Merge remote-tracking branch 'upstream/master' into fix-stream-compression-config-interface

45 files changed, 1120 insertions, 742 deletions

diff --git a/src/core/ext/census/base_resources.c b/src/core/ext/census/base_resources.c
index 2114bf04cd..1f2bb39fe0 100644
--- a/src/core/ext/census/base_resources.c
+++ b/src/core/ext/census/base_resources.c
@@ -37,20 +37,20 @@
 void define_base_resources() {
   google_census_Resource_BasicUnit numerator =
       google_census_Resource_BasicUnit_SECS;
-  resource r = {"client_rpc_latency",             // name
-                "Client RPC latency in seconds",  // description
-                0,                                // prefix
-                1,                                // n_numerators
-                &numerator,                       // numerators
-                0,                                // n_denominators
-                NULL};                            // denominators
+  resource r = {(char *)"client_rpc_latency",             // name
+                (char *)"Client RPC latency in seconds",  // description
+                0,                                        // prefix
+                1,                                        // n_numerators
+                &numerator,                               // numerators
+                0,                                        // n_denominators
+                NULL};                                    // denominators
   define_resource(&r);
-  r = (resource){"server_rpc_latency",             // name
-                 "Server RPC latency in seconds",  // description
-                 0,                                // prefix
-                 1,                                // n_numerators
-                 &numerator,                       // numerators
-                 0,                                // n_denominators
-                 NULL};                            // denominators
+  r = (resource){(char *)"server_rpc_latency",             // name
+                 (char *)"Server RPC latency in seconds",  // description
+                 0,                                        // prefix
+                 1,                                        // n_numerators
+                 &numerator,                               // numerators
+                 0,                                        // n_denominators
+                 NULL};                                    // denominators
   define_resource(&r);
 }
diff --git a/src/core/ext/filters/client_channel/channel_connectivity.c b/src/core/ext/filters/client_channel/channel_connectivity.c
index e5f6fa76ae..3844b98021 100644
--- a/src/core/ext/filters/client_channel/channel_connectivity.c
+++ b/src/core/ext/filters/client_channel/channel_connectivity.c
@@ -86,7 +86,7 @@ static void delete_state_watcher(grpc_exec_ctx *exec_ctx, state_watcher *w) {
 
 static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
                                 grpc_cq_completion *ignored) {
-  int delete = 0;
+  bool should_delete = false;
   state_watcher *w = (state_watcher *)pw;
   gpr_mu_lock(&w->mu);
   switch (w->phase) {
@@ -94,12 +94,12 @@ static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
     case READY_TO_CALL_BACK:
       GPR_UNREACHABLE_CODE(return );
     case CALLING_BACK_AND_FINISHED:
-      delete = 1;
+      should_delete = true;
       break;
   }
   gpr_mu_unlock(&w->mu);
 
-  if (delete) {
+  if (should_delete) {
     delete_state_watcher(exec_ctx, w);
   }
 }
@@ -161,12 +161,12 @@ static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
 
 static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw,
                            grpc_error *error) {
-  partly_done(exec_ctx, pw, true, GRPC_ERROR_REF(error));
+  partly_done(exec_ctx, (state_watcher *)pw, true, GRPC_ERROR_REF(error));
 }
 
 static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw,
                              grpc_error *error) {
-  partly_done(exec_ctx, pw, false, GRPC_ERROR_REF(error));
+  partly_done(exec_ctx, (state_watcher *)pw, false, GRPC_ERROR_REF(error));
 }
 
 int grpc_channel_num_external_connectivity_watchers(grpc_channel *channel) {
diff --git a/src/core/ext/filters/client_channel/client_channel.c b/src/core/ext/filters/client_channel/client_channel.c
index dad5c4fce5..016199b1f4 100644
--- a/src/core/ext/filters/client_channel/client_channel.c
+++ b/src/core/ext/filters/client_channel/client_channel.c
@@ -85,7 +85,7 @@ static void method_parameters_unref(method_parameters *method_params) {
 }
 
 static void method_parameters_free(grpc_exec_ctx *exec_ctx, void *value) {
-  method_parameters_unref(value);
+  method_parameters_unref((method_parameters *)value);
 }
 
 static bool parse_wait_for_ready(grpc_json *field,
@@ -375,7 +375,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   }
   // Extract the following fields from the resolver result, if non-NULL.
   bool lb_policy_updated = false;
-  char *lb_policy_name = NULL;
+  char *lb_policy_name_dup = NULL;
   bool lb_policy_name_changed = false;
   grpc_lb_policy *new_lb_policy = NULL;
   char *service_config_json = NULL;
@@ -383,6 +383,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   grpc_slice_hash_table *method_params_table = NULL;
   if (chand->resolver_result != NULL) {
     // Find LB policy name.
+    const char *lb_policy_name = NULL;
     const grpc_arg *channel_arg =
         grpc_channel_args_find(chand->resolver_result, GRPC_ARG_LB_POLICY_NAME);
     if (channel_arg != NULL) {
@@ -473,7 +474,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     // Before we clean up, save a copy of lb_policy_name, since it might
     // be pointing to data inside chand->resolver_result.
     // The copy will be saved in chand->lb_policy_name below.
-    lb_policy_name = gpr_strdup(lb_policy_name);
+    lb_policy_name_dup = gpr_strdup(lb_policy_name);
     grpc_channel_args_destroy(exec_ctx, chand->resolver_result);
     chand->resolver_result = NULL;
   }
@@ -481,8 +482,8 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     gpr_log(GPR_DEBUG,
             "chand=%p: resolver result: lb_policy_name=\"%s\"%s, "
             "service_config=\"%s\"",
-            chand, lb_policy_name, lb_policy_name_changed ? " (changed)" : "",
-            service_config_json);
+            chand, lb_policy_name_dup,
+            lb_policy_name_changed ? " (changed)" : "", service_config_json);
   }
   // Now swap out fields in chand.  Note that the new values may still
   // be NULL if (e.g.) the resolver failed to return results or the
@@ -490,9 +491,9 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
   //
   // First, swap out the data used by cc_get_channel_info().
   gpr_mu_lock(&chand->info_mu);
-  if (lb_policy_name != NULL) {
+  if (lb_policy_name_dup != NULL) {
     gpr_free(chand->info_lb_policy_name);
-    chand->info_lb_policy_name = lb_policy_name;
+    chand->info_lb_policy_name = lb_policy_name_dup;
   }
   if (service_config_json != NULL) {
     gpr_free(chand->info_service_config_json);
@@ -717,7 +718,8 @@ static grpc_error *cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
     return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
         "client channel factory arg must be a pointer");
   }
-  grpc_client_channel_factory_ref(arg->value.pointer.p);
+  grpc_client_channel_factory_ref(
+      (grpc_client_channel_factory *)arg->value.pointer.p);
   chand->client_channel_factory =
       (grpc_client_channel_factory *)arg->value.pointer.p;
   // Get server name to resolve, using proxy mapper if needed.
@@ -1016,13 +1018,11 @@ static void create_subchannel_call_locked(grpc_exec_ctx *exec_ctx,
   GRPC_ERROR_UNREF(error);
 }
 
-static void subchannel_ready_locked(grpc_exec_ctx *exec_ctx,
-                                    grpc_call_element *elem,
-                                    grpc_error *error) {
+// Invoked when a pick is completed, on both success or failure.
+static void pick_done_locked(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                             grpc_error *error) {
   call_data *calld = (call_data *)elem->call_data;
   channel_data *chand = (channel_data *)elem->channel_data;
-  grpc_polling_entity_del_from_pollset_set(exec_ctx, calld->pollent,
-                                           chand->interested_parties);
   if (calld->connected_subchannel == NULL) {
     // Failed to create subchannel.
     GRPC_ERROR_UNREF(calld->error);
@@ -1044,12 +1044,116 @@ static void subchannel_ready_locked(grpc_exec_ctx *exec_ctx,
   GRPC_ERROR_UNREF(error);
 }
 
-/** Return true if subchannel is available immediately (in which case
-    subchannel_ready_locked() should not be called), or false otherwise (in
-    which case subchannel_ready_locked() should be called when the subchannel
-    is available). */
-static bool pick_subchannel_locked(grpc_exec_ctx *exec_ctx,
-                                   grpc_call_element *elem);
+// A wrapper around pick_done_locked() that is used in cases where
+// either (a) the pick was deferred pending a resolver result or (b) the
+// pick was done asynchronously.  Removes the call's polling entity from
+// chand->interested_parties before invoking pick_done_locked().
+static void async_pick_done_locked(grpc_exec_ctx *exec_ctx,
+                                   grpc_call_element *elem, grpc_error *error) {
+  channel_data *chand = (channel_data *)elem->channel_data;
+  call_data *calld = (call_data *)elem->call_data;
+  grpc_polling_entity_del_from_pollset_set(exec_ctx, calld->pollent,
+                                           chand->interested_parties);
+  pick_done_locked(exec_ctx, elem, error);
+}
+
+// Note: This runs under the client_channel combiner, but will NOT be
+// holding the call combiner.
+static void pick_callback_cancel_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error) {
+  grpc_call_element *elem = (grpc_call_element *)arg;
+  channel_data *chand = (channel_data *)elem->channel_data;
+  call_data *calld = (call_data *)elem->call_data;
+  if (calld->lb_policy != NULL) {
+    if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
+      gpr_log(GPR_DEBUG, "chand=%p calld=%p: cancelling pick from LB policy %p",
+              chand, calld, calld->lb_policy);
+    }
+    grpc_lb_policy_cancel_pick_locked(exec_ctx, calld->lb_policy,
+                                      &calld->connected_subchannel,
+                                      GRPC_ERROR_REF(error));
+  }
+  GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_callback_cancel");
+}
+
+// Callback invoked by grpc_lb_policy_pick_locked() for async picks.
+// Unrefs the LB policy and invokes async_pick_done_locked().
+static void pick_callback_done_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                      grpc_error *error) {
+  grpc_call_element *elem = (grpc_call_element *)arg;
+  channel_data *chand = (channel_data *)elem->channel_data;
+  call_data *calld = (call_data *)elem->call_data;
+  if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
+    gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed asynchronously",
+            chand, calld);
+  }
+  GPR_ASSERT(calld->lb_policy != NULL);
+  GRPC_LB_POLICY_UNREF(exec_ctx, calld->lb_policy, "pick_subchannel");
+  calld->lb_policy = NULL;
+  async_pick_done_locked(exec_ctx, elem, GRPC_ERROR_REF(error));
+}
+
+// Takes a ref to chand->lb_policy and calls grpc_lb_policy_pick_locked().
+// If the pick was completed synchronously, unrefs the LB policy and
+// returns true.
+static bool pick_callback_start_locked(grpc_exec_ctx *exec_ctx,
+                                       grpc_call_element *elem) {
+  channel_data *chand = (channel_data *)elem->channel_data;
+  call_data *calld = (call_data *)elem->call_data;
+  if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
+    gpr_log(GPR_DEBUG, "chand=%p calld=%p: starting pick on lb_policy=%p",
+            chand, calld, chand->lb_policy);
+  }
+  apply_service_config_to_call_locked(exec_ctx, elem);
+  // If the application explicitly set wait_for_ready, use that.
+  // Otherwise, if the service config specified a value for this
+  // method, use that.
+  uint32_t initial_metadata_flags =
+      calld->initial_metadata_batch->payload->send_initial_metadata
+          .send_initial_metadata_flags;
+  const bool wait_for_ready_set_from_api =
+      initial_metadata_flags &
+      GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET;
+  const bool wait_for_ready_set_from_service_config =
+      calld->method_params != NULL &&
+      calld->method_params->wait_for_ready != WAIT_FOR_READY_UNSET;
+  if (!wait_for_ready_set_from_api && wait_for_ready_set_from_service_config) {
+    if (calld->method_params->wait_for_ready == WAIT_FOR_READY_TRUE) {
+      initial_metadata_flags |= GRPC_INITIAL_METADATA_WAIT_FOR_READY;
+    } else {
+      initial_metadata_flags &= ~GRPC_INITIAL_METADATA_WAIT_FOR_READY;
+    }
+  }
+  const grpc_lb_policy_pick_args inputs = {
+      calld->initial_metadata_batch->payload->send_initial_metadata
+          .send_initial_metadata,
+      initial_metadata_flags, &calld->lb_token_mdelem};
+  // Keep a ref to the LB policy in calld while the pick is pending.
+  GRPC_LB_POLICY_REF(chand->lb_policy, "pick_subchannel");
+  calld->lb_policy = chand->lb_policy;
+  GRPC_CLOSURE_INIT(&calld->lb_pick_closure, pick_callback_done_locked, elem,
+                    grpc_combiner_scheduler(chand->combiner));
+  const bool pick_done = grpc_lb_policy_pick_locked(
+      exec_ctx, chand->lb_policy, &inputs, &calld->connected_subchannel,
+      calld->subchannel_call_context, NULL, &calld->lb_pick_closure);
+  if (pick_done) {
+    /* synchronous grpc_lb_policy_pick call. Unref the LB policy. */
+    if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
+      gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed synchronously",
+              chand, calld);
+    }
+    GRPC_LB_POLICY_UNREF(exec_ctx, calld->lb_policy, "pick_subchannel");
+    calld->lb_policy = NULL;
+  } else {
+    GRPC_CALL_STACK_REF(calld->owning_call, "pick_callback_cancel");
+    grpc_call_combiner_set_notify_on_cancel(
+        exec_ctx, calld->call_combiner,
+        GRPC_CLOSURE_INIT(&calld->lb_pick_cancel_closure,
+                          pick_callback_cancel_locked, elem,
+                          grpc_combiner_scheduler(chand->combiner)));
+  }
+  return pick_done;
+}
 
 typedef struct {
   grpc_call_element *elem;
@@ -1069,17 +1173,17 @@ static void pick_after_resolver_result_cancel_locked(grpc_exec_ctx *exec_ctx,
     gpr_free(args);
     return;
   }
-  args->finished = true;
-  grpc_call_element *elem = args->elem;
-  channel_data *chand = (channel_data *)elem->channel_data;
-  call_data *calld = (call_data *)elem->call_data;
   // If we don't yet have a resolver result, then a closure for
   // pick_after_resolver_result_done_locked() will have been added to
   // chand->waiting_for_resolver_result_closures, and it may not be invoked
   // until after this call has been destroyed.  We mark the operation as
   // finished, so that when pick_after_resolver_result_done_locked()
   // is called, it will be a no-op.  We also immediately invoke
-  // subchannel_ready_locked() to propagate the error back to the caller.
+  // async_pick_done_locked() to propagate the error back to the caller.
+  args->finished = true;
+  grpc_call_element *elem = args->elem;
+  channel_data *chand = (channel_data *)elem->channel_data;
+  call_data *calld = (call_data *)elem->call_data;
   if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
     gpr_log(GPR_DEBUG,
             "chand=%p calld=%p: cancelling pick waiting for resolver result",
@@ -1087,12 +1191,12 @@ static void pick_after_resolver_result_cancel_locked(grpc_exec_ctx *exec_ctx,
   }
   // Note: Although we are not in the call combiner here, we are
   // basically stealing the call combiner from the pending pick, so
-  // it's safe to call subchannel_ready_locked() here -- we are
+  // it's safe to call async_pick_done_locked() here -- we are
   // essentially calling it here instead of calling it in
   // pick_after_resolver_result_done_locked().
-  subchannel_ready_locked(exec_ctx, elem,
-                          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
-                              "Pick cancelled", &error, 1));
+  async_pick_done_locked(exec_ctx, elem,
+                         GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
+                             "Pick cancelled", &error, 1));
 }
 
 static void pick_after_resolver_result_done_locked(grpc_exec_ctx *exec_ctx,
@@ -1117,14 +1221,19 @@ static void pick_after_resolver_result_done_locked(grpc_exec_ctx *exec_ctx,
       gpr_log(GPR_DEBUG, "chand=%p calld=%p: resolver failed to return data",
               chand, calld);
     }
-    subchannel_ready_locked(exec_ctx, elem, GRPC_ERROR_REF(error));
+    async_pick_done_locked(exec_ctx, elem, GRPC_ERROR_REF(error));
   } else {
     if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
       gpr_log(GPR_DEBUG, "chand=%p calld=%p: resolver returned, doing pick",
               chand, calld);
     }
-    if (pick_subchannel_locked(exec_ctx, elem)) {
-      subchannel_ready_locked(exec_ctx, elem, GRPC_ERROR_NONE);
+    if (pick_callback_start_locked(exec_ctx, elem)) {
+      // Even if the LB policy returns a result synchronously, we have
+      // already added our polling entity to chand->interested_parties
+      // in order to wait for the resolver result, so we need to
+      // remove it here.  Therefore, we call async_pick_done_locked()
+      // instead of pick_done_locked().
+      async_pick_done_locked(exec_ctx, elem, GRPC_ERROR_NONE);
     }
   }
 }
@@ -1152,154 +1261,38 @@ static void pick_after_resolver_result_start_locked(grpc_exec_ctx *exec_ctx,
                         grpc_combiner_scheduler(chand->combiner)));
 }
 
-// Note: This runs under the client_channel combiner, but will NOT be
-// holding the call combiner.
-static void pick_callback_cancel_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
-  grpc_call_element *elem = (grpc_call_element *)arg;
-  channel_data *chand = (channel_data *)elem->channel_data;
-  call_data *calld = (call_data *)elem->call_data;
-  if (error != GRPC_ERROR_NONE && calld->lb_policy != NULL) {
-    if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: cancelling pick from LB policy %p",
-              chand, calld, calld->lb_policy);
-    }
-    grpc_lb_policy_cancel_pick_locked(exec_ctx, calld->lb_policy,
-                                      &calld->connected_subchannel,
-                                      GRPC_ERROR_REF(error));
-  }
-  GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_callback_cancel");
-}
-
-// Callback invoked by grpc_lb_policy_pick_locked() for async picks.
-// Unrefs the LB policy and invokes subchannel_ready_locked().
-static void pick_callback_done_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                      grpc_error *error) {
+static void start_pick_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                              grpc_error *ignored) {
   grpc_call_element *elem = (grpc_call_element *)arg;
-  channel_data *chand = (channel_data *)elem->channel_data;
   call_data *calld = (call_data *)elem->call_data;
-  if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed asynchronously",
-            chand, calld);
-  }
-  GPR_ASSERT(calld->lb_policy != NULL);
-  GRPC_LB_POLICY_UNREF(exec_ctx, calld->lb_policy, "pick_subchannel");
-  calld->lb_policy = NULL;
-  subchannel_ready_locked(exec_ctx, elem, GRPC_ERROR_REF(error));
-}
-
-// Takes a ref to chand->lb_policy and calls grpc_lb_policy_pick_locked().
-// If the pick was completed synchronously, unrefs the LB policy and
-// returns true.
-static bool pick_callback_start_locked(grpc_exec_ctx *exec_ctx,
-                                       grpc_call_element *elem,
-                                       const grpc_lb_policy_pick_args *inputs) {
   channel_data *chand = (channel_data *)elem->channel_data;
-  call_data *calld = (call_data *)elem->call_data;
-  if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
-    gpr_log(GPR_DEBUG, "chand=%p calld=%p: starting pick on lb_policy=%p",
-            chand, calld, chand->lb_policy);
-  }
-  // Keep a ref to the LB policy in calld while the pick is pending.
-  GRPC_LB_POLICY_REF(chand->lb_policy, "pick_subchannel");
-  calld->lb_policy = chand->lb_policy;
-  GRPC_CLOSURE_INIT(&calld->lb_pick_closure, pick_callback_done_locked, elem,
-                    grpc_combiner_scheduler(chand->combiner));
-  const bool pick_done = grpc_lb_policy_pick_locked(
-      exec_ctx, chand->lb_policy, inputs, &calld->connected_subchannel,
-      calld->subchannel_call_context, NULL, &calld->lb_pick_closure);
-  if (pick_done) {
-    /* synchronous grpc_lb_policy_pick call. Unref the LB policy. */
-    if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: pick completed synchronously",
-              chand, calld);
+  GPR_ASSERT(calld->connected_subchannel == NULL);
+  if (chand->lb_policy != NULL) {
+    // We already have an LB policy, so ask it for a pick.
+    if (pick_callback_start_locked(exec_ctx, elem)) {
+      // Pick completed synchronously.
+      pick_done_locked(exec_ctx, elem, GRPC_ERROR_NONE);
+      return;
     }
-    GRPC_LB_POLICY_UNREF(exec_ctx, calld->lb_policy, "pick_subchannel");
-    calld->lb_policy = NULL;
   } else {
-    GRPC_CALL_STACK_REF(calld->owning_call, "pick_callback_cancel");
-    grpc_call_combiner_set_notify_on_cancel(
-        exec_ctx, calld->call_combiner,
-        GRPC_CLOSURE_INIT(&calld->lb_pick_cancel_closure,
-                          pick_callback_cancel_locked, elem,
-                          grpc_combiner_scheduler(chand->combiner)));
-  }
-  return pick_done;
-}
-
-static bool pick_subchannel_locked(grpc_exec_ctx *exec_ctx,
-                                   grpc_call_element *elem) {
-  GPR_TIMER_BEGIN("pick_subchannel", 0);
-  channel_data *chand = (channel_data *)elem->channel_data;
-  call_data *calld = (call_data *)elem->call_data;
-  bool pick_done = false;
-  if (chand->lb_policy != NULL) {
-    apply_service_config_to_call_locked(exec_ctx, elem);
-    // If the application explicitly set wait_for_ready, use that.
-    // Otherwise, if the service config specified a value for this
-    // method, use that.
-    uint32_t initial_metadata_flags =
-        calld->initial_metadata_batch->payload->send_initial_metadata
-            .send_initial_metadata_flags;
-    const bool wait_for_ready_set_from_api =
-        initial_metadata_flags &
-        GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET;
-    const bool wait_for_ready_set_from_service_config =
-        calld->method_params != NULL &&
-        calld->method_params->wait_for_ready != WAIT_FOR_READY_UNSET;
-    if (!wait_for_ready_set_from_api &&
-        wait_for_ready_set_from_service_config) {
-      if (calld->method_params->wait_for_ready == WAIT_FOR_READY_TRUE) {
-        initial_metadata_flags |= GRPC_INITIAL_METADATA_WAIT_FOR_READY;
-      } else {
-        initial_metadata_flags &= ~GRPC_INITIAL_METADATA_WAIT_FOR_READY;
-      }
+    // We do not yet have an LB policy, so wait for a resolver result.
+    if (chand->resolver == NULL) {
+      pick_done_locked(exec_ctx, elem,
+                       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Disconnected"));
+      return;
     }
-    const grpc_lb_policy_pick_args inputs = {
-        calld->initial_metadata_batch->payload->send_initial_metadata
-            .send_initial_metadata,
-        initial_metadata_flags, &calld->lb_token_mdelem};
-    pick_done = pick_callback_start_locked(exec_ctx, elem, &inputs);
-  } else if (chand->resolver != NULL) {
     if (!chand->started_resolving) {
       start_resolving_locked(exec_ctx, chand);
     }
     pick_after_resolver_result_start_locked(exec_ctx, elem);
-  } else {
-    subchannel_ready_locked(
-        exec_ctx, elem, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Disconnected"));
-  }
-  GPR_TIMER_END("pick_subchannel", 0);
-  return pick_done;
-}
-
-static void start_pick_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error_ignored) {
-  GPR_TIMER_BEGIN("start_pick_locked", 0);
-  grpc_call_element *elem = (grpc_call_element *)arg;
-  call_data *calld = (call_data *)elem->call_data;
-  channel_data *chand = (channel_data *)elem->channel_data;
-  GPR_ASSERT(calld->connected_subchannel == NULL);
-  if (pick_subchannel_locked(exec_ctx, elem)) {
-    // Pick was returned synchronously.
-    if (calld->connected_subchannel == NULL) {
-      GRPC_ERROR_UNREF(calld->error);
-      calld->error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-          "Call dropped by load balancing policy");
-      waiting_for_pick_batches_fail(exec_ctx, elem,
-                                    GRPC_ERROR_REF(calld->error));
-    } else {
-      // Create subchannel call.
-      create_subchannel_call_locked(exec_ctx, elem, GRPC_ERROR_NONE);
-    }
-  } else {
-    // Pick will be done asynchronously.  Add the call's polling entity to
-    // the channel's interested_parties, so that I/O for the resolver
-    // and LB policy can be done under it.
-    grpc_polling_entity_add_to_pollset_set(exec_ctx, calld->pollent,
-                                           chand->interested_parties);
   }
-  GPR_TIMER_END("start_pick_locked", 0);
+  // We need to wait for either a resolver result or for an async result
+  // from the LB policy.  Add the polling entity from call_data to the
+  // channel_data's interested_parties, so that the I/O of the LB policy
+  // and resolver can be done under it.  The polling entity will be
+  // removed in async_pick_done_locked().
+  grpc_polling_entity_add_to_pollset_set(exec_ctx, calld->pollent,
+                                         chand->interested_parties);
 }
 
 static void on_complete(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
@@ -1394,7 +1387,8 @@ static void cc_start_transport_stream_op_batch(
   // combiner to start a pick.
   if (batch->send_initial_metadata) {
     if (GRPC_TRACER_ON(grpc_client_channel_trace)) {
-      gpr_log(GPR_DEBUG, "chand=%p calld=%p: entering combiner", chand, calld);
+      gpr_log(GPR_DEBUG, "chand=%p calld=%p: entering client_channel combiner",
+              chand, calld);
     }
     GRPC_CLOSURE_SCHED(
         exec_ctx,
diff --git a/src/core/ext/filters/client_channel/client_channel_factory.c b/src/core/ext/filters/client_channel/client_channel_factory.c
index 7220a8639e..57eac8f875 100644
--- a/src/core/ext/filters/client_channel/client_channel_factory.c
+++ b/src/core/ext/filters/client_channel/client_channel_factory.c
@@ -43,14 +43,13 @@ grpc_channel* grpc_client_channel_factory_create_channel(
 }
 
 static void* factory_arg_copy(void* factory) {
-  grpc_client_channel_factory_ref(factory);
+  grpc_client_channel_factory_ref((grpc_client_channel_factory*)factory);
   return factory;
 }
 
 static void factory_arg_destroy(grpc_exec_ctx* exec_ctx, void* factory) {
-  // TODO(roth): Remove local exec_ctx when
-  // https://github.com/grpc/grpc/pull/8705 is merged.
-  grpc_client_channel_factory_unref(exec_ctx, factory);
+  grpc_client_channel_factory_unref(exec_ctx,
+                                    (grpc_client_channel_factory*)factory);
 }
 
 static int factory_arg_cmp(void* factory1, void* factory2) {
@@ -64,6 +63,6 @@ static const grpc_arg_pointer_vtable factory_arg_vtable = {
 
 grpc_arg grpc_client_channel_factory_create_channel_arg(
     grpc_client_channel_factory* factory) {
-  return grpc_channel_arg_pointer_create(GRPC_ARG_CLIENT_CHANNEL_FACTORY,
+  return grpc_channel_arg_pointer_create((char*)GRPC_ARG_CLIENT_CHANNEL_FACTORY,
                                          factory, &factory_arg_vtable);
 }
diff --git a/src/core/ext/filters/client_channel/client_channel_plugin.c b/src/core/ext/filters/client_channel/client_channel_plugin.c
index c32e83d012..1f71c5a7f9 100644
--- a/src/core/ext/filters/client_channel/client_channel_plugin.c
+++ b/src/core/ext/filters/client_channel/client_channel_plugin.c
@@ -54,8 +54,8 @@ static bool set_default_host_if_unset(grpc_exec_ctx *exec_ctx,
   char *default_authority = grpc_get_default_authority(
       exec_ctx, grpc_channel_stack_builder_get_target(builder));
   if (default_authority != NULL) {
-    grpc_arg arg = grpc_channel_arg_string_create(GRPC_ARG_DEFAULT_AUTHORITY,
-                                                  default_authority);
+    grpc_arg arg = grpc_channel_arg_string_create(
+        (char *)GRPC_ARG_DEFAULT_AUTHORITY, default_authority);
     grpc_channel_args *new_args = grpc_channel_args_copy_and_add(args, &arg, 1);
     grpc_channel_stack_builder_set_channel_arguments(exec_ctx, builder,
                                                      new_args);
diff --git a/src/core/ext/filters/client_channel/http_proxy.c b/src/core/ext/filters/client_channel/http_proxy.c
index ef3512ed83..c507a2750e 100644
--- a/src/core/ext/filters/client_channel/http_proxy.c
+++ b/src/core/ext/filters/client_channel/http_proxy.c
@@ -44,6 +44,8 @@ static char* get_http_proxy_server(grpc_exec_ctx* exec_ctx, char** user_cred) {
   GPR_ASSERT(user_cred != NULL);
   char* proxy_name = NULL;
   char* uri_str = gpr_getenv("http_proxy");
+  char** authority_strs = NULL;
+  size_t authority_nstrs;
   if (uri_str == NULL) return NULL;
   grpc_uri* uri =
       grpc_uri_parse(exec_ctx, uri_str, false /* suppress_errors */);
@@ -56,8 +58,6 @@ static char* get_http_proxy_server(grpc_exec_ctx* exec_ctx, char** user_cred) {
     goto done;
   }
   /* Split on '@' to separate user credentials from host */
-  char** authority_strs = NULL;
-  size_t authority_nstrs;
   gpr_string_split(uri->authority, "@", &authority_strs, &authority_nstrs);
   GPR_ASSERT(authority_nstrs != 0); /* should have at least 1 string */
   if (authority_nstrs == 1) {
@@ -157,7 +157,7 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
   }
   grpc_arg args_to_add[2];
   args_to_add[0] = grpc_channel_arg_string_create(
-      GRPC_ARG_HTTP_CONNECT_SERVER,
+      (char*)GRPC_ARG_HTTP_CONNECT_SERVER,
       uri->path[0] == '/' ? uri->path + 1 : uri->path);
   if (user_cred != NULL) {
     /* Use base64 encoding for user credentials as stated in RFC 7617 */
@@ -166,8 +166,8 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
     char* header;
     gpr_asprintf(&header, "Proxy-Authorization:Basic %s", encoded_user_cred);
     gpr_free(encoded_user_cred);
-    args_to_add[1] =
-        grpc_channel_arg_string_create(GRPC_ARG_HTTP_CONNECT_HEADERS, header);
+    args_to_add[1] = grpc_channel_arg_string_create(
+        (char*)GRPC_ARG_HTTP_CONNECT_HEADERS, header);
     *new_args = grpc_channel_args_copy_and_add(args, args_to_add, 2);
     gpr_free(header);
   } else {
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c
index bd290464c8..7ad322902b 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c
@@ -75,7 +75,8 @@ static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(args->context != NULL);
   GPR_ASSERT(args->context[GRPC_GRPCLB_CLIENT_STATS].value != NULL);
   calld->client_stats = grpc_grpclb_client_stats_ref(
-      args->context[GRPC_GRPCLB_CLIENT_STATS].value);
+      (grpc_grpclb_client_stats *)args->context[GRPC_GRPCLB_CLIENT_STATS]
+          .value);
   // Record call started.
   grpc_grpclb_client_stats_add_call_started(calld->client_stats);
   return GRPC_ERROR_NONE;
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
index 5aafed1374..85ef7894ea 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
@@ -101,6 +101,7 @@
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -137,7 +138,7 @@ static grpc_error *initial_metadata_add_lb_token(
 }
 
 static void destroy_client_stats(void *arg) {
-  grpc_grpclb_client_stats_unref(arg);
+  grpc_grpclb_client_stats_unref((grpc_grpclb_client_stats *)arg);
 }
 
 typedef struct wrapped_rr_closure_arg {
@@ -285,7 +286,7 @@ static void add_pending_ping(pending_ping **root, grpc_closure *notify) {
  * glb_lb_policy
  */
 typedef struct rr_connectivity_data rr_connectivity_data;
-static const grpc_lb_policy_vtable glb_lb_policy_vtable;
+
 typedef struct glb_lb_policy {
   /** base policy: must be first */
   grpc_lb_policy base;
@@ -727,7 +728,7 @@ static void create_rr_locked(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
   /* Allocate the data for the tracking of the new RR policy's connectivity.
    * It'll be deallocated in glb_rr_connectivity_changed() */
   rr_connectivity_data *rr_connectivity =
-      gpr_zalloc(sizeof(rr_connectivity_data));
+      (rr_connectivity_data *)gpr_zalloc(sizeof(rr_connectivity_data));
   GRPC_CLOSURE_INIT(&rr_connectivity->on_change,
                     glb_rr_connectivity_changed_locked, rr_connectivity,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
@@ -869,7 +870,8 @@ static grpc_channel_args *build_lb_channel_args(
   grpc_lb_addresses *lb_addresses =
       grpc_lb_addresses_create(num_grpclb_addrs, NULL);
   grpc_slice_hash_table_entry *targets_info_entries =
-      gpr_zalloc(sizeof(*targets_info_entries) * num_grpclb_addrs);
+      (grpc_slice_hash_table_entry *)gpr_zalloc(sizeof(*targets_info_entries) *
+                                                num_grpclb_addrs);
 
   size_t lb_addresses_idx = 0;
   for (size_t i = 0; i < addresses->num_addresses; ++i) {
@@ -911,92 +913,6 @@ static grpc_channel_args *build_lb_channel_args(
   return result;
 }
 
-static void glb_lb_channel_on_connectivity_changed_cb(grpc_exec_ctx *exec_ctx,
-                                                      void *arg,
-                                                      grpc_error *error);
-static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
-                                  grpc_lb_policy_factory *factory,
-                                  grpc_lb_policy_args *args) {
-  /* Count the number of gRPC-LB addresses. There must be at least one.
-   * TODO(roth): For now, we ignore non-balancer addresses, but in the
-   * future, we may change the behavior such that we fall back to using
-   * the non-balancer addresses if we cannot reach any balancers. In the
-   * fallback case, we should use the LB policy indicated by
-   * GRPC_ARG_LB_POLICY_NAME (although if that specifies grpclb or is
-   * unset, we should default to pick_first). */
-  const grpc_arg *arg =
-      grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
-  if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
-    return NULL;
-  }
-  grpc_lb_addresses *addresses = (grpc_lb_addresses *)arg->value.pointer.p;
-  size_t num_grpclb_addrs = 0;
-  for (size_t i = 0; i < addresses->num_addresses; ++i) {
-    if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
-  }
-  if (num_grpclb_addrs == 0) return NULL;
-
-  glb_lb_policy *glb_policy = (glb_lb_policy *)gpr_zalloc(sizeof(*glb_policy));
-
-  /* Get server name. */
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_SERVER_URI);
-  GPR_ASSERT(arg != NULL);
-  GPR_ASSERT(arg->type == GRPC_ARG_STRING);
-  grpc_uri *uri = grpc_uri_parse(exec_ctx, arg->value.string, true);
-  GPR_ASSERT(uri->path[0] != '\0');
-  glb_policy->server_name =
-      gpr_strdup(uri->path[0] == '/' ? uri->path + 1 : uri->path);
-  if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-    gpr_log(GPR_INFO, "Will use '%s' as the server name for LB request.",
-            glb_policy->server_name);
-  }
-  grpc_uri_destroy(uri);
-
-  glb_policy->cc_factory = args->client_channel_factory;
-  GPR_ASSERT(glb_policy->cc_factory != NULL);
-
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS);
-  glb_policy->lb_call_timeout_ms =
-      grpc_channel_arg_get_integer(arg, (grpc_integer_options){0, 0, INT_MAX});
-
-  // Make sure that GRPC_ARG_LB_POLICY_NAME is set in channel args,
-  // since we use this to trigger the client_load_reporting filter.
-  grpc_arg new_arg =
-      grpc_channel_arg_string_create(GRPC_ARG_LB_POLICY_NAME, "grpclb");
-  static const char *args_to_remove[] = {GRPC_ARG_LB_POLICY_NAME};
-  glb_policy->args = grpc_channel_args_copy_and_add_and_remove(
-      args->args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), &new_arg, 1);
-
-  /* Create a client channel over them to communicate with a LB service */
-  glb_policy->response_generator =
-      grpc_fake_resolver_response_generator_create();
-  grpc_channel_args *lb_channel_args = build_lb_channel_args(
-      exec_ctx, addresses, glb_policy->response_generator, args->args);
-  char *uri_str;
-  gpr_asprintf(&uri_str, "fake:///%s", glb_policy->server_name);
-  glb_policy->lb_channel = grpc_lb_policy_grpclb_create_lb_channel(
-      exec_ctx, uri_str, args->client_channel_factory, lb_channel_args);
-
-  /* Propagate initial resolution */
-  grpc_fake_resolver_response_generator_set_response(
-      exec_ctx, glb_policy->response_generator, lb_channel_args);
-  grpc_channel_args_destroy(exec_ctx, lb_channel_args);
-  gpr_free(uri_str);
-  if (glb_policy->lb_channel == NULL) {
-    gpr_free((void *)glb_policy->server_name);
-    grpc_channel_args_destroy(exec_ctx, glb_policy->args);
-    gpr_free(glb_policy);
-    return NULL;
-  }
-  GRPC_CLOSURE_INIT(&glb_policy->lb_channel_on_connectivity_changed,
-                    glb_lb_channel_on_connectivity_changed_cb, glb_policy,
-                    grpc_combiner_scheduler(args->combiner));
-  grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable, args->combiner);
-  grpc_connectivity_state_init(&glb_policy->state_tracker, GRPC_CHANNEL_IDLE,
-                               "grpclb");
-  return &glb_policy->base;
-}
-
 static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)pol;
   GPR_ASSERT(glb_policy->pending_picks == NULL);
@@ -1011,6 +927,7 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
   grpc_fake_resolver_response_generator_unref(glb_policy->response_generator);
+  grpc_subchannel_index_unref();
   if (glb_policy->pending_update_args != NULL) {
     grpc_channel_args_destroy(exec_ctx, glb_policy->pending_update_args->args);
     gpr_free(glb_policy->pending_update_args);
@@ -1303,7 +1220,8 @@ static void do_send_client_load_report_locked(grpc_exec_ctx *exec_ctx,
 
 static bool load_report_counters_are_zero(grpc_grpclb_request *request) {
   grpc_grpclb_dropped_call_counts *drop_entries =
-      request->client_stats.calls_finished_with_drop.arg;
+      (grpc_grpclb_dropped_call_counts *)
+          request->client_stats.calls_finished_with_drop.arg;
   return request->client_stats.num_calls_started == 0 &&
          request->client_stats.num_calls_finished == 0 &&
          request->client_stats.num_calls_finished_with_client_failed_to_send ==
@@ -1642,6 +1560,9 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
           exec_ctx, glb_policy->lb_call, ops, (size_t)(op - ops),
           &glb_policy->lb_on_response_received); /* loop */
       GPR_ASSERT(GRPC_CALL_OK == call_error);
+    } else {
+      GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                                "lb_on_response_received_locked_shutdown");
     }
   } else { /* empty payload: call cancelled. */
            /* dispose of the "lb_on_response_received_locked" weak ref taken in
@@ -1865,6 +1786,90 @@ static const grpc_lb_policy_vtable glb_lb_policy_vtable = {
     glb_notify_on_state_change_locked,
     glb_update_locked};
 
+static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
+                                  grpc_lb_policy_factory *factory,
+                                  grpc_lb_policy_args *args) {
+  /* Count the number of gRPC-LB addresses. There must be at least one.
+   * TODO(roth): For now, we ignore non-balancer addresses, but in the
+   * future, we may change the behavior such that we fall back to using
+   * the non-balancer addresses if we cannot reach any balancers. In the
+   * fallback case, we should use the LB policy indicated by
+   * GRPC_ARG_LB_POLICY_NAME (although if that specifies grpclb or is
+   * unset, we should default to pick_first). */
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
+    return NULL;
+  }
+  grpc_lb_addresses *addresses = (grpc_lb_addresses *)arg->value.pointer.p;
+  size_t num_grpclb_addrs = 0;
+  for (size_t i = 0; i < addresses->num_addresses; ++i) {
+    if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
+  }
+  if (num_grpclb_addrs == 0) return NULL;
+
+  glb_lb_policy *glb_policy = (glb_lb_policy *)gpr_zalloc(sizeof(*glb_policy));
+
+  /* Get server name. */
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_SERVER_URI);
+  GPR_ASSERT(arg != NULL);
+  GPR_ASSERT(arg->type == GRPC_ARG_STRING);
+  grpc_uri *uri = grpc_uri_parse(exec_ctx, arg->value.string, true);
+  GPR_ASSERT(uri->path[0] != '\0');
+  glb_policy->server_name =
+      gpr_strdup(uri->path[0] == '/' ? uri->path + 1 : uri->path);
+  if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+    gpr_log(GPR_INFO, "Will use '%s' as the server name for LB request.",
+            glb_policy->server_name);
+  }
+  grpc_uri_destroy(uri);
+
+  glb_policy->cc_factory = args->client_channel_factory;
+  GPR_ASSERT(glb_policy->cc_factory != NULL);
+
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS);
+  glb_policy->lb_call_timeout_ms =
+      grpc_channel_arg_get_integer(arg, (grpc_integer_options){0, 0, INT_MAX});
+
+  // Make sure that GRPC_ARG_LB_POLICY_NAME is set in channel args,
+  // since we use this to trigger the client_load_reporting filter.
+  grpc_arg new_arg = grpc_channel_arg_string_create(
+      (char *)GRPC_ARG_LB_POLICY_NAME, (char *)"grpclb");
+  static const char *args_to_remove[] = {GRPC_ARG_LB_POLICY_NAME};
+  glb_policy->args = grpc_channel_args_copy_and_add_and_remove(
+      args->args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), &new_arg, 1);
+
+  /* Create a client channel over them to communicate with a LB service */
+  glb_policy->response_generator =
+      grpc_fake_resolver_response_generator_create();
+  grpc_channel_args *lb_channel_args = build_lb_channel_args(
+      exec_ctx, addresses, glb_policy->response_generator, args->args);
+  char *uri_str;
+  gpr_asprintf(&uri_str, "fake:///%s", glb_policy->server_name);
+  glb_policy->lb_channel = grpc_lb_policy_grpclb_create_lb_channel(
+      exec_ctx, uri_str, args->client_channel_factory, lb_channel_args);
+
+  /* Propagate initial resolution */
+  grpc_fake_resolver_response_generator_set_response(
+      exec_ctx, glb_policy->response_generator, lb_channel_args);
+  grpc_channel_args_destroy(exec_ctx, lb_channel_args);
+  gpr_free(uri_str);
+  if (glb_policy->lb_channel == NULL) {
+    gpr_free((void *)glb_policy->server_name);
+    grpc_channel_args_destroy(exec_ctx, glb_policy->args);
+    gpr_free(glb_policy);
+    return NULL;
+  }
+  grpc_subchannel_index_ref();
+  GRPC_CLOSURE_INIT(&glb_policy->lb_channel_on_connectivity_changed,
+                    glb_lb_channel_on_connectivity_changed_cb, glb_policy,
+                    grpc_combiner_scheduler(args->combiner));
+  grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable, args->combiner);
+  grpc_connectivity_state_init(&glb_policy->state_tracker, GRPC_CHANNEL_IDLE,
+                               "grpclb");
+  return &glb_policy->base;
+}
+
 static void glb_factory_ref(grpc_lb_policy_factory *factory) {}
 
 static void glb_factory_unref(grpc_lb_policy_factory *factory) {}
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
index 407bd18adb..8ef6dfc6f4 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
@@ -148,7 +148,8 @@ grpc_slice grpc_grpclb_request_encode(const grpc_grpclb_request *request) {
 void grpc_grpclb_request_destroy(grpc_grpclb_request *request) {
   if (request->has_client_stats) {
     grpc_grpclb_dropped_call_counts *drop_entries =
-        request->client_stats.calls_finished_with_drop.arg;
+        (grpc_grpclb_dropped_call_counts *)
+            request->client_stats.calls_finished_with_drop.arg;
     grpc_grpclb_dropped_call_counts_destroy(drop_entries);
   }
   gpr_free(request);
@@ -170,7 +171,8 @@ grpc_grpclb_initial_response *grpc_grpclb_initial_response_parse(
   if (!res.has_initial_response) return NULL;
 
   grpc_grpclb_initial_response *initial_res =
-      gpr_malloc(sizeof(grpc_grpclb_initial_response));
+      (grpc_grpclb_initial_response *)gpr_malloc(
+          sizeof(grpc_grpclb_initial_response));
   memcpy(initial_res, &res.initial_response,
          sizeof(grpc_grpclb_initial_response));
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
index fab3073eb9..d20cbb8388 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
@@ -89,6 +89,7 @@ static void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
                                     "picked_first_destroy");
   }
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
+  grpc_subchannel_index_unref();
   if (p->pending_update_args != NULL) {
     grpc_channel_args_destroy(exec_ctx, p->pending_update_args->args);
     gpr_free(p->pending_update_args);
@@ -330,8 +331,8 @@ static void pf_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
     gpr_log(GPR_INFO, "Pick First %p received update with %lu addresses",
             (void *)p, (unsigned long)addresses->num_addresses);
   }
-  grpc_subchannel_args *sc_args =
-      gpr_zalloc(sizeof(*sc_args) * addresses->num_addresses);
+  grpc_subchannel_args *sc_args = (grpc_subchannel_args *)gpr_zalloc(
+      sizeof(*sc_args) * addresses->num_addresses);
   /* We remove the following keys in order for subchannel keys belonging to
    * subchannels point to the same address to match. */
   static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS,
@@ -403,7 +404,7 @@ static void pf_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
   }
   /* Create the subchannels for the new subchannel args/addresses. */
   grpc_subchannel **new_subchannels =
-      gpr_zalloc(sizeof(*new_subchannels) * sc_args_count);
+      (grpc_subchannel **)gpr_zalloc(sizeof(*new_subchannels) * sc_args_count);
   size_t num_new_subchannels = 0;
   for (size_t i = 0; i < sc_args_count; i++) {
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
@@ -686,6 +687,7 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
   }
   pf_update_locked(exec_ctx, &p->base, args);
   grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable, args->combiner);
+  grpc_subchannel_index_ref();
   GRPC_CLOSURE_INIT(&p->connectivity_changed, pf_connectivity_changed_locked, p,
                     grpc_combiner_scheduler(args->combiner));
   return &p->base;
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
index be91d3d651..a3a62e9f3c 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
@@ -30,6 +30,7 @@
 
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -310,6 +311,7 @@ static void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
             (void *)pol, (void *)pol);
   }
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
+  grpc_subchannel_index_unref();
   gpr_free(p);
 }
 
@@ -587,7 +589,7 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg,
   // Dispose of outdated subchannel lists.
   if (sd->subchannel_list != p->subchannel_list &&
       sd->subchannel_list != p->latest_pending_subchannel_list) {
-    char *reason = NULL;
+    const char *reason = NULL;
     if (sd->subchannel_list->shutting_down) {
       reason = "sl_outdated_straggler";
       rr_subchannel_list_unref(exec_ctx, sd->subchannel_list, reason);
@@ -890,6 +892,7 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(args->client_channel_factory != NULL);
   round_robin_lb_policy *p = (round_robin_lb_policy *)gpr_zalloc(sizeof(*p));
   grpc_lb_policy_init(&p->base, &round_robin_lb_policy_vtable, args->combiner);
+  grpc_subchannel_index_ref();
   grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
                                "round_robin");
   rr_update_locked(exec_ctx, &p->base, args);
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.c b/src/core/ext/filters/client_channel/lb_policy_factory.c
index cdcaf17544..4d1405454c 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.c
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.c
@@ -126,13 +126,14 @@ void grpc_lb_addresses_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 static void* lb_addresses_copy(void* addresses) {
-  return grpc_lb_addresses_copy(addresses);
+  return grpc_lb_addresses_copy((grpc_lb_addresses*)addresses);
 }
 static void lb_addresses_destroy(grpc_exec_ctx* exec_ctx, void* addresses) {
-  grpc_lb_addresses_destroy(exec_ctx, addresses);
+  grpc_lb_addresses_destroy(exec_ctx, (grpc_lb_addresses*)addresses);
 }
 static int lb_addresses_cmp(void* addresses1, void* addresses2) {
-  return grpc_lb_addresses_cmp(addresses1, addresses2);
+  return grpc_lb_addresses_cmp((grpc_lb_addresses*)addresses1,
+                               (grpc_lb_addresses*)addresses2);
 }
 static const grpc_arg_pointer_vtable lb_addresses_arg_vtable = {
     lb_addresses_copy, lb_addresses_destroy, lb_addresses_cmp};
@@ -140,7 +141,7 @@ static const grpc_arg_pointer_vtable lb_addresses_arg_vtable = {
 grpc_arg grpc_lb_addresses_create_channel_arg(
     const grpc_lb_addresses* addresses) {
   return grpc_channel_arg_pointer_create(
-      GRPC_ARG_LB_ADDRESSES, (void*)addresses, &lb_addresses_arg_vtable);
+      (char*)GRPC_ARG_LB_ADDRESSES, (void*)addresses, &lb_addresses_arg_vtable);
 }
 
 grpc_lb_addresses* grpc_lb_addresses_find_channel_arg(
@@ -149,7 +150,7 @@ grpc_lb_addresses* grpc_lb_addresses_find_channel_arg(
       grpc_channel_args_find(channel_args, GRPC_ARG_LB_ADDRESSES);
   if (lb_addresses_arg == NULL || lb_addresses_arg->type != GRPC_ARG_POINTER)
     return NULL;
-  return lb_addresses_arg->value.pointer.p;
+  return (grpc_lb_addresses*)lb_addresses_arg->value.pointer.p;
 }
 
 void grpc_lb_policy_factory_ref(grpc_lb_policy_factory* factory) {
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
index b87a3b7082..9bb229ad95 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
@@ -204,7 +204,7 @@ static char *choose_service_config(char *service_config_choice_json) {
         int random_pct = rand() % 100;
         int percentage;
         if (sscanf(field->value, "%d", &percentage) != 1 ||
-            random_pct > percentage) {
+            random_pct > percentage || percentage == 0) {
           service_config_json = NULL;
           break;
         }
@@ -249,7 +249,7 @@ static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
                 service_config_string);
         args_to_remove[num_args_to_remove++] = GRPC_ARG_SERVICE_CONFIG;
         new_args[num_args_to_add++] = grpc_channel_arg_string_create(
-            GRPC_ARG_SERVICE_CONFIG, service_config_string);
+            (char *)GRPC_ARG_SERVICE_CONFIG, service_config_string);
         service_config = grpc_service_config_create(service_config_string);
         if (service_config != NULL) {
           const char *lb_policy_name =
@@ -257,7 +257,7 @@ static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
           if (lb_policy_name != NULL) {
             args_to_remove[num_args_to_remove++] = GRPC_ARG_LB_POLICY_NAME;
             new_args[num_args_to_add++] = grpc_channel_arg_string_create(
-                GRPC_ARG_LB_POLICY_NAME, (char *)lb_policy_name);
+                (char *)GRPC_ARG_LB_POLICY_NAME, (char *)lb_policy_name);
           }
         }
       }
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
index 9747d39a16..c30cc93b6f 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
@@ -20,6 +20,7 @@
 #if GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET)
 
 #include <ares.h>
+#include <sys/ioctl.h>
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
 
@@ -37,8 +38,6 @@
 typedef struct fd_node {
   /** the owner of this fd node */
   grpc_ares_ev_driver *ev_driver;
-  /** the grpc_fd owned by this fd node */
-  grpc_fd *grpc_fd;
   /** a closure wrapping on_readable_cb, which should be invoked when the
       grpc_fd in this node becomes readable. */
   grpc_closure read_closure;
@@ -50,10 +49,14 @@ typedef struct fd_node {
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
+  /** the grpc_fd owned by this fd node */
+  grpc_fd *fd;
   /** if the readable closure has been registered */
   bool readable_registered;
   /** if the writable closure has been registered */
   bool writable_registered;
+  /** if the fd is being shut down */
+  bool shutting_down;
 } fd_node;
 
 struct grpc_ares_ev_driver {
@@ -96,19 +99,31 @@ static void grpc_ares_ev_driver_unref(grpc_ares_ev_driver *ev_driver) {
 }
 
 static void fd_node_destroy(grpc_exec_ctx *exec_ctx, fd_node *fdn) {
-  gpr_log(GPR_DEBUG, "delete fd: %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  gpr_log(GPR_DEBUG, "delete fd: %d", grpc_fd_wrapped_fd(fdn->fd));
   GPR_ASSERT(!fdn->readable_registered);
   GPR_ASSERT(!fdn->writable_registered);
   gpr_mu_destroy(&fdn->mu);
-  grpc_pollset_set_del_fd(exec_ctx, fdn->ev_driver->pollset_set, fdn->grpc_fd);
   /* c-ares library has closed the fd inside grpc_fd. This fd may be picked up
      immediately by another thread, and should not be closed by the following
      grpc_fd_orphan. */
-  grpc_fd_orphan(exec_ctx, fdn->grpc_fd, NULL, NULL, true /* already_closed */,
+  grpc_fd_orphan(exec_ctx, fdn->fd, NULL, NULL, true /* already_closed */,
                  "c-ares query finished");
   gpr_free(fdn);
 }
 
+static void fd_node_shutdown(grpc_exec_ctx *exec_ctx, fd_node *fdn) {
+  gpr_mu_lock(&fdn->mu);
+  fdn->shutting_down = true;
+  if (!fdn->readable_registered && !fdn->writable_registered) {
+    gpr_mu_unlock(&fdn->mu);
+    fd_node_destroy(exec_ctx, fdn);
+  } else {
+    grpc_fd_shutdown(exec_ctx, fdn->fd, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                            "c-ares fd shutdown"));
+    gpr_mu_unlock(&fdn->mu);
+  }
+}
+
 grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver,
                                        grpc_pollset_set *pollset_set) {
   *ev_driver = (grpc_ares_ev_driver *)gpr_malloc(sizeof(grpc_ares_ev_driver));
@@ -150,9 +165,8 @@ void grpc_ares_ev_driver_shutdown(grpc_exec_ctx *exec_ctx,
   ev_driver->shutting_down = true;
   fd_node *fn = ev_driver->fds;
   while (fn != NULL) {
-    grpc_fd_shutdown(
-        exec_ctx, fn->grpc_fd,
-        GRPC_ERROR_CREATE_FROM_STATIC_STRING("grpc_ares_ev_driver_shutdown"));
+    grpc_fd_shutdown(exec_ctx, fn->fd, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+                                           "grpc_ares_ev_driver_shutdown"));
     fn = fn->next;
   }
   gpr_mu_unlock(&ev_driver->mu);
@@ -165,7 +179,7 @@ static fd_node *pop_fd_node(fd_node **head, int fd) {
   dummy_head.next = *head;
   fd_node *node = &dummy_head;
   while (node->next != NULL) {
-    if (grpc_fd_wrapped_fd(node->next->grpc_fd) == fd) {
+    if (grpc_fd_wrapped_fd(node->next->fd) == fd) {
       fd_node *ret = node->next;
       node->next = node->next->next;
       *head = dummy_head.next;
@@ -176,18 +190,33 @@ static fd_node *pop_fd_node(fd_node **head, int fd) {
   return NULL;
 }
 
+/* Check if \a fd is still readable */
+static bool grpc_ares_is_fd_still_readable(grpc_ares_ev_driver *ev_driver,
+                                           int fd) {
+  size_t bytes_available = 0;
+  return ioctl(fd, FIONREAD, &bytes_available) == 0 && bytes_available > 0;
+}
+
 static void on_readable_cb(grpc_exec_ctx *exec_ctx, void *arg,
                            grpc_error *error) {
   fd_node *fdn = (fd_node *)arg;
   grpc_ares_ev_driver *ev_driver = fdn->ev_driver;
   gpr_mu_lock(&fdn->mu);
+  const int fd = grpc_fd_wrapped_fd(fdn->fd);
   fdn->readable_registered = false;
+  if (fdn->shutting_down && !fdn->writable_registered) {
+    gpr_mu_unlock(&fdn->mu);
+    fd_node_destroy(exec_ctx, fdn);
+    grpc_ares_ev_driver_unref(ev_driver);
+    return;
+  }
   gpr_mu_unlock(&fdn->mu);
 
-  gpr_log(GPR_DEBUG, "readable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  gpr_log(GPR_DEBUG, "readable on %d", fd);
   if (error == GRPC_ERROR_NONE) {
-    ares_process_fd(ev_driver->channel, grpc_fd_wrapped_fd(fdn->grpc_fd),
-                    ARES_SOCKET_BAD);
+    do {
+      ares_process_fd(ev_driver->channel, fd, ARES_SOCKET_BAD);
+    } while (grpc_ares_is_fd_still_readable(ev_driver, fd));
   } else {
     // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or
     // timed out. The pending lookups made on this ev_driver will be cancelled
@@ -208,13 +237,19 @@ static void on_writable_cb(grpc_exec_ctx *exec_ctx, void *arg,
   fd_node *fdn = (fd_node *)arg;
   grpc_ares_ev_driver *ev_driver = fdn->ev_driver;
   gpr_mu_lock(&fdn->mu);
+  const int fd = grpc_fd_wrapped_fd(fdn->fd);
   fdn->writable_registered = false;
+  if (fdn->shutting_down && !fdn->readable_registered) {
+    gpr_mu_unlock(&fdn->mu);
+    fd_node_destroy(exec_ctx, fdn);
+    grpc_ares_ev_driver_unref(ev_driver);
+    return;
+  }
   gpr_mu_unlock(&fdn->mu);
 
-  gpr_log(GPR_DEBUG, "writable on %d", grpc_fd_wrapped_fd(fdn->grpc_fd));
+  gpr_log(GPR_DEBUG, "writable on %d", fd);
   if (error == GRPC_ERROR_NONE) {
-    ares_process_fd(ev_driver->channel, ARES_SOCKET_BAD,
-                    grpc_fd_wrapped_fd(fdn->grpc_fd));
+    ares_process_fd(ev_driver->channel, ARES_SOCKET_BAD, fd);
   } else {
     // If error is not GRPC_ERROR_NONE, it means the fd has been shutdown or
     // timed out. The pending lookups made on this ev_driver will be cancelled
@@ -253,17 +288,17 @@ static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
           gpr_asprintf(&fd_name, "ares_ev_driver-%" PRIuPTR, i);
           fdn = (fd_node *)gpr_malloc(sizeof(fd_node));
           gpr_log(GPR_DEBUG, "new fd: %d", socks[i]);
-          fdn->grpc_fd = grpc_fd_create(socks[i], fd_name);
+          fdn->fd = grpc_fd_create(socks[i], fd_name);
           fdn->ev_driver = ev_driver;
           fdn->readable_registered = false;
           fdn->writable_registered = false;
+          fdn->shutting_down = false;
           gpr_mu_init(&fdn->mu);
           GRPC_CLOSURE_INIT(&fdn->read_closure, on_readable_cb, fdn,
                             grpc_schedule_on_exec_ctx);
           GRPC_CLOSURE_INIT(&fdn->write_closure, on_writable_cb, fdn,
                             grpc_schedule_on_exec_ctx);
-          grpc_pollset_set_add_fd(exec_ctx, ev_driver->pollset_set,
-                                  fdn->grpc_fd);
+          grpc_pollset_set_add_fd(exec_ctx, ev_driver->pollset_set, fdn->fd);
           gpr_free(fd_name);
         }
         fdn->next = new_list;
@@ -274,9 +309,8 @@ static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
         if (ARES_GETSOCK_READABLE(socks_bitmask, i) &&
             !fdn->readable_registered) {
           grpc_ares_ev_driver_ref(ev_driver);
-          gpr_log(GPR_DEBUG, "notify read on: %d",
-                  grpc_fd_wrapped_fd(fdn->grpc_fd));
-          grpc_fd_notify_on_read(exec_ctx, fdn->grpc_fd, &fdn->read_closure);
+          gpr_log(GPR_DEBUG, "notify read on: %d", grpc_fd_wrapped_fd(fdn->fd));
+          grpc_fd_notify_on_read(exec_ctx, fdn->fd, &fdn->read_closure);
           fdn->readable_registered = true;
         }
         // Register write_closure if the socket is writable and write_closure
@@ -284,9 +318,9 @@ static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
         if (ARES_GETSOCK_WRITABLE(socks_bitmask, i) &&
             !fdn->writable_registered) {
           gpr_log(GPR_DEBUG, "notify write on: %d",
-                  grpc_fd_wrapped_fd(fdn->grpc_fd));
+                  grpc_fd_wrapped_fd(fdn->fd));
           grpc_ares_ev_driver_ref(ev_driver);
-          grpc_fd_notify_on_write(exec_ctx, fdn->grpc_fd, &fdn->write_closure);
+          grpc_fd_notify_on_write(exec_ctx, fdn->fd, &fdn->write_closure);
           fdn->writable_registered = true;
         }
         gpr_mu_unlock(&fdn->mu);
@@ -299,7 +333,7 @@ static void grpc_ares_notify_on_event_locked(grpc_exec_ctx *exec_ctx,
   while (ev_driver->fds != NULL) {
     fd_node *cur = ev_driver->fds;
     ev_driver->fds = ev_driver->fds->next;
-    fd_node_destroy(exec_ctx, cur);
+    fd_node_shutdown(exec_ctx, cur);
   }
   ev_driver->fds = new_list;
   // If the ev driver has no working fd, all the tasks are done.
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
index 0d71f3560e..04379975e1 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
@@ -123,8 +123,8 @@ static void grpc_ares_request_unref(grpc_exec_ctx *exec_ctx,
 static grpc_ares_hostbyname_request *create_hostbyname_request(
     grpc_ares_request *parent_request, char *host, uint16_t port,
     bool is_balancer) {
-  grpc_ares_hostbyname_request *hr =
-      gpr_zalloc(sizeof(grpc_ares_hostbyname_request));
+  grpc_ares_hostbyname_request *hr = (grpc_ares_hostbyname_request *)gpr_zalloc(
+      sizeof(grpc_ares_hostbyname_request));
   hr->parent_request = parent_request;
   hr->host = gpr_strdup(host);
   hr->port = port;
@@ -174,7 +174,7 @@ static void on_hostbyname_done_cb(void *arg, int status, int timeouts,
           grpc_lb_addresses_set_address(
               *lb_addresses, i, &addr, addr_len,
               hr->is_balancer /* is_balancer */,
-              hr->is_balancer ? strdup(hr->host) : NULL /* balancer_name */,
+              hr->is_balancer ? hr->host : NULL /* balancer_name */,
               NULL /* user_data */);
           char output[INET6_ADDRSTRLEN];
           ares_inet_ntop(AF_INET6, &addr.sin6_addr, output, INET6_ADDRSTRLEN);
@@ -195,7 +195,7 @@ static void on_hostbyname_done_cb(void *arg, int status, int timeouts,
           grpc_lb_addresses_set_address(
               *lb_addresses, i, &addr, addr_len,
               hr->is_balancer /* is_balancer */,
-              hr->is_balancer ? strdup(hr->host) : NULL /* balancer_name */,
+              hr->is_balancer ? hr->host : NULL /* balancer_name */,
               NULL /* user_data */);
           char output[INET_ADDRSTRLEN];
           ares_inet_ntop(AF_INET, &addr.sin_addr, output, INET_ADDRSTRLEN);
@@ -275,14 +275,15 @@ static void on_txt_done_cb(void *arg, int status, int timeouts,
   gpr_log(GPR_DEBUG, "on_txt_done_cb");
   char *error_msg;
   grpc_ares_request *r = (grpc_ares_request *)arg;
+  const size_t prefix_len = sizeof(g_service_config_attribute_prefix) - 1;
+  struct ares_txt_ext *result = NULL;
+  struct ares_txt_ext *reply = NULL;
+  grpc_error *error = GRPC_ERROR_NONE;
   gpr_mu_lock(&r->mu);
   if (status != ARES_SUCCESS) goto fail;
-  struct ares_txt_ext *reply = NULL;
   status = ares_parse_txt_reply_ext(buf, len, &reply);
   if (status != ARES_SUCCESS) goto fail;
   // Find service config in TXT record.
-  const size_t prefix_len = sizeof(g_service_config_attribute_prefix) - 1;
-  struct ares_txt_ext *result;
   for (result = reply; result != NULL; result = result->next) {
     if (result->record_start &&
         memcmp(result->txt, g_service_config_attribute_prefix, prefix_len) ==
@@ -313,7 +314,7 @@ static void on_txt_done_cb(void *arg, int status, int timeouts,
 fail:
   gpr_asprintf(&error_msg, "C-ares TXT lookup status is not ARES_SUCCESS: %s",
                ares_strerror(status));
-  grpc_error *error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
+  error = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_msg);
   gpr_free(error_msg);
   if (r->error == GRPC_ERROR_NONE) {
     r->error = error;
@@ -331,6 +332,9 @@ static grpc_ares_request *grpc_dns_lookup_ares_impl(
     grpc_closure *on_done, grpc_lb_addresses **addrs, bool check_grpclb,
     char **service_config_json) {
   grpc_error *error = GRPC_ERROR_NONE;
+  grpc_ares_hostbyname_request *hr = NULL;
+  grpc_ares_request *r = NULL;
+  ares_channel *channel = NULL;
   /* TODO(zyc): Enable tracing after #9603 is checked in */
   /* if (grpc_dns_trace) {
       gpr_log(GPR_DEBUG, "resolve_address (blocking): name=%s, default_port=%s",
@@ -360,8 +364,7 @@ static grpc_ares_request *grpc_dns_lookup_ares_impl(
   error = grpc_ares_ev_driver_create(&ev_driver, interested_parties);
   if (error != GRPC_ERROR_NONE) goto error_cleanup;
 
-  grpc_ares_request *r =
-      (grpc_ares_request *)gpr_zalloc(sizeof(grpc_ares_request));
+  r = (grpc_ares_request *)gpr_zalloc(sizeof(grpc_ares_request));
   gpr_mu_init(&r->mu);
   r->ev_driver = ev_driver;
   r->on_done = on_done;
@@ -369,7 +372,7 @@ static grpc_ares_request *grpc_dns_lookup_ares_impl(
   r->service_config_json_out = service_config_json;
   r->success = false;
   r->error = GRPC_ERROR_NONE;
-  ares_channel *channel = grpc_ares_ev_driver_get_channel(r->ev_driver);
+  channel = grpc_ares_ev_driver_get_channel(r->ev_driver);
 
   // If dns_server is specified, use it.
   if (dns_server != NULL) {
@@ -410,12 +413,12 @@ static grpc_ares_request *grpc_dns_lookup_ares_impl(
   }
   gpr_ref_init(&r->pending_queries, 1);
   if (grpc_ipv6_loopback_available()) {
-    grpc_ares_hostbyname_request *hr = create_hostbyname_request(
-        r, host, strhtons(port), false /* is_balancer */);
+    hr = create_hostbyname_request(r, host, strhtons(port),
+                                   false /* is_balancer */);
     ares_gethostbyname(*channel, hr->host, AF_INET6, on_hostbyname_done_cb, hr);
   }
-  grpc_ares_hostbyname_request *hr = create_hostbyname_request(
-      r, host, strhtons(port), false /* is_balancer */);
+  hr = create_hostbyname_request(r, host, strhtons(port),
+                                 false /* is_balancer */);
   ares_gethostbyname(*channel, hr->host, AF_INET, on_hostbyname_done_cb, hr);
   if (check_grpclb) {
     /* Query the SRV record */
@@ -527,7 +530,8 @@ static void grpc_resolve_address_ares_impl(grpc_exec_ctx *exec_ctx,
                                            grpc_closure *on_done,
                                            grpc_resolved_addresses **addrs) {
   grpc_resolve_address_ares_request *r =
-      gpr_zalloc(sizeof(grpc_resolve_address_ares_request));
+      (grpc_resolve_address_ares_request *)gpr_zalloc(
+          sizeof(grpc_resolve_address_ares_request));
   r->addrs_out = addrs;
   r->on_resolve_address_done = on_done;
   GRPC_CLOSURE_INIT(&r->on_dns_lookup_done, on_dns_lookup_done_cb, r,
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c
index c4676e0299..69ea440ae6 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c
@@ -210,7 +210,7 @@ grpc_arg grpc_fake_resolver_response_generator_arg(
     grpc_fake_resolver_response_generator* generator) {
   grpc_arg arg;
   arg.type = GRPC_ARG_POINTER;
-  arg.key = GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR;
+  arg.key = (char*)GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR;
   arg.value.pointer.p = generator;
   arg.value.pointer.vtable = &response_generator_arg_vtable;
   return arg;
diff --git a/src/core/ext/filters/client_channel/retry_throttle.c b/src/core/ext/filters/client_channel/retry_throttle.c
index 6cd6654b6f..09dcade089 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.c
+++ b/src/core/ext/filters/client_channel/retry_throttle.c
@@ -99,7 +99,7 @@ static grpc_server_retry_throttle_data* grpc_server_retry_throttle_data_create(
     int max_milli_tokens, int milli_token_ratio,
     grpc_server_retry_throttle_data* old_throttle_data) {
   grpc_server_retry_throttle_data* throttle_data =
-      gpr_malloc(sizeof(*throttle_data));
+      (grpc_server_retry_throttle_data*)gpr_malloc(sizeof(*throttle_data));
   memset(throttle_data, 0, sizeof(*throttle_data));
   gpr_ref_init(&throttle_data->refs, 1);
   throttle_data->max_milli_tokens = max_milli_tokens;
@@ -131,11 +131,11 @@ static grpc_server_retry_throttle_data* grpc_server_retry_throttle_data_create(
 //
 
 static void* copy_server_name(void* key, void* unused) {
-  return gpr_strdup(key);
+  return gpr_strdup((const char*)key);
 }
 
 static long compare_server_name(void* key1, void* key2, void* unused) {
-  return strcmp(key1, key2);
+  return strcmp((const char*)key1, (const char*)key2);
 }
 
 static void destroy_server_retry_throttle_data(void* value, void* unused) {
@@ -177,7 +177,8 @@ grpc_server_retry_throttle_data* grpc_retry_throttle_map_get_data_for_server(
     const char* server_name, int max_milli_tokens, int milli_token_ratio) {
   gpr_mu_lock(&g_mu);
   grpc_server_retry_throttle_data* throttle_data =
-      gpr_avl_get(g_avl, (char*)server_name, NULL);
+      (grpc_server_retry_throttle_data*)gpr_avl_get(g_avl, (char*)server_name,
+                                                    NULL);
   if (throttle_data == NULL) {
     // Entry not found.  Create a new one.
     throttle_data = grpc_server_retry_throttle_data_create(
diff --git a/src/core/ext/filters/client_channel/subchannel.c b/src/core/ext/filters/client_channel/subchannel.c
index 05c55aaa89..40a51c72d6 100644
--- a/src/core/ext/filters/client_channel/subchannel.c
+++ b/src/core/ext/filters/client_channel/subchannel.c
@@ -32,6 +32,7 @@
 #include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/debug/stats.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
@@ -290,6 +291,7 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
     return c;
   }
 
+  GRPC_STATS_INC_CLIENT_SUBCHANNELS_CREATED(exec_ctx);
   c = (grpc_subchannel *)gpr_zalloc(sizeof(*c));
   c->key = key;
   gpr_atm_no_barrier_store(&c->ref_pair, 1 << INTERNAL_REF_BITS);
@@ -809,6 +811,6 @@ const char *grpc_get_subchannel_address_uri_arg(const grpc_channel_args *args) {
 
 grpc_arg grpc_create_subchannel_address_arg(const grpc_resolved_address *addr) {
   return grpc_channel_arg_string_create(
-      GRPC_ARG_SUBCHANNEL_ADDRESS,
+      (char *)GRPC_ARG_SUBCHANNEL_ADDRESS,
       addr->len > 0 ? grpc_sockaddr_to_uri(addr) : gpr_strdup(""));
 }
diff --git a/src/core/ext/filters/client_channel/subchannel_index.c b/src/core/ext/filters/client_channel/subchannel_index.c
index f57b631c41..d7a51f3899 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.c
+++ b/src/core/ext/filters/client_channel/subchannel_index.c
@@ -34,6 +34,8 @@ static gpr_avl g_subchannel_index;
 
 static gpr_mu g_mu;
 
+static gpr_refcount g_refcount;
+
 struct grpc_subchannel_key {
   grpc_subchannel_args args;
 };
@@ -88,24 +90,26 @@ void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
 
 static void sck_avl_destroy(void *p, void *user_data) {
   grpc_exec_ctx *exec_ctx = (grpc_exec_ctx *)user_data;
-  grpc_subchannel_key_destroy(exec_ctx, p);
+  grpc_subchannel_key_destroy(exec_ctx, (grpc_subchannel_key *)p);
 }
 
 static void *sck_avl_copy(void *p, void *unused) {
-  return subchannel_key_copy(p);
+  return subchannel_key_copy((grpc_subchannel_key *)p);
 }
 
 static long sck_avl_compare(void *a, void *b, void *unused) {
-  return grpc_subchannel_key_compare(a, b);
+  return grpc_subchannel_key_compare((grpc_subchannel_key *)a,
+                                     (grpc_subchannel_key *)b);
 }
 
 static void scv_avl_destroy(void *p, void *user_data) {
   grpc_exec_ctx *exec_ctx = (grpc_exec_ctx *)user_data;
-  GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, p, "subchannel_index");
+  GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, (grpc_subchannel *)p,
+                             "subchannel_index");
 }
 
 static void *scv_avl_copy(void *p, void *unused) {
-  GRPC_SUBCHANNEL_WEAK_REF(p, "subchannel_index");
+  GRPC_SUBCHANNEL_WEAK_REF((grpc_subchannel *)p, "subchannel_index");
   return p;
 }
 
@@ -119,15 +123,27 @@ static const gpr_avl_vtable subchannel_avl_vtable = {
 void grpc_subchannel_index_init(void) {
   g_subchannel_index = gpr_avl_create(&subchannel_avl_vtable);
   gpr_mu_init(&g_mu);
+  gpr_ref_init(&g_refcount, 1);
 }
 
 void grpc_subchannel_index_shutdown(void) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  gpr_mu_destroy(&g_mu);
-  gpr_avl_unref(g_subchannel_index, &exec_ctx);
-  grpc_exec_ctx_finish(&exec_ctx);
+  // TODO(juanlishen): This refcounting mechanism may lead to memory leackage.
+  // To solve that, we should force polling to flush any pending callbacks, then
+  // shutdown safely.
+  grpc_subchannel_index_unref();
+}
+
+void grpc_subchannel_index_unref(void) {
+  if (gpr_unref(&g_refcount)) {
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    gpr_mu_destroy(&g_mu);
+    gpr_avl_unref(g_subchannel_index, &exec_ctx);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
 }
 
+void grpc_subchannel_index_ref(void) { gpr_ref_non_zero(&g_refcount); }
+
 grpc_subchannel *grpc_subchannel_index_find(grpc_exec_ctx *exec_ctx,
                                             grpc_subchannel_key *key) {
   // Lock, and take a reference to the subchannel index.
diff --git a/src/core/ext/filters/client_channel/subchannel_index.h b/src/core/ext/filters/client_channel/subchannel_index.h
index 98d882a453..92e36d5283 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.h
+++ b/src/core/ext/filters/client_channel/subchannel_index.h
@@ -59,6 +59,13 @@ void grpc_subchannel_index_init(void);
 /** Shutdown the subchannel index (global) */
 void grpc_subchannel_index_shutdown(void);
 
+/** Increment the refcount (non-zero) of subchannel index (global). */
+void grpc_subchannel_index_ref(void);
+
+/** Decrement the refcount of subchannel index (global). If the refcount drops
+    to zero, unref the subchannel index and destroy its mutex. */
+void grpc_subchannel_index_unref(void);
+
 /** \em TEST ONLY.
  * If \a force_creation is true, all key comparisons will be false, resulting in
  * new subchannels always being created. Otherwise, the keys will be compared as
diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.c b/src/core/ext/filters/http/message_compress/message_compress_filter.c
index a66916fbe1..f4c01f75a6 100644
--- a/src/core/ext/filters/http/message_compress/message_compress_filter.c
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.c
@@ -225,7 +225,7 @@ static void finish_send_message(grpc_exec_ctx *exec_ctx,
       exec_ctx, calld->message_compression_algorithm, &calld->slices, &tmp);
   if (did_compress) {
     if (GRPC_TRACER_ON(grpc_compression_trace)) {
-      char *algo_name;
+      const char *algo_name;
       const size_t before_size = calld->slices.length;
       const size_t after_size = tmp.length;
       const float savings_ratio = 1.0f - (float)after_size / (float)before_size;
@@ -239,7 +239,7 @@ static void finish_send_message(grpc_exec_ctx *exec_ctx,
     send_flags |= GRPC_WRITE_INTERNAL_COMPRESS;
   } else {
     if (GRPC_TRACER_ON(grpc_compression_trace)) {
-      char *algo_name;
+      const char *algo_name;
       GPR_ASSERT(grpc_message_compression_algorithm_name(
           calld->message_compression_algorithm, &algo_name));
       gpr_log(GPR_DEBUG,
diff --git a/src/core/ext/filters/http/server/http_server_filter.c b/src/core/ext/filters/http/server/http_server_filter.c
index 554a7f530d..03958136b4 100644
--- a/src/core/ext/filters/http/server/http_server_filter.c
+++ b/src/core/ext/filters/http/server/http_server_filter.c
@@ -83,12 +83,12 @@ static grpc_error *server_filter_outgoing_metadata(grpc_exec_ctx *exec_ctx,
 }
 
 static void add_error(const char *error_name, grpc_error **cumulative,
-                      grpc_error *new) {
-  if (new == GRPC_ERROR_NONE) return;
+                      grpc_error *new_err) {
+  if (new_err == GRPC_ERROR_NONE) return;
   if (*cumulative == GRPC_ERROR_NONE) {
     *cumulative = GRPC_ERROR_CREATE_FROM_COPIED_STRING(error_name);
   }
-  *cumulative = grpc_error_add_child(*cumulative, new);
+  *cumulative = grpc_error_add_child(*cumulative, new_err);
 }
 
 static grpc_error *server_filter_incoming_metadata(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c
index f56afd27d2..2486ead427 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c
@@ -55,7 +55,8 @@ static bool maybe_add_server_load_reporting_filter(
 }
 
 grpc_arg grpc_load_reporting_enable_arg() {
-  return grpc_channel_arg_integer_create(GRPC_ARG_ENABLE_LOAD_REPORTING, 1);
+  return grpc_channel_arg_integer_create((char *)GRPC_ARG_ENABLE_LOAD_REPORTING,
+                                         1);
 }
 
 /* Plugin registration */
diff --git a/src/core/ext/filters/max_age/max_age_filter.c b/src/core/ext/filters/max_age/max_age_filter.c
index 450f67746f..0ac803ed41 100644
--- a/src/core/ext/filters/max_age/max_age_filter.c
+++ b/src/core/ext/filters/max_age/max_age_filter.c
@@ -402,7 +402,7 @@ static bool maybe_add_max_age_filter(grpc_exec_ctx* exec_ctx,
   bool enable =
       grpc_channel_arg_get_integer(
           grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_AGE_MS),
-          MAX_CONNECTION_AGE_INTEGER_OPTIONS) != INT_MAX &&
+          MAX_CONNECTION_AGE_INTEGER_OPTIONS) != INT_MAX ||
       grpc_channel_arg_get_integer(
           grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_IDLE_MS),
           MAX_CONNECTION_IDLE_INTEGER_OPTIONS) != INT_MAX;
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.c b/src/core/ext/transport/chttp2/client/chttp2_connector.c
index 0ec9353c04..202bcd47f5 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.c
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.c
@@ -161,7 +161,7 @@ static void connected(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
       grpc_endpoint_shutdown(exec_ctx, c->endpoint, GRPC_ERROR_REF(error));
     }
     gpr_mu_unlock(&c->mu);
-    chttp2_connector_unref(exec_ctx, arg);
+    chttp2_connector_unref(exec_ctx, (grpc_connector *)arg);
   } else {
     GPR_ASSERT(c->endpoint != NULL);
     start_handshake_locked(exec_ctx, c);
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
index cccb347bf1..6410a6043d 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -55,7 +55,7 @@ static grpc_channel *client_channel_factory_create_channel(
   }
   // Add channel arg containing the server URI.
   grpc_arg arg = grpc_channel_arg_string_create(
-      GRPC_ARG_SERVER_URI,
+      (char *)GRPC_ARG_SERVER_URI,
       grpc_resolver_factory_add_default_prefix_if_needed(exec_ctx, target));
   const char *to_remove[] = {GRPC_ARG_SERVER_URI};
   grpc_channel_args *new_args =
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c
index 0346d50b6c..dd88136f7b 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c
@@ -42,7 +42,7 @@ grpc_channel *grpc_insecure_channel_create_from_fd(
                  (target, fd, args));
 
   grpc_arg default_authority_arg = grpc_channel_arg_string_create(
-      GRPC_ARG_DEFAULT_AUTHORITY, "test.authority");
+      (char *)GRPC_ARG_DEFAULT_AUTHORITY, (char *)"test.authority");
   grpc_channel_args *final_args =
       grpc_channel_args_copy_and_add(args, &default_authority_arg, 1);
 
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.c
index d7add0538b..60244e163b 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.c
@@ -52,7 +52,7 @@ typedef struct {
 } server_state;
 
 typedef struct {
-  server_state *server_state;
+  server_state *svr_state;
   grpc_pollset *accepting_pollset;
   grpc_tcp_server_acceptor *acceptor;
   grpc_handshake_manager *handshake_mgr;
@@ -63,8 +63,8 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_handshaker_args *args = (grpc_handshaker_args *)arg;
   server_connection_state *connection_state =
       (server_connection_state *)args->user_data;
-  gpr_mu_lock(&connection_state->server_state->mu);
-  if (error != GRPC_ERROR_NONE || connection_state->server_state->shutdown) {
+  gpr_mu_lock(&connection_state->svr_state->mu);
+  if (error != GRPC_ERROR_NONE || connection_state->svr_state->shutdown) {
     const char *error_str = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "Handshaking failed: %s", error_str);
 
@@ -89,7 +89,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
       grpc_transport *transport =
           grpc_create_chttp2_transport(exec_ctx, args->args, args->endpoint, 0);
       grpc_server_setup_transport(
-          exec_ctx, connection_state->server_state->server, transport,
+          exec_ctx, connection_state->svr_state->server, transport,
           connection_state->accepting_pollset, args->args);
       grpc_chttp2_transport_start_reading(exec_ctx, transport,
                                           args->read_buffer);
@@ -97,11 +97,11 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
     }
   }
   grpc_handshake_manager_pending_list_remove(
-      &connection_state->server_state->pending_handshake_mgrs,
+      &connection_state->svr_state->pending_handshake_mgrs,
       connection_state->handshake_mgr);
-  gpr_mu_unlock(&connection_state->server_state->mu);
+  gpr_mu_unlock(&connection_state->svr_state->mu);
   grpc_handshake_manager_destroy(exec_ctx, connection_state->handshake_mgr);
-  grpc_tcp_server_unref(exec_ctx, connection_state->server_state->tcp_server);
+  grpc_tcp_server_unref(exec_ctx, connection_state->svr_state->tcp_server);
   gpr_free(connection_state->acceptor);
   gpr_free(connection_state);
 }
@@ -124,8 +124,8 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
   gpr_mu_unlock(&state->mu);
   grpc_tcp_server_ref(state->tcp_server);
   server_connection_state *connection_state =
-      gpr_malloc(sizeof(*connection_state));
-  connection_state->server_state = state;
+      (server_connection_state *)gpr_malloc(sizeof(*connection_state));
+  connection_state->svr_state = state;
   connection_state->accepting_pollset = accepting_pollset;
   connection_state->acceptor = acceptor;
   connection_state->handshake_mgr = handshake_mgr;
@@ -201,6 +201,7 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
   grpc_error *err = GRPC_ERROR_NONE;
   server_state *state = NULL;
   grpc_error **errors = NULL;
+  size_t naddrs = 0;
 
   *port_num = -1;
 
@@ -225,7 +226,7 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
   state->shutdown = true;
   gpr_mu_init(&state->mu);
 
-  const size_t naddrs = resolved->naddrs;
+  naddrs = resolved->naddrs;
   errors = (grpc_error **)gpr_malloc(sizeof(*errors) * naddrs);
   for (i = 0; i < naddrs; i++) {
     errors[i] =
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
index 78551df9c3..6d09953830 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
@@ -23,6 +23,7 @@
 void grpc_chttp2_plugin_init(void) {
   grpc_register_tracer(&grpc_http_trace);
   grpc_register_tracer(&grpc_flowctl_trace);
+  grpc_register_tracer(&grpc_trace_http2_stream_state);
 #ifndef NDEBUG
   grpc_register_tracer(&grpc_trace_chttp2_refcount);
 #endif
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 3fd701fe2f..acf49632ff 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -64,6 +64,11 @@
 #define DEFAULT_KEEPALIVE_PERMIT_WITHOUT_CALLS false
 #define KEEPALIVE_TIME_BACKOFF_MULTIPLIER 2
 
+#define DEFAULT_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS 300000 /* 5 minutes */
+#define DEFAULT_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS 300000 /* 5 minutes */
+#define DEFAULT_MAX_PINGS_BETWEEN_DATA 0                      /* unlimited */
+#define DEFAULT_MAX_PING_STRIKES 2
+
 static int g_default_client_keepalive_time_ms =
     DEFAULT_CLIENT_KEEPALIVE_TIME_MS;
 static int g_default_client_keepalive_timeout_ms =
@@ -75,6 +80,13 @@ static int g_default_server_keepalive_timeout_ms =
 static bool g_default_keepalive_permit_without_calls =
     DEFAULT_KEEPALIVE_PERMIT_WITHOUT_CALLS;
 
+static int g_default_min_sent_ping_interval_without_data_ms =
+    DEFAULT_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS;
+static int g_default_min_recv_ping_interval_without_data_ms =
+    DEFAULT_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS;
+static int g_default_max_pings_without_data = DEFAULT_MAX_PINGS_BETWEEN_DATA;
+static int g_default_max_ping_strikes = DEFAULT_MAX_PING_STRIKES;
+
 #define MAX_CLIENT_STREAM_ID 0x7fffffffu
 grpc_tracer_flag grpc_http_trace = GRPC_TRACER_INITIALIZER(false, "http");
 grpc_tracer_flag grpc_flowctl_trace = GRPC_TRACER_INITIALIZER(false, "flowctl");
@@ -144,18 +156,14 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error);
-static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_ping_type ping_type,
-                             grpc_closure *on_initiate,
-                             grpc_closure *on_complete);
+static void send_ping_locked(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
+    grpc_closure *on_complete,
+    grpc_chttp2_initiate_write_reason initiate_write_reason);
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error);
 
-#define DEFAULT_MIN_TIME_BETWEEN_PINGS_MS 0
-#define DEFAULT_MAX_PINGS_BETWEEN_DATA 3
-#define DEFAULT_MAX_PING_STRIKES 2
-#define DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS 300000 /* 5 minutes */
-
 /** keepalive-relevant functions */
 static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                        grpc_error *error);
@@ -346,7 +354,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   if (is_client) {
     grpc_slice_buffer_add(&t->outbuf, grpc_slice_from_copied_string(
                                           GRPC_CHTTP2_CLIENT_CONNECT_STRING));
-    grpc_chttp2_initiate_write(exec_ctx, t, "initial_write");
   }
 
   /* configure http2 the way we like it */
@@ -362,14 +369,12 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   queue_setting_update(exec_ctx, t,
                        GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA, 1);
 
-  t->ping_policy = (grpc_chttp2_repeated_ping_policy){
-      .max_pings_without_data = DEFAULT_MAX_PINGS_BETWEEN_DATA,
-      .min_time_between_pings =
-          gpr_time_from_millis(DEFAULT_MIN_TIME_BETWEEN_PINGS_MS, GPR_TIMESPAN),
-      .max_ping_strikes = DEFAULT_MAX_PING_STRIKES,
-      .min_ping_interval_without_data = gpr_time_from_millis(
-          DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS, GPR_TIMESPAN),
-  };
+  t->ping_policy.max_pings_without_data = g_default_max_pings_without_data;
+  t->ping_policy.min_sent_ping_interval_without_data = gpr_time_from_millis(
+      g_default_min_sent_ping_interval_without_data_ms, GPR_TIMESPAN);
+  t->ping_policy.max_ping_strikes = g_default_max_ping_strikes;
+  t->ping_policy.min_recv_ping_interval_without_data = gpr_time_from_millis(
+      g_default_min_recv_ping_interval_without_data_ms, GPR_TIMESPAN);
 
   /* Keepalive setting */
   if (t->is_client) {
@@ -428,29 +433,37 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA)) {
         t->ping_policy.max_pings_without_data = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){DEFAULT_MAX_PINGS_BETWEEN_DATA, 0, INT_MAX});
+            (grpc_integer_options){g_default_max_pings_without_data, 0,
+                                   INT_MAX});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_MAX_PING_STRIKES)) {
         t->ping_policy.max_ping_strikes = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){DEFAULT_MAX_PING_STRIKES, 0, INT_MAX});
-      } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_HTTP2_MIN_TIME_BETWEEN_PINGS_MS)) {
-        t->ping_policy.min_time_between_pings = gpr_time_from_millis(
-            grpc_channel_arg_get_integer(
-                &channel_args->args[i],
-                (grpc_integer_options){DEFAULT_MIN_TIME_BETWEEN_PINGS_MS, 0,
-                                       INT_MAX}),
-            GPR_TIMESPAN);
+            (grpc_integer_options){g_default_max_ping_strikes, 0, INT_MAX});
       } else if (0 ==
-                 strcmp(channel_args->args[i].key,
-                        GRPC_ARG_HTTP2_MIN_PING_INTERVAL_WITHOUT_DATA_MS)) {
-        t->ping_policy.min_ping_interval_without_data = gpr_time_from_millis(
-            grpc_channel_arg_get_integer(
-                &channel_args->args[i],
-                (grpc_integer_options){
-                    DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS, 0, INT_MAX}),
-            GPR_TIMESPAN);
+                 strcmp(
+                     channel_args->args[i].key,
+                     GRPC_ARG_HTTP2_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS)) {
+        t->ping_policy.min_sent_ping_interval_without_data =
+            gpr_time_from_millis(
+                grpc_channel_arg_get_integer(
+                    &channel_args->args[i],
+                    (grpc_integer_options){
+                        g_default_min_sent_ping_interval_without_data_ms, 0,
+                        INT_MAX}),
+                GPR_TIMESPAN);
+      } else if (0 ==
+                 strcmp(
+                     channel_args->args[i].key,
+                     GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS)) {
+        t->ping_policy.min_recv_ping_interval_without_data =
+            gpr_time_from_millis(
+                grpc_channel_arg_get_integer(
+                    &channel_args->args[i],
+                    (grpc_integer_options){
+                        g_default_min_recv_ping_interval_without_data_ms, 0,
+                        INT_MAX}),
+                GPR_TIMESPAN);
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_WRITE_BUFFER_SIZE)) {
         t->write_buffer_size = (uint32_t)grpc_channel_arg_get_integer(
@@ -557,8 +570,8 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     }
   }
 
-  t->ping_state.pings_before_data_required =
-      t->ping_policy.max_pings_without_data;
+  /* No pings allowed before receiving a header or data frame. */
+  t->ping_state.pings_before_data_required = 0;
   t->ping_state.is_delayed_ping_timer_set = false;
 
   t->ping_recv_state.last_ping_recv_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -578,7 +591,8 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED;
   }
 
-  grpc_chttp2_initiate_write(exec_ctx, t, "init");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE);
   post_benign_reclaimer(exec_ctx, t);
 }
 
@@ -624,6 +638,9 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
     connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_SHUTDOWN,
                            GRPC_ERROR_REF(error), "close_transport");
     grpc_endpoint_shutdown(exec_ctx, t->ep, GRPC_ERROR_REF(error));
+    if (t->ping_state.is_delayed_ping_timer_set) {
+      grpc_timer_cancel(exec_ctx, &t->ping_state.delayed_ping_timer);
+    }
     switch (t->keepalive_state) {
       case GRPC_CHTTP2_KEEPALIVE_STATE_WAITING:
         grpc_timer_cancel(exec_ctx, &t->keepalive_ping_timer);
@@ -689,7 +706,10 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                     grpc_schedule_on_exec_ctx);
   grpc_slice_buffer_init(&s->unprocessed_incoming_frames_buffer);
   grpc_slice_buffer_init(&s->frame_storage);
+  grpc_slice_buffer_init(&s->compressed_data_buffer);
+  grpc_slice_buffer_init(&s->decompressed_data_buffer);
   s->pending_byte_stream = false;
+  s->decompressed_header_bytes = 0;
   GRPC_CLOSURE_INIT(&s->reset_byte_stream, reset_byte_stream, s,
                     grpc_combiner_scheduler(t->combiner));
 
@@ -723,14 +743,8 @@ static void destroy_stream_locked(grpc_exec_ctx *exec_ctx, void *sp,
   grpc_slice_buffer_destroy_internal(exec_ctx,
                                      &s->unprocessed_incoming_frames_buffer);
   grpc_slice_buffer_destroy_internal(exec_ctx, &s->frame_storage);
-  if (s->compressed_data_buffer) {
-    grpc_slice_buffer_destroy_internal(exec_ctx, s->compressed_data_buffer);
-    gpr_free(s->compressed_data_buffer);
-  }
-  if (s->decompressed_data_buffer) {
-    grpc_slice_buffer_destroy_internal(exec_ctx, s->decompressed_data_buffer);
-    gpr_free(s->decompressed_data_buffer);
-  }
+  grpc_slice_buffer_destroy_internal(exec_ctx, &s->compressed_data_buffer);
+  grpc_slice_buffer_destroy_internal(exec_ctx, &s->decompressed_data_buffer);
 
   grpc_chttp2_list_remove_stalled_by_transport(t, s);
   grpc_chttp2_list_remove_stalled_by_stream(t, s);
@@ -846,13 +860,91 @@ static void set_write_state(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   }
 }
 
+static void inc_initiate_write_reason(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_initiate_write_reason reason) {
+  switch (reason) {
+    case GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_INITIAL_WRITE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_START_NEW_STREAM(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_MESSAGE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_INITIAL_METADATA(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_TRAILING_METADATA(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RETRY_SEND_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CONTINUE_PINGS(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_GOAWAY_SENT(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_RST_STREAM(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_CLOSE_FROM_API(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_APPLICATION_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_KEEPALIVE_PING(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL_UNSTALLED(
+          exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_PING_RESPONSE(exec_ctx);
+      break;
+    case GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FORCE_RST_STREAM(exec_ctx);
+      break;
+  }
+}
+
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport *t, const char *reason) {
+                                grpc_chttp2_transport *t,
+                                grpc_chttp2_initiate_write_reason reason) {
   GPR_TIMER_BEGIN("grpc_chttp2_initiate_write", 0);
 
   switch (t->write_state) {
     case GRPC_CHTTP2_WRITE_STATE_IDLE:
-      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING, reason);
+      inc_initiate_write_reason(exec_ctx, reason);
+      set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING,
+                      grpc_chttp2_initiate_write_reason_string(reason));
       t->is_first_write_in_batch = true;
       GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
       GRPC_CLOSURE_SCHED(
@@ -864,7 +956,7 @@ void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING:
       set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE,
-                      reason);
+                      grpc_chttp2_initiate_write_reason_string(reason));
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE:
       break;
@@ -872,16 +964,12 @@ void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
   GPR_TIMER_END("grpc_chttp2_initiate_write", 0);
 }
 
-void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
-                                 grpc_chttp2_transport *t,
-                                 grpc_chttp2_stream *s,
-                                 bool also_initiate_write, const char *reason) {
+void grpc_chttp2_mark_stream_writable(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t,
+                                      grpc_chttp2_stream *s) {
   if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
     GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:become");
   }
-  if (also_initiate_write) {
-    grpc_chttp2_initiate_write(exec_ctx, t, reason);
-  }
 }
 
 static grpc_closure_scheduler *write_scheduler(grpc_chttp2_transport *t,
@@ -1105,7 +1193,9 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx,
 
     grpc_chttp2_stream_map_add(&t->stream_map, s->id, s);
     post_destructive_reclaimer(exec_ctx, t);
-    grpc_chttp2_become_writable(exec_ctx, t, s, true, "new_stream");
+    grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM);
   }
   /* cancel out streams that will never be started */
   while (t->next_stream_id >= MAX_CLIENT_STREAM_ID &&
@@ -1202,7 +1292,9 @@ static void maybe_become_writable_due_to_send_msg(grpc_exec_ctx *exec_ctx,
                                                   grpc_chttp2_stream *s) {
   if (s->id != 0 && (!s->write_buffering ||
                      s->flow_controlled_buffer.length > t->write_buffer_size)) {
-    grpc_chttp2_become_writable(exec_ctx, t, s, true, "op.send_message");
+    grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE);
   }
 }
 
@@ -1353,12 +1445,14 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     on_complete->next_data.scratch |= CLOSURE_BARRIER_MAY_COVER_WRITE;
 
     /* Identify stream compression */
-    if ((s->stream_compression_send_enabled =
-             (op_payload->send_initial_metadata.send_initial_metadata->idx.named
-                  .content_encoding != NULL)) == true) {
-      s->compressed_data_buffer =
-          (grpc_slice_buffer *)gpr_malloc(sizeof(grpc_slice_buffer));
-      grpc_slice_buffer_init(s->compressed_data_buffer);
+    if (op_payload->send_initial_metadata.send_initial_metadata->idx.named
+                .content_encoding == NULL ||
+        grpc_stream_compression_method_parse(
+            GRPC_MDVALUE(
+                op_payload->send_initial_metadata.send_initial_metadata->idx
+                    .named.content_encoding->md),
+            true, &s->stream_compression_method) == 0) {
+      s->stream_compression_method = GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS;
     }
 
     s->send_initial_metadata_finished = add_closure_barrier(on_complete);
@@ -1404,14 +1498,13 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           }
         } else {
           GPR_ASSERT(s->id != 0);
-          bool initiate_write = true;
-          if (op->send_message &&
-              (op->payload->send_message.send_message->flags &
-               GRPC_WRITE_BUFFER_HINT)) {
-            initiate_write = false;
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          if (!(op->send_message &&
+                (op->payload->send_message.send_message->flags &
+                 GRPC_WRITE_BUFFER_HINT))) {
+            grpc_chttp2_initiate_write(
+                exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA);
           }
-          grpc_chttp2_become_writable(exec_ctx, t, s, initiate_write,
-                                      "op.send_initial_metadata");
         }
       } else {
         s->send_initial_metadata = NULL;
@@ -1519,8 +1612,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
       } 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, t, s, true,
-                                    "op.send_trailing_metadata");
+        grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+        grpc_chttp2_initiate_write(
+            exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA);
       }
     }
   }
@@ -1632,15 +1726,17 @@ static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   GRPC_ERROR_UNREF(error);
 }
 
-static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_ping_type ping_type,
-                             grpc_closure *on_initiate, grpc_closure *on_ack) {
+static void send_ping_locked(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
+    grpc_closure *on_ack,
+    grpc_chttp2_initiate_write_reason initiate_write_reason) {
   grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
   grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_INITIATE], on_initiate,
                            GRPC_ERROR_NONE);
   if (grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
                                GRPC_ERROR_NONE)) {
-    grpc_chttp2_initiate_write(exec_ctx, t, "send_ping");
+    grpc_chttp2_initiate_write(exec_ctx, t, initiate_write_reason);
   }
 }
 
@@ -1648,7 +1744,10 @@ static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)tp;
   t->ping_state.is_delayed_ping_timer_set = false;
-  grpc_chttp2_initiate_write(exec_ctx, t, "retry_send_ping");
+  if (error == GRPC_ERROR_NONE) {
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING);
+  }
 }
 
 void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
@@ -1663,7 +1762,8 @@ void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   }
   GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[GRPC_CHTTP2_PCL_INFLIGHT]);
   if (!grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_NEXT])) {
-    grpc_chttp2_initiate_write(exec_ctx, t, "continue_pings");
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS);
   }
 }
 
@@ -1676,7 +1776,8 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                         &slice, &http_error);
   grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
                             grpc_slice_ref_internal(slice), &t->qbuf);
-  grpc_chttp2_initiate_write(exec_ctx, t, "goaway_sent");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT);
   GRPC_ERROR_UNREF(error);
 }
 
@@ -1723,7 +1824,8 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
 
   if (op->send_ping) {
     send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, NULL,
-                     op->send_ping);
+                     op->send_ping,
+                     GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
   }
 
   if (op->on_connectivity_state_change != NULL) {
@@ -1799,20 +1901,20 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_exec_ctx *exec_ctx,
                                  &s->frame_storage);
           s->unprocessed_incoming_frames_decompressed = false;
         }
-        if (s->stream_compression_recv_enabled &&
-            !s->unprocessed_incoming_frames_decompressed) {
-          GPR_ASSERT(s->decompressed_data_buffer->length == 0);
+        if (!s->unprocessed_incoming_frames_decompressed) {
+          GPR_ASSERT(s->decompressed_data_buffer.length == 0);
           bool end_of_context;
           if (!s->stream_decompression_ctx) {
             s->stream_decompression_ctx =
                 grpc_stream_compression_context_create(
-                    GRPC_STREAM_COMPRESSION_DECOMPRESS);
+                    s->stream_decompression_method);
           }
-          if (!grpc_stream_decompress(s->stream_decompression_ctx,
-                                      &s->unprocessed_incoming_frames_buffer,
-                                      s->decompressed_data_buffer, NULL,
-                                      GRPC_HEADER_SIZE_IN_BYTES,
-                                      &end_of_context)) {
+          if (!grpc_stream_decompress(
+                  s->stream_decompression_ctx,
+                  &s->unprocessed_incoming_frames_buffer,
+                  &s->decompressed_data_buffer, NULL,
+                  GRPC_HEADER_SIZE_IN_BYTES - s->decompressed_header_bytes,
+                  &end_of_context)) {
             grpc_slice_buffer_reset_and_unref_internal(exec_ctx,
                                                        &s->frame_storage);
             grpc_slice_buffer_reset_and_unref_internal(
@@ -1820,9 +1922,13 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_exec_ctx *exec_ctx,
             error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
                 "Stream decompression error.");
           } else {
+            s->decompressed_header_bytes += s->decompressed_data_buffer.length;
+            if (s->decompressed_header_bytes == GRPC_HEADER_SIZE_IN_BYTES) {
+              s->decompressed_header_bytes = 0;
+            }
             error = grpc_deframe_unprocessed_incoming_frames(
-                exec_ctx, &s->data_parser, s, s->decompressed_data_buffer, NULL,
-                s->recv_message);
+                exec_ctx, &s->data_parser, s, &s->decompressed_data_buffer,
+                NULL, s->recv_message);
             if (end_of_context) {
               grpc_stream_compression_context_destroy(
                   s->stream_decompression_ctx);
@@ -1871,15 +1977,14 @@ void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
     }
     bool pending_data = s->pending_byte_stream ||
                         s->unprocessed_incoming_frames_buffer.length > 0;
-    if (s->stream_compression_recv_enabled && s->read_closed &&
-        s->frame_storage.length > 0 && !pending_data && !s->seen_error &&
-        s->recv_trailing_metadata_finished != NULL) {
+    if (s->read_closed && s->frame_storage.length > 0 && !pending_data &&
+        !s->seen_error && s->recv_trailing_metadata_finished != NULL) {
       /* Maybe some SYNC_FLUSH data is left in frame_storage. Consume them and
        * maybe decompress the next 5 bytes in the stream. */
       bool end_of_context;
       if (!s->stream_decompression_ctx) {
         s->stream_decompression_ctx = grpc_stream_compression_context_create(
-            GRPC_STREAM_COMPRESSION_DECOMPRESS);
+            s->stream_decompression_method);
       }
       if (!grpc_stream_decompress(s->stream_decompression_ctx,
                                   &s->frame_storage,
@@ -1892,6 +1997,7 @@ void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
       } else {
         if (s->unprocessed_incoming_frames_buffer.length > 0) {
           s->unprocessed_incoming_frames_decompressed = true;
+          pending_data = true;
         }
         if (end_of_context) {
           grpc_stream_compression_context_destroy(s->stream_decompression_ctx);
@@ -1968,7 +2074,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
                                                   &s->stats.outgoing));
-      grpc_chttp2_initiate_write(exec_ctx, t, "rst_stream");
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM);
     }
   }
   if (due_to_error != GRPC_ERROR_NONE && !s->seen_error) {
@@ -2289,7 +2396,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                                               &s->stats.outgoing));
 
   grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, error);
-  grpc_chttp2_initiate_write(exec_ctx, t, "close_from_api");
+  grpc_chttp2_initiate_write(exec_ctx, t,
+                             GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API);
 }
 
 typedef struct {
@@ -2324,19 +2432,20 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
     case GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED:
       break;
     case GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY:
-      grpc_chttp2_become_writable(exec_ctx, t, s, true,
-                                  "immediate stream flowctl");
+      grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+      grpc_chttp2_initiate_write(
+          exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL);
       break;
     case GRPC_CHTTP2_FLOWCTL_QUEUE_UPDATE:
-      grpc_chttp2_become_writable(exec_ctx, t, s, false,
-                                  "queue stream flowctl");
+      grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
       break;
   }
   switch (action.send_transport_update) {
     case GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED:
       break;
     case GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY:
-      grpc_chttp2_initiate_write(exec_ctx, t, "immediate transport flowctl");
+      grpc_chttp2_initiate_write(
+          exec_ctx, t, GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL);
       break;
     // this is the same as no action b/c every time the transport enters the
     // writing path it will maybe do an update
@@ -2354,7 +2463,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
                            (uint32_t)action.max_frame_size);
     }
     if (action.send_setting_update == GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY) {
-      grpc_chttp2_initiate_write(exec_ctx, t, "immediate setting update");
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS);
     }
   }
   if (action.need_ping) {
@@ -2362,7 +2472,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
     grpc_bdp_estimator_schedule_ping(&t->flow_control.bdp_estimator);
     send_ping_locked(exec_ctx, t,
                      GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked);
+                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked,
+                     GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING);
   }
 }
 
@@ -2441,7 +2552,10 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
       if (t->flow_control.initial_window_update > 0) {
         grpc_chttp2_stream *s;
         while (grpc_chttp2_list_pop_stalled_by_stream(t, &s)) {
-          grpc_chttp2_become_writable(exec_ctx, t, s, true, "unstalled");
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          grpc_chttp2_initiate_write(
+              exec_ctx, t,
+              GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING);
         }
       }
       t->flow_control.initial_window_update = 0;
@@ -2538,6 +2652,36 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
                 &args->args[i],
                 (grpc_integer_options){g_default_keepalive_permit_without_calls,
                                        0, 1});
+      } else if (0 ==
+                 strcmp(args->args[i].key, GRPC_ARG_HTTP2_MAX_PING_STRIKES)) {
+        g_default_max_ping_strikes = grpc_channel_arg_get_integer(
+            &args->args[i],
+            (grpc_integer_options){g_default_max_ping_strikes, 0, INT_MAX});
+      } else if (0 == strcmp(args->args[i].key,
+                             GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA)) {
+        g_default_max_pings_without_data = grpc_channel_arg_get_integer(
+            &args->args[i], (grpc_integer_options){
+                                g_default_max_pings_without_data, 0, INT_MAX});
+      } else if (0 ==
+                 strcmp(
+                     args->args[i].key,
+                     GRPC_ARG_HTTP2_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS)) {
+        g_default_min_sent_ping_interval_without_data_ms =
+            grpc_channel_arg_get_integer(
+                &args->args[i],
+                (grpc_integer_options){
+                    g_default_min_sent_ping_interval_without_data_ms, 0,
+                    INT_MAX});
+      } else if (0 ==
+                 strcmp(
+                     args->args[i].key,
+                     GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS)) {
+        g_default_min_recv_ping_interval_without_data_ms =
+            grpc_channel_arg_get_integer(
+                &args->args[i],
+                (grpc_integer_options){
+                    g_default_min_recv_ping_interval_without_data_ms, 0,
+                    INT_MAX});
       }
     }
   }
@@ -2556,7 +2700,8 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
       GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive ping end");
       send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE,
                        &t->start_keepalive_ping_locked,
-                       &t->finish_keepalive_ping_locked);
+                       &t->finish_keepalive_ping_locked,
+                       GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
     } else {
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
       grpc_timer_init(
@@ -2671,7 +2816,7 @@ static void reset_byte_stream(grpc_exec_ctx *exec_ctx, void *arg,
     GRPC_ERROR_UNREF(s->byte_stream_error);
     s->byte_stream_error = GRPC_ERROR_NONE;
     grpc_chttp2_cancel_stream(exec_ctx, s->t, s, GRPC_ERROR_REF(error));
-    s->byte_stream_error = error;
+    s->byte_stream_error = GRPC_ERROR_REF(error);
   }
 }
 
@@ -2769,24 +2914,23 @@ static grpc_error *incoming_byte_stream_pull(grpc_exec_ctx *exec_ctx,
   grpc_error *error;
 
   if (s->unprocessed_incoming_frames_buffer.length > 0) {
-    if (s->stream_compression_recv_enabled &&
-        !s->unprocessed_incoming_frames_decompressed) {
+    if (!s->unprocessed_incoming_frames_decompressed) {
       bool end_of_context;
       if (!s->stream_decompression_ctx) {
         s->stream_decompression_ctx = grpc_stream_compression_context_create(
-            GRPC_STREAM_COMPRESSION_DECOMPRESS);
+            s->stream_decompression_method);
       }
       if (!grpc_stream_decompress(s->stream_decompression_ctx,
                                   &s->unprocessed_incoming_frames_buffer,
-                                  s->decompressed_data_buffer, NULL, MAX_SIZE_T,
-                                  &end_of_context)) {
+                                  &s->decompressed_data_buffer, NULL,
+                                  MAX_SIZE_T, &end_of_context)) {
         error =
             GRPC_ERROR_CREATE_FROM_STATIC_STRING("Stream decompression error.");
         return error;
       }
       GPR_ASSERT(s->unprocessed_incoming_frames_buffer.length == 0);
       grpc_slice_buffer_swap(&s->unprocessed_incoming_frames_buffer,
-                             s->decompressed_data_buffer);
+                             &s->decompressed_data_buffer);
       s->unprocessed_incoming_frames_decompressed = true;
       if (end_of_context) {
         grpc_stream_compression_context_destroy(s->stream_decompression_ctx);
@@ -2912,7 +3056,8 @@ grpc_chttp2_incoming_byte_stream *grpc_chttp2_incoming_byte_stream_create(
     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));
+      (grpc_chttp2_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;
@@ -3016,6 +3161,56 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
 /*******************************************************************************
  * MONITORING
  */
+
+const char *grpc_chttp2_initiate_write_reason_string(
+    grpc_chttp2_initiate_write_reason reason) {
+  switch (reason) {
+    case GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE:
+      return "INITIAL_WRITE";
+    case GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM:
+      return "START_NEW_STREAM";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE:
+      return "SEND_MESSAGE";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA:
+      return "SEND_INITIAL_METADATA";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA:
+      return "SEND_TRAILING_METADATA";
+    case GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING:
+      return "RETRY_SEND_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS:
+      return "CONTINUE_PINGS";
+    case GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT:
+      return "GOAWAY_SENT";
+    case GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM:
+      return "RST_STREAM";
+    case GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API:
+      return "CLOSE_FROM_API";
+    case GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL:
+      return "STREAM_FLOW_CONTROL";
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL:
+      return "TRANSPORT_FLOW_CONTROL";
+    case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
+      return "SEND_SETTINGS";
+    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
+      return "BDP_ESTIMATOR_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
+      return "FLOW_CONTROL_UNSTALLED_BY_SETTING";
+    case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
+      return "FLOW_CONTROL_UNSTALLED_BY_UPDATE";
+    case GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING:
+      return "APPLICATION_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING:
+      return "KEEPALIVE_PING";
+    case GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED:
+      return "TRANSPORT_FLOW_CONTROL_UNSTALLED";
+    case GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE:
+      return "PING_RESPONSE";
+    case GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM:
+      return "FORCE_RST_STREAM";
+  }
+  GPR_UNREACHABLE_CODE(return "unknown");
+}
+
 static grpc_endpoint *chttp2_get_endpoint(grpc_exec_ctx *exec_ctx,
                                           grpc_transport *t) {
   return ((grpc_chttp2_transport *)t)->ep;
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.h b/src/core/ext/transport/chttp2/transport/chttp2_transport.h
index 0c4e2a91c0..55fb1a8343 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.h
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.h
@@ -25,6 +25,7 @@
 
 extern grpc_tracer_flag grpc_http_trace;
 extern grpc_tracer_flag grpc_flowctl_trace;
+extern grpc_tracer_flag grpc_trace_http2_stream_state;
 
 #ifndef NDEBUG
 extern grpc_tracer_flag grpc_trace_chttp2_refcount;
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.c b/src/core/ext/transport/chttp2/transport/flow_control.c
index cec99f6fb6..569a6349d3 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.c
+++ b/src/core/ext/transport/chttp2/transport/flow_control.c
@@ -18,6 +18,7 @@
 
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 
+#include <limits.h>
 #include <math.h>
 #include <string.h>
 
@@ -59,24 +60,24 @@ static void pretrace(shadow_flow_control* shadow_fc,
 
 #define TRACE_PADDING 30
 
-static char* fmt_int64_diff_str(int64_t old, int64_t new) {
+static char* fmt_int64_diff_str(int64_t old_val, int64_t new_val) {
   char* str;
-  if (old != new) {
-    gpr_asprintf(&str, "%" PRId64 " -> %" PRId64 "", old, new);
+  if (old_val != new_val) {
+    gpr_asprintf(&str, "%" PRId64 " -> %" PRId64 "", old_val, new_val);
   } else {
-    gpr_asprintf(&str, "%" PRId64 "", old);
+    gpr_asprintf(&str, "%" PRId64 "", old_val);
   }
   char* str_lp = gpr_leftpad(str, ' ', TRACE_PADDING);
   gpr_free(str);
   return str_lp;
 }
 
-static char* fmt_uint32_diff_str(uint32_t old, uint32_t new) {
+static char* fmt_uint32_diff_str(uint32_t old_val, uint32_t new_val) {
   char* str;
-  if (new > 0 && old != new) {
-    gpr_asprintf(&str, "%" PRIu32 " -> %" PRIu32 "", old, new);
+  if (new_val > 0 && old_val != new_val) {
+    gpr_asprintf(&str, "%" PRIu32 " -> %" PRIu32 "", old_val, new_val);
   } else {
-    gpr_asprintf(&str, "%" PRIu32 "", old);
+    gpr_asprintf(&str, "%" PRIu32 "", old_val);
   }
   char* str_lp = gpr_leftpad(str, ' ', TRACE_PADDING);
   gpr_free(str);
@@ -483,7 +484,8 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
     if (grpc_bdp_estimator_get_bw(&tfc->bdp_estimator, &bw_dbl)) {
       // we target the max of BDP or bandwidth in microseconds.
       int32_t frame_size = (int32_t)GPR_CLAMP(
-          GPR_MAX((int32_t)bw_dbl / 1000, bdp), 16384, 16777215);
+          GPR_MAX((int32_t)GPR_CLAMP(bw_dbl, 0, INT_MAX) / 1000, bdp), 16384,
+          16777215);
       grpc_chttp2_flowctl_urgency frame_size_urgency = delta_is_significant(
           tfc, frame_size, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE);
       if (frame_size_urgency != GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED) {
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.c b/src/core/ext/transport/chttp2/transport/frame_data.c
index 222d2177b2..73aaab1802 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.c
+++ b/src/core/ext/transport/chttp2/transport/frame_data.c
@@ -210,7 +210,7 @@ grpc_error *grpc_deframe_unprocessed_incoming_frames(
 
         if (cur != end) {
           grpc_slice_buffer_undo_take_first(
-              &s->unprocessed_incoming_frames_buffer,
+              slices,
               grpc_slice_sub(slice, (size_t)(cur - beg), (size_t)(end - beg)));
         }
         grpc_slice_unref_internal(exec_ctx, slice);
@@ -277,7 +277,7 @@ grpc_error *grpc_deframe_unprocessed_incoming_frames(
           p->state = GRPC_CHTTP2_DATA_FH_0;
           cur += p->frame_size;
           grpc_slice_buffer_undo_take_first(
-              &s->unprocessed_incoming_frames_buffer,
+              slices,
               grpc_slice_sub(slice, (size_t)(cur - beg), (size_t)(end - beg)));
           grpc_slice_unref_internal(exec_ctx, slice);
           return GRPC_ERROR_NONE;
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.c
index 582fd7bfaa..d431d6b2df 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.c
@@ -92,7 +92,7 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
         gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
         gpr_timespec next_allowed_ping =
             gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                         t->ping_policy.min_ping_interval_without_data);
+                         t->ping_policy.min_recv_ping_interval_without_data);
 
         if (t->keepalive_permit_without_calls == 0 &&
             grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
@@ -117,7 +117,8 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
               t->ping_acks, t->ping_ack_capacity * sizeof(*t->ping_acks));
         }
         t->ping_acks[t->ping_ack_count++] = p->opaque_8bytes;
-        grpc_chttp2_initiate_write(exec_ctx, t, "ping response");
+        grpc_chttp2_initiate_write(exec_ctx, t,
+                                   GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE);
       }
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.c b/src/core/ext/transport/chttp2/transport/frame_settings.c
index 806100adaa..2995bf7310 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.c
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.c
@@ -44,7 +44,8 @@ static uint8_t *fill_header(uint8_t *out, uint32_t length, uint8_t flags) {
   return out;
 }
 
-grpc_slice grpc_chttp2_settings_create(uint32_t *old, const uint32_t *new,
+grpc_slice grpc_chttp2_settings_create(uint32_t *old_settings,
+                                       const uint32_t *new_settings,
                                        uint32_t force_mask, size_t count) {
   size_t i;
   uint32_t n = 0;
@@ -52,21 +53,21 @@ grpc_slice grpc_chttp2_settings_create(uint32_t *old, const uint32_t *new,
   uint8_t *p;
 
   for (i = 0; i < count; i++) {
-    n += (new[i] != old[i] || (force_mask & (1u << i)) != 0);
+    n += (new_settings[i] != old_settings[i] || (force_mask & (1u << i)) != 0);
   }
 
   output = GRPC_SLICE_MALLOC(9 + 6 * n);
   p = fill_header(GRPC_SLICE_START_PTR(output), 6 * n, 0);
 
   for (i = 0; i < count; i++) {
-    if (new[i] != old[i] || (force_mask & (1u << i)) != 0) {
+    if (new_settings[i] != old_settings[i] || (force_mask & (1u << i)) != 0) {
       *p++ = (uint8_t)(grpc_setting_id_to_wire_id[i] >> 8);
       *p++ = (uint8_t)(grpc_setting_id_to_wire_id[i]);
-      *p++ = (uint8_t)(new[i] >> 24);
-      *p++ = (uint8_t)(new[i] >> 16);
-      *p++ = (uint8_t)(new[i] >> 8);
-      *p++ = (uint8_t)(new[i]);
-      old[i] = new[i];
+      *p++ = (uint8_t)(new_settings[i] >> 24);
+      *p++ = (uint8_t)(new_settings[i] >> 16);
+      *p++ = (uint8_t)(new_settings[i] >> 8);
+      *p++ = (uint8_t)(new_settings[i]);
+      old_settings[i] = new_settings[i];
     }
   }
 
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 c94f7725bf..c9ab8d1b50 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.c
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.c
@@ -99,8 +99,10 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
         grpc_chttp2_flowctl_recv_stream_update(
             &t->flow_control, &s->flow_control, received_update);
         if (grpc_chttp2_list_remove_stalled_by_stream(t, s)) {
-          grpc_chttp2_become_writable(exec_ctx, t, s, true,
-                                      "stream.read_flow_control");
+          grpc_chttp2_mark_stream_writable(exec_ctx, t, s);
+          grpc_chttp2_initiate_write(
+              exec_ctx, t,
+              GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE);
         }
       }
     } else {
@@ -109,7 +111,9 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
                                                 received_update);
       bool is_zero = t->flow_control.remote_window <= 0;
       if (was_zero && !is_zero) {
-        grpc_chttp2_initiate_write(exec_ctx, t, "new_global_flow_control");
+        grpc_chttp2_initiate_write(
+            exec_ctx, t,
+            GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED);
       }
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.c b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
index 3cd1a7ee5c..a404b664e3 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
@@ -33,6 +33,7 @@
 #include "src/core/ext/transport/chttp2/transport/bin_encoder.h"
 #include "src/core/ext/transport/chttp2/transport/hpack_table.h"
 #include "src/core/ext/transport/chttp2/transport/varint.h"
+#include "src/core/lib/debug/stats.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/transport/metadata.h"
@@ -51,8 +52,10 @@
 #define MAX_DECODER_SPACE_USAGE 512
 
 static grpc_slice_refcount terminal_slice_refcount = {NULL, NULL};
-static const grpc_slice terminal_slice = {&terminal_slice_refcount,
-                                          .data.refcounted = {0, 0}};
+static const grpc_slice terminal_slice = {
+    &terminal_slice_refcount, /* refcount */
+    {{0, 0}}                  /* data.refcounted */
+};
 
 extern grpc_tracer_flag grpc_http_trace;
 
@@ -269,8 +272,10 @@ static void add_elem(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   }
 }
 
-static void emit_indexed(grpc_chttp2_hpack_compressor *c, uint32_t elem_index,
+static void emit_indexed(grpc_exec_ctx *exec_ctx,
+                         grpc_chttp2_hpack_compressor *c, uint32_t elem_index,
                          framer_state *st) {
+  GRPC_STATS_INC_HPACK_SEND_INDEXED(exec_ctx);
   uint32_t len = GRPC_CHTTP2_VARINT_LENGTH(elem_index, 1);
   GRPC_CHTTP2_WRITE_VARINT(elem_index, 1, 0x80, add_tiny_header_data(st, len),
                            len);
@@ -282,30 +287,31 @@ typedef struct {
   bool insert_null_before_wire_value;
 } wire_value;
 
-static wire_value get_wire_value(grpc_mdelem elem, bool true_binary_enabled) {
+static wire_value get_wire_value(grpc_exec_ctx *exec_ctx, grpc_mdelem elem,
+                                 bool true_binary_enabled) {
+  wire_value wire_val;
   if (grpc_is_binary_header(GRPC_MDKEY(elem))) {
     if (true_binary_enabled) {
-      return (wire_value){
-          .huffman_prefix = 0x00,
-          .insert_null_before_wire_value = true,
-          .data = grpc_slice_ref_internal(GRPC_MDVALUE(elem)),
-      };
+      GRPC_STATS_INC_HPACK_SEND_BINARY(exec_ctx);
+      wire_val.huffman_prefix = 0x00;
+      wire_val.insert_null_before_wire_value = true;
+      wire_val.data = grpc_slice_ref_internal(GRPC_MDVALUE(elem));
+
     } else {
-      return (wire_value){
-          .huffman_prefix = 0x80,
-          .insert_null_before_wire_value = false,
-          .data = grpc_chttp2_base64_encode_and_huffman_compress(
-              GRPC_MDVALUE(elem)),
-      };
+      GRPC_STATS_INC_HPACK_SEND_BINARY_BASE64(exec_ctx);
+      wire_val.huffman_prefix = 0x80;
+      wire_val.insert_null_before_wire_value = false;
+      wire_val.data =
+          grpc_chttp2_base64_encode_and_huffman_compress(GRPC_MDVALUE(elem));
     }
   } else {
     /* TODO(ctiller): opportunistically compress non-binary headers */
-    return (wire_value){
-        .huffman_prefix = 0x00,
-        .insert_null_before_wire_value = false,
-        .data = grpc_slice_ref_internal(GRPC_MDVALUE(elem)),
-    };
+    GRPC_STATS_INC_HPACK_SEND_UNCOMPRESSED(exec_ctx);
+    wire_val.huffman_prefix = 0x00;
+    wire_val.insert_null_before_wire_value = false;
+    wire_val.data = grpc_slice_ref_internal(GRPC_MDVALUE(elem));
   }
+  return wire_val;
 }
 
 static size_t wire_value_length(wire_value v) {
@@ -317,11 +323,14 @@ static void add_wire_value(framer_state *st, wire_value v) {
   add_header_data(st, v.data);
 }
 
-static void emit_lithdr_incidx(grpc_chttp2_hpack_compressor *c,
+static void emit_lithdr_incidx(grpc_exec_ctx *exec_ctx,
+                               grpc_chttp2_hpack_compressor *c,
                                uint32_t key_index, grpc_mdelem elem,
                                framer_state *st) {
+  GRPC_STATS_INC_HPACK_SEND_LITHDR_INCIDX(exec_ctx);
   uint32_t len_pfx = GRPC_CHTTP2_VARINT_LENGTH(key_index, 2);
-  wire_value value = get_wire_value(elem, st->use_true_binary_metadata);
+  wire_value value =
+      get_wire_value(exec_ctx, elem, st->use_true_binary_metadata);
   size_t len_val = wire_value_length(value);
   uint32_t len_val_len;
   GPR_ASSERT(len_val <= UINT32_MAX);
@@ -333,11 +342,14 @@ static void emit_lithdr_incidx(grpc_chttp2_hpack_compressor *c,
   add_wire_value(st, value);
 }
 
-static void emit_lithdr_noidx(grpc_chttp2_hpack_compressor *c,
+static void emit_lithdr_noidx(grpc_exec_ctx *exec_ctx,
+                              grpc_chttp2_hpack_compressor *c,
                               uint32_t key_index, grpc_mdelem elem,
                               framer_state *st) {
+  GRPC_STATS_INC_HPACK_SEND_LITHDR_NOTIDX(exec_ctx);
   uint32_t len_pfx = GRPC_CHTTP2_VARINT_LENGTH(key_index, 4);
-  wire_value value = get_wire_value(elem, st->use_true_binary_metadata);
+  wire_value value =
+      get_wire_value(exec_ctx, elem, st->use_true_binary_metadata);
   size_t len_val = wire_value_length(value);
   uint32_t len_val_len;
   GPR_ASSERT(len_val <= UINT32_MAX);
@@ -349,10 +361,14 @@ static void emit_lithdr_noidx(grpc_chttp2_hpack_compressor *c,
   add_wire_value(st, value);
 }
 
-static void emit_lithdr_incidx_v(grpc_chttp2_hpack_compressor *c,
+static void emit_lithdr_incidx_v(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_hpack_compressor *c,
                                  grpc_mdelem elem, framer_state *st) {
+  GRPC_STATS_INC_HPACK_SEND_LITHDR_INCIDX_V(exec_ctx);
+  GRPC_STATS_INC_HPACK_SEND_UNCOMPRESSED(exec_ctx);
   uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
-  wire_value value = get_wire_value(elem, st->use_true_binary_metadata);
+  wire_value value =
+      get_wire_value(exec_ctx, elem, st->use_true_binary_metadata);
   uint32_t len_val = (uint32_t)wire_value_length(value);
   uint32_t len_key_len = GRPC_CHTTP2_VARINT_LENGTH(len_key, 1);
   uint32_t len_val_len = GRPC_CHTTP2_VARINT_LENGTH(len_val, 1);
@@ -367,10 +383,14 @@ static void emit_lithdr_incidx_v(grpc_chttp2_hpack_compressor *c,
   add_wire_value(st, value);
 }
 
-static void emit_lithdr_noidx_v(grpc_chttp2_hpack_compressor *c,
+static void emit_lithdr_noidx_v(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_hpack_compressor *c,
                                 grpc_mdelem elem, framer_state *st) {
+  GRPC_STATS_INC_HPACK_SEND_LITHDR_NOTIDX_V(exec_ctx);
+  GRPC_STATS_INC_HPACK_SEND_UNCOMPRESSED(exec_ctx);
   uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
-  wire_value value = get_wire_value(elem, st->use_true_binary_metadata);
+  wire_value value =
+      get_wire_value(exec_ctx, elem, st->use_true_binary_metadata);
   uint32_t len_val = (uint32_t)wire_value_length(value);
   uint32_t len_key_len = GRPC_CHTTP2_VARINT_LENGTH(len_key, 1);
   uint32_t len_val_len = GRPC_CHTTP2_VARINT_LENGTH(len_val, 1);
@@ -423,7 +443,7 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
     gpr_free(v);
   }
   if (!GRPC_MDELEM_IS_INTERNED(elem)) {
-    emit_lithdr_noidx_v(c, elem, st);
+    emit_lithdr_noidx_v(exec_ctx, c, elem, st);
     return;
   }
 
@@ -445,16 +465,16 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_2(elem_hash)], elem) &&
       c->indices_elems[HASH_FRAGMENT_2(elem_hash)] > c->tail_remote_index) {
     /* HIT: complete element (first cuckoo hash) */
-    emit_indexed(c, dynidx(c, c->indices_elems[HASH_FRAGMENT_2(elem_hash)]),
-                 st);
+    emit_indexed(exec_ctx, c,
+                 dynidx(c, c->indices_elems[HASH_FRAGMENT_2(elem_hash)]), st);
     return;
   }
 
   if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_3(elem_hash)], elem) &&
       c->indices_elems[HASH_FRAGMENT_3(elem_hash)] > c->tail_remote_index) {
     /* HIT: complete element (second cuckoo hash) */
-    emit_indexed(c, dynidx(c, c->indices_elems[HASH_FRAGMENT_3(elem_hash)]),
-                 st);
+    emit_indexed(exec_ctx, c,
+                 dynidx(c, c->indices_elems[HASH_FRAGMENT_3(elem_hash)]), st);
     return;
   }
 
@@ -472,11 +492,11 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
       indices_key > c->tail_remote_index) {
     /* HIT: key (first cuckoo hash) */
     if (should_add_elem) {
-      emit_lithdr_incidx(c, dynidx(c, indices_key), elem, st);
+      emit_lithdr_incidx(exec_ctx, c, dynidx(c, indices_key), elem, st);
       add_elem(exec_ctx, c, elem);
       return;
     } else {
-      emit_lithdr_noidx(c, dynidx(c, indices_key), elem, st);
+      emit_lithdr_noidx(exec_ctx, c, dynidx(c, indices_key), elem, st);
       return;
     }
     GPR_UNREACHABLE_CODE(return );
@@ -488,11 +508,11 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
       indices_key > c->tail_remote_index) {
     /* HIT: key (first cuckoo hash) */
     if (should_add_elem) {
-      emit_lithdr_incidx(c, dynidx(c, indices_key), elem, st);
+      emit_lithdr_incidx(exec_ctx, c, dynidx(c, indices_key), elem, st);
       add_elem(exec_ctx, c, elem);
       return;
     } else {
-      emit_lithdr_noidx(c, dynidx(c, indices_key), elem, st);
+      emit_lithdr_noidx(exec_ctx, c, dynidx(c, indices_key), elem, st);
       return;
     }
     GPR_UNREACHABLE_CODE(return );
@@ -501,11 +521,11 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   /* no elem, key in the table... fall back to literal emission */
 
   if (should_add_elem) {
-    emit_lithdr_incidx_v(c, elem, st);
+    emit_lithdr_incidx_v(exec_ctx, c, elem, st);
     add_elem(exec_ctx, c, elem);
     return;
   } else {
-    emit_lithdr_noidx_v(c, elem, st);
+    emit_lithdr_noidx_v(exec_ctx, c, elem, st);
     return;
   }
   GPR_UNREACHABLE_CODE(return );
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.c
index 82ff2c8e2c..3d1df19bc3 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.c
@@ -30,6 +30,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/ext/transport/chttp2/transport/bin_encoder.h"
+#include "src/core/lib/debug/stats.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/support/string.h"
@@ -777,8 +778,7 @@ static grpc_error *parse_stream_dep0(grpc_exec_ctx *exec_ctx,
   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 */
+/* emit an indexed field; jumps to begin the next field on completion */
 static grpc_error *finish_indexed_field(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
@@ -792,6 +792,7 @@ static grpc_error *finish_indexed_field(grpc_exec_ctx *exec_ctx,
         GRPC_ERROR_INT_SIZE, (intptr_t)p->table.num_ents);
   }
   GRPC_MDELEM_REF(md);
+  GRPC_STATS_INC_HPACK_RECV_INDEXED(exec_ctx);
   grpc_error *err = on_hdr(exec_ctx, p, md, 0);
   if (err != GRPC_ERROR_NONE) return err;
   return parse_begin(exec_ctx, p, cur, end);
@@ -820,14 +821,14 @@ static grpc_error *parse_indexed_field_x(grpc_exec_ctx *exec_ctx,
   return parse_value0(exec_ctx, p, cur + 1, end);
 }
 
-/* finish a literal header with incremental indexing: just log, and jump to '
-   begin */
+/* finish a literal header with incremental indexing */
 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(!GRPC_MDISNULL(md)); /* handled in string parsing */
+  GRPC_STATS_INC_HPACK_RECV_LITHDR_INCIDX(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
@@ -842,6 +843,7 @@ 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_STATS_INC_HPACK_RECV_LITHDR_INCIDX_V(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
@@ -898,6 +900,7 @@ static grpc_error *finish_lithdr_notidx(grpc_exec_ctx *exec_ctx,
                                         const uint8_t *end) {
   grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   GPR_ASSERT(!GRPC_MDISNULL(md)); /* handled in string parsing */
+  GRPC_STATS_INC_HPACK_RECV_LITHDR_NOTIDX(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
@@ -912,6 +915,7 @@ 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_STATS_INC_HPACK_RECV_LITHDR_NOTIDX_V(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
@@ -968,6 +972,7 @@ static grpc_error *finish_lithdr_nvridx(grpc_exec_ctx *exec_ctx,
                                         const uint8_t *end) {
   grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
   GPR_ASSERT(!GRPC_MDISNULL(md)); /* handled in string parsing */
+  GRPC_STATS_INC_HPACK_RECV_LITHDR_NVRIDX(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
@@ -982,6 +987,7 @@ 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_STATS_INC_HPACK_RECV_LITHDR_NVRIDX_V(exec_ctx);
   grpc_error *err = on_hdr(
       exec_ctx, p,
       grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
@@ -1310,9 +1316,11 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
         /* 'true-binary' case */
         ++cur;
         p->binary = NOT_BINARY;
+        GRPC_STATS_INC_HPACK_RECV_BINARY(exec_ctx);
         append_bytes(str, cur, (size_t)(end - cur));
         return GRPC_ERROR_NONE;
       }
+      GRPC_STATS_INC_HPACK_RECV_BINARY_BASE64(exec_ctx);
     /* fallthrough */
     b64_byte0:
     case B64_BYTE0:
@@ -1510,6 +1518,7 @@ static grpc_error *begin_parse_string(grpc_exec_ctx *exec_ctx,
                                       grpc_chttp2_hpack_parser_string *str) {
   if (!p->huff && binary == NOT_BINARY && (end - cur) >= (intptr_t)p->strlen &&
       p->current_slice_refcount != NULL) {
+    GRPC_STATS_INC_HPACK_RECV_UNCOMPRESSED(exec_ctx);
     str->copied = false;
     str->data.referenced.refcount = p->current_slice_refcount;
     str->data.referenced.data.refcounted.bytes = (uint8_t *)cur;
@@ -1523,6 +1532,20 @@ static grpc_error *begin_parse_string(grpc_exec_ctx *exec_ctx,
   p->parsing.str = str;
   p->huff_state = 0;
   p->binary = binary;
+  switch (p->binary) {
+    case NOT_BINARY:
+      if (p->huff) {
+        GRPC_STATS_INC_HPACK_RECV_HUFFMAN(exec_ctx);
+      } else {
+        GRPC_STATS_INC_HPACK_RECV_UNCOMPRESSED(exec_ctx);
+      }
+      break;
+    case BINARY_BEGIN:
+      /* stats incremented later: don't know true binary or not */
+      break;
+    default:
+      abort();
+  }
   return parse_string(exec_ctx, p, cur, end);
 }
 
@@ -1649,7 +1672,8 @@ static void force_client_rst_stream(grpc_exec_ctx *exec_ctx, void *sp,
     grpc_slice_buffer_add(
         &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR,
                                                 &s->stats.outgoing));
-    grpc_chttp2_initiate_write(exec_ctx, t, "force_rst_stream");
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM);
     grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, true, GRPC_ERROR_NONE);
   }
   GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "final_rst");
@@ -1659,17 +1683,12 @@ static void parse_stream_compression_md(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_transport *t,
                                         grpc_chttp2_stream *s,
                                         grpc_metadata_batch *initial_metadata) {
-  if (initial_metadata->idx.named.content_encoding != NULL) {
-    grpc_slice content_encoding =
-        GRPC_MDVALUE(initial_metadata->idx.named.content_encoding->md);
-    if (!grpc_slice_eq(content_encoding, GRPC_MDSTR_IDENTITY)) {
-      if (grpc_slice_eq(content_encoding, GRPC_MDSTR_GZIP)) {
-        s->stream_compression_recv_enabled = true;
-        s->decompressed_data_buffer =
-            (grpc_slice_buffer *)gpr_malloc(sizeof(grpc_slice_buffer));
-        grpc_slice_buffer_init(s->decompressed_data_buffer);
-      }
-    }
+  if (initial_metadata->idx.named.content_encoding == NULL ||
+      grpc_stream_compression_method_parse(
+          GRPC_MDVALUE(initial_metadata->idx.named.content_encoding->md), false,
+          &s->stream_decompression_method) == 0) {
+    s->stream_decompression_method =
+        GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS;
   }
 }
 
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.c b/src/core/ext/transport/chttp2/transport/incoming_metadata.c
index cf0a9ca920..ba680a89db 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.c
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.c
@@ -42,8 +42,9 @@ grpc_error *grpc_chttp2_incoming_metadata_buffer_add(
     grpc_mdelem elem) {
   buffer->size += GRPC_MDELEM_LENGTH(elem);
   return grpc_metadata_batch_add_tail(
-      exec_ctx, &buffer->batch,
-      gpr_arena_alloc(buffer->arena, sizeof(grpc_linked_mdelem)), elem);
+      exec_ctx, &buffer->batch, (grpc_linked_mdelem *)gpr_arena_alloc(
+                                    buffer->arena, sizeof(grpc_linked_mdelem)),
+      elem);
 }
 
 grpc_error *grpc_chttp2_incoming_metadata_buffer_replace_or_add(
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 0fbedd1e56..49022155aa 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -79,16 +79,43 @@ typedef enum {
   GRPC_CHTTP2_PCL_COUNT /* must be last */
 } grpc_chttp2_ping_closure_list;
 
+typedef enum {
+  GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE,
+  GRPC_CHTTP2_INITIATE_WRITE_START_NEW_STREAM,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_MESSAGE,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_INITIAL_METADATA,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_TRAILING_METADATA,
+  GRPC_CHTTP2_INITIATE_WRITE_RETRY_SEND_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_CONTINUE_PINGS,
+  GRPC_CHTTP2_INITIATE_WRITE_GOAWAY_SENT,
+  GRPC_CHTTP2_INITIATE_WRITE_RST_STREAM,
+  GRPC_CHTTP2_INITIATE_WRITE_CLOSE_FROM_API,
+  GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL,
+  GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL,
+  GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS,
+  GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING,
+  GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
+  GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING,
+  GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED,
+  GRPC_CHTTP2_INITIATE_WRITE_PING_RESPONSE,
+  GRPC_CHTTP2_INITIATE_WRITE_FORCE_RST_STREAM,
+} grpc_chttp2_initiate_write_reason;
+
+const char *grpc_chttp2_initiate_write_reason_string(
+    grpc_chttp2_initiate_write_reason reason);
+
 typedef struct {
   grpc_closure_list lists[GRPC_CHTTP2_PCL_COUNT];
   uint64_t inflight_id;
 } grpc_chttp2_ping_queue;
 
 typedef struct {
-  gpr_timespec min_time_between_pings;
   int max_pings_without_data;
   int max_ping_strikes;
-  gpr_timespec min_ping_interval_without_data;
+  gpr_timespec min_sent_ping_interval_without_data;
+  gpr_timespec min_recv_ping_interval_without_data;
 } grpc_chttp2_repeated_ping_policy;
 
 typedef struct {
@@ -565,25 +592,27 @@ struct grpc_chttp2_stream {
   grpc_chttp2_write_cb *finish_after_write;
   size_t sending_bytes;
 
-  /** Whether stream compression send is enabled */
-  bool stream_compression_recv_enabled;
-  /** Whether stream compression recv is enabled */
-  bool stream_compression_send_enabled;
-  /** Whether bytes stored in unprocessed_incoming_byte_stream is decompressed
-   */
-  bool unprocessed_incoming_frames_decompressed;
+  /* Stream compression method to be used. */
+  grpc_stream_compression_method stream_compression_method;
+  /* Stream decompression method to be used. */
+  grpc_stream_compression_method stream_decompression_method;
   /** Stream compression decompress context */
   grpc_stream_compression_context *stream_decompression_ctx;
   /** Stream compression compress context */
   grpc_stream_compression_context *stream_compression_ctx;
 
   /** Buffer storing data that is compressed but not sent */
-  grpc_slice_buffer *compressed_data_buffer;
+  grpc_slice_buffer compressed_data_buffer;
   /** Amount of uncompressed bytes sent out when compressed_data_buffer is
    * emptied */
   size_t uncompressed_data_size;
   /** Temporary buffer storing decompressed data */
-  grpc_slice_buffer *decompressed_data_buffer;
+  grpc_slice_buffer decompressed_data_buffer;
+  /** Whether bytes stored in unprocessed_incoming_byte_stream is decompressed
+   */
+  bool unprocessed_incoming_frames_decompressed;
+  /** gRPC header bytes that are already decompressed */
+  size_t decompressed_header_bytes;
 };
 
 /** Transport writing call flow:
@@ -599,7 +628,8 @@ 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 *t, const char *reason);
+                                grpc_chttp2_transport *t,
+                                grpc_chttp2_initiate_write_reason reason);
 
 typedef struct {
   /** are we writing? */
@@ -851,10 +881,9 @@ void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
 
 /** 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 *t,
-                                 grpc_chttp2_stream *s,
-                                 bool also_initiate_write, const char *reason);
+void grpc_chttp2_mark_stream_writable(grpc_exec_ctx *exec_ctx,
+                                      grpc_chttp2_transport *t,
+                                      grpc_chttp2_stream *s);
 
 void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
                                grpc_chttp2_transport *t, grpc_chttp2_stream *s,
diff --git a/src/core/ext/transport/chttp2/transport/parsing.c b/src/core/ext/transport/chttp2/transport/parsing.c
index 6c12c91365..3db1ad4123 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.c
@@ -383,6 +383,9 @@ error_handler:
     /* t->parser = grpc_chttp2_data_parser_parse;*/
     t->parser = grpc_chttp2_data_parser_parse;
     t->parser_data = &s->data_parser;
+    t->ping_state.pings_before_data_required =
+        t->ping_policy.max_pings_without_data;
+    t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
     return GRPC_ERROR_NONE;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, NULL)) {
     /* handle stream errors by closing the stream */
@@ -559,6 +562,10 @@ static grpc_error *init_header_frame_parser(grpc_exec_ctx *exec_ctx,
         (t->incoming_frame_flags & GRPC_CHTTP2_DATA_FLAG_END_STREAM) != 0;
   }
 
+  t->ping_state.pings_before_data_required =
+      t->ping_policy.max_pings_without_data;
+  t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+
   /* could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream */
   s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
   if (s == NULL) {
diff --git a/src/core/ext/transport/chttp2/transport/stream_lists.c b/src/core/ext/transport/chttp2/transport/stream_lists.c
index 7cc85dea9c..47cd22d177 100644
--- a/src/core/ext/transport/chttp2/transport/stream_lists.c
+++ b/src/core/ext/transport/chttp2/transport/stream_lists.c
@@ -20,6 +20,27 @@
 
 #include <grpc/support/log.h>
 
+static char *stream_list_id_string(grpc_chttp2_stream_list_id id) {
+  switch (id) {
+    case GRPC_CHTTP2_LIST_WRITABLE:
+      return "writable";
+    case GRPC_CHTTP2_LIST_WRITING:
+      return "writing";
+    case GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT:
+      return "stalled_by_transport";
+    case GRPC_CHTTP2_LIST_STALLED_BY_STREAM:
+      return "stalled_by_stream";
+    case GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY:
+      return "waiting_for_concurrency";
+    case STREAM_LIST_COUNT:
+      GPR_UNREACHABLE_CODE(return "unknown");
+  }
+  GPR_UNREACHABLE_CODE(return "unknown");
+}
+
+grpc_tracer_flag grpc_trace_http2_stream_state =
+    GRPC_TRACER_INITIALIZER(false, "http2_stream_state");
+
 /* core list management */
 
 static bool stream_list_empty(grpc_chttp2_transport *t,
@@ -44,6 +65,10 @@ static bool stream_list_pop(grpc_chttp2_transport *t,
     s->included[id] = 0;
   }
   *stream = s;
+  if (s && GRPC_TRACER_ON(grpc_trace_http2_stream_state)) {
+    gpr_log(GPR_DEBUG, "%p[%d][%s]: pop from %s", t, s->id,
+            t->is_client ? "cli" : "svr", stream_list_id_string(id));
+  }
   return s != 0;
 }
 
@@ -62,6 +87,10 @@ static void stream_list_remove(grpc_chttp2_transport *t, grpc_chttp2_stream *s,
   } else {
     t->lists[id].tail = s->links[id].prev;
   }
+  if (GRPC_TRACER_ON(grpc_trace_http2_stream_state)) {
+    gpr_log(GPR_DEBUG, "%p[%d][%s]: remove from %s", t, s->id,
+            t->is_client ? "cli" : "svr", stream_list_id_string(id));
+  }
 }
 
 static bool stream_list_maybe_remove(grpc_chttp2_transport *t,
@@ -90,6 +119,10 @@ static void stream_list_add_tail(grpc_chttp2_transport *t,
   }
   t->lists[id].tail = s;
   s->included[id] = 1;
+  if (GRPC_TRACER_ON(grpc_trace_http2_stream_state)) {
+    gpr_log(GPR_DEBUG, "%p[%d][%s]: add to %s", t, s->id,
+            t->is_client ? "cli" : "svr", stream_list_id_string(id));
+  }
 }
 
 static bool stream_list_add(grpc_chttp2_transport *t, grpc_chttp2_stream *s,
@@ -150,17 +183,12 @@ void grpc_chttp2_list_remove_waiting_for_concurrency(grpc_chttp2_transport *t,
 
 void grpc_chttp2_list_add_stalled_by_transport(grpc_chttp2_transport *t,
                                                grpc_chttp2_stream *s) {
-  GRPC_FLOW_CONTROL_IF_TRACING(
-      gpr_log(GPR_DEBUG, "stream %u stalled by transport", s->id));
   stream_list_add(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
 }
 
 bool grpc_chttp2_list_pop_stalled_by_transport(grpc_chttp2_transport *t,
                                                grpc_chttp2_stream **s) {
-  bool ret = stream_list_pop(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
-  GRPC_FLOW_CONTROL_IF_TRACING(if (ret) gpr_log(
-      GPR_DEBUG, "stream %u un-stalled by transport", (*s)->id));
-  return ret;
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
 }
 
 void grpc_chttp2_list_remove_stalled_by_transport(grpc_chttp2_transport *t,
@@ -170,23 +198,15 @@ void grpc_chttp2_list_remove_stalled_by_transport(grpc_chttp2_transport *t,
 
 void grpc_chttp2_list_add_stalled_by_stream(grpc_chttp2_transport *t,
                                             grpc_chttp2_stream *s) {
-  GRPC_FLOW_CONTROL_IF_TRACING(
-      gpr_log(GPR_DEBUG, "stream %u stalled by stream", s->id));
   stream_list_add(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
 }
 
 bool grpc_chttp2_list_pop_stalled_by_stream(grpc_chttp2_transport *t,
                                             grpc_chttp2_stream **s) {
-  bool ret = stream_list_pop(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
-  GRPC_FLOW_CONTROL_IF_TRACING(
-      if (ret) gpr_log(GPR_DEBUG, "stream %u un-stalled by stream", (*s)->id));
-  return ret;
+  return stream_list_pop(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
 }
 
 bool grpc_chttp2_list_remove_stalled_by_stream(grpc_chttp2_transport *t,
                                                grpc_chttp2_stream *s) {
-  bool ret = stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
-  GRPC_FLOW_CONTROL_IF_TRACING(
-      if (ret) gpr_log(GPR_DEBUG, "stream %u un-stalled by stream", s->id));
-  return ret;
+  return stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_STALLED_BY_STREAM);
 }
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.c b/src/core/ext/transport/chttp2/transport/stream_map.c
index 650090d8f0..d6079a9a33 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.c
+++ b/src/core/ext/transport/chttp2/transport/stream_map.c
@@ -72,8 +72,10 @@ void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key,
       /* resize when less than 25% of the table is free, because compaction
          won't help much */
       map->capacity = capacity = 3 * capacity / 2;
-      map->keys = keys = gpr_realloc(keys, capacity * sizeof(uint32_t));
-      map->values = values = gpr_realloc(values, capacity * sizeof(void *));
+      map->keys = keys =
+          (uint32_t *)gpr_realloc(keys, capacity * sizeof(uint32_t));
+      map->values = values =
+          (void **)gpr_realloc(values, capacity * sizeof(void *));
     }
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index fa224a49a4..be1af16019 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -68,7 +68,7 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
   }
   if (t->ping_state.pings_before_data_required == 0 &&
       t->ping_policy.max_pings_without_data != 0) {
-    /* need to send something of substance before sending a ping again */
+    /* need to receive something of substance before sending a ping again */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_DEBUG, "Ping delayed [%p]: too many recent pings: %d/%d",
@@ -78,11 +78,18 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     return;
   }
   gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec elapsed = gpr_time_sub(now, t->ping_state.last_ping_sent_time);
-  /*gpr_log(GPR_DEBUG, "elapsed:%d.%09d min:%d.%09d", (int)elapsed.tv_sec,
-          elapsed.tv_nsec, (int)t->ping_policy.min_time_between_pings.tv_sec,
-          (int)t->ping_policy.min_time_between_pings.tv_nsec);*/
-  if (gpr_time_cmp(elapsed, t->ping_policy.min_time_between_pings) < 0) {
+  gpr_timespec next_allowed_ping =
+      gpr_time_add(t->ping_state.last_ping_sent_time,
+                   t->ping_policy.min_sent_ping_interval_without_data);
+  if (t->keepalive_permit_without_calls == 0 &&
+      grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
+    next_allowed_ping = gpr_time_add(t->ping_recv_state.last_ping_recv_time,
+                                     gpr_time_from_seconds(7200, GPR_TIMESPAN));
+  }
+  /* gpr_log(GPR_DEBUG, "next_allowed_ping:%d.%09d now:%d.%09d",
+          (int)next_allowed_ping.tv_sec, (int)next_allowed_ping.tv_nsec,
+          (int)now.tv_sec, (int)now.tv_nsec); */
+  if (gpr_time_cmp(next_allowed_ping, now) > 0) {
     /* not enough elapsed time between successive pings */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
@@ -93,9 +100,7 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     if (!t->ping_state.is_delayed_ping_timer_set) {
       t->ping_state.is_delayed_ping_timer_set = true;
       grpc_timer_init(exec_ctx, &t->ping_state.delayed_ping_timer,
-                      gpr_time_add(t->ping_state.last_ping_sent_time,
-                                   t->ping_policy.min_time_between_pings),
-                      &t->retry_initiate_ping_locked,
+                      next_allowed_ping, &t->retry_initiate_ping_locked,
                       gpr_now(GPR_CLOCK_MONOTONIC));
     }
     return;
@@ -119,6 +124,12 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
                         grpc_chttp2_ping_create(false, pq->inflight_id));
   GRPC_STATS_INC_HTTP2_PINGS_SENT(exec_ctx);
   t->ping_state.last_ping_sent_time = now;
+  if (GRPC_TRACER_ON(grpc_http_trace) ||
+      GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
+    gpr_log(GPR_DEBUG, "Ping sent [%p]: %d/%d", t->peer_string,
+            t->ping_state.pings_before_data_required,
+            t->ping_policy.max_pings_without_data);
+  }
   t->ping_state.pings_before_data_required -=
       (t->ping_state.pings_before_data_required != 0);
 }
@@ -201,9 +212,8 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
 
   if (t->flow_control.remote_window > 0) {
     while (grpc_chttp2_list_pop_stalled_by_transport(t, &s)) {
-      if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s) &&
-          stream_ref_if_not_destroyed(&s->refcount->refs)) {
-        grpc_chttp2_initiate_write(exec_ctx, t, "transport.read_flow_control");
+      if (!t->closed && grpc_chttp2_list_add_writable_stream(t, s)) {
+        stream_ref_if_not_destroyed(&s->refcount->refs);
       }
     }
   }
@@ -258,8 +268,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
             .stats = &s->stats.outgoing};
         grpc_chttp2_encode_header(exec_ctx, &t->hpack_compressor, NULL, 0,
                                   s->send_initial_metadata, &hopt, &t->outbuf);
-        t->ping_state.pings_before_data_required =
-            t->ping_policy.max_pings_without_data;
+        now_writing = true;
         if (!t->is_client) {
           t->ping_recv_state.last_ping_recv_time =
               gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -298,8 +307,6 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
       grpc_slice_buffer_add(
           &t->outbuf, grpc_chttp2_window_update_create(s->id, stream_announce,
                                                        &s->stats.outgoing));
-      t->ping_state.pings_before_data_required =
-          t->ping_policy.max_pings_without_data;
       if (!t->is_client) {
         t->ping_recv_state.last_ping_recv_time =
             gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -310,8 +317,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
     if (sent_initial_metadata) {
       /* send any body bytes, if allowed by flow control */
       if (s->flow_controlled_buffer.length > 0 ||
-          (s->stream_compression_send_enabled &&
-           s->compressed_data_buffer->length > 0)) {
+          s->compressed_data_buffer.length > 0) {
         uint32_t stream_remote_window = (uint32_t)GPR_MAX(
             0,
             s->flow_control.remote_window_delta +
@@ -325,59 +331,60 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
           bool is_last_data_frame = false;
           bool is_last_frame = false;
           size_t sending_bytes_before = s->sending_bytes;
-          if (s->stream_compression_send_enabled) {
-            while ((s->flow_controlled_buffer.length > 0 ||
-                    s->compressed_data_buffer->length > 0) &&
-                   max_outgoing > 0) {
-              if (s->compressed_data_buffer->length > 0) {
-                uint32_t send_bytes = (uint32_t)GPR_MIN(
-                    max_outgoing, s->compressed_data_buffer->length);
-                is_last_data_frame =
-                    (send_bytes == s->compressed_data_buffer->length &&
-                     s->flow_controlled_buffer.length == 0 &&
-                     s->fetching_send_message == NULL);
-                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->compressed_data_buffer,
-                                        send_bytes, is_last_frame,
-                                        &s->stats.outgoing, &t->outbuf);
-                grpc_chttp2_flowctl_sent_data(&t->flow_control,
-                                              &s->flow_control, send_bytes);
-                max_outgoing -= send_bytes;
-                if (s->compressed_data_buffer->length == 0) {
-                  s->sending_bytes += s->uncompressed_data_size;
-                }
-              } else {
-                if (s->stream_compression_ctx == NULL) {
-                  s->stream_compression_ctx =
-                      grpc_stream_compression_context_create(
-                          GRPC_STREAM_COMPRESSION_COMPRESS);
+          while ((s->flow_controlled_buffer.length > 0 ||
+                  s->compressed_data_buffer.length > 0) &&
+                 max_outgoing > 0) {
+            if (s->compressed_data_buffer.length > 0) {
+              uint32_t send_bytes = (uint32_t)GPR_MIN(
+                  max_outgoing, s->compressed_data_buffer.length);
+              is_last_data_frame =
+                  (send_bytes == s->compressed_data_buffer.length &&
+                   s->flow_controlled_buffer.length == 0 &&
+                   s->fetching_send_message == NULL);
+              if (is_last_data_frame && s->send_trailing_metadata != NULL &&
+                  s->stream_compression_ctx != NULL) {
+                if (!grpc_stream_compress(
+                        s->stream_compression_ctx, &s->flow_controlled_buffer,
+                        &s->compressed_data_buffer, NULL, MAX_SIZE_T,
+                        GRPC_STREAM_COMPRESSION_FLUSH_FINISH)) {
+                  gpr_log(GPR_ERROR, "Stream compression failed.");
                 }
-                s->uncompressed_data_size = s->flow_controlled_buffer.length;
-                GPR_ASSERT(grpc_stream_compress(
-                    s->stream_compression_ctx, &s->flow_controlled_buffer,
-                    s->compressed_data_buffer, NULL, MAX_SIZE_T,
-                    GRPC_STREAM_COMPRESSION_FLUSH_SYNC));
+                grpc_stream_compression_context_destroy(
+                    s->stream_compression_ctx);
+                s->stream_compression_ctx = NULL;
+                /* After finish, bytes in s->compressed_data_buffer may be
+                 * more than max_outgoing. Start another round of the current
+                 * while loop so that send_bytes and is_last_data_frame are
+                 * recalculated. */
+                continue;
+              }
+              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->compressed_data_buffer,
+                                      send_bytes, is_last_frame,
+                                      &s->stats.outgoing, &t->outbuf);
+              grpc_chttp2_flowctl_sent_data(&t->flow_control, &s->flow_control,
+                                            send_bytes);
+              max_outgoing -= send_bytes;
+              if (s->compressed_data_buffer.length == 0) {
+                s->sending_bytes += s->uncompressed_data_size;
+              }
+            } else {
+              if (s->stream_compression_ctx == NULL) {
+                s->stream_compression_ctx =
+                    grpc_stream_compression_context_create(
+                        s->stream_compression_method);
+              }
+              s->uncompressed_data_size = s->flow_controlled_buffer.length;
+              if (!grpc_stream_compress(
+                      s->stream_compression_ctx, &s->flow_controlled_buffer,
+                      &s->compressed_data_buffer, NULL, MAX_SIZE_T,
+                      GRPC_STREAM_COMPRESSION_FLUSH_SYNC)) {
+                gpr_log(GPR_ERROR, "Stream compression failed.");
               }
             }
-          } else {
-            uint32_t send_bytes = (uint32_t)GPR_MIN(
-                max_outgoing, s->flow_controlled_buffer.length);
-            is_last_data_frame = s->fetching_send_message == NULL &&
-                                 send_bytes == s->flow_controlled_buffer.length;
-            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_flowctl_sent_data(&t->flow_control, &s->flow_control,
-                                          send_bytes);
-            s->sending_bytes += send_bytes;
           }
-          t->ping_state.pings_before_data_required =
-              t->ping_policy.max_pings_without_data;
           if (!t->is_client) {
             t->ping_recv_state.last_ping_recv_time =
                 gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -391,6 +398,8 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
                                                     s->id, GRPC_HTTP2_NO_ERROR,
                                                     &s->stats.outgoing));
             }
+            grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
+                                           GRPC_ERROR_NONE);
           }
           result.early_results_scheduled |=
               update_list(exec_ctx, t, s,
@@ -399,8 +408,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
                           &s->flow_controlled_bytes_flowed, GRPC_ERROR_NONE);
           now_writing = true;
           if (s->flow_controlled_buffer.length > 0 ||
-              (s->stream_compression_send_enabled &&
-               s->compressed_data_buffer->length > 0)) {
+              s->compressed_data_buffer.length > 0) {
             GRPC_CHTTP2_STREAM_REF(s, "chttp2_writing:fork");
             grpc_chttp2_list_add_writable_stream(t, s);
           }
@@ -416,8 +424,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
       if (s->send_trailing_metadata != NULL &&
           s->fetching_send_message == NULL &&
           s->flow_controlled_buffer.length == 0 &&
-          (!s->stream_compression_send_enabled ||
-           s->compressed_data_buffer->length == 0)) {
+          s->compressed_data_buffer.length == 0) {
         GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_INFO, "sending trailing_metadata"));
         if (grpc_metadata_batch_is_empty(s->send_trailing_metadata)) {
           grpc_chttp2_encode_data(s->id, &s->flow_controlled_buffer, 0, true,
@@ -449,6 +456,8 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
               &t->outbuf, grpc_chttp2_rst_stream_create(
                               s->id, GRPC_HTTP2_NO_ERROR, &s->stats.outgoing));
         }
+        grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
+                                       GRPC_ERROR_NONE);
         now_writing = true;
         result.early_results_scheduled = true;
         grpc_chttp2_complete_closure_step(
@@ -484,8 +493,6 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
     grpc_slice_buffer_add(
         &t->outbuf, grpc_chttp2_window_update_create(0, transport_announce,
                                                      &throwaway_stats));
-    t->ping_state.pings_before_data_required =
-        t->ping_policy.max_pings_without_data;
     if (!t->is_client) {
       t->ping_recv_state.last_ping_recv_time =
           gpr_inf_past(GPR_CLOCK_MONOTONIC);
@@ -519,10 +526,6 @@ void grpc_chttp2_end_write(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                   GRPC_ERROR_REF(error));
       s->sending_bytes = 0;
     }
-    if (s->sent_trailing_metadata) {
-      grpc_chttp2_mark_stream_closed(exec_ctx, t, s, !t->is_client, 1,
-                                     GRPC_ERROR_REF(error));
-    }
     GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2_writing:end");
   }
   grpc_slice_buffer_reset_and_unref_internal(exec_ctx, &t->outbuf);
diff --git a/src/core/ext/transport/inproc/inproc_transport.c b/src/core/ext/transport/inproc/inproc_transport.c
index 036853a53b..31739d07dd 100644
--- a/src/core/ext/transport/inproc/inproc_transport.c
+++ b/src/core/ext/transport/inproc/inproc_transport.c
@@ -37,7 +37,6 @@
     if (GRPC_TRACER_ON(grpc_inproc_trace)) gpr_log(__VA_ARGS__); \
   } while (0)
 
-static const grpc_transport_vtable inproc_vtable;
 static grpc_slice g_empty_slice;
 static grpc_slice g_fake_path_key;
 static grpc_slice g_fake_path_value;
@@ -1167,6 +1166,55 @@ static void destroy_transport(grpc_exec_ctx *exec_ctx, grpc_transport *gt) {
 }
 
 /*******************************************************************************
+ * INTEGRATION GLUE
+ */
+
+static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
+                        grpc_stream *gs, grpc_pollset *pollset) {
+  // Nothing to do here
+}
+
+static void set_pollset_set(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
+                            grpc_stream *gs, grpc_pollset_set *pollset_set) {
+  // Nothing to do here
+}
+
+static grpc_endpoint *get_endpoint(grpc_exec_ctx *exec_ctx, grpc_transport *t) {
+  return NULL;
+}
+
+/*******************************************************************************
+ * GLOBAL INIT AND DESTROY
+ */
+static void do_nothing(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {}
+
+void grpc_inproc_transport_init(void) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GRPC_CLOSURE_INIT(&do_nothing_closure, do_nothing, NULL,
+                    grpc_schedule_on_exec_ctx);
+  g_empty_slice = grpc_slice_from_static_buffer(NULL, 0);
+
+  grpc_slice key_tmp = grpc_slice_from_static_string(":path");
+  g_fake_path_key = grpc_slice_intern(key_tmp);
+  grpc_slice_unref_internal(&exec_ctx, key_tmp);
+
+  g_fake_path_value = grpc_slice_from_static_string("/");
+
+  grpc_slice auth_tmp = grpc_slice_from_static_string(":authority");
+  g_fake_auth_key = grpc_slice_intern(auth_tmp);
+  grpc_slice_unref_internal(&exec_ctx, auth_tmp);
+
+  g_fake_auth_value = grpc_slice_from_static_string("inproc-fail");
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static const grpc_transport_vtable inproc_vtable = {
+    sizeof(inproc_stream), "inproc",        init_stream,
+    set_pollset,           set_pollset_set, perform_stream_op,
+    perform_transport_op,  destroy_stream,  destroy_transport,
+    get_endpoint};
+
+/*******************************************************************************
  * Main inproc transport functions
  */
 static void inproc_transports_create(grpc_exec_ctx *exec_ctx,
@@ -1178,7 +1226,7 @@ static void inproc_transports_create(grpc_exec_ctx *exec_ctx,
   inproc_transport *st = (inproc_transport *)gpr_zalloc(sizeof(*st));
   inproc_transport *ct = (inproc_transport *)gpr_zalloc(sizeof(*ct));
   // Share one lock between both sides since both sides get affected
-  st->mu = ct->mu = gpr_malloc(sizeof(*st->mu));
+  st->mu = ct->mu = (shared_mu *)gpr_malloc(sizeof(*st->mu));
   gpr_mu_init(&st->mu->mu);
   gpr_ref_init(&st->mu->refs, 2);
   st->base.vtable = &inproc_vtable;
@@ -1215,8 +1263,8 @@ grpc_channel *grpc_inproc_channel_create(grpc_server *server,
 
   grpc_arg default_authority_arg;
   default_authority_arg.type = GRPC_ARG_STRING;
-  default_authority_arg.key = GRPC_ARG_DEFAULT_AUTHORITY;
-  default_authority_arg.value.string = "inproc.authority";
+  default_authority_arg.key = (char *)GRPC_ARG_DEFAULT_AUTHORITY;
+  default_authority_arg.value.string = (char *)"inproc.authority";
   grpc_channel_args *client_args =
       grpc_channel_args_copy_and_add(args, &default_authority_arg, 1);
 
@@ -1240,55 +1288,6 @@ grpc_channel *grpc_inproc_channel_create(grpc_server *server,
   return channel;
 }
 
-/*******************************************************************************
- * INTEGRATION GLUE
- */
-
-static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
-                        grpc_stream *gs, grpc_pollset *pollset) {
-  // Nothing to do here
-}
-
-static void set_pollset_set(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
-                            grpc_stream *gs, grpc_pollset_set *pollset_set) {
-  // Nothing to do here
-}
-
-static grpc_endpoint *get_endpoint(grpc_exec_ctx *exec_ctx, grpc_transport *t) {
-  return NULL;
-}
-
-static const grpc_transport_vtable inproc_vtable = {
-    sizeof(inproc_stream), "inproc",        init_stream,
-    set_pollset,           set_pollset_set, perform_stream_op,
-    perform_transport_op,  destroy_stream,  destroy_transport,
-    get_endpoint};
-
-/*******************************************************************************
- * GLOBAL INIT AND DESTROY
- */
-static void do_nothing(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {}
-
-void grpc_inproc_transport_init(void) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  GRPC_CLOSURE_INIT(&do_nothing_closure, do_nothing, NULL,
-                    grpc_schedule_on_exec_ctx);
-  g_empty_slice = grpc_slice_from_static_buffer(NULL, 0);
-
-  grpc_slice key_tmp = grpc_slice_from_static_string(":path");
-  g_fake_path_key = grpc_slice_intern(key_tmp);
-  grpc_slice_unref_internal(&exec_ctx, key_tmp);
-
-  g_fake_path_value = grpc_slice_from_static_string("/");
-
-  grpc_slice auth_tmp = grpc_slice_from_static_string(":authority");
-  g_fake_auth_key = grpc_slice_intern(auth_tmp);
-  grpc_slice_unref_internal(&exec_ctx, auth_tmp);
-
-  g_fake_auth_value = grpc_slice_from_static_string("inproc-fail");
-  grpc_exec_ctx_finish(&exec_ctx);
-}
-
 void grpc_inproc_transport_shutdown(void) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_slice_unref_internal(&exec_ctx, g_empty_slice);