stream StreamingOutputCallRequest)
       returns (stream StreamingOutputCallResponse);
+
+  // The test server will not implement this method. It will be used
+  // to test the behavior when clients call unimplemented methods.
+  rpc UnimplementedMethod(grpc.testing.Empty) returns (grpc.testing.Empty);
 }
 
 // A simple service NOT implemented at servers so clients can test for
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
index ad20c94de9..9560fad137 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
@@ -173,10 +173,14 @@ cdef extern from "grpc/grpc.h":
     GRPC_ARG_INTEGER
     GRPC_ARG_POINTER
 
-  ctypedef struct grpc_arg_value_pointer:
-    void *address "p"
+  ctypedef struct grpc_arg_pointer_vtable:
     void *(*copy)(void *)
     void (*destroy)(void *)
+    int (*cmp)(void *, void *)
+
+  ctypedef struct grpc_arg_value_pointer:
+    void *address "p"
+    grpc_arg_pointer_vtable *vtable
 
   union grpc_arg_value:
     char *string
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd.pxi
index 96c5b02bc2..00ec91b131 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd.pxi
@@ -84,6 +84,7 @@ cdef class SslPemKeyCertPair:
 cdef class ChannelArg:
 
   cdef grpc_arg c_arg
+  cdef grpc_arg_pointer_vtable ptr_vtable
   cdef readonly object key, value
 
 
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
index 5a11a08f54..8a4eef4d2e 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
@@ -27,6 +27,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+from libc.stdint cimport intptr_t
 
 class ConnectivityState:
   idle = GRPC_CHANNEL_IDLE
@@ -304,20 +305,49 @@ cdef class SslPemKeyCertPair:
     self.c_pair.certificate_chain = self.certificate_chain
 
 
+
+cdef void* copy_ptr(void* ptr):
+  return ptr
+
+
+cdef void destroy_ptr(void* ptr):
+  pass
+
+
+cdef int compare_ptr(void* ptr1, void* ptr2):
+  if ptr1 < ptr2:
+    return -1
+  elif ptr1 > ptr2:
+    return 1
+  else:
+    return 0
+
+
 cdef class ChannelArg:
 
   def __cinit__(self, bytes key, value):
     self.key = key
+    self.value = value
     self.c_arg.key = self.key
     if isinstance(value, int):
-      self.value = value
       self.c_arg.type = GRPC_ARG_INTEGER
       self.c_arg.value.integer = self.value
     elif isinstance(value, bytes):
-      self.value = value
       self.c_arg.type = GRPC_ARG_STRING
       self.c_arg.value.string = self.value
+    elif hasattr(value, '__int__'):
+      # Pointer objects must override __int__() to return
+      # the underlying C address (Python ints are word size).  The
+      # lifecycle of the pointer is fixed to the lifecycle of the 
+      # python object wrapping it.
+      self.ptr_vtable.copy = &copy_ptr
+      self.ptr_vtable.destroy = &destroy_ptr
+      self.ptr_vtable.cmp = &compare_ptr
+      self.c_arg.type = GRPC_ARG_POINTER
+      self.c_arg.value.pointer.vtable = &self.ptr_vtable
+      self.c_arg.value.pointer.address = <void*>(<intptr_t>int(self.value))
     else:
+      # TODO Add supported pointer types to this message
       raise TypeError('Expected int or bytes, got {}'.format(type(value)))
 
 
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 2bebf48c70..406f88a02d 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -134,11 +134,11 @@ CORE_SOURCE_FILES = [
   'src/core/lib/iomgr/udp_server.c',
   'src/core/lib/iomgr/unix_sockets_posix.c',
   'src/core/lib/iomgr/unix_sockets_posix_noop.c',
+  'src/core/lib/iomgr/wakeup_fd_cv.c',
   'src/core/lib/iomgr/wakeup_fd_eventfd.c',
   'src/core/lib/iomgr/wakeup_fd_nospecial.c',
   'src/core/lib/iomgr/wakeup_fd_pipe.c',
   'src/core/lib/iomgr/wakeup_fd_posix.c',
-  'src/core/lib/iomgr/workqueue_posix.c',
   'src/core/lib/iomgr/workqueue_windows.c',
   'src/core/lib/json/json.c',
   'src/core/lib/json/json_reader.c',
diff --git a/src/python/grpcio_tests/tests/unit/_channel_args_test.py b/src/python/grpcio_tests/tests/unit/_channel_args_test.py
index 6a636d7993..b46497afd6 100644
--- a/src/python/grpcio_tests/tests/unit/_channel_args_test.py
+++ b/src/python/grpcio_tests/tests/unit/_channel_args_test.py
@@ -33,11 +33,18 @@ import unittest
 
 import grpc
 
+class TestPointerWrapper(object):
+
+  def __int__(self):
+    return 123456
+
+
 TEST_CHANNEL_ARGS = (
     ('arg1', b'bytes_val'),
     ('arg2', 'str_val'),
     ('arg3', 1),
     (b'arg4', 'str_val'),
+    ('arg6', TestPointerWrapper()),
 )
 
 
diff --git a/src/ruby/spec/generic/active_call_spec.rb b/src/ruby/spec/generic/active_call_spec.rb
index 48bc61e494..5ae4f25537 100644
--- a/src/ruby/spec/generic/active_call_spec.rb
+++ b/src/ruby/spec/generic/active_call_spec.rb
@@ -137,6 +137,8 @@ describe GRPC::ActiveCall do
         msg = 'message is a string'
         client_call.write_flag = f
         client_call.remote_send(msg)
+        # flush the message in case writes are set to buffered
+        call.run_batch(CallOps::SEND_CLOSE_FROM_CLIENT => nil) if f == 1
 
         # confirm that the message was marshalled
         recvd_rpc =  @server.request_call