19 files changed, 253 insertions, 287 deletions

diff --git a/src/core/client_config/client_config.c b/src/core/client_config/client_config.c
index 4453824148..0780880473 100644
--- a/src/core/client_config/client_config.c
+++ b/src/core/client_config/client_config.c
@@ -51,21 +51,20 @@ grpc_client_config *grpc_client_config_create() {
 
 void grpc_client_config_ref(grpc_client_config *c) { gpr_ref(&c->refs); }
 
-void grpc_client_config_unref(grpc_client_config *c) {
+void grpc_client_config_unref(grpc_client_config *c,
+                              grpc_call_list *call_list) {
   if (gpr_unref(&c->refs)) {
-    GRPC_LB_POLICY_UNREF(c->lb_policy, "client_config");
+    GRPC_LB_POLICY_UNREF(c->lb_policy, "client_config", call_list);
     gpr_free(c);
   }
 }
 
 void grpc_client_config_set_lb_policy(grpc_client_config *c,
                                       grpc_lb_policy *lb_policy) {
+  GPR_ASSERT(c->lb_policy == NULL);
   if (lb_policy) {
     GRPC_LB_POLICY_REF(lb_policy, "client_config");
   }
-  if (c->lb_policy) {
-    GRPC_LB_POLICY_UNREF(c->lb_policy, "client_config");
-  }
   c->lb_policy = lb_policy;
 }
 
diff --git a/src/core/client_config/client_config.h b/src/core/client_config/client_config.h
index 47612da42c..76a5c66594 100644
--- a/src/core/client_config/client_config.h
+++ b/src/core/client_config/client_config.h
@@ -42,7 +42,8 @@ typedef struct grpc_client_config grpc_client_config;
 
 grpc_client_config *grpc_client_config_create();
 void grpc_client_config_ref(grpc_client_config *client_config);
-void grpc_client_config_unref(grpc_client_config *client_config);
+void grpc_client_config_unref(grpc_client_config *client_config,
+                              grpc_call_list *call_list);
 
 void grpc_client_config_set_lb_policy(grpc_client_config *client_config,
                                       grpc_lb_policy *lb_policy);
diff --git a/src/core/client_config/connector.c b/src/core/client_config/connector.c
index 6252d57271..31f0b84efe 100644
--- a/src/core/client_config/connector.c
+++ b/src/core/client_config/connector.c
@@ -44,10 +44,11 @@ void grpc_connector_unref(grpc_connector *connector) {
 void grpc_connector_connect(grpc_connector *connector,
                             const grpc_connect_in_args *in_args,
                             grpc_connect_out_args *out_args,
-                            grpc_closure *notify) {
-  connector->vtable->connect(connector, in_args, out_args, notify);
+                            grpc_closure *notify, grpc_call_list *call_list) {
+  connector->vtable->connect(connector, in_args, out_args, notify, call_list);
 }
 
-void grpc_connector_shutdown(grpc_connector *connector) {
-  connector->vtable->shutdown(connector);
+void grpc_connector_shutdown(grpc_connector *connector,
+                             grpc_call_list *call_list) {
+  connector->vtable->shutdown(connector, call_list);
 }
diff --git a/src/core/client_config/connector.h b/src/core/client_config/connector.h
index fc1f6708de..388f656c44 100644
--- a/src/core/client_config/connector.h
+++ b/src/core/client_config/connector.h
@@ -55,10 +55,6 @@ typedef struct {
   gpr_timespec deadline;
   /** channel arguments (to be passed to transport) */
   const grpc_channel_args *channel_args;
-  /** metadata context */
-  grpc_mdctx *metadata_context;
-  /** workqueue */
-  grpc_workqueue *workqueue;
 } grpc_connect_in_args;
 
 typedef struct {
@@ -71,23 +67,25 @@ typedef struct {
 
 struct grpc_connector_vtable {
   void (*ref)(grpc_connector *connector);
-  void (*unref)(grpc_connector *connector);
+  void (*unref)(grpc_connector *connector, grpc_call_list *call_list);
   /** Implementation of grpc_connector_shutdown */
-  void (*shutdown)(grpc_connector *connector);
+  void (*shutdown)(grpc_connector *connector, grpc_call_list *call_list);
   /** Implementation of grpc_connector_connect */
   void (*connect)(grpc_connector *connector,
                   const grpc_connect_in_args *in_args,
-                  grpc_connect_out_args *out_args, grpc_closure *notify);
+                  grpc_connect_out_args *out_args, grpc_closure *notify,
+                  grpc_call_list *call_list);
 };
 
 void grpc_connector_ref(grpc_connector *connector);
-void grpc_connector_unref(grpc_connector *connector);
+void grpc_connector_unref(grpc_connector *connector, grpc_call_list *call_list);
 /** Connect using the connector: max one outstanding call at a time */
 void grpc_connector_connect(grpc_connector *connector,
                             const grpc_connect_in_args *in_args,
                             grpc_connect_out_args *out_args,
-                            grpc_closure *notify);
+                            grpc_closure *notify, grpc_call_list *call_list);
 /** Cancel any pending connection */
-void grpc_connector_shutdown(grpc_connector *connector);
+void grpc_connector_shutdown(grpc_connector *connector,
+                             grpc_call_list *call_list);
 
 #endif
diff --git a/src/core/client_config/lb_policies/pick_first.c b/src/core/client_config/lb_policies/pick_first.c
index 852eed310d..6dc52f43ce 100644
--- a/src/core/client_config/lb_policies/pick_first.c
+++ b/src/core/client_config/lb_policies/pick_first.c
@@ -52,8 +52,6 @@ typedef struct {
   /** all our subchannels */
   grpc_subchannel **subchannels;
   size_t num_subchannels;
-  /** workqueue for async work */
-  grpc_workqueue *workqueue;
 
   grpc_closure connectivity_changed;
 
@@ -78,33 +76,34 @@ typedef struct {
   grpc_connectivity_state_tracker state_tracker;
 } pick_first_lb_policy;
 
-static void del_interested_parties_locked(pick_first_lb_policy *p) {
+static void del_interested_parties_locked(pick_first_lb_policy *p,
+                                          grpc_call_list *call_list) {
   pending_pick *pp;
   for (pp = p->pending_picks; pp; pp = pp->next) {
     grpc_subchannel_del_interested_party(p->subchannels[p->checking_subchannel],
-                                         pp->pollset);
+                                         pp->pollset, call_list);
   }
 }
 
-static void add_interested_parties_locked(pick_first_lb_policy *p) {
+static void add_interested_parties_locked(pick_first_lb_policy *p,
+                                          grpc_call_list *call_list) {
   pending_pick *pp;
   for (pp = p->pending_picks; pp; pp = pp->next) {
     grpc_subchannel_add_interested_party(p->subchannels[p->checking_subchannel],
-                                         pp->pollset);
+                                         pp->pollset, call_list);
   }
 }
 
-void pf_destroy(grpc_lb_policy *pol) {
+void pf_destroy(grpc_lb_policy *pol, grpc_call_list *call_list) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   size_t i;
-  del_interested_parties_locked(p);
+  GPR_ASSERT(p->shutdown);
   for (i = 0; i < p->num_subchannels; i++) {
-    GRPC_SUBCHANNEL_UNREF(p->subchannels[i], "pick_first");
+    GRPC_SUBCHANNEL_UNREF(p->subchannels[i], "pick_first", call_list);
   }
   grpc_connectivity_state_destroy(&p->state_tracker);
   gpr_free(p->subchannels);
   gpr_mu_destroy(&p->mu);
-  GRPC_WORKQUEUE_UNREF(p->workqueue, "pick_first");
   gpr_free(p);
 }
 
@@ -112,7 +111,7 @@ void pf_shutdown(grpc_lb_policy *pol, grpc_call_list *call_list) {
   pick_first_lb_policy *p = (pick_first_lb_policy *)pol;
   pending_pick *pp;
   gpr_mu_lock(&p->mu);
-  del_interested_parties_locked(p);
+  del_interested_parties_locked(p, call_list);
   p->shutdown = 1;
   pp = p->pending_picks;
   p->pending_picks = NULL;
@@ -156,13 +155,13 @@ void pf_pick(grpc_lb_policy *pol, grpc_pollset *pollset,
   if (p->selected) {
     gpr_mu_unlock(&p->mu);
     *target = p->selected;
-    on_complete->cb(on_complete->cb_arg, 1);
+    grpc_call_list_add(call_list, on_complete, 1);
   } else {
     if (!p->started_picking) {
       start_picking(p, call_list);
     }
     grpc_subchannel_add_interested_party(p->subchannels[p->checking_subchannel],
-                                         pollset);
+                                         pollset, call_list);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
     pp->pollset = pollset;
@@ -173,58 +172,58 @@ void pf_pick(grpc_lb_policy *pol, grpc_pollset *pollset,
   }
 }
 
-static void pf_connectivity_changed(void *arg, int iomgr_success) {
+static void pf_connectivity_changed(void *arg, int iomgr_success,
+                                    grpc_call_list *call_list) {
   pick_first_lb_policy *p = arg;
   pending_pick *pp;
-  int unref = 0;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
 
   gpr_mu_lock(&p->mu);
 
   if (p->shutdown) {
-    unref = 1;
+    GRPC_LB_POLICY_UNREF(&p->base, "pick_first_connectivity", call_list);
   } else if (p->selected != NULL) {
     grpc_connectivity_state_set(&p->state_tracker, p->checking_connectivity,
-                                "selected_changed", &call_list);
+                                "selected_changed", call_list);
     if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE) {
       grpc_subchannel_notify_on_state_change(
           p->selected, &p->checking_connectivity, &p->connectivity_changed,
-          &call_list);
+          call_list);
     } else {
-      unref = 1;
+      GRPC_LB_POLICY_UNREF(&p->base, "pick_first_connectivity", call_list);
     }
   } else {
   loop:
     switch (p->checking_connectivity) {
       case GRPC_CHANNEL_READY:
         grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_READY,
-                                    "connecting_ready", &call_list);
+                                    "connecting_ready", call_list);
         p->selected = p->subchannels[p->checking_subchannel];
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
           *pp->target = p->selected;
-          grpc_subchannel_del_interested_party(p->selected, pp->pollset);
-          grpc_call_list_add(&call_list, pp->on_complete, 1);
+          grpc_subchannel_del_interested_party(p->selected, pp->pollset,
+                                               call_list);
+          grpc_call_list_add(call_list, pp->on_complete, 1);
           gpr_free(pp);
         }
         grpc_subchannel_notify_on_state_change(
             p->selected, &p->checking_connectivity, &p->connectivity_changed,
-            &call_list);
+            call_list);
         break;
       case GRPC_CHANNEL_TRANSIENT_FAILURE:
         grpc_connectivity_state_set(&p->state_tracker,
                                     GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                    "connecting_transient_failure", &call_list);
-        del_interested_parties_locked(p);
+                                    "connecting_transient_failure", call_list);
+        del_interested_parties_locked(p, call_list);
         p->checking_subchannel =
             (p->checking_subchannel + 1) % p->num_subchannels;
         p->checking_connectivity = grpc_subchannel_check_connectivity(
             p->subchannels[p->checking_subchannel]);
-        add_interested_parties_locked(p);
+        add_interested_parties_locked(p, call_list);
         if (p->checking_connectivity == GRPC_CHANNEL_TRANSIENT_FAILURE) {
           grpc_subchannel_notify_on_state_change(
               p->subchannels[p->checking_subchannel], &p->checking_connectivity,
-              &p->connectivity_changed, &call_list);
+              &p->connectivity_changed, call_list);
         } else {
           goto loop;
         }
@@ -232,48 +231,43 @@ static void pf_connectivity_changed(void *arg, int iomgr_success) {
       case GRPC_CHANNEL_CONNECTING:
       case GRPC_CHANNEL_IDLE:
         grpc_connectivity_state_set(&p->state_tracker, p->checking_connectivity,
-                                    "connecting_changed", &call_list);
+                                    "connecting_changed", call_list);
         grpc_subchannel_notify_on_state_change(
             p->subchannels[p->checking_subchannel], &p->checking_connectivity,
-            &p->connectivity_changed, &call_list);
+            &p->connectivity_changed, call_list);
         break;
       case GRPC_CHANNEL_FATAL_FAILURE:
-        del_interested_parties_locked(p);
+        del_interested_parties_locked(p, call_list);
         GPR_SWAP(grpc_subchannel *, p->subchannels[p->checking_subchannel],
                  p->subchannels[p->num_subchannels - 1]);
         p->num_subchannels--;
-        GRPC_SUBCHANNEL_UNREF(p->subchannels[p->num_subchannels], "pick_first");
+        GRPC_SUBCHANNEL_UNREF(p->subchannels[p->num_subchannels], "pick_first",
+                              call_list);
         if (p->num_subchannels == 0) {
           grpc_connectivity_state_set(&p->state_tracker,
                                       GRPC_CHANNEL_FATAL_FAILURE,
-                                      "no_more_channels", &call_list);
+                                      "no_more_channels", call_list);
           while ((pp = p->pending_picks)) {
             p->pending_picks = pp->next;
             *pp->target = NULL;
-            grpc_call_list_add(&call_list, pp->on_complete, 1);
+            grpc_call_list_add(call_list, pp->on_complete, 1);
             gpr_free(pp);
           }
-          unref = 1;
+          GRPC_LB_POLICY_UNREF(&p->base, "pick_first_connectivity", call_list);
         } else {
           grpc_connectivity_state_set(&p->state_tracker,
                                       GRPC_CHANNEL_TRANSIENT_FAILURE,
-                                      "subchannel_failed", &call_list);
+                                      "subchannel_failed", call_list);
           p->checking_subchannel %= p->num_subchannels;
           p->checking_connectivity = grpc_subchannel_check_connectivity(
               p->subchannels[p->checking_subchannel]);
-          add_interested_parties_locked(p);
+          add_interested_parties_locked(p, call_list);
           goto loop;
         }
     }
   }
 
   gpr_mu_unlock(&p->mu);
-
-  grpc_call_list_run(call_list);
-
-  if (unref) {
-    GRPC_LB_POLICY_UNREF(&p->base, "pick_first_connectivity");
-  }
 }
 
 static void pf_broadcast(grpc_lb_policy *pol, grpc_transport_op *op,
@@ -293,8 +287,8 @@ static void pf_broadcast(grpc_lb_policy *pol, grpc_transport_op *op,
   gpr_mu_unlock(&p->mu);
 
   for (i = 0; i < n; i++) {
-    grpc_subchannel_process_transport_op(subchannels[i], op);
-    GRPC_SUBCHANNEL_UNREF(subchannels[i], "pf_broadcast");
+    grpc_subchannel_process_transport_op(subchannels[i], op, call_list);
+    GRPC_SUBCHANNEL_UNREF(subchannels[i], "pf_broadcast", call_list);
   }
   gpr_free(subchannels);
 }
@@ -341,8 +335,6 @@ static grpc_lb_policy *create_pick_first(grpc_lb_policy_factory *factory,
   grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable);
   p->subchannels = gpr_malloc(sizeof(grpc_subchannel *) * args->num_subchannels);
   p->num_subchannels = args->num_subchannels;
-  p->workqueue = args->workqueue;
-  GRPC_WORKQUEUE_REF(p->workqueue, "pick_first");
   grpc_connectivity_state_init(&p->state_tracker, GRPC_CHANNEL_IDLE,
                                "pick_first");
   memcpy(p->subchannels, args->subchannels,
diff --git a/src/core/client_config/lb_policy.c b/src/core/client_config/lb_policy.c
index 95ab29cd88..84a033d583 100644
--- a/src/core/client_config/lb_policy.c
+++ b/src/core/client_config/lb_policy.c
@@ -51,15 +51,15 @@ void grpc_lb_policy_ref(grpc_lb_policy *policy) {
 }
 
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
-void grpc_lb_policy_unref(grpc_lb_policy *policy, const char *file, int line,
-                          const char *reason) {
+void grpc_lb_policy_unref(grpc_lb_policy *policy, grpc_call_list *call_list,
+                          const char *file, int line, const char *reason) {
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "LB_POLICY:%p unref %d -> %d %s",
           policy, (int)policy->refs.count, (int)policy->refs.count - 1, reason);
 #else
-void grpc_lb_policy_unref(grpc_lb_policy *policy) {
+void grpc_lb_policy_unref(grpc_lb_policy *policy, grpc_call_list *call_list) {
 #endif
   if (gpr_unref(&policy->refs)) {
-    policy->vtable->destroy(policy);
+    policy->vtable->destroy(policy, call_list);
   }
 }
 
diff --git a/src/core/client_config/lb_policy.h b/src/core/client_config/lb_policy.h
index e445d2cded..f9430b4250 100644
--- a/src/core/client_config/lb_policy.h
+++ b/src/core/client_config/lb_policy.h
@@ -51,7 +51,7 @@ struct grpc_lb_policy {
 };
 
 struct grpc_lb_policy_vtable {
-  void (*destroy)(grpc_lb_policy *policy);
+  void (*destroy)(grpc_lb_policy *policy, grpc_call_list *call_list);
 
   void (*shutdown)(grpc_lb_policy *policy, grpc_call_list *call_list);
 
@@ -82,17 +82,17 @@ struct grpc_lb_policy_vtable {
 #ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
 #define GRPC_LB_POLICY_REF(p, r) \
   grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_LB_POLICY_UNREF(p, r) \
-  grpc_lb_policy_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_LB_POLICY_UNREF(p, r, cl) \
+  grpc_lb_policy_unref((p), (cl), __FILE__, __LINE__, (r))
 void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
                         const char *reason);
-void grpc_lb_policy_unref(grpc_lb_policy *policy, const char *file, int line,
-                          const char *reason);
+void grpc_lb_policy_unref(grpc_lb_policy *policy, grpc_call_list *call_list,
+                          const char *file, int line, const char *reason);
 #else
 #define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p))
-#define GRPC_LB_POLICY_UNREF(p, r) grpc_lb_policy_unref((p))
+#define GRPC_LB_POLICY_UNREF(p, r, cl) grpc_lb_policy_unref((p), (cl))
 void grpc_lb_policy_ref(grpc_lb_policy *policy);
-void grpc_lb_policy_unref(grpc_lb_policy *policy);
+void grpc_lb_policy_unref(grpc_lb_policy *policy, grpc_call_list *call_list);
 #endif
 
 /** called by concrete implementations to initialize the base struct */
diff --git a/src/core/client_config/lb_policy_factory.h b/src/core/client_config/lb_policy_factory.h
index 755faf8813..04610316ee 100644
--- a/src/core/client_config/lb_policy_factory.h
+++ b/src/core/client_config/lb_policy_factory.h
@@ -36,7 +36,6 @@
 
 #include "src/core/client_config/lb_policy.h"
 #include "src/core/client_config/subchannel.h"
-#include "src/core/iomgr/workqueue.h"
 
 typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
 typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;
@@ -50,7 +49,6 @@ struct grpc_lb_policy_factory {
 typedef struct grpc_lb_policy_args {
   grpc_subchannel **subchannels;
   size_t num_subchannels;
-  grpc_workqueue *workqueue;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
diff --git a/src/core/client_config/resolver.c b/src/core/client_config/resolver.c
index 6a7d73c54f..eae8ec6ddf 100644
--- a/src/core/client_config/resolver.c
+++ b/src/core/client_config/resolver.c
@@ -40,8 +40,8 @@ void grpc_resolver_init(grpc_resolver *resolver,
 }
 
 #ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
-void grpc_resolver_ref(grpc_resolver *resolver, const char *file, int line,
-                       const char *reason) {
+void grpc_resolver_ref(grpc_resolver *resolver, grpc_call_list *call_list,
+                       const char *file, int line, const char *reason) {
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p   ref %d -> %d %s",
           resolver, (int)resolver->refs.count, (int)resolver->refs.count + 1,
           reason);
@@ -52,32 +52,34 @@ void grpc_resolver_ref(grpc_resolver *resolver) {
 }
 
 #ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
-void grpc_resolver_unref(grpc_resolver *resolver, const char *file, int line,
-                         const char *reason) {
+void grpc_resolver_unref(grpc_resolver *resolver, grpc_call_list *call_list,
+                         const char *file, int line, const char *reason) {
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "RESOLVER:%p unref %d -> %d %s",
           resolver, (int)resolver->refs.count, (int)resolver->refs.count - 1,
           reason);
 #else
-void grpc_resolver_unref(grpc_resolver *resolver) {
+void grpc_resolver_unref(grpc_resolver *resolver, grpc_call_list *call_list) {
 #endif
   if (gpr_unref(&resolver->refs)) {
-    resolver->vtable->destroy(resolver);
+    resolver->vtable->destroy(resolver, call_list);
   }
 }
 
-void grpc_resolver_shutdown(grpc_resolver *resolver) {
-  resolver->vtable->shutdown(resolver);
+void grpc_resolver_shutdown(grpc_resolver *resolver,
+                            grpc_call_list *call_list) {
+  resolver->vtable->shutdown(resolver, call_list);
 }
 
 void grpc_resolver_channel_saw_error(grpc_resolver *resolver,
                                      struct sockaddr *failing_address,
-                                     int failing_address_len) {
+                                     int failing_address_len,
+                                     grpc_call_list *call_list) {
   resolver->vtable->channel_saw_error(resolver, failing_address,
-                                      failing_address_len);
+                                      failing_address_len, call_list);
 }
 
 void grpc_resolver_next(grpc_resolver *resolver,
                         grpc_client_config **target_config,
-                        grpc_closure *on_complete) {
-  resolver->vtable->next(resolver, target_config, on_complete);
+                        grpc_closure *on_complete, grpc_call_list *call_list) {
+  resolver->vtable->next(resolver, target_config, on_complete, call_list);
 }
diff --git a/src/core/client_config/resolver.h b/src/core/client_config/resolver.h
index 217d061abe..7960bcb92f 100644
--- a/src/core/client_config/resolver.h
+++ b/src/core/client_config/resolver.h
@@ -49,40 +49,41 @@ struct grpc_resolver {
 };
 
 struct grpc_resolver_vtable {
-  void (*destroy)(grpc_resolver *resolver);
-  void (*shutdown)(grpc_resolver *resolver);
+  void (*destroy)(grpc_resolver *resolver, grpc_call_list *call_list);
+  void (*shutdown)(grpc_resolver *resolver, grpc_call_list *call_list);
   void (*channel_saw_error)(grpc_resolver *resolver,
                             struct sockaddr *failing_address,
-                            int failing_address_len);
+                            int failing_address_len, grpc_call_list *call_list);
   void (*next)(grpc_resolver *resolver, grpc_client_config **target_config,
-               grpc_closure *on_complete);
+               grpc_closure *on_complete, grpc_call_list *call_list);
 };
 
 #ifdef GRPC_RESOLVER_REFCOUNT_DEBUG
 #define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_RESOLVER_UNREF(p, r) \
-  grpc_resolver_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_RESOLVER_UNREF(p, r, cl) \
+  grpc_resolver_unref((p), (cl), __FILE__, __LINE__, (r))
 void grpc_resolver_ref(grpc_resolver *policy, const char *file, int line,
                        const char *reason);
-void grpc_resolver_unref(grpc_resolver *policy, const char *file, int line,
-                         const char *reason);
+void grpc_resolver_unref(grpc_resolver *policy, grpc_call_list *call_list,
+                         const char *file, int line, const char *reason);
 #else
 #define GRPC_RESOLVER_REF(p, r) grpc_resolver_ref((p))
-#define GRPC_RESOLVER_UNREF(p, r) grpc_resolver_unref((p))
+#define GRPC_RESOLVER_UNREF(p, r, cl) grpc_resolver_unref((p), (cl))
 void grpc_resolver_ref(grpc_resolver *policy);
-void grpc_resolver_unref(grpc_resolver *policy);
+void grpc_resolver_unref(grpc_resolver *policy, grpc_call_list *call_list);
 #endif
 
 void grpc_resolver_init(grpc_resolver *resolver,
                         const grpc_resolver_vtable *vtable);
 
-void grpc_resolver_shutdown(grpc_resolver *resolver);
+void grpc_resolver_shutdown(grpc_resolver *resolver, grpc_call_list *call_list);
 
 /** Notification that the channel has seen an error on some address.
     Can be used as a hint that re-resolution is desirable soon. */
 void grpc_resolver_channel_saw_error(grpc_resolver *resolver,
                                      struct sockaddr *failing_address,
-                                     int failing_address_len);
+                                     int failing_address_len,
+                                     grpc_call_list *call_list);
 
 /** Get the next client config. Called by the channel to fetch a new
     configuration. Expected to set *target_config with a new configuration,
@@ -92,6 +93,6 @@ void grpc_resolver_channel_saw_error(grpc_resolver *resolver,
     schedule on_complete. */
 void grpc_resolver_next(grpc_resolver *resolver,
                         grpc_client_config **target_config,
-                        grpc_closure *on_complete);
+                        grpc_closure *on_complete, grpc_call_list *call_list);
 
 #endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_H */
diff --git a/src/core/client_config/resolver_factory.h b/src/core/client_config/resolver_factory.h
index 24da84d89d..4c4df353f7 100644
--- a/src/core/client_config/resolver_factory.h
+++ b/src/core/client_config/resolver_factory.h
@@ -37,7 +37,6 @@
 #include "src/core/client_config/resolver.h"
 #include "src/core/client_config/subchannel_factory.h"
 #include "src/core/client_config/uri_parser.h"
-#include "src/core/iomgr/workqueue.h"
 
 typedef struct grpc_resolver_factory grpc_resolver_factory;
 typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
@@ -51,7 +50,6 @@ struct grpc_resolver_factory {
 typedef struct grpc_resolver_args {
   grpc_uri *uri;
   grpc_subchannel_factory *subchannel_factory;
-  grpc_workqueue *workqueue;
 } grpc_resolver_args;
 
 struct grpc_resolver_factory_vtable {
diff --git a/src/core/client_config/resolver_registry.c b/src/core/client_config/resolver_registry.c
index 3611252bda..89a945c2d3 100644
--- a/src/core/client_config/resolver_registry.c
+++ b/src/core/client_config/resolver_registry.c
@@ -114,9 +114,8 @@ static grpc_resolver_factory *resolve_factory(const char *target,
   return factory;
 }
 
-grpc_resolver *grpc_resolver_create(const char *target,
-                                    grpc_subchannel_factory *subchannel_factory,
-                                    grpc_workqueue *workqueue) {
+grpc_resolver *grpc_resolver_create(
+    const char *target, grpc_subchannel_factory *subchannel_factory) {
   grpc_uri *uri = NULL;
   grpc_resolver_factory *factory = resolve_factory(target, &uri);
   grpc_resolver *resolver;
@@ -124,7 +123,6 @@ grpc_resolver *grpc_resolver_create(const char *target,
   memset(&args, 0, sizeof(args));
   args.uri = uri;
   args.subchannel_factory = subchannel_factory;
-  args.workqueue = workqueue;
   resolver = grpc_resolver_factory_create_resolver(factory, &args);
   grpc_uri_destroy(uri);
   return resolver;
diff --git a/src/core/client_config/resolver_registry.h b/src/core/client_config/resolver_registry.h
index 9a9a628262..5a7193b7ae 100644
--- a/src/core/client_config/resolver_registry.h
+++ b/src/core/client_config/resolver_registry.h
@@ -55,9 +55,8 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory);
     If a resolver factory was found, use it to instantiate a resolver and
     return it.
     If a resolver factory was not found, return NULL. */
-grpc_resolver *grpc_resolver_create(const char *target,
-                                    grpc_subchannel_factory *subchannel_factory,
-                                    grpc_workqueue *workqueue);
+grpc_resolver *grpc_resolver_create(
+    const char *target, grpc_subchannel_factory *subchannel_factory);
 
 /** Given a target, return a (freshly allocated with gpr_malloc) string
     representing the default authority to pass from a client. */
diff --git a/src/core/client_config/resolvers/dns_resolver.c b/src/core/client_config/resolvers/dns_resolver.c
index e251664e03..9e9b3d4917 100644
--- a/src/core/client_config/resolvers/dns_resolver.c
+++ b/src/core/client_config/resolvers/dns_resolver.c
@@ -49,8 +49,6 @@ typedef struct {
   grpc_resolver base;
   /** refcount */
   gpr_refcount refs;
-  /** workqueue */
-  grpc_workqueue *workqueue;
   /** name to resolve */
   char *name;
   /** default port to use */
@@ -76,37 +74,36 @@ typedef struct {
   grpc_client_config *resolved_config;
 } dns_resolver;
 
-static void dns_destroy(grpc_resolver *r);
+static void dns_destroy(grpc_resolver *r, grpc_call_list *call_list);
 
 static void dns_start_resolving_locked(dns_resolver *r);
-static grpc_closure *dns_maybe_finish_next_locked(dns_resolver *r)
-    GRPC_MUST_USE_RESULT;
+static void dns_maybe_finish_next_locked(dns_resolver *r,
+                                         grpc_call_list *call_list);
 
-static void dns_shutdown(grpc_resolver *r);
+static void dns_shutdown(grpc_resolver *r, grpc_call_list *call_list);
 static void dns_channel_saw_error(grpc_resolver *r,
                                   struct sockaddr *failing_address,
-                                  int failing_address_len);
+                                  int failing_address_len,
+                                  grpc_call_list *call_list);
 static void dns_next(grpc_resolver *r, grpc_client_config **target_config,
-                     grpc_closure *on_complete);
+                     grpc_closure *on_complete, grpc_call_list *call_list);
 
 static const grpc_resolver_vtable dns_resolver_vtable = {
     dns_destroy, dns_shutdown, dns_channel_saw_error, dns_next};
 
-static void dns_shutdown(grpc_resolver *resolver) {
+static void dns_shutdown(grpc_resolver *resolver, grpc_call_list *call_list) {
   dns_resolver *r = (dns_resolver *)resolver;
-  grpc_closure *next_completion;
   gpr_mu_lock(&r->mu);
-  next_completion = r->next_completion;
-  r->next_completion = NULL;
-  gpr_mu_unlock(&r->mu);
-  if (next_completion != NULL) {
+  if (r->next_completion != NULL) {
     *r->target_config = NULL;
-    next_completion->cb(next_completion->cb_arg, 1);
+    grpc_call_list_add(call_list, r->next_completion, 1);
+    r->next_completion = NULL;
   }
+  gpr_mu_unlock(&r->mu);
 }
 
 static void dns_channel_saw_error(grpc_resolver *resolver, struct sockaddr *sa,
-                                  int len) {
+                                  int len, grpc_call_list *call_list) {
   dns_resolver *r = (dns_resolver *)resolver;
   gpr_mu_lock(&r->mu);
   if (!r->resolving) {
@@ -117,9 +114,8 @@ static void dns_channel_saw_error(grpc_resolver *resolver, struct sockaddr *sa,
 
 static void dns_next(grpc_resolver *resolver,
                      grpc_client_config **target_config,
-                     grpc_closure *on_complete) {
+                     grpc_closure *on_complete, grpc_call_list *call_list) {
   dns_resolver *r = (dns_resolver *)resolver;
-  grpc_closure *call = NULL;
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(!r->next_completion);
   r->next_completion = on_complete;
@@ -127,21 +123,18 @@ static void dns_next(grpc_resolver *resolver,
   if (r->resolved_version == 0 && !r->resolving) {
     dns_start_resolving_locked(r);
   } else {
-    call = dns_maybe_finish_next_locked(r);
+    dns_maybe_finish_next_locked(r, call_list);
   }
   gpr_mu_unlock(&r->mu);
-  if (call) {
-    call->cb(call->cb_arg, 1);
-  }
 }
 
-static void dns_on_resolved(void *arg, grpc_resolved_addresses *addresses) {
+static void dns_on_resolved(void *arg, grpc_resolved_addresses *addresses,
+                            grpc_call_list *call_list) {
   dns_resolver *r = arg;
   grpc_client_config *config = NULL;
   grpc_subchannel **subchannels;
   grpc_subchannel_args args;
   grpc_lb_policy *lb_policy;
-  grpc_closure *call;
   size_t i;
   if (addresses) {
     grpc_lb_policy_args lb_policy_args;
@@ -157,10 +150,9 @@ static void dns_on_resolved(void *arg, grpc_resolved_addresses *addresses) {
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
     lb_policy_args.subchannels = subchannels;
     lb_policy_args.num_subchannels = addresses->naddrs;
-    lb_policy_args.workqueue = r->workqueue;
     lb_policy = grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
     grpc_client_config_set_lb_policy(config, lb_policy);
-    GRPC_LB_POLICY_UNREF(lb_policy, "construction");
+    GRPC_LB_POLICY_UNREF(lb_policy, "construction", call_list);
     grpc_resolved_addresses_destroy(addresses);
     gpr_free(subchannels);
   }
@@ -168,17 +160,14 @@ static void dns_on_resolved(void *arg, grpc_resolved_addresses *addresses) {
   GPR_ASSERT(r->resolving);
   r->resolving = 0;
   if (r->resolved_config) {
-    grpc_client_config_unref(r->resolved_config);
+    grpc_client_config_unref(r->resolved_config, call_list);
   }
   r->resolved_config = config;
   r->resolved_version++;
-  call = dns_maybe_finish_next_locked(r);
+  dns_maybe_finish_next_locked(r, call_list);
   gpr_mu_unlock(&r->mu);
-  if (call) {
-    call->cb(call->cb_arg, 1);
-  }
 
-  GRPC_RESOLVER_UNREF(&r->base, "dns-resolving");
+  GRPC_RESOLVER_UNREF(&r->base, "dns-resolving", call_list);
 }
 
 static void dns_start_resolving_locked(dns_resolver *r) {
@@ -188,29 +177,27 @@ static void dns_start_resolving_locked(dns_resolver *r) {
   grpc_resolve_address(r->name, r->default_port, dns_on_resolved, r);
 }
 
-static grpc_closure *dns_maybe_finish_next_locked(dns_resolver *r) {
-  grpc_closure *ret = NULL;
+static void dns_maybe_finish_next_locked(dns_resolver *r,
+                                         grpc_call_list *call_list) {
   if (r->next_completion != NULL &&
       r->resolved_version != r->published_version) {
     *r->target_config = r->resolved_config;
     if (r->resolved_config) {
       grpc_client_config_ref(r->resolved_config);
     }
-    ret = r->next_completion;
+    grpc_call_list_add(call_list, r->next_completion, 1);
     r->next_completion = NULL;
     r->published_version = r->resolved_version;
   }
-  return ret;
 }
 
-static void dns_destroy(grpc_resolver *gr) {
+static void dns_destroy(grpc_resolver *gr, grpc_call_list *call_list) {
   dns_resolver *r = (dns_resolver *)gr;
   gpr_mu_destroy(&r->mu);
   if (r->resolved_config) {
-    grpc_client_config_unref(r->resolved_config);
+    grpc_client_config_unref(r->resolved_config, call_list);
   }
   grpc_subchannel_factory_unref(r->subchannel_factory);
-  GRPC_WORKQUEUE_UNREF(r->workqueue, "dns");
   gpr_free(r->name);
   gpr_free(r->default_port);
   gpr_free(r->lb_policy_name);
@@ -239,8 +226,6 @@ static grpc_resolver *dns_create(grpc_resolver_args *args,
   r->default_port = gpr_strdup(default_port);
   r->subchannel_factory = args->subchannel_factory;
   grpc_subchannel_factory_ref(r->subchannel_factory);
-  r->workqueue = args->workqueue;
-  GRPC_WORKQUEUE_REF(r->workqueue, "dns");
   r->lb_policy_name = gpr_strdup(lb_policy_name);
   return &r->base;
 }
diff --git a/src/core/client_config/resolvers/sockaddr_resolver.c b/src/core/client_config/resolvers/sockaddr_resolver.c
index 47fe5fad4a..15eb60b93a 100644
--- a/src/core/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/client_config/resolvers/sockaddr_resolver.c
@@ -56,8 +56,6 @@ typedef struct {
   gpr_refcount refs;
   /** subchannel factory */
   grpc_subchannel_factory *subchannel_factory;
-  /** workqueue */
-  grpc_workqueue *workqueue;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -78,61 +76,59 @@ typedef struct {
   grpc_client_config **target_config;
 } sockaddr_resolver;
 
-static void sockaddr_destroy(grpc_resolver *r);
+static void sockaddr_destroy(grpc_resolver *r, grpc_call_list *call_list);
 
-static grpc_closure *sockaddr_maybe_finish_next_locked(sockaddr_resolver *r)
-    GRPC_MUST_USE_RESULT;
+static void sockaddr_maybe_finish_next_locked(sockaddr_resolver *r,
+                                              grpc_call_list *call_list);
 
-static void sockaddr_shutdown(grpc_resolver *r);
+static void sockaddr_shutdown(grpc_resolver *r, grpc_call_list *call_list);
 static void sockaddr_channel_saw_error(grpc_resolver *r,
                                        struct sockaddr *failing_address,
-                                       int failing_address_len);
+                                       int failing_address_len,
+                                       grpc_call_list *call_list);
 static void sockaddr_next(grpc_resolver *r, grpc_client_config **target_config,
-                          grpc_closure *on_complete);
+                          grpc_closure *on_complete, grpc_call_list *call_list);
 
 static const grpc_resolver_vtable sockaddr_resolver_vtable = {
     sockaddr_destroy, sockaddr_shutdown, sockaddr_channel_saw_error,
     sockaddr_next};
 
-static void sockaddr_shutdown(grpc_resolver *resolver) {
+static void sockaddr_shutdown(grpc_resolver *resolver,
+                              grpc_call_list *call_list) {
   sockaddr_resolver *r = (sockaddr_resolver *)resolver;
-  grpc_closure *call = NULL;
   gpr_mu_lock(&r->mu);
   if (r->next_completion != NULL) {
     *r->target_config = NULL;
-    call = r->next_completion;
+    grpc_call_list_add(call_list, r->next_completion, 1);
     r->next_completion = NULL;
   }
   gpr_mu_unlock(&r->mu);
-  if (call) {
-    call->cb(call->cb_arg, 1);
-  }
 }
 
 static void sockaddr_channel_saw_error(grpc_resolver *resolver,
-                                       struct sockaddr *sa, int len) {}
+                                       struct sockaddr *sa, int len,
+                                       grpc_call_list *call_list) {}
 
 static void sockaddr_next(grpc_resolver *resolver,
                           grpc_client_config **target_config,
-                          grpc_closure *on_complete) {
+                          grpc_closure *on_complete,
+                          grpc_call_list *call_list) {
   sockaddr_resolver *r = (sockaddr_resolver *)resolver;
-  grpc_closure *call = NULL;
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(!r->next_completion);
   r->next_completion = on_complete;
   r->target_config = target_config;
-  call = sockaddr_maybe_finish_next_locked(r);
+  sockaddr_maybe_finish_next_locked(r, call_list);
   gpr_mu_unlock(&r->mu);
-  if (call) call->cb(call->cb_arg, 1);
 }
 
-static grpc_closure *sockaddr_maybe_finish_next_locked(sockaddr_resolver *r) {
+static void sockaddr_maybe_finish_next_locked(sockaddr_resolver *r,
+                                              grpc_call_list *call_list) {
   grpc_client_config *cfg;
   grpc_lb_policy *lb_policy;
   grpc_lb_policy_args lb_policy_args;
   grpc_subchannel **subchannels;
   grpc_subchannel_args args;
-  grpc_closure *call = NULL;
 
   if (r->next_completion != NULL && !r->published) {
     size_t i;
@@ -148,26 +144,22 @@ static grpc_closure *sockaddr_maybe_finish_next_locked(sockaddr_resolver *r) {
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
     lb_policy_args.subchannels = subchannels;
     lb_policy_args.num_subchannels = r->num_addrs;
-    lb_policy_args.workqueue = r->workqueue;
     lb_policy =
         grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
     gpr_free(subchannels);
     grpc_client_config_set_lb_policy(cfg, lb_policy);
-    GRPC_LB_POLICY_UNREF(lb_policy, "unix");
+    GRPC_LB_POLICY_UNREF(lb_policy, "sockaddr", call_list);
     r->published = 1;
     *r->target_config = cfg;
-    call = r->next_completion;
+    grpc_call_list_add(call_list, r->next_completion, 1);
     r->next_completion = NULL;
   }
-
-  return call;
 }
 
-static void sockaddr_destroy(grpc_resolver *gr) {
+static void sockaddr_destroy(grpc_resolver *gr, grpc_call_list *call_list) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
   grpc_subchannel_factory_unref(r->subchannel_factory);
-  GRPC_WORKQUEUE_UNREF(r->workqueue, "sockaddr");
   gpr_free(r->addrs);
   gpr_free(r->addrs_len);
   gpr_free(r->lb_policy_name);
@@ -340,8 +332,6 @@ static grpc_resolver *sockaddr_create(
   grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
   r->subchannel_factory = args->subchannel_factory;
   grpc_subchannel_factory_ref(r->subchannel_factory);
-  r->workqueue = args->workqueue;
-  GRPC_WORKQUEUE_REF(r->workqueue, "sockaddr");
   r->lb_policy_name = gpr_strdup(lb_policy_name);
 
   return &r->base;
diff --git a/src/core/client_config/resolvers/zookeeper_resolver.c b/src/core/client_config/resolvers/zookeeper_resolver.c
index 5632f0425e..c785e76939 100644
--- a/src/core/client_config/resolvers/zookeeper_resolver.c
+++ b/src/core/client_config/resolvers/zookeeper_resolver.c
@@ -61,8 +61,6 @@ typedef struct {
   grpc_subchannel_factory *subchannel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
-  /** work queue */
-  grpc_workqueue *workqueue;
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
@@ -436,7 +434,6 @@ static void zookeeper_destroy(grpc_resolver *gr) {
     grpc_client_config_unref(r->resolved_config);
   }
   grpc_subchannel_factory_unref(r->subchannel_factory);
-  grpc_workqueue_unref(r->workqueue);
   gpr_free(r->name);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
@@ -466,9 +463,6 @@ static grpc_resolver *zookeeper_create(grpc_resolver_args *args,
   grpc_resolver_init(&r->base, &zookeeper_resolver_vtable);
   r->name = gpr_strdup(path);
 
-  r->workqueue = args->workqueue;
-  grpc_workqueue_ref(r->workqueue);
-
   r->subchannel_factory = args->subchannel_factory;
   grpc_subchannel_factory_ref(r->subchannel_factory);
 
diff --git a/src/core/client_config/subchannel.c b/src/core/client_config/subchannel.c
index 99310e02e5..937b3cd71c 100644
--- a/src/core/client_config/subchannel.c
+++ b/src/core/client_config/subchannel.c
@@ -76,7 +76,6 @@ typedef struct waiting_for_connect {
 
 struct grpc_subchannel {
   grpc_connector *connector;
-  grpc_workqueue *workqueue;
 
   /** non-transport related channel filters */
   const grpc_channel_filter **filters;
@@ -150,7 +149,8 @@ static void connectivity_state_changed_locked(grpc_subchannel *c,
                                               grpc_call_list *call_list);
 static grpc_connectivity_state compute_connectivity_locked(grpc_subchannel *c);
 static gpr_timespec compute_connect_deadline(grpc_subchannel *c);
-static void subchannel_connected(void *subchannel, int iomgr_success);
+static void subchannel_connected(void *subchannel, int iomgr_success,
+                                 grpc_call_list *call_list);
 
 static void subchannel_ref_locked(
     grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
@@ -158,8 +158,9 @@ static int subchannel_unref_locked(
     grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) GRPC_MUST_USE_RESULT;
 static void connection_ref_locked(connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 static grpc_subchannel *connection_unref_locked(
-    connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) GRPC_MUST_USE_RESULT;
-static void subchannel_destroy(grpc_subchannel *c);
+    connection *c, grpc_call_list *call_list GRPC_SUBCHANNEL_REF_EXTRA_ARGS)
+    GRPC_MUST_USE_RESULT;
+static void subchannel_destroy(grpc_subchannel *c, grpc_call_list *call_list);
 
 #ifdef GRPC_SUBCHANNEL_REFCOUNT_DEBUG
 #define SUBCHANNEL_REF_LOCKED(p, r) \
@@ -168,8 +169,8 @@ static void subchannel_destroy(grpc_subchannel *c);
   subchannel_unref_locked((p), __FILE__, __LINE__, (r))
 #define CONNECTION_REF_LOCKED(p, r) \
   connection_ref_locked((p), __FILE__, __LINE__, (r))
-#define CONNECTION_UNREF_LOCKED(p, r) \
-  connection_unref_locked((p), __FILE__, __LINE__, (r))
+#define CONNECTION_UNREF_LOCKED(p, r, cl) \
+  connection_unref_locked((p), (cl), __FILE__, __LINE__, (r))
 #define REF_PASS_ARGS , file, line, reason
 #define REF_LOG(name, p)                                                  \
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "%s: %p   ref %d -> %d %s", \
@@ -181,7 +182,7 @@ static void subchannel_destroy(grpc_subchannel *c);
 #define SUBCHANNEL_REF_LOCKED(p, r) subchannel_ref_locked((p))
 #define SUBCHANNEL_UNREF_LOCKED(p, r) subchannel_unref_locked((p))
 #define CONNECTION_REF_LOCKED(p, r) connection_ref_locked((p))
-#define CONNECTION_UNREF_LOCKED(p, r) connection_unref_locked((p))
+#define CONNECTION_UNREF_LOCKED(p, r, cl) connection_unref_locked((p), (cl))
 #define REF_PASS_ARGS
 #define REF_LOG(name, p) \
   do {                   \
@@ -195,9 +196,9 @@ static void subchannel_destroy(grpc_subchannel *c);
  * connection implementation
  */
 
-static void connection_destroy(connection *c) {
+static void connection_destroy(connection *c, grpc_call_list *call_list) {
   GPR_ASSERT(c->refs == 0);
-  grpc_channel_stack_destroy(CHANNEL_STACK_FROM_CONNECTION(c));
+  grpc_channel_stack_destroy(CHANNEL_STACK_FROM_CONNECTION(c), call_list);
   gpr_free(c);
 }
 
@@ -209,14 +210,14 @@ static void connection_ref_locked(
 }
 
 static grpc_subchannel *connection_unref_locked(
-    connection *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+    connection *c, grpc_call_list *call_list GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
   grpc_subchannel *destroy = NULL;
   UNREF_LOG("CONNECTION", c);
   if (subchannel_unref_locked(c->subchannel REF_PASS_ARGS)) {
     destroy = c->subchannel;
   }
   if (--c->refs == 0 && c->subchannel->active != c) {
-    connection_destroy(c);
+    connection_destroy(c, call_list);
   }
   return destroy;
 }
@@ -243,17 +244,19 @@ void grpc_subchannel_ref(grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
   gpr_mu_unlock(&c->mu);
 }
 
-void grpc_subchannel_unref(grpc_subchannel *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+void grpc_subchannel_unref(grpc_subchannel *c,
+                           grpc_call_list *call_list
+                               GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
   int destroy;
   gpr_mu_lock(&c->mu);
   destroy = subchannel_unref_locked(c REF_PASS_ARGS);
   gpr_mu_unlock(&c->mu);
-  if (destroy) subchannel_destroy(c);
+  if (destroy) subchannel_destroy(c, call_list);
 }
 
-static void subchannel_destroy(grpc_subchannel *c) {
+static void subchannel_destroy(grpc_subchannel *c, grpc_call_list *call_list) {
   if (c->active != NULL) {
-    connection_destroy(c->active);
+    connection_destroy(c->active, call_list);
   }
   gpr_free(c->filters);
   grpc_channel_args_destroy(c->args);
@@ -261,18 +264,19 @@ static void subchannel_destroy(grpc_subchannel *c) {
   grpc_mdctx_unref(c->mdctx);
   grpc_connectivity_state_destroy(&c->state_tracker);
   grpc_connector_unref(c->connector);
-  GRPC_WORKQUEUE_UNREF(c->workqueue, "subchannel");
   gpr_free(c);
 }
 
 void grpc_subchannel_add_interested_party(grpc_subchannel *c,
-                                          grpc_pollset *pollset) {
-  grpc_pollset_set_add_pollset(c->pollset_set, pollset);
+                                          grpc_pollset *pollset,
+                                          grpc_call_list *call_list) {
+  grpc_pollset_set_add_pollset(c->pollset_set, pollset, call_list);
 }
 
 void grpc_subchannel_del_interested_party(grpc_subchannel *c,
-                                          grpc_pollset *pollset) {
-  grpc_pollset_set_del_pollset(c->pollset_set, pollset);
+                                          grpc_pollset *pollset,
+                                          grpc_call_list *call_list) {
+  grpc_pollset_set_del_pollset(c->pollset_set, pollset, call_list);
 }
 
 static gpr_uint32 random_seed() {
@@ -298,8 +302,6 @@ grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
   c->args = grpc_channel_args_copy(args->args);
   c->mdctx = args->mdctx;
   c->master = args->master;
-  c->workqueue = grpc_channel_get_workqueue(c->master);
-  GRPC_WORKQUEUE_REF(c->workqueue, "subchannel");
   c->pollset_set = grpc_client_channel_get_connecting_pollset_set(parent_elem);
   c->random = random_seed();
   grpc_mdctx_ref(c->mdctx);
@@ -310,7 +312,7 @@ grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
   return c;
 }
 
-static void continue_connect(grpc_subchannel *c) {
+static void continue_connect(grpc_subchannel *c, grpc_call_list *call_list) {
   grpc_connect_in_args args;
 
   args.interested_parties = c->pollset_set;
@@ -321,24 +323,25 @@ static void continue_connect(grpc_subchannel *c) {
   args.metadata_context = c->mdctx;
 
   grpc_connector_connect(c->connector, &args, &c->connecting_result,
-                         &c->connected);
+                         &c->connected, call_list);
 }
 
-static void start_connect(grpc_subchannel *c) {
+static void start_connect(grpc_subchannel *c, grpc_call_list *call_list) {
   c->backoff_delta = gpr_time_from_seconds(
       GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS, GPR_TIMESPAN);
   c->next_attempt =
       gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), c->backoff_delta);
-  continue_connect(c);
+  continue_connect(c, call_list);
 }
 
-static void continue_creating_call(void *arg, int iomgr_success) {
+static void continue_creating_call(void *arg, int iomgr_success,
+                                   grpc_call_list *call_list) {
   waiting_for_connect *w4c = arg;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
-  grpc_subchannel_del_interested_party(w4c->subchannel, w4c->pollset);
+  grpc_subchannel_del_interested_party(w4c->subchannel, w4c->pollset,
+                                       call_list);
   grpc_subchannel_create_call(w4c->subchannel, w4c->pollset, w4c->target,
-                              w4c->notify, &call_list);
-  GRPC_SUBCHANNEL_UNREF(w4c->subchannel, "waiting_for_connect");
+                              w4c->notify, call_list);
+  GRPC_SUBCHANNEL_UNREF(w4c->subchannel, "waiting_for_connect", call_list);
   gpr_free(w4c);
 }
 
@@ -354,7 +357,7 @@ void grpc_subchannel_create_call(grpc_subchannel *c, grpc_pollset *pollset,
     gpr_mu_unlock(&c->mu);
 
     *target = create_call(con);
-    notify->cb(notify->cb_arg, 1);
+    notify->cb(notify->cb_arg, 1, call_list);
   } else {
     waiting_for_connect *w4c = gpr_malloc(sizeof(*w4c));
     w4c->next = c->waiting;
@@ -366,7 +369,7 @@ void grpc_subchannel_create_call(grpc_subchannel *c, grpc_pollset *pollset,
     SUBCHANNEL_REF_LOCKED(c, "waiting_for_connect");
     grpc_closure_init(&w4c->continuation, continue_creating_call, w4c);
     c->waiting = w4c;
-    grpc_subchannel_add_interested_party(c, pollset);
+    grpc_subchannel_add_interested_party(c, pollset, call_list);
     if (!c->connecting) {
       c->connecting = 1;
       connectivity_state_changed_locked(c, "create_call", call_list);
@@ -375,7 +378,7 @@ void grpc_subchannel_create_call(grpc_subchannel *c, grpc_pollset *pollset,
       GRPC_CHANNEL_INTERNAL_REF(c->master, "connecting");
       gpr_mu_unlock(&c->mu);
 
-      start_connect(c);
+      start_connect(c, call_list);
     } else {
       gpr_mu_unlock(&c->mu);
     }
@@ -408,16 +411,16 @@ void grpc_subchannel_notify_on_state_change(grpc_subchannel *c,
   gpr_mu_unlock(&c->mu);
 
   if (do_connect) {
-    start_connect(c);
+    start_connect(c, call_list);
   }
 }
 
 void grpc_subchannel_process_transport_op(grpc_subchannel *c,
-                                          grpc_transport_op *op) {
+                                          grpc_transport_op *op,
+                                          grpc_call_list *call_list) {
   connection *con = NULL;
   grpc_subchannel *destroy;
   int cancel_alarm = 0;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
   gpr_mu_lock(&c->mu);
   if (c->active != NULL) {
     con = c->active;
@@ -425,7 +428,7 @@ void grpc_subchannel_process_transport_op(grpc_subchannel *c,
   }
   if (op->disconnect) {
     c->disconnected = 1;
-    connectivity_state_changed_locked(c, "disconnect", &call_list);
+    connectivity_state_changed_locked(c, "disconnect", call_list);
     if (c->have_alarm) {
       cancel_alarm = 1;
     }
@@ -436,28 +439,27 @@ void grpc_subchannel_process_transport_op(grpc_subchannel *c,
     grpc_channel_stack *channel_stack = CHANNEL_STACK_FROM_CONNECTION(con);
     grpc_channel_element *top_elem =
         grpc_channel_stack_element(channel_stack, 0);
-    top_elem->filter->start_transport_op(top_elem, op);
+    top_elem->filter->start_transport_op(top_elem, op, call_list);
 
     gpr_mu_lock(&c->mu);
-    destroy = CONNECTION_UNREF_LOCKED(con, "transport-op");
+    destroy = CONNECTION_UNREF_LOCKED(con, "transport-op", call_list);
     gpr_mu_unlock(&c->mu);
     if (destroy) {
-      subchannel_destroy(destroy);
+      subchannel_destroy(destroy, call_list);
     }
   }
 
   if (cancel_alarm) {
-    grpc_alarm_cancel(&c->alarm);
+    grpc_alarm_cancel(&c->alarm, call_list);
   }
 
   if (op->disconnect) {
-    grpc_connector_shutdown(c->connector);
+    grpc_connector_shutdown(c->connector, call_list);
   }
-
-  grpc_call_list_run(call_list);
 }
 
-static void on_state_changed(void *p, int iomgr_success) {
+static void on_state_changed(void *p, int iomgr_success,
+                             grpc_call_list *call_list) {
   state_watcher *sw = p;
   grpc_subchannel *c = sw->subchannel;
   gpr_mu *mu = &c->mu;
@@ -465,7 +467,6 @@ static void on_state_changed(void *p, int iomgr_success) {
   grpc_transport_op op;
   grpc_channel_element *elem;
   connection *destroy_connection = NULL;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
 
   gpr_mu_lock(mu);
 
@@ -485,7 +486,7 @@ static void on_state_changed(void *p, int iomgr_success) {
       op.on_connectivity_state_change = &sw->closure;
       elem = grpc_channel_stack_element(
           CHANNEL_STACK_FROM_CONNECTION(c->active), 0);
-      elem->filter->start_transport_op(elem, &op);
+      elem->filter->start_transport_op(elem, &op, call_list);
       /* early out */
       gpr_mu_unlock(mu);
       return;
@@ -499,22 +500,21 @@ static void on_state_changed(void *p, int iomgr_success) {
       grpc_connectivity_state_set(
           &c->state_tracker, c->disconnected ? GRPC_CHANNEL_FATAL_FAILURE
                                              : GRPC_CHANNEL_TRANSIENT_FAILURE,
-          "connection_failed", &call_list);
+          "connection_failed", call_list);
       break;
   }
 
 done:
-  connectivity_state_changed_locked(c, "transport_state_changed", &call_list);
+  connectivity_state_changed_locked(c, "transport_state_changed", call_list);
   destroy = SUBCHANNEL_UNREF_LOCKED(c, "state_watcher");
   gpr_free(sw);
   gpr_mu_unlock(mu);
   if (destroy) {
-    subchannel_destroy(c);
+    subchannel_destroy(c, call_list);
   }
   if (destroy_connection != NULL) {
-    connection_destroy(destroy_connection);
+    connection_destroy(destroy_connection, call_list);
   }
-  grpc_call_list_run(call_list);
 }
 
 static void publish_transport(grpc_subchannel *c, grpc_call_list *call_list) {
@@ -544,7 +544,7 @@ static void publish_transport(grpc_subchannel *c, grpc_call_list *call_list) {
   con->refs = 0;
   con->subchannel = c;
   grpc_channel_stack_init(filters, num_filters, c->master, c->args, c->mdctx,
-                          stk);
+                          stk, call_list);
   grpc_connected_channel_bind_transport(stk, c->connecting_result.transport);
   gpr_free(c->connecting_result.filters);
   memset(&c->connecting_result, 0, sizeof(c->connecting_result));
@@ -561,9 +561,9 @@ static void publish_transport(grpc_subchannel *c, grpc_call_list *call_list) {
     gpr_mu_unlock(&c->mu);
     gpr_free(sw);
     gpr_free(filters);
-    grpc_channel_stack_destroy(stk);
+    grpc_channel_stack_destroy(stk, call_list);
     GRPC_CHANNEL_INTERNAL_UNREF(c->master, "connecting");
-    GRPC_SUBCHANNEL_UNREF(c, "connecting");
+    GRPC_SUBCHANNEL_UNREF(c, "connecting", call_list);
     return;
   }
 
@@ -587,7 +587,7 @@ static void publish_transport(grpc_subchannel *c, grpc_call_list *call_list) {
   GPR_ASSERT(!SUBCHANNEL_UNREF_LOCKED(c, "connecting"));
   elem =
       grpc_channel_stack_element(CHANNEL_STACK_FROM_CONNECTION(c->active), 0);
-  elem->filter->start_transport_op(elem, &op);
+  elem->filter->start_transport_op(elem, &op, call_list);
 
   /* signal completion */
   connectivity_state_changed_locked(c, "connected", call_list);
@@ -605,7 +605,7 @@ static void publish_transport(grpc_subchannel *c, grpc_call_list *call_list) {
   gpr_free(filters);
 
   if (destroy_connection != NULL) {
-    connection_destroy(destroy_connection);
+    connection_destroy(destroy_connection, call_list);
   }
 }
 
@@ -638,41 +638,38 @@ static void update_reconnect_parameters(grpc_subchannel *c) {
       gpr_time_add(c->next_attempt, gpr_time_from_millis(jitter, GPR_TIMESPAN));
 }
 
-static void on_alarm(void *arg, int iomgr_success) {
+static void on_alarm(void *arg, int iomgr_success, grpc_call_list *call_list) {
   grpc_subchannel *c = arg;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
   gpr_mu_lock(&c->mu);
   c->have_alarm = 0;
   if (c->disconnected) {
     iomgr_success = 0;
   }
-  connectivity_state_changed_locked(c, "alarm", &call_list);
+  connectivity_state_changed_locked(c, "alarm", call_list);
   gpr_mu_unlock(&c->mu);
   if (iomgr_success) {
     update_reconnect_parameters(c);
-    continue_connect(c);
+    continue_connect(c, call_list);
   } else {
     GRPC_CHANNEL_INTERNAL_UNREF(c->master, "connecting");
-    GRPC_SUBCHANNEL_UNREF(c, "connecting");
+    GRPC_SUBCHANNEL_UNREF(c, "connecting", call_list);
   }
-  grpc_call_list_run(call_list);
 }
 
-static void subchannel_connected(void *arg, int iomgr_success) {
+static void subchannel_connected(void *arg, int iomgr_success,
+                                 grpc_call_list *call_list) {
   grpc_subchannel *c = arg;
-  grpc_call_list call_list = GRPC_CALL_LIST_INIT;
   if (c->connecting_result.transport != NULL) {
-    publish_transport(c, &call_list);
+    publish_transport(c, call_list);
   } else {
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_mu_lock(&c->mu);
     GPR_ASSERT(!c->have_alarm);
     c->have_alarm = 1;
-    connectivity_state_changed_locked(c, "connect_failed", &call_list);
-    grpc_alarm_init(&c->alarm, c->next_attempt, on_alarm, c, now);
+    connectivity_state_changed_locked(c, "connect_failed", call_list);
+    grpc_alarm_init(&c->alarm, c->next_attempt, on_alarm, c, now, call_list);
     gpr_mu_unlock(&c->mu);
   }
-  grpc_call_list_run(call_list);
 }
 
 static gpr_timespec compute_connect_deadline(grpc_subchannel *c) {
@@ -718,33 +715,36 @@ void grpc_subchannel_call_ref(
   gpr_ref(&c->refs);
 }
 
-void grpc_subchannel_call_unref(
-    grpc_subchannel_call *c GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
+void grpc_subchannel_call_unref(grpc_subchannel_call *c,
+                                grpc_call_list *call_list
+                                    GRPC_SUBCHANNEL_REF_EXTRA_ARGS) {
   if (gpr_unref(&c->refs)) {
     gpr_mu *mu = &c->connection->subchannel->mu;
     grpc_subchannel *destroy;
-    grpc_call_stack_destroy(SUBCHANNEL_CALL_TO_CALL_STACK(c));
+    grpc_call_stack_destroy(SUBCHANNEL_CALL_TO_CALL_STACK(c), call_list);
     gpr_mu_lock(mu);
-    destroy = CONNECTION_UNREF_LOCKED(c->connection, "call");
+    destroy = CONNECTION_UNREF_LOCKED(c->connection, "call", call_list);
     gpr_mu_unlock(mu);
     gpr_free(c);
     if (destroy != NULL) {
-      subchannel_destroy(destroy);
+      subchannel_destroy(destroy, call_list);
     }
   }
 }
 
-char *grpc_subchannel_call_get_peer(grpc_subchannel_call *call) {
+char *grpc_subchannel_call_get_peer(grpc_subchannel_call *call,
+                                    grpc_call_list *call_list) {
   grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
   grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
-  return top_elem->filter->get_peer(top_elem);
+  return top_elem->filter->get_peer(top_elem, call_list);
 }
 
 void grpc_subchannel_call_process_op(grpc_subchannel_call *call,
-                                     grpc_transport_stream_op *op) {
+                                     grpc_transport_stream_op *op,
+                                     grpc_call_list *call_list) {
   grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
   grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
-  top_elem->filter->start_transport_stream_op(top_elem, op);
+  top_elem->filter->start_transport_stream_op(top_elem, op, call_list);
 }
 
 grpc_subchannel_call *create_call(connection *con) {
diff --git a/src/core/client_config/subchannel.h b/src/core/client_config/subchannel.h
index 189e531d35..0ebfc7c29a 100644
--- a/src/core/client_config/subchannel.h
+++ b/src/core/client_config/subchannel.h
@@ -47,30 +47,33 @@ typedef struct grpc_subchannel_args grpc_subchannel_args;
 #ifdef GRPC_SUBCHANNEL_REFCOUNT_DEBUG
 #define GRPC_SUBCHANNEL_REF(p, r) \
   grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_SUBCHANNEL_UNREF(p, r) \
-  grpc_subchannel_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_UNREF(p, r, cl) \
+  grpc_subchannel_unref((p), (cl), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) \
   grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) \
-  grpc_subchannel_call_unref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r, cl) \
+  grpc_subchannel_call_unref((p), (cl), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_REF_EXTRA_ARGS \
   , const char *file, int line, const char *reason
 #else
 #define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
-#define GRPC_SUBCHANNEL_UNREF(p, r) grpc_subchannel_unref((p))
+#define GRPC_SUBCHANNEL_UNREF(p, r, cl) grpc_subchannel_unref((p), (cl))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
-#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) grpc_subchannel_call_unref((p))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r, cl) \
+  grpc_subchannel_call_unref((p), (cl))
 #define GRPC_SUBCHANNEL_REF_EXTRA_ARGS
 #endif
 
 void grpc_subchannel_ref(
     grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_subchannel_unref(
-    grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_unref(grpc_subchannel *channel,
+                           grpc_call_list *call_list
+                               GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 void grpc_subchannel_call_ref(
     grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_subchannel_call_unref(
-    grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_unref(grpc_subchannel_call *call,
+                                grpc_call_list *call_list
+                                    GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 
 /** construct a call (possibly asynchronously) */
 void grpc_subchannel_create_call(grpc_subchannel *subchannel,
@@ -81,7 +84,8 @@ void grpc_subchannel_create_call(grpc_subchannel *subchannel,
 
 /** process a transport level op */
 void grpc_subchannel_process_transport_op(grpc_subchannel *subchannel,
-                                          grpc_transport_op *op);
+                                          grpc_transport_op *op,
+                                          grpc_call_list *call_list);
 
 /** poll the current connectivity state of a channel */
 grpc_connectivity_state grpc_subchannel_check_connectivity(
@@ -96,17 +100,21 @@ void grpc_subchannel_notify_on_state_change(grpc_subchannel *channel,
 
 /** express interest in \a channel's activities through \a pollset. */
 void grpc_subchannel_add_interested_party(grpc_subchannel *channel,
-                                          grpc_pollset *pollset);
+                                          grpc_pollset *pollset,
+                                          grpc_call_list *call_list);
 /** stop following \a channel's activity through \a pollset. */
 void grpc_subchannel_del_interested_party(grpc_subchannel *channel,
-                                          grpc_pollset *pollset);
+                                          grpc_pollset *pollset,
+                                          grpc_call_list *call_list);
 
 /** continue processing a transport op */
 void grpc_subchannel_call_process_op(grpc_subchannel_call *subchannel_call,
-                                     grpc_transport_stream_op *op);
+                                     grpc_transport_stream_op *op,
+                                     grpc_call_list *call_list);
 
 /** continue querying for peer */
-char *grpc_subchannel_call_get_peer(grpc_subchannel_call *subchannel_call);
+char *grpc_subchannel_call_get_peer(grpc_subchannel_call *subchannel_call,
+                                    grpc_call_list *call_list);
 
 struct grpc_subchannel_args {
   /** Channel filters for this channel - wrapped factories will likely
diff --git a/src/core/client_config/subchannel_factory.h b/src/core/client_config/subchannel_factory.h
index d7eae1c964..b588580edb 100644
--- a/src/core/client_config/subchannel_factory.h
+++ b/src/core/client_config/subchannel_factory.h
@@ -50,7 +50,8 @@ struct grpc_subchannel_factory_vtable {
   void (*ref)(grpc_subchannel_factory *factory);
   void (*unref)(grpc_subchannel_factory *factory);
   grpc_subchannel *(*create_subchannel)(grpc_subchannel_factory *factory,
-                                        grpc_subchannel_args *args);
+                                        grpc_subchannel_args *args,
+                                        grpc_call_list *call_list);
 };
 
 void grpc_subchannel_factory_ref(grpc_subchannel_factory *factory);
@@ -58,6 +59,7 @@ void grpc_subchannel_factory_unref(grpc_subchannel_factory *factory);
 
 /** Create a new grpc_subchannel */
 grpc_subchannel *grpc_subchannel_factory_create_subchannel(
-    grpc_subchannel_factory *factory, grpc_subchannel_args *args);
+    grpc_subchannel_factory *factory, grpc_subchannel_args *args,
+    grpc_call_list *call_list);
 
 #endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_FACTORY_H */