Move argument passing to start of list

66 files changed, 682 insertions, 682 deletions

diff --git a/src/core/census/grpc_filter.c b/src/core/census/grpc_filter.c
index eed9523d72..485987a295 100644
--- a/src/core/census/grpc_filter.c
+++ b/src/core/census/grpc_filter.c
@@ -99,7 +99,7 @@ static void
 client_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_transport_stream_op * op)
 {
   client_mutate_op (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 static void
@@ -112,7 +112,7 @@ server_on_done_recv (grpc_exec_ctx * exec_ctx, void *ptr, int success)
     {
       extract_and_annotate_method_tag (calld->recv_ops, calld, chand);
     }
-  calld->on_done_recv->cb (calld->on_done_recv->cb_arg, success, closure_list);
+  calld->on_done_recv->cb (exec_ctx, calld->on_done_recv->cb_arg, success);
 }
 
 static void
@@ -134,7 +134,7 @@ server_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, g
   call_data *calld = elem->call_data;
   GPR_ASSERT ((calld->op_id.upper != 0) || (calld->op_id.lower != 0));
   server_mutate_op (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 static void
diff --git a/src/core/channel/channel_stack.c b/src/core/channel/channel_stack.c
index 07b118f74a..199862dddd 100644
--- a/src/core/channel/channel_stack.c
+++ b/src/core/channel/channel_stack.c
@@ -120,7 +120,7 @@ grpc_channel_stack_init (grpc_exec_ctx * exec_ctx, const grpc_channel_filter **
     {
       elems[i].filter = filters[i];
       elems[i].channel_data = user_data;
-      elems[i].filter->init_channel_elem (&elems[i], master, args, metadata_context, i == 0, i == (filter_count - 1), closure_list);
+      elems[i].filter->init_channel_elem (&elems[i], master, args, metadata_context, i == 0, i == (exec_ctx, filter_count - 1));
       user_data += ROUND_UP_TO_ALIGNMENT_SIZE (filters[i]->sizeof_channel_data);
       call_size += ROUND_UP_TO_ALIGNMENT_SIZE (filters[i]->sizeof_call_data);
     }
@@ -141,7 +141,7 @@ grpc_channel_stack_destroy (grpc_exec_ctx * exec_ctx, grpc_channel_stack * stack
   /* destroy per-filter data */
   for (i = 0; i < count; i++)
     {
-      channel_elems[i].filter->destroy_channel_elem (&channel_elems[i], closure_list);
+      channel_elems[i].filter->destroy_channel_elem (exec_ctx, &channel_elems[i]);
     }
 }
 
@@ -164,7 +164,7 @@ grpc_call_stack_init (grpc_exec_ctx * exec_ctx, grpc_channel_stack * channel_sta
       call_elems[i].filter = channel_elems[i].filter;
       call_elems[i].channel_data = channel_elems[i].channel_data;
       call_elems[i].call_data = user_data;
-      call_elems[i].filter->init_call_elem (&call_elems[i], transport_server_data, initial_op, closure_list);
+      call_elems[i].filter->init_call_elem (exec_ctx, &call_elems[i], transport_server_data, initial_op);
       user_data += ROUND_UP_TO_ALIGNMENT_SIZE (call_elems[i].filter->sizeof_call_data);
     }
 }
@@ -179,7 +179,7 @@ grpc_call_stack_destroy (grpc_exec_ctx * exec_ctx, grpc_call_stack * stack)
   /* destroy per-filter data */
   for (i = 0; i < count; i++)
     {
-      elems[i].filter->destroy_call_elem (&elems[i], closure_list);
+      elems[i].filter->destroy_call_elem (exec_ctx, &elems[i]);
     }
 }
 
@@ -187,21 +187,21 @@ void
 grpc_call_next_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_transport_stream_op * op)
 {
   grpc_call_element *next_elem = elem + 1;
-  next_elem->filter->start_transport_stream_op (next_elem, op, closure_list);
+  next_elem->filter->start_transport_stream_op (exec_ctx, next_elem, op);
 }
 
 char *
 grpc_call_next_get_peer (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
 {
   grpc_call_element *next_elem = elem + 1;
-  return next_elem->filter->get_peer (next_elem, closure_list);
+  return next_elem->filter->get_peer (exec_ctx, next_elem);
 }
 
 void
 grpc_channel_next_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, grpc_transport_op * op)
 {
   grpc_channel_element *next_elem = elem + 1;
-  next_elem->filter->start_transport_op (next_elem, op, closure_list);
+  next_elem->filter->start_transport_op (exec_ctx, next_elem, op);
 }
 
 grpc_channel_stack *
@@ -222,5 +222,5 @@ grpc_call_element_send_cancel (grpc_exec_ctx * exec_ctx, grpc_call_element * cur
   grpc_transport_stream_op op;
   memset (&op, 0, sizeof (op));
   op.cancel_with_status = GRPC_STATUS_CANCELLED;
-  grpc_call_next_op (cur_elem, &op, closure_list);
+  grpc_call_next_op (exec_ctx, cur_elem, &op);
 }
diff --git a/src/core/channel/client_channel.c b/src/core/channel/client_channel.c
index d0be3ca7b6..9a7c1c77ca 100644
--- a/src/core/channel/client_channel.c
+++ b/src/core/channel/client_channel.c
@@ -138,7 +138,7 @@ merge_into_waiting_op (grpc_call_element * elem, grpc_transport_stream_op * new_
   if (op->send_ops)
     {
       grpc_stream_ops_unref_owned_objects (op->send_ops->ops, op->send_ops->nops);
-      op->on_done_send->cb (op->on_done_send->cb_arg, 0, closure_list);
+      op->on_done_send->cb (exec_ctx, op->on_done_send->cb_arg, 0);
     }
   if (op->recv_ops)
     {
@@ -156,11 +156,11 @@ merge_into_waiting_op (grpc_call_element * elem, grpc_transport_stream_op * new_
       mdb.deadline = gpr_inf_future (GPR_CLOCK_REALTIME);
       grpc_sopb_add_metadata (op->recv_ops, mdb);
       *op->recv_state = GRPC_STREAM_CLOSED;
-      op->on_done_recv->cb (op->on_done_recv->cb_arg, 1, closure_list);
+      op->on_done_recv->cb (exec_ctx, op->on_done_recv->cb_arg, 1);
     }
   if (op->on_consumed)
     {
-      op->on_consumed->cb (op->on_consumed->cb_arg, 0, closure_list);
+      op->on_consumed->cb (exec_ctx, op->on_consumed->cb_arg, 0);
     }
 }
 
@@ -177,7 +177,7 @@ continue_with_pick (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 {
   waiting_call *wc = arg;
   call_data *calld = wc->elem->call_data;
-  perform_transport_stream_op (wc->elem, &calld->waiting_op, 1, closure_list);
+  perform_transport_stream_op (exec_ctx, wc->elem, &calld->waiting_op, 1);
   gpr_free (wc);
 }
 
@@ -217,7 +217,7 @@ started_call (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
       memset (&op, 0, sizeof (op));
       op.cancel_with_status = GRPC_STATUS_CANCELLED;
       gpr_mu_unlock (&calld->mu_state);
-      grpc_subchannel_call_process_op (calld->subchannel_call, &op, closure_list);
+      grpc_subchannel_call_process_op (exec_ctx, calld->subchannel_call, &op);
     }
   else if (calld->state == CALL_WAITING_FOR_CALL)
     {
@@ -228,7 +228,7 @@ started_call (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	  gpr_mu_unlock (&calld->mu_state);
 	  if (have_waiting)
 	    {
-	      grpc_subchannel_call_process_op (calld->subchannel_call, &calld->waiting_op, closure_list);
+	      grpc_subchannel_call_process_op (exec_ctx, calld->subchannel_call, &calld->waiting_op);
 	    }
 	}
       else
@@ -237,7 +237,7 @@ started_call (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	  gpr_mu_unlock (&calld->mu_state);
 	  if (have_waiting)
 	    {
-	      handle_op_after_cancellation (calld->elem, &calld->waiting_op, closure_list);
+	      handle_op_after_cancellation (exec_ctx, calld->elem, &calld->waiting_op);
 	    }
 	}
     }
@@ -258,7 +258,7 @@ picked_target (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
     {
       /* treat this like a cancellation */
       calld->waiting_op.cancel_with_status = GRPC_STATUS_UNAVAILABLE;
-      perform_transport_stream_op (calld->elem, &calld->waiting_op, 1, closure_list);
+      perform_transport_stream_op (exec_ctx, calld->elem, &calld->waiting_op, 1);
     }
   else
     {
@@ -266,7 +266,7 @@ picked_target (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
       if (calld->state == CALL_CANCELLED)
 	{
 	  gpr_mu_unlock (&calld->mu_state);
-	  handle_op_after_cancellation (calld->elem, &calld->waiting_op, closure_list);
+	  handle_op_after_cancellation (exec_ctx, calld->elem, &calld->waiting_op);
 	}
       else
 	{
@@ -275,7 +275,7 @@ picked_target (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	  pollset = calld->waiting_op.bind_pollset;
 	  gpr_mu_unlock (&calld->mu_state);
 	  grpc_closure_init (&calld->async_setup_task, started_call, calld);
-	  grpc_subchannel_create_call (calld->picked_channel, pollset, &calld->subchannel_call, &calld->async_setup_task, closure_list);
+	  grpc_subchannel_create_call (exec_ctx, calld->picked_channel, pollset, &calld->subchannel_call, &calld->async_setup_task);
 	}
     }
 }
@@ -329,8 +329,8 @@ cc_get_peer (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
       subchannel_call = calld->subchannel_call;
       GRPC_SUBCHANNEL_CALL_REF (subchannel_call, "get_peer");
       gpr_mu_unlock (&calld->mu_state);
-      result = grpc_subchannel_call_get_peer (subchannel_call, closure_list);
-      GRPC_SUBCHANNEL_CALL_UNREF (subchannel_call, "get_peer", closure_list);
+      result = grpc_subchannel_call_get_peer (exec_ctx, subchannel_call);
+      GRPC_SUBCHANNEL_CALL_UNREF (exec_ctx, subchannel_call, "get_peer");
       return result;
     }
   else
@@ -358,11 +358,11 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
       GPR_ASSERT (!continuation);
       subchannel_call = calld->subchannel_call;
       gpr_mu_unlock (&calld->mu_state);
-      grpc_subchannel_call_process_op (subchannel_call, op, closure_list);
+      grpc_subchannel_call_process_op (exec_ctx, subchannel_call, op);
       break;
     case CALL_CANCELLED:
       gpr_mu_unlock (&calld->mu_state);
-      handle_op_after_cancellation (elem, op, closure_list);
+      handle_op_after_cancellation (exec_ctx, elem, op);
       break;
     case CALL_WAITING_FOR_SEND:
       GPR_ASSERT (!continuation);
@@ -397,8 +397,8 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 		  op2.on_consumed = NULL;
 		}
 	      gpr_mu_unlock (&calld->mu_state);
-	      handle_op_after_cancellation (elem, op, closure_list);
-	      handle_op_after_cancellation (elem, &op2, closure_list);
+	      handle_op_after_cancellation (exec_ctx, elem, op);
+	      handle_op_after_cancellation (exec_ctx, elem, &op2);
 	    }
 	  else
 	    {
@@ -413,7 +413,7 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 	{
 	  calld->state = CALL_CANCELLED;
 	  gpr_mu_unlock (&calld->mu_state);
-	  handle_op_after_cancellation (elem, op, closure_list);
+	  handle_op_after_cancellation (exec_ctx, elem, op);
 	}
       else
 	{
@@ -446,9 +446,9 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 		  gpr_mu_unlock (&calld->mu_state);
 
 		  grpc_closure_init (&calld->async_setup_task, picked_target, calld);
-		  grpc_lb_policy_pick (lb_policy, bind_pollset, initial_metadata, &calld->picked_channel, &calld->async_setup_task, closure_list);
+		  grpc_lb_policy_pick (exec_ctx, lb_policy, bind_pollset, initial_metadata, &calld->picked_channel, &calld->async_setup_task);
 
-		  GRPC_LB_POLICY_UNREF (lb_policy, "pick", closure_list);
+		  GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "pick");
 		}
 	      else if (chand->resolver != NULL)
 		{
@@ -458,7 +458,7 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 		    {
 		      GRPC_CHANNEL_INTERNAL_REF (chand->master, "resolver");
 		      chand->started_resolving = 1;
-		      grpc_resolver_next (chand->resolver, &chand->incoming_configuration, &chand->on_config_changed, closure_list);
+		      grpc_resolver_next (exec_ctx, chand->resolver, &chand->incoming_configuration, &chand->on_config_changed);
 		    }
 		  gpr_mu_unlock (&chand->mu_config);
 		  gpr_mu_unlock (&calld->mu_state);
@@ -468,7 +468,7 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 		  calld->state = CALL_CANCELLED;
 		  gpr_mu_unlock (&chand->mu_config);
 		  gpr_mu_unlock (&calld->mu_state);
-		  handle_op_after_cancellation (elem, op, closure_list);
+		  handle_op_after_cancellation (exec_ctx, elem, op);
 		}
 	    }
 	}
@@ -479,7 +479,7 @@ perform_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem,
 static void
 cc_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_transport_stream_op * op)
 {
-  perform_transport_stream_op (elem, op, 0, closure_list);
+  perform_transport_stream_op (exec_ctx, elem, op, 0);
 }
 
 static void watch_lb_policy (channel_data * chand, grpc_lb_policy * lb_policy, grpc_connectivity_state current_state, grpc_closure_list * cl);
@@ -504,10 +504,10 @@ on_lb_policy_state_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_succe
   lb_policy_connectivity_watcher *w = arg;
 
   gpr_mu_lock (&w->chand->mu_config);
-  on_lb_policy_state_changed_locked (w, closure_list);
+  on_lb_policy_state_changed_locked (exec_ctx, w);
   gpr_mu_unlock (&w->chand->mu_config);
 
-  GRPC_CHANNEL_INTERNAL_UNREF (w->chand->master, "watch_lb_policy", closure_list);
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, w->chand->master, "watch_lb_policy");
   gpr_free (w);
 }
 
@@ -521,7 +521,7 @@ watch_lb_policy (grpc_exec_ctx * exec_ctx, channel_data * chand, grpc_lb_policy
   grpc_closure_init (&w->on_changed, on_lb_policy_state_changed, w);
   w->state = current_state;
   w->lb_policy = lb_policy;
-  grpc_lb_policy_notify_on_state_change (lb_policy, &w->state, &w->on_changed, closure_list);
+  grpc_lb_policy_notify_on_state_change (exec_ctx, lb_policy, &w->state, &w->on_changed);
 }
 
 static void
@@ -541,10 +541,10 @@ cc_on_config_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	{
 	  GRPC_LB_POLICY_REF (lb_policy, "channel");
 	  GRPC_LB_POLICY_REF (lb_policy, "config_change");
-	  state = grpc_lb_policy_check_connectivity (lb_policy, closure_list);
+	  state = grpc_lb_policy_check_connectivity (exec_ctx, lb_policy);
 	}
 
-      grpc_client_config_unref (chand->incoming_configuration, closure_list);
+      grpc_client_config_unref (exec_ctx, chand->incoming_configuration);
     }
 
   chand->incoming_configuration = NULL;
@@ -554,7 +554,7 @@ cc_on_config_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
   chand->lb_policy = lb_policy;
   if (lb_policy != NULL || chand->resolver == NULL /* disconnected */ )
     {
-      grpc_closure_list_move (&chand->waiting_for_config_closures, closure_list);
+      grpc_closure_list_move (exec_ctx, &chand->waiting_for_config_closures);
     }
   if (lb_policy != NULL && chand->exit_idle_when_lb_policy_arrives)
     {
@@ -567,47 +567,47 @@ cc_on_config_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
     {
       grpc_resolver *resolver = chand->resolver;
       GRPC_RESOLVER_REF (resolver, "channel-next");
-      grpc_connectivity_state_set (&chand->state_tracker, state, "new_lb+resolver", closure_list);
+      grpc_connectivity_state_set (exec_ctx, &chand->state_tracker, state, "new_lb+resolver");
       if (lb_policy != NULL)
 	{
-	  watch_lb_policy (chand, lb_policy, state, closure_list);
+	  watch_lb_policy (exec_ctx, chand, lb_policy, state);
 	}
       gpr_mu_unlock (&chand->mu_config);
       GRPC_CHANNEL_INTERNAL_REF (chand->master, "resolver");
-      grpc_resolver_next (resolver, &chand->incoming_configuration, &chand->on_config_changed, closure_list);
-      GRPC_RESOLVER_UNREF (resolver, "channel-next", closure_list);
+      grpc_resolver_next (exec_ctx, resolver, &chand->incoming_configuration, &chand->on_config_changed);
+      GRPC_RESOLVER_UNREF (exec_ctx, resolver, "channel-next");
     }
   else
     {
       old_resolver = chand->resolver;
       chand->resolver = NULL;
-      grpc_connectivity_state_set (&chand->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone", closure_list);
+      grpc_connectivity_state_set (exec_ctx, &chand->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
       gpr_mu_unlock (&chand->mu_config);
       if (old_resolver != NULL)
 	{
-	  grpc_resolver_shutdown (old_resolver, closure_list);
-	  GRPC_RESOLVER_UNREF (old_resolver, "channel", closure_list);
+	  grpc_resolver_shutdown (exec_ctx, old_resolver);
+	  GRPC_RESOLVER_UNREF (exec_ctx, old_resolver, "channel");
 	}
     }
 
   if (exit_idle)
     {
-      grpc_lb_policy_exit_idle (lb_policy, closure_list);
-      GRPC_LB_POLICY_UNREF (lb_policy, "exit_idle", closure_list);
+      grpc_lb_policy_exit_idle (exec_ctx, lb_policy);
+      GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "exit_idle");
     }
 
   if (old_lb_policy != NULL)
     {
-      grpc_lb_policy_shutdown (old_lb_policy, closure_list);
-      GRPC_LB_POLICY_UNREF (old_lb_policy, "channel", closure_list);
+      grpc_lb_policy_shutdown (exec_ctx, old_lb_policy);
+      GRPC_LB_POLICY_UNREF (exec_ctx, old_lb_policy, "channel");
     }
 
   if (lb_policy != NULL)
     {
-      GRPC_LB_POLICY_UNREF (lb_policy, "config_change", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "config_change");
     }
 
-  GRPC_CHANNEL_INTERNAL_UNREF (chand->master, "resolver", closure_list);
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, chand->master, "resolver");
 }
 
 static void
@@ -625,7 +625,7 @@ cc_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, gr
   gpr_mu_lock (&chand->mu_config);
   if (op->on_connectivity_state_change != NULL)
     {
-      grpc_connectivity_state_notify_on_state_change (&chand->state_tracker, op->connectivity_state, op->on_connectivity_state_change, closure_list);
+      grpc_connectivity_state_notify_on_state_change (exec_ctx, &chand->state_tracker, op->connectivity_state, op->on_connectivity_state_change);
       op->on_connectivity_state_change = NULL;
       op->connectivity_state = NULL;
     }
@@ -641,13 +641,13 @@ cc_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, gr
 
   if (op->disconnect && chand->resolver != NULL)
     {
-      grpc_connectivity_state_set (&chand->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "disconnect", closure_list);
+      grpc_connectivity_state_set (exec_ctx, &chand->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
       destroy_resolver = chand->resolver;
       chand->resolver = NULL;
       if (chand->lb_policy != NULL)
 	{
-	  grpc_lb_policy_shutdown (chand->lb_policy, closure_list);
-	  GRPC_LB_POLICY_UNREF (chand->lb_policy, "channel", closure_list);
+	  grpc_lb_policy_shutdown (exec_ctx, chand->lb_policy);
+	  GRPC_LB_POLICY_UNREF (exec_ctx, chand->lb_policy, "channel");
 	  chand->lb_policy = NULL;
 	}
     }
@@ -655,14 +655,14 @@ cc_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, gr
 
   if (destroy_resolver)
     {
-      grpc_resolver_shutdown (destroy_resolver, closure_list);
-      GRPC_RESOLVER_UNREF (destroy_resolver, "channel", closure_list);
+      grpc_resolver_shutdown (exec_ctx, destroy_resolver);
+      GRPC_RESOLVER_UNREF (exec_ctx, destroy_resolver, "channel");
     }
 
   if (lb_policy)
     {
-      grpc_lb_policy_broadcast (lb_policy, op, closure_list);
-      GRPC_LB_POLICY_UNREF (lb_policy, "broadcast", closure_list);
+      grpc_lb_policy_broadcast (exec_ctx, lb_policy, op);
+      GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "broadcast");
     }
 }
 
@@ -699,7 +699,7 @@ destroy_call_elem (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
     case CALL_ACTIVE:
       subchannel_call = calld->subchannel_call;
       gpr_mu_unlock (&calld->mu_state);
-      GRPC_SUBCHANNEL_CALL_UNREF (subchannel_call, "client_channel", closure_list);
+      GRPC_SUBCHANNEL_CALL_UNREF (exec_ctx, subchannel_call, "client_channel");
       break;
     case CALL_CREATED:
     case CALL_CANCELLED:
@@ -743,14 +743,14 @@ destroy_channel_elem (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem)
 
   if (chand->resolver != NULL)
     {
-      grpc_resolver_shutdown (chand->resolver, closure_list);
-      GRPC_RESOLVER_UNREF (chand->resolver, "channel", closure_list);
+      grpc_resolver_shutdown (exec_ctx, chand->resolver);
+      GRPC_RESOLVER_UNREF (exec_ctx, chand->resolver, "channel");
     }
   if (chand->lb_policy != NULL)
     {
-      GRPC_LB_POLICY_UNREF (chand->lb_policy, "channel", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, chand->lb_policy, "channel");
     }
-  grpc_connectivity_state_destroy (&chand->state_tracker, closure_list);
+  grpc_connectivity_state_destroy (exec_ctx, &chand->state_tracker);
   grpc_pollset_set_destroy (&chand->pollset_set);
   gpr_mu_destroy (&chand->mu_config);
 }
@@ -782,7 +782,7 @@ grpc_client_channel_set_resolver (grpc_exec_ctx * exec_ctx, grpc_channel_stack *
     {
       chand->started_resolving = 1;
       GRPC_CHANNEL_INTERNAL_REF (chand->master, "resolver");
-      grpc_resolver_next (resolver, &chand->incoming_configuration, &chand->on_config_changed, closure_list);
+      grpc_resolver_next (exec_ctx, resolver, &chand->incoming_configuration, &chand->on_config_changed);
     }
   gpr_mu_unlock (&chand->mu_config);
 }
@@ -798,7 +798,7 @@ grpc_client_channel_check_connectivity_state (grpc_exec_ctx * exec_ctx, grpc_cha
     {
       if (chand->lb_policy != NULL)
 	{
-	  grpc_lb_policy_exit_idle (chand->lb_policy, closure_list);
+	  grpc_lb_policy_exit_idle (exec_ctx, chand->lb_policy);
 	}
       else
 	{
@@ -807,7 +807,7 @@ grpc_client_channel_check_connectivity_state (grpc_exec_ctx * exec_ctx, grpc_cha
 	    {
 	      GRPC_CHANNEL_INTERNAL_REF (chand->master, "resolver");
 	      chand->started_resolving = 1;
-	      grpc_resolver_next (chand->resolver, &chand->incoming_configuration, &chand->on_config_changed, closure_list);
+	      grpc_resolver_next (exec_ctx, chand->resolver, &chand->incoming_configuration, &chand->on_config_changed);
 	    }
 	}
     }
@@ -820,7 +820,7 @@ grpc_client_channel_watch_connectivity_state (grpc_exec_ctx * exec_ctx, grpc_cha
 {
   channel_data *chand = elem->channel_data;
   gpr_mu_lock (&chand->mu_config);
-  grpc_connectivity_state_notify_on_state_change (&chand->state_tracker, state, on_complete, closure_list);
+  grpc_connectivity_state_notify_on_state_change (exec_ctx, &chand->state_tracker, state, on_complete);
   gpr_mu_unlock (&chand->mu_config);
 }
 
@@ -835,12 +835,12 @@ void
 grpc_client_channel_add_interested_party (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, grpc_pollset * pollset)
 {
   channel_data *chand = elem->channel_data;
-  grpc_pollset_set_add_pollset (&chand->pollset_set, pollset, closure_list);
+  grpc_pollset_set_add_pollset (exec_ctx, &chand->pollset_set, pollset);
 }
 
 void
 grpc_client_channel_del_interested_party (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, grpc_pollset * pollset)
 {
   channel_data *chand = elem->channel_data;
-  grpc_pollset_set_del_pollset (&chand->pollset_set, pollset, closure_list);
+  grpc_pollset_set_del_pollset (exec_ctx, &chand->pollset_set, pollset);
 }
diff --git a/src/core/channel/compress_filter.c b/src/core/channel/compress_filter.c
index bf3c5a9457..6acdc72075 100644
--- a/src/core/channel/compress_filter.c
+++ b/src/core/channel/compress_filter.c
@@ -283,7 +283,7 @@ compress_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element
     }
 
   /* pass control down the stack */
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/channel/connected_channel.c b/src/core/channel/connected_channel.c
index 2fd80d2207..71d18849f2 100644
--- a/src/core/channel/connected_channel.c
+++ b/src/core/channel/connected_channel.c
@@ -73,14 +73,14 @@ con_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * ele
   GPR_ASSERT (elem->filter == &grpc_connected_channel_filter);
   GRPC_CALL_LOG_OP (GPR_INFO, elem, op);
 
-  grpc_transport_perform_stream_op (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (calld), op, closure_list);
+  grpc_transport_perform_stream_op (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (exec_ctx, calld), op);
 }
 
 static void
 con_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem, grpc_transport_op * op)
 {
   channel_data *chand = elem->channel_data;
-  grpc_transport_perform_op (chand->transport, op, closure_list);
+  grpc_transport_perform_op (exec_ctx, chand->transport, op);
 }
 
 /* Constructor for call_data */
@@ -92,7 +92,7 @@ init_call_elem (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, const void *
   int r;
 
   GPR_ASSERT (elem->filter == &grpc_connected_channel_filter);
-  r = grpc_transport_init_stream (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (calld), server_transport_data, initial_op, closure_list);
+  r = grpc_transport_init_stream (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (exec_ctx, calld), server_transport_data, initial_op);
   GPR_ASSERT (r == 0);
 }
 
@@ -103,7 +103,7 @@ destroy_call_elem (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   GPR_ASSERT (elem->filter == &grpc_connected_channel_filter);
-  grpc_transport_destroy_stream (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (calld), closure_list);
+  grpc_transport_destroy_stream (chand->transport, TRANSPORT_STREAM_FROM_CALL_DATA (exec_ctx, calld));
 }
 
 /* Constructor for channel_data */
@@ -122,14 +122,14 @@ destroy_channel_elem (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem)
 {
   channel_data *cd = (channel_data *) elem->channel_data;
   GPR_ASSERT (elem->filter == &grpc_connected_channel_filter);
-  grpc_transport_destroy (cd->transport, closure_list);
+  grpc_transport_destroy (exec_ctx, cd->transport);
 }
 
 static char *
 con_get_peer (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
 {
   channel_data *chand = elem->channel_data;
-  return grpc_transport_get_peer (chand->transport, closure_list);
+  return grpc_transport_get_peer (exec_ctx, chand->transport);
 }
 
 const grpc_channel_filter grpc_connected_channel_filter = {
diff --git a/src/core/channel/http_client_filter.c b/src/core/channel/http_client_filter.c
index b2cc69bb4a..7c8d7c0240 100644
--- a/src/core/channel/http_client_filter.c
+++ b/src/core/channel/http_client_filter.c
@@ -116,7 +116,7 @@ hc_on_recv (grpc_exec_ctx * exec_ctx, void *user_data, int success)
       a.closure_list = closure_list;
       grpc_metadata_batch_filter (&op->data.metadata, client_recv_filter, &a);
     }
-  calld->on_done_recv->cb (calld->on_done_recv->cb_arg, success, closure_list);
+  calld->on_done_recv->cb (exec_ctx, calld->on_done_recv->cb_arg, success);
 }
 
 static grpc_mdelem *
@@ -181,7 +181,7 @@ hc_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_
 {
   GRPC_CALL_LOG_OP (GPR_INFO, elem, op);
   hc_mutate_op (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/channel/http_server_filter.c b/src/core/channel/http_server_filter.c
index 62be4167f7..6c5902e426 100644
--- a/src/core/channel/http_server_filter.c
+++ b/src/core/channel/http_server_filter.c
@@ -219,11 +219,11 @@ hs_on_recv (grpc_exec_ctx * exec_ctx, void *user_data, int success)
 		}
 	      /* Error this call out */
 	      success = 0;
-	      grpc_call_element_send_cancel (elem, closure_list);
+	      grpc_call_element_send_cancel (exec_ctx, elem);
 	    }
 	}
     }
-  calld->on_done_recv->cb (calld->on_done_recv->cb_arg, success, closure_list);
+  calld->on_done_recv->cb (exec_ctx, calld->on_done_recv->cb_arg, success);
 }
 
 static void
@@ -264,7 +264,7 @@ hs_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_
 {
   GRPC_CALL_LOG_OP (GPR_INFO, elem, op);
   hs_mutate_op (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/channel/noop_filter.c b/src/core/channel/noop_filter.c
index 3a3f1254bd..7e566642f9 100644
--- a/src/core/channel/noop_filter.c
+++ b/src/core/channel/noop_filter.c
@@ -74,7 +74,7 @@ noop_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * el
   noop_mutate_op (elem, op);
 
   /* pass control down the stack */
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/client_config/client_config.c b/src/core/client_config/client_config.c
index ceb52e93e5..fc6448201f 100644
--- a/src/core/client_config/client_config.c
+++ b/src/core/client_config/client_config.c
@@ -63,7 +63,7 @@ grpc_client_config_unref (grpc_exec_ctx * exec_ctx, grpc_client_config * c)
 {
   if (gpr_unref (&c->refs))
     {
-      GRPC_LB_POLICY_UNREF (c->lb_policy, "client_config", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, c->lb_policy, "client_config");
       gpr_free (c);
     }
 }
diff --git a/src/core/client_config/connector.c b/src/core/client_config/connector.c
index 823b82af5c..209c3f1767 100644
--- a/src/core/client_config/connector.c
+++ b/src/core/client_config/connector.c
@@ -42,17 +42,17 @@ grpc_connector_ref (grpc_connector * connector)
 void
 grpc_connector_unref (grpc_exec_ctx * exec_ctx, grpc_connector * connector)
 {
-  connector->vtable->unref (connector, closure_list);
+  connector->vtable->unref (exec_ctx, connector);
 }
 
 void
 grpc_connector_connect (grpc_exec_ctx * exec_ctx, 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, closure_list);
+  connector->vtable->connect (exec_ctx, connector, in_args, out_args, notify);
 }
 
 void
 grpc_connector_shutdown (grpc_exec_ctx * exec_ctx, grpc_connector * connector)
 {
-  connector->vtable->shutdown (connector, closure_list);
+  connector->vtable->shutdown (exec_ctx, connector);
 }
diff --git a/src/core/client_config/lb_policies/pick_first.c b/src/core/client_config/lb_policies/pick_first.c
index 02aaac1dc3..c07cc81b27 100644
--- a/src/core/client_config/lb_policies/pick_first.c
+++ b/src/core/client_config/lb_policies/pick_first.c
@@ -84,7 +84,7 @@ del_interested_parties_locked (grpc_exec_ctx * exec_ctx, pick_first_lb_policy *
   pending_pick *pp;
   for (pp = p->pending_picks; pp; pp = pp->next)
     {
-      grpc_subchannel_del_interested_party (p->subchannels[p->checking_subchannel], pp->pollset, closure_list);
+      grpc_subchannel_del_interested_party (exec_ctx, p->subchannels[p->checking_subchannel], pp->pollset);
     }
 }
 
@@ -94,7 +94,7 @@ add_interested_parties_locked (grpc_exec_ctx * exec_ctx, pick_first_lb_policy *
   pending_pick *pp;
   for (pp = p->pending_picks; pp; pp = pp->next)
     {
-      grpc_subchannel_add_interested_party (p->subchannels[p->checking_subchannel], pp->pollset, closure_list);
+      grpc_subchannel_add_interested_party (exec_ctx, p->subchannels[p->checking_subchannel], pp->pollset);
     }
 }
 
@@ -106,9 +106,9 @@ pf_destroy (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
   GPR_ASSERT (p->pending_picks == NULL);
   for (i = 0; i < p->num_subchannels; i++)
     {
-      GRPC_SUBCHANNEL_UNREF (p->subchannels[i], "pick_first", closure_list);
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, p->subchannels[i], "pick_first");
     }
-  grpc_connectivity_state_destroy (&p->state_tracker, closure_list);
+  grpc_connectivity_state_destroy (exec_ctx, &p->state_tracker);
   gpr_free (p->subchannels);
   gpr_mu_destroy (&p->mu);
   gpr_free (p);
@@ -120,11 +120,11 @@ pf_shutdown (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
   pick_first_lb_policy *p = (pick_first_lb_policy *) pol;
   pending_pick *pp;
   gpr_mu_lock (&p->mu);
-  del_interested_parties_locked (p, closure_list);
+  del_interested_parties_locked (exec_ctx, p);
   p->shutdown = 1;
   pp = p->pending_picks;
   p->pending_picks = NULL;
-  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "shutdown", closure_list);
+  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
   gpr_mu_unlock (&p->mu);
   while (pp != NULL)
     {
@@ -143,7 +143,7 @@ start_picking (grpc_exec_ctx * exec_ctx, pick_first_lb_policy * p)
   p->checking_subchannel = 0;
   p->checking_connectivity = GRPC_CHANNEL_IDLE;
   GRPC_LB_POLICY_REF (&p->base, "pick_first_connectivity");
-  grpc_subchannel_notify_on_state_change (p->subchannels[p->checking_subchannel], &p->checking_connectivity, &p->connectivity_changed, closure_list);
+  grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[p->checking_subchannel], &p->checking_connectivity, &p->connectivity_changed);
 }
 
 void
@@ -153,7 +153,7 @@ pf_exit_idle (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
   gpr_mu_lock (&p->mu);
   if (!p->started_picking)
     {
-      start_picking (p, closure_list);
+      start_picking (exec_ctx, p);
     }
   gpr_mu_unlock (&p->mu);
 }
@@ -174,9 +174,9 @@ pf_pick (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_pollset * pollset,
     {
       if (!p->started_picking)
 	{
-	  start_picking (p, closure_list);
+	  start_picking (exec_ctx, p);
 	}
-      grpc_subchannel_add_interested_party (p->subchannels[p->checking_subchannel], pollset, closure_list);
+      grpc_subchannel_add_interested_party (exec_ctx, p->subchannels[p->checking_subchannel], pollset);
       pp = gpr_malloc (sizeof (*pp));
       pp->next = p->pending_picks;
       pp->pollset = pollset;
@@ -198,19 +198,19 @@ pf_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
   if (p->shutdown)
     {
       gpr_mu_unlock (&p->mu);
-      GRPC_LB_POLICY_UNREF (&p->base, "pick_first_connectivity", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, &p->base, "pick_first_connectivity");
       return;
     }
   else if (p->selected != NULL)
     {
-      grpc_connectivity_state_set (&p->state_tracker, p->checking_connectivity, "selected_changed", closure_list);
+      grpc_connectivity_state_set (exec_ctx, &p->state_tracker, p->checking_connectivity, "selected_changed");
       if (p->checking_connectivity != GRPC_CHANNEL_FATAL_FAILURE)
 	{
-	  grpc_subchannel_notify_on_state_change (p->selected, &p->checking_connectivity, &p->connectivity_changed, closure_list);
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->selected, &p->checking_connectivity, &p->connectivity_changed);
 	}
       else
 	{
-	  GRPC_LB_POLICY_UNREF (&p->base, "pick_first_connectivity", closure_list);
+	  GRPC_LB_POLICY_UNREF (exec_ctx, &p->base, "pick_first_connectivity");
 	}
     }
   else
@@ -219,27 +219,27 @@ pf_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
       switch (p->checking_connectivity)
 	{
 	case GRPC_CHANNEL_READY:
-	  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_READY, "connecting_ready", closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_READY, "connecting_ready");
 	  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, closure_list);
+	      grpc_subchannel_del_interested_party (exec_ctx, p->selected, pp->pollset);
 	      grpc_closure_list_add (closure_list, pp->on_complete, 1);
 	      gpr_free (pp);
 	    }
-	  grpc_subchannel_notify_on_state_change (p->selected, &p->checking_connectivity, &p->connectivity_changed, closure_list);
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->selected, &p->checking_connectivity, &p->connectivity_changed);
 	  break;
 	case GRPC_CHANNEL_TRANSIENT_FAILURE:
-	  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "connecting_transient_failure", closure_list);
-	  del_interested_parties_locked (p, closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "connecting_transient_failure");
+	  del_interested_parties_locked (exec_ctx, p);
 	  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, closure_list);
+	  add_interested_parties_locked (exec_ctx, p);
 	  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, closure_list);
+	      grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[p->checking_subchannel], &p->checking_connectivity, &p->connectivity_changed);
 	    }
 	  else
 	    {
@@ -248,17 +248,17 @@ pf_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	  break;
 	case GRPC_CHANNEL_CONNECTING:
 	case GRPC_CHANNEL_IDLE:
-	  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_CONNECTING, "connecting_changed", closure_list);
-	  grpc_subchannel_notify_on_state_change (p->subchannels[p->checking_subchannel], &p->checking_connectivity, &p->connectivity_changed, closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_CONNECTING, "connecting_changed");
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[p->checking_subchannel], &p->checking_connectivity, &p->connectivity_changed);
 	  break;
 	case GRPC_CHANNEL_FATAL_FAILURE:
-	  del_interested_parties_locked (p, closure_list);
+	  del_interested_parties_locked (exec_ctx, p);
 	  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", closure_list);
+	  GRPC_SUBCHANNEL_UNREF (exec_ctx, p->subchannels[p->num_subchannels], "pick_first");
 	  if (p->num_subchannels == 0)
 	    {
-	      grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "no_more_channels", closure_list);
+	      grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "no_more_channels");
 	      while ((pp = p->pending_picks))
 		{
 		  p->pending_picks = pp->next;
@@ -266,14 +266,14 @@ pf_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 		  grpc_closure_list_add (closure_list, pp->on_complete, 1);
 		  gpr_free (pp);
 		}
-	      GRPC_LB_POLICY_UNREF (&p->base, "pick_first_connectivity", closure_list);
+	      GRPC_LB_POLICY_UNREF (exec_ctx, &p->base, "pick_first_connectivity");
 	    }
 	  else
 	    {
-	      grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "subchannel_failed", closure_list);
+	      grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "subchannel_failed");
 	      p->checking_subchannel %= p->num_subchannels;
 	      p->checking_connectivity = grpc_subchannel_check_connectivity (p->subchannels[p->checking_subchannel]);
-	      add_interested_parties_locked (p, closure_list);
+	      add_interested_parties_locked (exec_ctx, p);
 	      goto loop;
 	    }
 	}
@@ -302,8 +302,8 @@ pf_broadcast (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_transport_op
 
   for (i = 0; i < n; i++)
     {
-      grpc_subchannel_process_transport_op (subchannels[i], op, closure_list);
-      GRPC_SUBCHANNEL_UNREF (subchannels[i], "pf_broadcast", closure_list);
+      grpc_subchannel_process_transport_op (exec_ctx, subchannels[i], op);
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, subchannels[i], "pf_broadcast");
     }
   gpr_free (subchannels);
 }
@@ -324,7 +324,7 @@ pf_notify_on_state_change (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_
 {
   pick_first_lb_policy *p = (pick_first_lb_policy *) pol;
   gpr_mu_lock (&p->mu);
-  grpc_connectivity_state_notify_on_state_change (&p->state_tracker, current, notify, closure_list);
+  grpc_connectivity_state_notify_on_state_change (exec_ctx, &p->state_tracker, current, notify);
   gpr_mu_unlock (&p->mu);
 }
 
diff --git a/src/core/client_config/lb_policies/round_robin.c b/src/core/client_config/lb_policies/round_robin.c
index 959d9e1c32..b745628bbc 100644
--- a/src/core/client_config/lb_policies/round_robin.c
+++ b/src/core/client_config/lb_policies/round_robin.c
@@ -233,7 +233,7 @@ del_interested_parties_locked (grpc_exec_ctx * exec_ctx, round_robin_lb_policy *
   pending_pick *pp;
   for (pp = p->pending_picks; pp; pp = pp->next)
     {
-      grpc_subchannel_del_interested_party (p->subchannels[subchannel_idx], pp->pollset, closure_list);
+      grpc_subchannel_del_interested_party (exec_ctx, p->subchannels[subchannel_idx], pp->pollset);
     }
 }
 
@@ -245,16 +245,16 @@ rr_destroy (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
   ready_list *elem;
   for (i = 0; i < p->num_subchannels; i++)
     {
-      del_interested_parties_locked (p, i, closure_list);
+      del_interested_parties_locked (exec_ctx, p, i);
     }
   for (i = 0; i < p->num_subchannels; i++)
     {
-      GRPC_SUBCHANNEL_UNREF (p->subchannels[i], "round_robin", closure_list);
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, p->subchannels[i], "round_robin");
     }
   gpr_free (p->connectivity_changed_cbs);
   gpr_free (p->subchannel_connectivity);
 
-  grpc_connectivity_state_destroy (&p->state_tracker, closure_list);
+  grpc_connectivity_state_destroy (exec_ctx, &p->state_tracker);
   gpr_free (p->subchannels);
   gpr_mu_destroy (&p->mu);
 
@@ -284,7 +284,7 @@ rr_shutdown (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
 
   for (i = 0; i < p->num_subchannels; i++)
     {
-      del_interested_parties_locked (p, i, closure_list);
+      del_interested_parties_locked (exec_ctx, p, i);
     }
 
   p->shutdown = 1;
@@ -295,7 +295,7 @@ rr_shutdown (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
       grpc_closure_list_add (closure_list, pp->on_complete, 0);
       gpr_free (pp);
     }
-  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "shutdown", closure_list);
+  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "shutdown");
   gpr_mu_unlock (&p->mu);
 }
 
@@ -308,7 +308,7 @@ start_picking (grpc_exec_ctx * exec_ctx, round_robin_lb_policy * p)
   for (i = 0; i < p->num_subchannels; i++)
     {
       p->subchannel_connectivity[i] = GRPC_CHANNEL_IDLE;
-      grpc_subchannel_notify_on_state_change (p->subchannels[i], &p->subchannel_connectivity[i], &p->connectivity_changed_cbs[i], closure_list);
+      grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[i], &p->subchannel_connectivity[i], &p->connectivity_changed_cbs[i]);
       GRPC_LB_POLICY_REF (&p->base, "round_robin_connectivity");
     }
 }
@@ -320,7 +320,7 @@ rr_exit_idle (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol)
   gpr_mu_lock (&p->mu);
   if (!p->started_picking)
     {
-      start_picking (p, closure_list);
+      start_picking (exec_ctx, p);
     }
   gpr_mu_unlock (&p->mu);
 }
@@ -343,17 +343,17 @@ rr_pick (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_pollset * pollset,
 	}
       /* only advance the last picked pointer if the selection was used */
       advance_last_picked_locked (p);
-      on_complete->cb (on_complete->cb_arg, 1, closure_list);
+      on_complete->cb (exec_ctx, on_complete->cb_arg, 1);
     }
   else
     {
       if (!p->started_picking)
 	{
-	  start_picking (p, closure_list);
+	  start_picking (exec_ctx, p);
 	}
       for (i = 0; i < p->num_subchannels; i++)
 	{
-	  grpc_subchannel_add_interested_party (p->subchannels[i], pollset, closure_list);
+	  grpc_subchannel_add_interested_party (exec_ctx, p->subchannels[i], pollset);
 	}
       pp = gpr_malloc (sizeof (*pp));
       pp->next = p->pending_picks;
@@ -393,7 +393,7 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
       switch (*this_connectivity)
 	{
 	case GRPC_CHANNEL_READY:
-	  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_READY, "connecting_ready", closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_READY, "connecting_ready");
 	  /* add the newly connected subchannel to the list of connected ones.
 	   * Note that it goes to the "end of the line". */
 	  p->subchannel_index_to_readylist_node[this_idx] = add_connected_sc_locked (p, p->subchannels[this_idx]);
@@ -415,21 +415,21 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 		{
 		  gpr_log (GPR_DEBUG, "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)", selected->subchannel, selected);
 		}
-	      grpc_subchannel_del_interested_party (selected->subchannel, pp->pollset, closure_list);
+	      grpc_subchannel_del_interested_party (exec_ctx, selected->subchannel, pp->pollset);
 	      grpc_closure_list_add (closure_list, pp->on_complete, 1);
 	      gpr_free (pp);
 	    }
-	  grpc_subchannel_notify_on_state_change (p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx], closure_list);
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx]);
 	  break;
 	case GRPC_CHANNEL_CONNECTING:
 	case GRPC_CHANNEL_IDLE:
-	  grpc_connectivity_state_set (&p->state_tracker, *this_connectivity, "connecting_changed", closure_list);
-	  grpc_subchannel_notify_on_state_change (p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx], closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, *this_connectivity, "connecting_changed");
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx]);
 	  break;
 	case GRPC_CHANNEL_TRANSIENT_FAILURE:
-	  del_interested_parties_locked (p, this_idx, closure_list);
+	  del_interested_parties_locked (exec_ctx, p, this_idx);
 	  /* renew state notification */
-	  grpc_subchannel_notify_on_state_change (p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx], closure_list);
+	  grpc_subchannel_notify_on_state_change (exec_ctx, p->subchannels[this_idx], this_connectivity, &p->connectivity_changed_cbs[this_idx]);
 
 	  /* remove from ready list if still present */
 	  if (p->subchannel_index_to_readylist_node[this_idx] != NULL)
@@ -437,10 +437,10 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	      remove_disconnected_sc_locked (p, p->subchannel_index_to_readylist_node[this_idx]);
 	      p->subchannel_index_to_readylist_node[this_idx] = NULL;
 	    }
-	  grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "connecting_transient_failure", closure_list);
+	  grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "connecting_transient_failure");
 	  break;
 	case GRPC_CHANNEL_FATAL_FAILURE:
-	  del_interested_parties_locked (p, this_idx, closure_list);
+	  del_interested_parties_locked (exec_ctx, p, this_idx);
 	  if (p->subchannel_index_to_readylist_node[this_idx] != NULL)
 	    {
 	      remove_disconnected_sc_locked (p, p->subchannel_index_to_readylist_node[this_idx]);
@@ -449,11 +449,11 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 
 	  GPR_SWAP (grpc_subchannel *, p->subchannels[this_idx], p->subchannels[p->num_subchannels - 1]);
 	  p->num_subchannels--;
-	  GRPC_SUBCHANNEL_UNREF (p->subchannels[p->num_subchannels], "round_robin", closure_list);
+	  GRPC_SUBCHANNEL_UNREF (exec_ctx, p->subchannels[p->num_subchannels], "round_robin");
 
 	  if (p->num_subchannels == 0)
 	    {
-	      grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "no_more_channels", closure_list);
+	      grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_FATAL_FAILURE, "no_more_channels");
 	      while ((pp = p->pending_picks))
 		{
 		  p->pending_picks = pp->next;
@@ -465,7 +465,7 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 	    }
 	  else
 	    {
-	      grpc_connectivity_state_set (&p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "subchannel_failed", closure_list);
+	      grpc_connectivity_state_set (exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, "subchannel_failed");
 	    }
 	}			/* switch */
     }				/* !unref */
@@ -474,7 +474,7 @@ rr_connectivity_changed (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 
   if (unref)
     {
-      GRPC_LB_POLICY_UNREF (&p->base, "round_robin_connectivity", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, &p->base, "round_robin_connectivity");
     }
 }
 
@@ -498,8 +498,8 @@ rr_broadcast (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_transport_op
 
   for (i = 0; i < n; i++)
     {
-      grpc_subchannel_process_transport_op (subchannels[i], op, closure_list);
-      GRPC_SUBCHANNEL_UNREF (subchannels[i], "rr_broadcast", closure_list);
+      grpc_subchannel_process_transport_op (exec_ctx, subchannels[i], op);
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, subchannels[i], "rr_broadcast");
     }
   gpr_free (subchannels);
 }
@@ -520,7 +520,7 @@ rr_notify_on_state_change (grpc_exec_ctx * exec_ctx, grpc_lb_policy * pol, grpc_
 {
   round_robin_lb_policy *p = (round_robin_lb_policy *) pol;
   gpr_mu_lock (&p->mu);
-  grpc_connectivity_state_notify_on_state_change (&p->state_tracker, current, notify, closure_list);
+  grpc_connectivity_state_notify_on_state_change (exec_ctx, &p->state_tracker, current, notify);
   gpr_mu_unlock (&p->mu);
 }
 
diff --git a/src/core/client_config/lb_policy.c b/src/core/client_config/lb_policy.c
index 06ac41ff56..6a9cf66887 100644
--- a/src/core/client_config/lb_policy.c
+++ b/src/core/client_config/lb_policy.c
@@ -65,42 +65,42 @@ grpc_lb_policy_unref (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy)
 #endif
   if (gpr_unref (&policy->refs))
     {
-      policy->vtable->destroy (policy, closure_list);
+      policy->vtable->destroy (exec_ctx, policy);
     }
 }
 
 void
 grpc_lb_policy_shutdown (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy)
 {
-  policy->vtable->shutdown (policy, closure_list);
+  policy->vtable->shutdown (exec_ctx, policy);
 }
 
 void
 grpc_lb_policy_pick (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy, grpc_pollset * pollset, grpc_metadata_batch * initial_metadata, grpc_subchannel ** target, grpc_closure * on_complete)
 {
-  policy->vtable->pick (policy, pollset, initial_metadata, target, on_complete, closure_list);
+  policy->vtable->pick (exec_ctx, policy, pollset, initial_metadata, target, on_complete);
 }
 
 void
 grpc_lb_policy_broadcast (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy, grpc_transport_op * op)
 {
-  policy->vtable->broadcast (policy, op, closure_list);
+  policy->vtable->broadcast (exec_ctx, policy, op);
 }
 
 void
 grpc_lb_policy_exit_idle (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy)
 {
-  policy->vtable->exit_idle (policy, closure_list);
+  policy->vtable->exit_idle (exec_ctx, policy);
 }
 
 void
 grpc_lb_policy_notify_on_state_change (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy, grpc_connectivity_state * state, grpc_closure * closure)
 {
-  policy->vtable->notify_on_state_change (policy, state, closure, closure_list);
+  policy->vtable->notify_on_state_change (exec_ctx, policy, state, closure);
 }
 
 grpc_connectivity_state
 grpc_lb_policy_check_connectivity (grpc_exec_ctx * exec_ctx, grpc_lb_policy * policy)
 {
-  return policy->vtable->check_connectivity (policy, closure_list);
+  return policy->vtable->check_connectivity (exec_ctx, policy);
 }
diff --git a/src/core/client_config/resolver.c b/src/core/client_config/resolver.c
index cb5a6a5333..a55daad5a2 100644
--- a/src/core/client_config/resolver.c
+++ b/src/core/client_config/resolver.c
@@ -65,24 +65,24 @@ grpc_resolver_unref (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver)
 #endif
   if (gpr_unref (&resolver->refs))
     {
-      resolver->vtable->destroy (resolver, closure_list);
+      resolver->vtable->destroy (exec_ctx, resolver);
     }
 }
 
 void
 grpc_resolver_shutdown (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver)
 {
-  resolver->vtable->shutdown (resolver, closure_list);
+  resolver->vtable->shutdown (exec_ctx, resolver);
 }
 
 void
 grpc_resolver_channel_saw_error (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver, struct sockaddr *failing_address, int failing_address_len)
 {
-  resolver->vtable->channel_saw_error (resolver, failing_address, failing_address_len, closure_list);
+  resolver->vtable->channel_saw_error (exec_ctx, resolver, failing_address, failing_address_len);
 }
 
 void
 grpc_resolver_next (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver, grpc_client_config ** target_config, grpc_closure * on_complete)
 {
-  resolver->vtable->next (resolver, target_config, on_complete, closure_list);
+  resolver->vtable->next (exec_ctx, resolver, target_config, on_complete);
 }
diff --git a/src/core/client_config/resolvers/dns_resolver.c b/src/core/client_config/resolvers/dns_resolver.c
index 66430c43cb..781f1a9e23 100644
--- a/src/core/client_config/resolvers/dns_resolver.c
+++ b/src/core/client_config/resolvers/dns_resolver.c
@@ -128,7 +128,7 @@ dns_next (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver, grpc_client_config
     }
   else
     {
-      dns_maybe_finish_next_locked (r, closure_list);
+      dns_maybe_finish_next_locked (exec_ctx, r);
     }
   gpr_mu_unlock (&r->mu);
 }
@@ -152,14 +152,14 @@ dns_on_resolved (grpc_exec_ctx * exec_ctx, void *arg, grpc_resolved_addresses *
 	  memset (&args, 0, sizeof (args));
 	  args.addr = (struct sockaddr *) (addresses->addrs[i].addr);
 	  args.addr_len = (size_t) addresses->addrs[i].len;
-	  subchannels[i] = grpc_subchannel_factory_create_subchannel (r->subchannel_factory, &args, closure_list);
+	  subchannels[i] = grpc_subchannel_factory_create_subchannel (exec_ctx, r->subchannel_factory, &args);
 	}
       memset (&lb_policy_args, 0, sizeof (lb_policy_args));
       lb_policy_args.subchannels = subchannels;
       lb_policy_args.num_subchannels = addresses->naddrs;
       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", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "construction");
       grpc_resolved_addresses_destroy (addresses);
       gpr_free (subchannels);
     }
@@ -168,14 +168,14 @@ dns_on_resolved (grpc_exec_ctx * exec_ctx, void *arg, grpc_resolved_addresses *
   r->resolving = 0;
   if (r->resolved_config)
     {
-      grpc_client_config_unref (r->resolved_config, closure_list);
+      grpc_client_config_unref (exec_ctx, r->resolved_config);
     }
   r->resolved_config = config;
   r->resolved_version++;
-  dns_maybe_finish_next_locked (r, closure_list);
+  dns_maybe_finish_next_locked (exec_ctx, r);
   gpr_mu_unlock (&r->mu);
 
-  GRPC_RESOLVER_UNREF (&r->base, "dns-resolving", closure_list);
+  GRPC_RESOLVER_UNREF (exec_ctx, &r->base, "dns-resolving");
 }
 
 static void
@@ -210,9 +210,9 @@ dns_destroy (grpc_exec_ctx * exec_ctx, grpc_resolver * gr)
   gpr_mu_destroy (&r->mu);
   if (r->resolved_config)
     {
-      grpc_client_config_unref (r->resolved_config, closure_list);
+      grpc_client_config_unref (exec_ctx, r->resolved_config);
     }
-  grpc_subchannel_factory_unref (r->subchannel_factory, closure_list);
+  grpc_subchannel_factory_unref (exec_ctx, r->subchannel_factory);
   gpr_free (r->name);
   gpr_free (r->default_port);
   gpr_free (r->lb_policy_name);
diff --git a/src/core/client_config/resolvers/sockaddr_resolver.c b/src/core/client_config/resolvers/sockaddr_resolver.c
index 2887cffcd4..1b2eac997d 100644
--- a/src/core/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/client_config/resolvers/sockaddr_resolver.c
@@ -117,7 +117,7 @@ sockaddr_next (grpc_exec_ctx * exec_ctx, grpc_resolver * resolver, grpc_client_c
   GPR_ASSERT (!r->next_completion);
   r->next_completion = on_complete;
   r->target_config = target_config;
-  sockaddr_maybe_finish_next_locked (r, closure_list);
+  sockaddr_maybe_finish_next_locked (exec_ctx, r);
   gpr_mu_unlock (&r->mu);
 }
 
@@ -140,7 +140,7 @@ sockaddr_maybe_finish_next_locked (grpc_exec_ctx * exec_ctx, sockaddr_resolver *
 	  memset (&args, 0, sizeof (args));
 	  args.addr = (struct sockaddr *) &r->addrs[i];
 	  args.addr_len = r->addrs_len[i];
-	  subchannels[i] = grpc_subchannel_factory_create_subchannel (r->subchannel_factory, &args, closure_list);
+	  subchannels[i] = grpc_subchannel_factory_create_subchannel (exec_ctx, r->subchannel_factory, &args);
 	}
       memset (&lb_policy_args, 0, sizeof (lb_policy_args));
       lb_policy_args.subchannels = subchannels;
@@ -148,7 +148,7 @@ sockaddr_maybe_finish_next_locked (grpc_exec_ctx * exec_ctx, sockaddr_resolver *
       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, "sockaddr", closure_list);
+      GRPC_LB_POLICY_UNREF (exec_ctx, lb_policy, "sockaddr");
       r->published = 1;
       *r->target_config = cfg;
       grpc_closure_list_add (closure_list, r->next_completion, 1);
@@ -161,7 +161,7 @@ sockaddr_destroy (grpc_exec_ctx * exec_ctx, grpc_resolver * gr)
 {
   sockaddr_resolver *r = (sockaddr_resolver *) gr;
   gpr_mu_destroy (&r->mu);
-  grpc_subchannel_factory_unref (r->subchannel_factory, closure_list);
+  grpc_subchannel_factory_unref (exec_ctx, r->subchannel_factory);
   gpr_free (r->addrs);
   gpr_free (r->addrs_len);
   gpr_free (r->lb_policy_name);
diff --git a/src/core/client_config/subchannel.c b/src/core/client_config/subchannel.c
index 1ab348da83..3db2fae593 100644
--- a/src/core/client_config/subchannel.c
+++ b/src/core/client_config/subchannel.c
@@ -199,7 +199,7 @@ subchannel_unref_locked (grpc_subchannel * c GRPC_SUBCHANNEL_REF_EXTRA_ARGS)
      static void connection_destroy (grpc_exec_ctx * exec_ctx, connection * c)
 {
   GPR_ASSERT (c->refs == 0);
-  grpc_channel_stack_destroy (CHANNEL_STACK_FROM_CONNECTION (c), closure_list);
+  grpc_channel_stack_destroy (CHANNEL_STACK_FROM_CONNECTION (exec_ctx, c));
   gpr_free (c);
 }
 
@@ -222,7 +222,7 @@ connection_unref_locked (connection * c, grpc_closure_list * closure_list GRPC_S
     }
   if (--c->refs == 0 && c->subchannel->active != c)
     {
-      connection_destroy (c, closure_list);
+      connection_destroy (exec_ctx, c);
     }
   return destroy;
 }
@@ -261,7 +261,7 @@ grpc_subchannel_unref (grpc_subchannel * c, grpc_closure_list * closure_list GRP
   destroy = subchannel_unref_locked (c REF_PASS_ARGS);
   gpr_mu_unlock (&c->mu);
   if (destroy)
-    subchannel_destroy (c, closure_list);
+    subchannel_destroy (exec_ctx, c);
 }
 
 static void
@@ -269,27 +269,27 @@ subchannel_destroy (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
 {
   if (c->active != NULL)
     {
-      connection_destroy (c->active, closure_list);
+      connection_destroy (exec_ctx, c->active);
     }
   gpr_free (c->filters);
   grpc_channel_args_destroy (c->args);
   gpr_free (c->addr);
   grpc_mdctx_unref (c->mdctx);
-  grpc_connectivity_state_destroy (&c->state_tracker, closure_list);
-  grpc_connector_unref (c->connector, closure_list);
+  grpc_connectivity_state_destroy (exec_ctx, &c->state_tracker);
+  grpc_connector_unref (exec_ctx, c->connector);
   gpr_free (c);
 }
 
 void
 grpc_subchannel_add_interested_party (grpc_exec_ctx * exec_ctx, grpc_subchannel * c, grpc_pollset * pollset)
 {
-  grpc_pollset_set_add_pollset (c->pollset_set, pollset, closure_list);
+  grpc_pollset_set_add_pollset (exec_ctx, c->pollset_set, pollset);
 }
 
 void
 grpc_subchannel_del_interested_party (grpc_exec_ctx * exec_ctx, grpc_subchannel * c, grpc_pollset * pollset)
 {
-  grpc_pollset_set_del_pollset (c->pollset_set, pollset, closure_list);
+  grpc_pollset_set_del_pollset (exec_ctx, c->pollset_set, pollset);
 }
 
 static gpr_uint32
@@ -336,7 +336,7 @@ continue_connect (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
   args.deadline = compute_connect_deadline (c);
   args.channel_args = c->args;
 
-  grpc_connector_connect (c->connector, &args, &c->connecting_result, &c->connected, closure_list);
+  grpc_connector_connect (exec_ctx, c->connector, &args, &c->connecting_result, &c->connected);
 }
 
 static void
@@ -344,16 +344,16 @@ start_connect (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
 {
   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, closure_list);
+  continue_connect (exec_ctx, c);
 }
 
 static void
 continue_creating_call (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
 {
   waiting_for_connect *w4c = arg;
-  grpc_subchannel_del_interested_party (w4c->subchannel, w4c->pollset, closure_list);
-  grpc_subchannel_create_call (w4c->subchannel, w4c->pollset, w4c->target, w4c->notify, closure_list);
-  GRPC_SUBCHANNEL_UNREF (w4c->subchannel, "waiting_for_connect", closure_list);
+  grpc_subchannel_del_interested_party (exec_ctx, w4c->subchannel, w4c->pollset);
+  grpc_subchannel_create_call (exec_ctx, w4c->subchannel, w4c->pollset, w4c->target, w4c->notify);
+  GRPC_SUBCHANNEL_UNREF (exec_ctx, w4c->subchannel, "waiting_for_connect");
   gpr_free (w4c);
 }
 
@@ -368,8 +368,8 @@ grpc_subchannel_create_call (grpc_exec_ctx * exec_ctx, grpc_subchannel * c, grpc
       CONNECTION_REF_LOCKED (con, "call");
       gpr_mu_unlock (&c->mu);
 
-      *target = create_call (con, closure_list);
-      notify->cb (notify->cb_arg, 1, closure_list);
+      *target = create_call (exec_ctx, con);
+      notify->cb (exec_ctx, notify->cb_arg, 1);
     }
   else
     {
@@ -383,17 +383,17 @@ grpc_subchannel_create_call (grpc_exec_ctx * exec_ctx, grpc_subchannel * c, grpc
       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, closure_list);
+      grpc_subchannel_add_interested_party (exec_ctx, c, pollset);
       if (!c->connecting)
 	{
 	  c->connecting = 1;
-	  connectivity_state_changed_locked (c, "create_call", closure_list);
+	  connectivity_state_changed_locked (exec_ctx, c, "create_call");
 	  /* released by connection */
 	  SUBCHANNEL_REF_LOCKED (c, "connecting");
 	  GRPC_CHANNEL_INTERNAL_REF (c->master, "connecting");
 	  gpr_mu_unlock (&c->mu);
 
-	  start_connect (c, closure_list);
+	  start_connect (exec_ctx, c);
 	}
       else
 	{
@@ -417,20 +417,20 @@ grpc_subchannel_notify_on_state_change (grpc_exec_ctx * exec_ctx, grpc_subchanne
 {
   int do_connect = 0;
   gpr_mu_lock (&c->mu);
-  if (grpc_connectivity_state_notify_on_state_change (&c->state_tracker, state, notify, closure_list))
+  if (grpc_connectivity_state_notify_on_state_change (exec_ctx, &c->state_tracker, state, notify))
     {
       do_connect = 1;
       c->connecting = 1;
       /* released by connection */
       SUBCHANNEL_REF_LOCKED (c, "connecting");
       GRPC_CHANNEL_INTERNAL_REF (c->master, "connecting");
-      connectivity_state_changed_locked (c, "state_change", closure_list);
+      connectivity_state_changed_locked (exec_ctx, c, "state_change");
     }
   gpr_mu_unlock (&c->mu);
 
   if (do_connect)
     {
-      start_connect (c, closure_list);
+      start_connect (exec_ctx, c);
     }
 }
 
@@ -449,7 +449,7 @@ grpc_subchannel_process_transport_op (grpc_exec_ctx * exec_ctx, grpc_subchannel
   if (op->disconnect)
     {
       c->disconnected = 1;
-      connectivity_state_changed_locked (c, "disconnect", closure_list);
+      connectivity_state_changed_locked (exec_ctx, c, "disconnect");
       if (c->have_alarm)
 	{
 	  cancel_alarm = 1;
@@ -461,25 +461,25 @@ grpc_subchannel_process_transport_op (grpc_exec_ctx * exec_ctx, grpc_subchannel
     {
       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, closure_list);
+      top_elem->filter->start_transport_op (exec_ctx, top_elem, op);
 
       gpr_mu_lock (&c->mu);
-      destroy = CONNECTION_UNREF_LOCKED (con, "transport-op", closure_list);
+      destroy = CONNECTION_UNREF_LOCKED (exec_ctx, con, "transport-op");
       gpr_mu_unlock (&c->mu);
       if (destroy)
 	{
-	  subchannel_destroy (destroy, closure_list);
+	  subchannel_destroy (exec_ctx, destroy);
 	}
     }
 
   if (cancel_alarm)
     {
-      grpc_alarm_cancel (&c->alarm, closure_list);
+      grpc_alarm_cancel (exec_ctx, &c->alarm);
     }
 
   if (op->disconnect)
     {
-      grpc_connector_shutdown (c->connector, closure_list);
+      grpc_connector_shutdown (exec_ctx, c->connector);
     }
 }
 
@@ -513,7 +513,7 @@ on_state_changed (grpc_exec_ctx * exec_ctx, void *p, int iomgr_success)
       op.connectivity_state = &sw->connectivity_state;
       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, closure_list);
+      elem->filter->start_transport_op (exec_ctx, elem, &op);
       /* early out */
       gpr_mu_unlock (mu);
       return;
@@ -525,22 +525,22 @@ on_state_changed (grpc_exec_ctx * exec_ctx, void *p, int iomgr_success)
 	  destroy_connection = sw->subchannel->active;
 	}
       sw->subchannel->active = NULL;
-      grpc_connectivity_state_set (&c->state_tracker, c->disconnected ? GRPC_CHANNEL_FATAL_FAILURE : GRPC_CHANNEL_TRANSIENT_FAILURE, "connection_failed", closure_list);
+      grpc_connectivity_state_set (exec_ctx, &c->state_tracker, c->disconnected ? GRPC_CHANNEL_FATAL_FAILURE : GRPC_CHANNEL_TRANSIENT_FAILURE, "connection_failed");
       break;
     }
 
 done:
-  connectivity_state_changed_locked (c, "transport_state_changed", closure_list);
+  connectivity_state_changed_locked (exec_ctx, c, "transport_state_changed");
   destroy = SUBCHANNEL_UNREF_LOCKED (c, "state_watcher");
   gpr_free (sw);
   gpr_mu_unlock (mu);
   if (destroy)
     {
-      subchannel_destroy (c, closure_list);
+      subchannel_destroy (exec_ctx, c);
     }
   if (destroy_connection != NULL)
     {
-      connection_destroy (destroy_connection, closure_list);
+      connection_destroy (exec_ctx, destroy_connection);
     }
 }
 
@@ -571,7 +571,7 @@ publish_transport (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
   stk = (grpc_channel_stack *) (con + 1);
   con->refs = 0;
   con->subchannel = c;
-  grpc_channel_stack_init (filters, num_filters, c->master, c->args, c->mdctx, stk, closure_list);
+  grpc_channel_stack_init (exec_ctx, filters, num_filters, c->master, c->args, c->mdctx, stk);
   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));
@@ -589,9 +589,9 @@ publish_transport (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
       gpr_mu_unlock (&c->mu);
       gpr_free (sw);
       gpr_free (filters);
-      grpc_channel_stack_destroy (stk, closure_list);
-      GRPC_CHANNEL_INTERNAL_UNREF (c->master, "connecting", closure_list);
-      GRPC_SUBCHANNEL_UNREF (c, "connecting", closure_list);
+      grpc_channel_stack_destroy (exec_ctx, stk);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, c->master, "connecting");
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, c, "connecting");
       return;
     }
 
@@ -612,13 +612,13 @@ publish_transport (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
   op.on_connectivity_state_change = &sw->closure;
   op.bind_pollset_set = c->pollset_set;
   SUBCHANNEL_REF_LOCKED (c, "state_watcher");
-  GRPC_CHANNEL_INTERNAL_UNREF (c->master, "connecting", closure_list);
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, c->master, "connecting");
   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, closure_list);
+  elem->filter->start_transport_op (exec_ctx, elem, &op);
 
   /* signal completion */
-  connectivity_state_changed_locked (c, "connected", closure_list);
+  connectivity_state_changed_locked (exec_ctx, c, "connected");
   w4c = c->waiting;
   c->waiting = NULL;
 
@@ -635,7 +635,7 @@ publish_transport (grpc_exec_ctx * exec_ctx, grpc_subchannel * c)
 
   if (destroy_connection != NULL)
     {
-      connection_destroy (destroy_connection, closure_list);
+      connection_destroy (exec_ctx, destroy_connection);
     }
 }
 
@@ -677,17 +677,17 @@ on_alarm (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
     {
       iomgr_success = 0;
     }
-  connectivity_state_changed_locked (c, "alarm", closure_list);
+  connectivity_state_changed_locked (exec_ctx, c, "alarm");
   gpr_mu_unlock (&c->mu);
   if (iomgr_success)
     {
       update_reconnect_parameters (c);
-      continue_connect (c, closure_list);
+      continue_connect (exec_ctx, c);
     }
   else
     {
-      GRPC_CHANNEL_INTERNAL_UNREF (c->master, "connecting", closure_list);
-      GRPC_SUBCHANNEL_UNREF (c, "connecting", closure_list);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, c->master, "connecting");
+      GRPC_SUBCHANNEL_UNREF (exec_ctx, c, "connecting");
     }
 }
 
@@ -697,7 +697,7 @@ subchannel_connected (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
   grpc_subchannel *c = arg;
   if (c->connecting_result.transport != NULL)
     {
-      publish_transport (c, closure_list);
+      publish_transport (exec_ctx, c);
     }
   else
     {
@@ -705,8 +705,8 @@ subchannel_connected (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_success)
       gpr_mu_lock (&c->mu);
       GPR_ASSERT (!c->have_alarm);
       c->have_alarm = 1;
-      connectivity_state_changed_locked (c, "connect_failed", closure_list);
-      grpc_alarm_init (&c->alarm, c->next_attempt, on_alarm, c, now, closure_list);
+      connectivity_state_changed_locked (exec_ctx, c, "connect_failed");
+      grpc_alarm_init (exec_ctx, &c->alarm, c->next_attempt, on_alarm, c, now);
       gpr_mu_unlock (&c->mu);
     }
 }
@@ -747,7 +747,7 @@ static void
 connectivity_state_changed_locked (grpc_exec_ctx * exec_ctx, grpc_subchannel * c, const char *reason)
 {
   grpc_connectivity_state current = compute_connectivity_locked (c);
-  grpc_connectivity_state_set (&c->state_tracker, current, reason, closure_list);
+  grpc_connectivity_state_set (exec_ctx, &c->state_tracker, current, reason);
 }
 
 /*
@@ -767,14 +767,14 @@ grpc_subchannel_call_unref (grpc_subchannel_call * c, grpc_closure_list * closur
     {
       gpr_mu *mu = &c->connection->subchannel->mu;
       grpc_subchannel *destroy;
-      grpc_call_stack_destroy (SUBCHANNEL_CALL_TO_CALL_STACK (c), closure_list);
+      grpc_call_stack_destroy (SUBCHANNEL_CALL_TO_CALL_STACK (exec_ctx, c));
       gpr_mu_lock (mu);
-      destroy = CONNECTION_UNREF_LOCKED (c->connection, "call", closure_list);
+      destroy = CONNECTION_UNREF_LOCKED (exec_ctx, c->connection, "call");
       gpr_mu_unlock (mu);
       gpr_free (c);
       if (destroy != NULL)
 	{
-	  subchannel_destroy (destroy, closure_list);
+	  subchannel_destroy (exec_ctx, destroy);
 	}
     }
 }
@@ -784,7 +784,7 @@ grpc_subchannel_call_get_peer (grpc_exec_ctx * exec_ctx, grpc_subchannel_call *
 {
   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, closure_list);
+  return top_elem->filter->get_peer (exec_ctx, top_elem);
 }
 
 void
@@ -792,7 +792,7 @@ grpc_subchannel_call_process_op (grpc_exec_ctx * exec_ctx, grpc_subchannel_call
 {
   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, closure_list);
+  top_elem->filter->start_transport_stream_op (exec_ctx, top_elem, op);
 }
 
 static grpc_subchannel_call *
@@ -803,6 +803,6 @@ create_call (grpc_exec_ctx * exec_ctx, connection * con)
   grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK (call);
   call->connection = con;
   gpr_ref_init (&call->refs, 1);
-  grpc_call_stack_init (chanstk, NULL, NULL, callstk, closure_list);
+  grpc_call_stack_init (exec_ctx, chanstk, NULL, NULL, callstk);
   return call;
 }
diff --git a/src/core/client_config/subchannel_factory.c b/src/core/client_config/subchannel_factory.c
index 82b851c2f7..f60cd02421 100644
--- a/src/core/client_config/subchannel_factory.c
+++ b/src/core/client_config/subchannel_factory.c
@@ -42,11 +42,11 @@ grpc_subchannel_factory_ref (grpc_subchannel_factory * factory)
 void
 grpc_subchannel_factory_unref (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * factory)
 {
-  factory->vtable->unref (factory, closure_list);
+  factory->vtable->unref (exec_ctx, factory);
 }
 
 grpc_subchannel *
 grpc_subchannel_factory_create_subchannel (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * factory, grpc_subchannel_args * args)
 {
-  return factory->vtable->create_subchannel (factory, args, closure_list);
+  return factory->vtable->create_subchannel (exec_ctx, factory, args);
 }
diff --git a/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c b/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c
index 59af175da1..442862a4b8 100644
--- a/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c
+++ b/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c
@@ -56,7 +56,7 @@ merge_args_factory_unref (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * sc
   merge_args_factory *f = (merge_args_factory *) scf;
   if (gpr_unref (&f->refs))
     {
-      grpc_subchannel_factory_unref (f->wrapped, closure_list);
+      grpc_subchannel_factory_unref (exec_ctx, f->wrapped);
       grpc_channel_args_destroy (f->merge_args);
       gpr_free (f);
     }
@@ -69,7 +69,7 @@ merge_args_factory_create_subchannel (grpc_exec_ctx * exec_ctx, grpc_subchannel_
   grpc_channel_args *final_args = grpc_channel_args_merge (args->args, f->merge_args);
   grpc_subchannel *s;
   args->args = final_args;
-  s = grpc_subchannel_factory_create_subchannel (f->wrapped, args, closure_list);
+  s = grpc_subchannel_factory_create_subchannel (exec_ctx, f->wrapped, args);
   grpc_channel_args_destroy (final_args);
   return s;
 }
diff --git a/src/core/httpcli/httpcli.c b/src/core/httpcli/httpcli.c
index fac80a44a1..b9dc350df9 100644
--- a/src/core/httpcli/httpcli.c
+++ b/src/core/httpcli/httpcli.c
@@ -75,7 +75,7 @@ static grpc_httpcli_post_override g_post_override = NULL;
 static void
 plaintext_handshake (void *arg, grpc_endpoint * endpoint, const char *host, void (*on_done) (grpc_exec_ctx * exec_ctx, void *arg, grpc_endpoint * endpoint, grpc_closure_list * closure_list))
 {
-  on_done (arg, endpoint, closure_list);
+  on_done (exec_ctx, arg, endpoint);
 }
 
 const grpc_httpcli_handshaker grpc_httpcli_plaintext = { "http",
@@ -99,8 +99,8 @@ static void next_address (grpc_exec_ctx * exec_ctx, internal_request * req);
 static void
 finish (grpc_exec_ctx * exec_ctx, internal_request * req, int success)
 {
-  grpc_pollset_set_del_pollset (&req->context->pollset_set, req->pollset, closure_list);
-  req->on_response (req->user_data, success ? &req->parser.r : NULL, closure_list);
+  grpc_pollset_set_del_pollset (exec_ctx, &req->context->pollset_set, req->pollset);
+  req->on_response (exec_ctx, req->user_data, success ? &req->parser.r : NULL);
   grpc_httpcli_parser_destroy (&req->parser);
   if (req->addresses != NULL)
     {
@@ -108,7 +108,7 @@ finish (grpc_exec_ctx * exec_ctx, internal_request * req, int success)
     }
   if (req->ep != NULL)
     {
-      grpc_endpoint_destroy (req->ep, closure_list);
+      grpc_endpoint_destroy (exec_ctx, req->ep);
     }
   gpr_slice_unref (req->request_text);
   gpr_free (req->host);
@@ -123,7 +123,7 @@ static void on_read (grpc_exec_ctx * exec_ctx, void *user_data, int success);
 static void
 do_read (grpc_exec_ctx * exec_ctx, internal_request * req)
 {
-  grpc_endpoint_read (req->ep, &req->incoming, &req->on_read, closure_list);
+  grpc_endpoint_read (exec_ctx, req->ep, &req->incoming, &req->on_read);
 }
 
 static void
@@ -139,7 +139,7 @@ on_read (grpc_exec_ctx * exec_ctx, void *user_data, int success)
 	  req->have_read_byte = 1;
 	  if (!grpc_httpcli_parser_parse (&req->parser, req->incoming.slices[i]))
 	    {
-	      finish (req, 0, closure_list);
+	      finish (exec_ctx, req, 0);
 	      return;
 	    }
 	}
@@ -147,22 +147,22 @@ on_read (grpc_exec_ctx * exec_ctx, void *user_data, int success)
 
   if (success)
     {
-      do_read (req, closure_list);
+      do_read (exec_ctx, req);
     }
   else if (!req->have_read_byte)
     {
-      next_address (req, closure_list);
+      next_address (exec_ctx, req);
     }
   else
     {
-      finish (req, grpc_httpcli_parser_eof (&req->parser), closure_list);
+      finish (req, grpc_httpcli_parser_eof (exec_ctx, &req->parser));
     }
 }
 
 static void
 on_written (grpc_exec_ctx * exec_ctx, internal_request * req)
 {
-  do_read (req, closure_list);
+  do_read (exec_ctx, req);
 }
 
 static void
@@ -171,11 +171,11 @@ done_write (grpc_exec_ctx * exec_ctx, void *arg, int success)
   internal_request *req = arg;
   if (success)
     {
-      on_written (req, closure_list);
+      on_written (exec_ctx, req);
     }
   else
     {
-      next_address (req, closure_list);
+      next_address (exec_ctx, req);
     }
 }
 
@@ -184,7 +184,7 @@ start_write (grpc_exec_ctx * exec_ctx, internal_request * req)
 {
   gpr_slice_ref (req->request_text);
   gpr_slice_buffer_add (&req->outgoing, req->request_text);
-  grpc_endpoint_write (req->ep, &req->outgoing, &req->done_write, closure_list);
+  grpc_endpoint_write (exec_ctx, req->ep, &req->outgoing, &req->done_write);
 }
 
 static void
@@ -194,12 +194,12 @@ on_handshake_done (grpc_exec_ctx * exec_ctx, void *arg, grpc_endpoint * ep)
 
   if (!ep)
     {
-      next_address (req, closure_list);
+      next_address (exec_ctx, req);
       return;
     }
 
   req->ep = ep;
-  start_write (req, closure_list);
+  start_write (exec_ctx, req);
 }
 
 static void
@@ -209,10 +209,10 @@ on_connected (grpc_exec_ctx * exec_ctx, void *arg, int success)
 
   if (!req->ep)
     {
-      next_address (req, closure_list);
+      next_address (exec_ctx, req);
       return;
     }
-  req->handshaker->handshake (req, req->ep, req->host, on_handshake_done, closure_list);
+  req->handshaker->handshake (exec_ctx, req, req->ep, req->host, on_handshake_done);
 }
 
 static void
@@ -221,12 +221,12 @@ next_address (grpc_exec_ctx * exec_ctx, internal_request * req)
   grpc_resolved_address *addr;
   if (req->next_address == req->addresses->naddrs)
     {
-      finish (req, 0, closure_list);
+      finish (exec_ctx, req, 0);
       return;
     }
   addr = &req->addresses->addrs[req->next_address++];
   grpc_closure_init (&req->connected, on_connected, req);
-  grpc_tcp_client_connect (&req->connected, &req->ep, &req->context->pollset_set, (struct sockaddr *) &addr->addr, addr->len, req->deadline, closure_list);
+  grpc_tcp_client_connect (&req->connected, &req->ep, &req->context->pollset_set, (exec_ctx, struct sockaddr *) &addr->addr, addr->len, req->deadline);
 }
 
 static void
@@ -235,12 +235,12 @@ on_resolved (grpc_exec_ctx * exec_ctx, void *arg, grpc_resolved_addresses * addr
   internal_request *req = arg;
   if (!addresses)
     {
-      finish (req, 0, closure_list);
+      finish (exec_ctx, req, 0);
       return;
     }
   req->addresses = addresses;
   req->next_address = 0;
-  next_address (req, closure_list);
+  next_address (exec_ctx, req);
 }
 
 static void
@@ -263,7 +263,7 @@ internal_request_begin (grpc_exec_ctx * exec_ctx, grpc_httpcli_context * context
   grpc_iomgr_register_object (&req->iomgr_obj, name);
   req->host = gpr_strdup (request->host);
 
-  grpc_pollset_set_add_pollset (&req->context->pollset_set, req->pollset, closure_list);
+  grpc_pollset_set_add_pollset (exec_ctx, &req->context->pollset_set, req->pollset);
   grpc_resolve_address (request->host, req->handshaker->default_port, on_resolved, req);
 }
 
@@ -271,12 +271,12 @@ void
 grpc_httpcli_get (grpc_exec_ctx * exec_ctx, grpc_httpcli_context * context, grpc_pollset * pollset, const grpc_httpcli_request * request, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data)
 {
   char *name;
-  if (g_get_override && g_get_override (request, deadline, on_response, user_data, closure_list))
+  if (g_get_override && g_get_override (exec_ctx, request, deadline, on_response, user_data))
     {
       return;
     }
   gpr_asprintf (&name, "HTTP:GET:%s:%s", request->host, request->path);
-  internal_request_begin (context, pollset, request, deadline, on_response, user_data, name, grpc_httpcli_format_get_request (request), closure_list);
+  internal_request_begin (context, pollset, request, deadline, on_response, user_data, name, grpc_httpcli_format_get_request (exec_ctx, request));
   gpr_free (name);
 }
 
@@ -284,12 +284,12 @@ void
 grpc_httpcli_post (grpc_exec_ctx * exec_ctx, grpc_httpcli_context * context, grpc_pollset * pollset, const grpc_httpcli_request * request, const char *body_bytes, size_t body_size, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data)
 {
   char *name;
-  if (g_post_override && g_post_override (request, body_bytes, body_size, deadline, on_response, user_data, closure_list))
+  if (g_post_override && g_post_override (exec_ctx, request, body_bytes, body_size, deadline, on_response, user_data))
     {
       return;
     }
   gpr_asprintf (&name, "HTTP:POST:%s:%s", request->host, request->path);
-  internal_request_begin (context, pollset, request, deadline, on_response, user_data, name, grpc_httpcli_format_post_request (request, body_bytes, body_size), closure_list);
+  internal_request_begin (context, pollset, request, deadline, on_response, user_data, name, grpc_httpcli_format_post_request (exec_ctx, request, body_bytes, body_size));
   gpr_free (name);
 }
 
diff --git a/src/core/httpcli/httpcli_security_connector.c b/src/core/httpcli/httpcli_security_connector.c
index 5760f27f09..a6ecfa993b 100644
--- a/src/core/httpcli/httpcli_security_connector.c
+++ b/src/core/httpcli/httpcli_security_connector.c
@@ -70,18 +70,18 @@ httpcli_ssl_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_connector * sc
   tsi_handshaker *handshaker;
   if (c->handshaker_factory == NULL)
     {
-      cb (user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL, closure_list);
+      cb (exec_ctx, user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL);
       return;
     }
   result = tsi_ssl_handshaker_factory_create_handshaker (c->handshaker_factory, c->secure_peer_name, &handshaker);
   if (result != TSI_OK)
     {
       gpr_log (GPR_ERROR, "Handshaker creation failed with error %s.", tsi_result_to_string (result));
-      cb (user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL, closure_list);
+      cb (exec_ctx, user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL);
     }
   else
     {
-      grpc_do_security_handshake (handshaker, sc, nonsecure_endpoint, cb, user_data, closure_list);
+      grpc_do_security_handshake (exec_ctx, handshaker, sc, nonsecure_endpoint, cb, user_data);
     }
 }
 
@@ -154,11 +154,11 @@ on_secure_transport_setup_done (grpc_exec_ctx * exec_ctx, void *rp, grpc_securit
   if (status != GRPC_SECURITY_OK)
     {
       gpr_log (GPR_ERROR, "Secure transport setup failed with error %d.", status);
-      c->func (c->arg, NULL, closure_list);
+      c->func (exec_ctx, c->arg, NULL);
     }
   else
     {
-      c->func (c->arg, secure_endpoint, closure_list);
+      c->func (exec_ctx, c->arg, secure_endpoint);
     }
   gpr_free (c);
 }
@@ -173,14 +173,14 @@ ssl_handshake (void *arg, grpc_endpoint * tcp, const char *host, void (*on_done)
   if (pem_root_certs == NULL || pem_root_certs_size == 0)
     {
       gpr_log (GPR_ERROR, "Could not get default pem root certs.");
-      on_done (arg, NULL, closure_list);
+      on_done (exec_ctx, arg, NULL);
       gpr_free (c);
       return;
     }
   c->func = on_done;
   c->arg = arg;
   GPR_ASSERT (httpcli_ssl_channel_security_connector_create (pem_root_certs, pem_root_certs_size, host, &sc) == GRPC_SECURITY_OK);
-  grpc_security_connector_do_handshake (&sc->base, tcp, on_secure_transport_setup_done, c, closure_list);
+  grpc_security_connector_do_handshake (exec_ctx, &sc->base, tcp, on_secure_transport_setup_done, c);
   GRPC_SECURITY_CONNECTOR_UNREF (&sc->base, "httpcli");
 }
 
diff --git a/src/core/iomgr/alarm.c b/src/core/iomgr/alarm.c
index b10335c613..3110bd3cdf 100644
--- a/src/core/iomgr/alarm.c
+++ b/src/core/iomgr/alarm.c
@@ -108,7 +108,7 @@ void
 grpc_alarm_list_shutdown (grpc_closure_list * closure_list)
 {
   int i;
-  run_some_expired_alarms (gpr_inf_future (g_clock_type), NULL, 0, closure_list);
+  run_some_expired_alarms (gpr_inf_future (exec_ctx, g_clock_type), NULL, 0);
   for (i = 0; i < NUM_SHARDS; i++)
     {
       shard_type *shard = &g_shards[i];
@@ -346,7 +346,7 @@ run_some_expired_alarms (grpc_exec_ctx * exec_ctx, gpr_timespec now, gpr_timespe
 	  /* For efficiency, we pop as many available alarms as we can from the
 	     shard.  This may violate perfect alarm deadline ordering, but that
 	     shouldn't be a big deal because we don't make ordering guarantees. */
-	  n += pop_alarms (g_shard_queue[0], now, &new_min_deadline, success, closure_list);
+	  n += pop_alarms (exec_ctx, g_shard_queue[0], now, &new_min_deadline, success);
 
 	  /* An grpc_alarm_init() on the shard could intervene here, adding a new
 	     alarm that is earlier than new_min_deadline.  However,
@@ -373,7 +373,7 @@ int
 grpc_alarm_check (grpc_exec_ctx * exec_ctx, gpr_timespec now, gpr_timespec * next)
 {
   GPR_ASSERT (now.clock_type == g_clock_type);
-  return run_some_expired_alarms (now, next, gpr_time_cmp (now, gpr_inf_future (now.clock_type)) != 0, closure_list);
+  return run_some_expired_alarms (now, next, gpr_time_cmp (now, gpr_inf_future (exec_ctx, now.clock_type)) != 0);
 }
 
 gpr_timespec
diff --git a/src/core/iomgr/closure.c b/src/core/iomgr/closure.c
index ae4350e8a9..cd02aac75e 100644
--- a/src/core/iomgr/closure.c
+++ b/src/core/iomgr/closure.c
@@ -69,7 +69,7 @@ grpc_closure_list_run (grpc_closure_list * closure_list)
       while (c != NULL)
 	{
 	  grpc_closure *next = c->next;
-	  c->cb (c->cb_arg, c->success, closure_list);
+	  c->cb (exec_ctx, c->cb_arg, c->success);
 	  c = next;
 	}
     }
diff --git a/src/core/iomgr/endpoint.c b/src/core/iomgr/endpoint.c
index 20ad7fee13..d0f272a00b 100644
--- a/src/core/iomgr/endpoint.c
+++ b/src/core/iomgr/endpoint.c
@@ -36,37 +36,37 @@
 void
 grpc_endpoint_read (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, gpr_slice_buffer * slices, grpc_closure * cb)
 {
-  ep->vtable->read (ep, slices, cb, closure_list);
+  ep->vtable->read (exec_ctx, ep, slices, cb);
 }
 
 void
 grpc_endpoint_write (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, gpr_slice_buffer * slices, grpc_closure * cb)
 {
-  ep->vtable->write (ep, slices, cb, closure_list);
+  ep->vtable->write (exec_ctx, ep, slices, cb);
 }
 
 void
 grpc_endpoint_add_to_pollset (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, grpc_pollset * pollset)
 {
-  ep->vtable->add_to_pollset (ep, pollset, closure_list);
+  ep->vtable->add_to_pollset (exec_ctx, ep, pollset);
 }
 
 void
 grpc_endpoint_add_to_pollset_set (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, grpc_pollset_set * pollset_set)
 {
-  ep->vtable->add_to_pollset_set (ep, pollset_set, closure_list);
+  ep->vtable->add_to_pollset_set (exec_ctx, ep, pollset_set);
 }
 
 void
 grpc_endpoint_shutdown (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep)
 {
-  ep->vtable->shutdown (ep, closure_list);
+  ep->vtable->shutdown (exec_ctx, ep);
 }
 
 void
 grpc_endpoint_destroy (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep)
 {
-  ep->vtable->destroy (ep, closure_list);
+  ep->vtable->destroy (exec_ctx, ep);
 }
 
 char *
diff --git a/src/core/iomgr/fd_posix.c b/src/core/iomgr/fd_posix.c
index 8ae63e2a89..fb4e99605d 100644
--- a/src/core/iomgr/fd_posix.c
+++ b/src/core/iomgr/fd_posix.c
@@ -370,7 +370,7 @@ set_ready (grpc_exec_ctx * exec_ctx, grpc_fd * fd, gpr_atm * st)
   /* only one set_ready can be active at once (but there may be a racing
      notify_on) */
   gpr_mu_lock (&fd->set_state_mu);
-  set_ready_locked (fd, st, closure_list);
+  set_ready_locked (exec_ctx, fd, st);
   gpr_mu_unlock (&fd->set_state_mu);
 }
 
@@ -380,21 +380,21 @@ grpc_fd_shutdown (grpc_exec_ctx * exec_ctx, grpc_fd * fd)
   gpr_mu_lock (&fd->set_state_mu);
   GPR_ASSERT (!gpr_atm_no_barrier_load (&fd->shutdown));
   gpr_atm_rel_store (&fd->shutdown, 1);
-  set_ready_locked (fd, &fd->readst, closure_list);
-  set_ready_locked (fd, &fd->writest, closure_list);
+  set_ready_locked (exec_ctx, fd, &fd->readst);
+  set_ready_locked (exec_ctx, fd, &fd->writest);
   gpr_mu_unlock (&fd->set_state_mu);
 }
 
 void
 grpc_fd_notify_on_read (grpc_exec_ctx * exec_ctx, grpc_fd * fd, grpc_closure * closure)
 {
-  notify_on (fd, &fd->readst, closure, closure_list);
+  notify_on (exec_ctx, fd, &fd->readst, closure);
 }
 
 void
 grpc_fd_notify_on_write (grpc_exec_ctx * exec_ctx, grpc_fd * fd, grpc_closure * closure)
 {
-  notify_on (fd, &fd->writest, closure, closure_list);
+  notify_on (exec_ctx, fd, &fd->writest, closure);
 }
 
 gpr_uint32
@@ -493,13 +493,13 @@ grpc_fd_end_poll (grpc_exec_ctx * exec_ctx, grpc_fd_watcher * watcher, int got_r
 void
 grpc_fd_become_readable (grpc_exec_ctx * exec_ctx, grpc_fd * fd)
 {
-  set_ready (fd, &fd->readst, closure_list);
+  set_ready (exec_ctx, fd, &fd->readst);
 }
 
 void
 grpc_fd_become_writable (grpc_exec_ctx * exec_ctx, grpc_fd * fd)
 {
-  set_ready (fd, &fd->writest, closure_list);
+  set_ready (exec_ctx, fd, &fd->writest);
 }
 
 #endif
diff --git a/src/core/iomgr/pollset_multipoller_with_epoll.c b/src/core/iomgr/pollset_multipoller_with_epoll.c
index e5f0d99e54..a9ee5a4574 100644
--- a/src/core/iomgr/pollset_multipoller_with_epoll.c
+++ b/src/core/iomgr/pollset_multipoller_with_epoll.c
@@ -90,7 +90,7 @@ finally_add_fd (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_fd * fd)
 	    }
 	}
     }
-  grpc_fd_end_poll (&watcher, 0, 0, closure_list);
+  grpc_fd_end_poll (exec_ctx, &watcher, 0, 0);
 }
 
 static void
@@ -100,7 +100,7 @@ perform_delayed_add (grpc_exec_ctx * exec_ctx, void *arg, int iomgr_status)
 
   if (!grpc_fd_is_orphaned (da->fd))
     {
-      finally_add_fd (da->pollset, da->fd, closure_list);
+      finally_add_fd (exec_ctx, da->pollset, da->fd);
     }
 
   gpr_mu_lock (&da->pollset->mu);
@@ -127,7 +127,7 @@ multipoll_with_epoll_pollset_add_fd (grpc_exec_ctx * exec_ctx, grpc_pollset * po
   if (and_unlock_pollset)
     {
       gpr_mu_unlock (&pollset->mu);
-      finally_add_fd (pollset, fd, closure_list);
+      finally_add_fd (exec_ctx, pollset, fd);
     }
   else
     {
@@ -235,11 +235,11 @@ multipoll_with_epoll_pollset_maybe_work_and_unlock (grpc_exec_ctx * exec_ctx, gr
 		      int write = ep_ev[i].events & EPOLLOUT;
 		      if (read || cancel)
 			{
-			  grpc_fd_become_readable (fd, closure_list);
+			  grpc_fd_become_readable (exec_ctx, fd);
 			}
 		      if (write || cancel)
 			{
-			  grpc_fd_become_writable (fd, closure_list);
+			  grpc_fd_become_writable (exec_ctx, fd);
 			}
 		    }
 		}
@@ -286,7 +286,7 @@ epoll_become_multipoller (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc
     }
   for (i = 0; i < nfds; i++)
     {
-      multipoll_with_epoll_pollset_add_fd (pollset, fds[i], 0, closure_list);
+      multipoll_with_epoll_pollset_add_fd (exec_ctx, pollset, fds[i], 0);
     }
 }
 
diff --git a/src/core/iomgr/pollset_multipoller_with_poll_posix.c b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
index 8417b7491a..b7eb6c0ab0 100644
--- a/src/core/iomgr/pollset_multipoller_with_poll_posix.c
+++ b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
@@ -163,7 +163,7 @@ multipoll_with_poll_pollset_maybe_work_and_unlock (grpc_exec_ctx * exec_ctx, grp
 
   for (i = 1; i < pfd_count; i++)
     {
-      grpc_fd_end_poll (&watchers[i], pfds[i].revents & POLLIN, pfds[i].revents & POLLOUT, closure_list);
+      grpc_fd_end_poll (exec_ctx, &watchers[i], pfds[i].revents & POLLIN, pfds[i].revents & POLLOUT);
     }
 
   if (r < 0)
@@ -191,11 +191,11 @@ multipoll_with_poll_pollset_maybe_work_and_unlock (grpc_exec_ctx * exec_ctx, grp
 	    }
 	  if (pfds[i].revents & (POLLIN | POLLHUP | POLLERR))
 	    {
-	      grpc_fd_become_readable (watchers[i].fd, closure_list);
+	      grpc_fd_become_readable (exec_ctx, watchers[i].fd);
 	    }
 	  if (pfds[i].revents & (POLLOUT | POLLHUP | POLLERR))
 	    {
-	      grpc_fd_become_writable (watchers[i].fd, closure_list);
+	      grpc_fd_become_writable (exec_ctx, watchers[i].fd);
 	    }
 	}
     }
diff --git a/src/core/iomgr/pollset_posix.c b/src/core/iomgr/pollset_posix.c
index ad5c42aac3..c15b1f1908 100644
--- a/src/core/iomgr/pollset_posix.c
+++ b/src/core/iomgr/pollset_posix.c
@@ -172,7 +172,7 @@ void
 grpc_pollset_add_fd (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_fd * fd)
 {
   gpr_mu_lock (&pollset->mu);
-  pollset->vtable->add_fd (pollset, fd, 1, closure_list);
+  pollset->vtable->add_fd (exec_ctx, pollset, fd, 1);
 /* the following (enabled only in debug) will reacquire and then release
    our lock - meaning that if the unlocking flag passed to del_fd above is
    not respected, the code will deadlock (in a way that we have a chance of
@@ -187,7 +187,7 @@ void
 grpc_pollset_del_fd (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_fd * fd)
 {
   gpr_mu_lock (&pollset->mu);
-  pollset->vtable->del_fd (pollset, fd, 1, closure_list);
+  pollset->vtable->del_fd (exec_ctx, pollset, fd, 1);
 /* the following (enabled only in debug) will reacquire and then release
    our lock - meaning that if the unlocking flag passed to del_fd above is
    not respected, the code will deadlock (in a way that we have a chance of
@@ -217,10 +217,10 @@ grpc_pollset_work (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_pollse
   grpc_wakeup_fd_init (&worker->wakeup_fd);
   if (!grpc_pollset_has_workers (pollset) && !grpc_closure_list_empty (pollset->idle_jobs))
     {
-      grpc_closure_list_move (&pollset->idle_jobs, closure_list);
+      grpc_closure_list_move (exec_ctx, &pollset->idle_jobs);
       goto done;
     }
-  if (grpc_alarm_check (now, &deadline, closure_list))
+  if (grpc_alarm_check (exec_ctx, now, &deadline))
     {
       goto done;
     }
@@ -240,7 +240,7 @@ grpc_pollset_work (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_pollse
       push_front_worker (pollset, worker);
       added_worker = 1;
       gpr_tls_set (&g_current_thread_poller, (gpr_intptr) pollset);
-      pollset->vtable->maybe_work_and_unlock (pollset, worker, deadline, now, closure_list);
+      pollset->vtable->maybe_work_and_unlock (exec_ctx, pollset, worker, deadline, now);
       locked = 0;
       gpr_tls_set (&g_current_thread_poller, 0);
     }
@@ -270,7 +270,7 @@ done:
 	{
 	  pollset->called_shutdown = 1;
 	  gpr_mu_unlock (&pollset->mu);
-	  finish_shutdown (pollset, closure_list);
+	  finish_shutdown (exec_ctx, pollset);
 	  grpc_closure_list_run (closure_list);
 	  /* Continuing to access pollset here is safe -- it is the caller's
 	   * responsibility to not destroy when it has outstanding calls to
@@ -299,7 +299,7 @@ grpc_pollset_shutdown (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_cl
 
   if (call_shutdown)
     {
-      finish_shutdown (pollset, closure_list);
+      finish_shutdown (exec_ctx, pollset);
     }
 }
 
@@ -387,7 +387,7 @@ basic_do_promote (grpc_exec_ctx * exec_ctx, void *args, int success)
     }
   else if (pollset->vtable != original_vtable)
     {
-      pollset->vtable->add_fd (pollset, fd, 0, closure_list);
+      pollset->vtable->add_fd (exec_ctx, pollset, fd, 0);
     }
   else if (fd != pollset->data.ptr)
     {
@@ -397,7 +397,7 @@ basic_do_promote (grpc_exec_ctx * exec_ctx, void *args, int success)
 
       if (fds[0] && !grpc_fd_is_orphaned (fds[0]))
 	{
-	  grpc_platform_become_multipoller (pollset, fds, GPR_ARRAY_SIZE (fds), closure_list);
+	  grpc_platform_become_multipoller (pollset, fds, GPR_ARRAY_SIZE (exec_ctx, fds));
 	  GRPC_FD_UNREF (fds[0], "basicpoll");
 	}
       else
@@ -445,7 +445,7 @@ basic_pollset_add_fd (grpc_exec_ctx * exec_ctx, grpc_pollset * pollset, grpc_fd
 	}
       else if (!grpc_fd_is_orphaned (fds[0]))
 	{
-	  grpc_platform_become_multipoller (pollset, fds, GPR_ARRAY_SIZE (fds), closure_list);
+	  grpc_platform_become_multipoller (pollset, fds, GPR_ARRAY_SIZE (exec_ctx, fds));
 	  GRPC_FD_UNREF (fds[0], "basicpoll");
 	}
       else
@@ -540,7 +540,7 @@ basic_pollset_maybe_work_and_unlock (grpc_exec_ctx * exec_ctx, grpc_pollset * po
 
   if (fd)
     {
-      grpc_fd_end_poll (&fd_watcher, pfd[1].revents & POLLIN, pfd[1].revents & POLLOUT, closure_list);
+      grpc_fd_end_poll (exec_ctx, &fd_watcher, pfd[1].revents & POLLIN, pfd[1].revents & POLLOUT);
     }
 
   if (r < 0)
@@ -564,11 +564,11 @@ basic_pollset_maybe_work_and_unlock (grpc_exec_ctx * exec_ctx, grpc_pollset * po
 	{
 	  if (pfd[1].revents & (POLLIN | POLLHUP | POLLERR))
 	    {
-	      grpc_fd_become_readable (fd, closure_list);
+	      grpc_fd_become_readable (exec_ctx, fd);
 	    }
 	  if (pfd[1].revents & (POLLOUT | POLLHUP | POLLERR))
 	    {
-	      grpc_fd_become_writable (fd, closure_list);
+	      grpc_fd_become_writable (exec_ctx, fd);
 	    }
 	}
     }
diff --git a/src/core/iomgr/pollset_set_posix.c b/src/core/iomgr/pollset_set_posix.c
index 83be0b91c9..cb2e6aede3 100644
--- a/src/core/iomgr/pollset_set_posix.c
+++ b/src/core/iomgr/pollset_set_posix.c
@@ -82,7 +82,7 @@ grpc_pollset_set_add_pollset (grpc_exec_ctx * exec_ctx, grpc_pollset_set * polls
 	}
       else
 	{
-	  grpc_pollset_add_fd (pollset, pollset_set->fds[i], closure_list);
+	  grpc_pollset_add_fd (exec_ctx, pollset, pollset_set->fds[i]);
 	  pollset_set->fds[j++] = pollset_set->fds[i];
 	}
     }
@@ -121,7 +121,7 @@ grpc_pollset_set_add_fd (grpc_exec_ctx * exec_ctx, grpc_pollset_set * pollset_se
   pollset_set->fds[pollset_set->fd_count++] = fd;
   for (i = 0; i < pollset_set->pollset_count; i++)
     {
-      grpc_pollset_add_fd (pollset_set->pollsets[i], fd, closure_list);
+      grpc_pollset_add_fd (exec_ctx, pollset_set->pollsets[i], fd);
     }
   gpr_mu_unlock (&pollset_set->mu);
 }
diff --git a/src/core/iomgr/tcp_client_posix.c b/src/core/iomgr/tcp_client_posix.c
index cca626228a..69384ef484 100644
--- a/src/core/iomgr/tcp_client_posix.c
+++ b/src/core/iomgr/tcp_client_posix.c
@@ -106,7 +106,7 @@ tc_on_alarm (grpc_exec_ctx * exec_ctx, void *acp, int success)
   gpr_mu_lock (&ac->mu);
   if (ac->fd != NULL)
     {
-      grpc_fd_shutdown (ac->fd, closure_list);
+      grpc_fd_shutdown (exec_ctx, ac->fd);
     }
   done = (--ac->refs == 0);
   gpr_mu_unlock (&ac->mu);
@@ -141,7 +141,7 @@ on_writable (grpc_exec_ctx * exec_ctx, void *acp, int success)
   ac->fd = NULL;
   gpr_mu_unlock (&ac->mu);
 
-  grpc_alarm_cancel (&ac->alarm, closure_list);
+  grpc_alarm_cancel (exec_ctx, &ac->alarm);
 
   gpr_mu_lock (&ac->mu);
   if (success)
@@ -177,7 +177,7 @@ on_writable (grpc_exec_ctx * exec_ctx, void *acp, int success)
 	         don't do that! */
 	      gpr_log (GPR_ERROR, "kernel out of buffers");
 	      gpr_mu_unlock (&ac->mu);
-	      grpc_fd_notify_on_write (fd, &ac->write_closure, closure_list);
+	      grpc_fd_notify_on_write (exec_ctx, fd, &ac->write_closure);
 	      return;
 	    }
 	  else
@@ -196,7 +196,7 @@ on_writable (grpc_exec_ctx * exec_ctx, void *acp, int success)
 	}
       else
 	{
-	  grpc_pollset_set_del_fd (ac->interested_parties, fd, closure_list);
+	  grpc_pollset_set_del_fd (exec_ctx, ac->interested_parties, fd);
 	  *ep = grpc_tcp_create (fd, GRPC_TCP_DEFAULT_READ_SLICE_SIZE, ac->addr_str);
 	  fd = NULL;
 	  goto finish;
@@ -213,8 +213,8 @@ on_writable (grpc_exec_ctx * exec_ctx, void *acp, int success)
 finish:
   if (fd != NULL)
     {
-      grpc_pollset_set_del_fd (ac->interested_parties, fd, closure_list);
-      grpc_fd_orphan (fd, NULL, "tcp_client_orphan", closure_list);
+      grpc_pollset_set_del_fd (exec_ctx, ac->interested_parties, fd);
+      grpc_fd_orphan (exec_ctx, fd, NULL, "tcp_client_orphan");
       fd = NULL;
     }
   done = (--ac->refs == 0);
@@ -290,12 +290,12 @@ grpc_tcp_client_connect (grpc_exec_ctx * exec_ctx, grpc_closure * closure, grpc_
   if (errno != EWOULDBLOCK && errno != EINPROGRESS)
     {
       gpr_log (GPR_ERROR, "connect error to '%s': %s", addr_str, strerror (errno));
-      grpc_fd_orphan (fdobj, NULL, "tcp_client_connect_error", closure_list);
+      grpc_fd_orphan (exec_ctx, fdobj, NULL, "tcp_client_connect_error");
       grpc_closure_list_add (closure_list, closure, 0);
       goto done;
     }
 
-  grpc_pollset_set_add_fd (interested_parties, fdobj, closure_list);
+  grpc_pollset_set_add_fd (exec_ctx, interested_parties, fdobj);
 
   ac = gpr_malloc (sizeof (async_connect));
   ac->closure = closure;
@@ -315,8 +315,8 @@ grpc_tcp_client_connect (grpc_exec_ctx * exec_ctx, grpc_closure * closure, grpc_
     }
 
   gpr_mu_lock (&ac->mu);
-  grpc_alarm_init (&ac->alarm, gpr_convert_clock_type (deadline, GPR_CLOCK_MONOTONIC), tc_on_alarm, ac, gpr_now (GPR_CLOCK_MONOTONIC), closure_list);
-  grpc_fd_notify_on_write (ac->fd, &ac->write_closure, closure_list);
+  grpc_alarm_init (&ac->alarm, gpr_convert_clock_type (deadline, GPR_CLOCK_MONOTONIC), tc_on_alarm, ac, gpr_now (exec_ctx, GPR_CLOCK_MONOTONIC));
+  grpc_fd_notify_on_write (exec_ctx, ac->fd, &ac->write_closure);
   gpr_mu_unlock (&ac->mu);
 
 done:
diff --git a/src/core/iomgr/tcp_posix.c b/src/core/iomgr/tcp_posix.c
index bc9f566c6a..66895f3744 100644
--- a/src/core/iomgr/tcp_posix.c
+++ b/src/core/iomgr/tcp_posix.c
@@ -104,13 +104,13 @@ static void
 tcp_shutdown (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep)
 {
   grpc_tcp *tcp = (grpc_tcp *) ep;
-  grpc_fd_shutdown (tcp->em_fd, closure_list);
+  grpc_fd_shutdown (exec_ctx, tcp->em_fd);
 }
 
 static void
 tcp_free (grpc_exec_ctx * exec_ctx, grpc_tcp * tcp)
 {
-  grpc_fd_orphan (tcp->em_fd, NULL, "tcp_unref_orphan", closure_list);
+  grpc_fd_orphan (exec_ctx, tcp->em_fd, NULL, "tcp_unref_orphan");
   gpr_free (tcp->peer_string);
   gpr_free (tcp);
 }
@@ -126,7 +126,7 @@ tcp_unref (grpc_tcp * tcp, grpc_closure_list * closure_list, const char *reason,
   gpr_log (file, line, GPR_LOG_SEVERITY_DEBUG, "TCP unref %p : %s %d -> %d", tcp, reason, tcp->refcount.count, tcp->refcount.count - 1);
   if (gpr_unref (&tcp->refcount))
     {
-      tcp_free (tcp, closure_list);
+      tcp_free (exec_ctx, tcp);
     }
 }
 
@@ -144,7 +144,7 @@ tcp_unref (grpc_exec_ctx * exec_ctx, grpc_tcp * tcp)
 {
   if (gpr_unref (&tcp->refcount))
     {
-      tcp_free (tcp, closure_list);
+      tcp_free (exec_ctx, tcp);
     }
 }
 
@@ -159,7 +159,7 @@ static void
 tcp_destroy (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep)
 {
   grpc_tcp *tcp = (grpc_tcp *) ep;
-  TCP_UNREF (tcp, "destroy", closure_list);
+  TCP_UNREF (exec_ctx, tcp, "destroy");
 }
 
 static void
@@ -182,7 +182,7 @@ call_read_cb (grpc_exec_ctx * exec_ctx, grpc_tcp * tcp, int success)
 
   tcp->read_cb = NULL;
   tcp->incoming_buffer = NULL;
-  cb->cb (cb->cb_arg, success, closure_list);
+  cb->cb (exec_ctx, cb->cb_arg, success);
 }
 
 #define MAX_READ_IOVEC 4
@@ -236,22 +236,22 @@ tcp_continue_read (grpc_exec_ctx * exec_ctx, grpc_tcp * tcp)
 	      tcp->iov_size /= 2;
 	    }
 	  /* We've consumed the edge, request a new one */
-	  grpc_fd_notify_on_read (tcp->em_fd, &tcp->read_closure, closure_list);
+	  grpc_fd_notify_on_read (exec_ctx, tcp->em_fd, &tcp->read_closure);
 	}
       else
 	{
 	  /* TODO(klempner): Log interesting errors */
 	  gpr_slice_buffer_reset_and_unref (tcp->incoming_buffer);
-	  call_read_cb (tcp, 0, closure_list);
-	  TCP_UNREF (tcp, "read", closure_list);
+	  call_read_cb (exec_ctx, tcp, 0);
+	  TCP_UNREF (exec_ctx, tcp, "read");
 	}
     }
   else if (read_bytes == 0)
     {
       /* 0 read size ==> end of stream */
       gpr_slice_buffer_reset_and_unref (tcp->incoming_buffer);
-      call_read_cb (tcp, 0, closure_list);
-      TCP_UNREF (tcp, "read", closure_list);
+      call_read_cb (exec_ctx, tcp, 0);
+      TCP_UNREF (exec_ctx, tcp, "read");
     }
   else
     {
@@ -265,8 +265,8 @@ tcp_continue_read (grpc_exec_ctx * exec_ctx, grpc_tcp * tcp)
 	  ++tcp->iov_size;
 	}
       GPR_ASSERT ((size_t) read_bytes == tcp->incoming_buffer->length);
-      call_read_cb (tcp, 1, closure_list);
-      TCP_UNREF (tcp, "read", closure_list);
+      call_read_cb (exec_ctx, tcp, 1);
+      TCP_UNREF (exec_ctx, tcp, "read");
     }
 
   GRPC_TIMER_END (GRPC_PTAG_HANDLE_READ, 0);
@@ -282,12 +282,12 @@ tcp_handle_read (void *arg /* grpc_tcp */ , int success,
   if (!success)
     {
       gpr_slice_buffer_reset_and_unref (tcp->incoming_buffer);
-      call_read_cb (tcp, 0, closure_list);
-      TCP_UNREF (tcp, "read", closure_list);
+      call_read_cb (exec_ctx, tcp, 0);
+      TCP_UNREF (exec_ctx, tcp, "read");
     }
   else
     {
-      tcp_continue_read (tcp, closure_list);
+      tcp_continue_read (exec_ctx, tcp);
     }
 }
 
@@ -303,7 +303,7 @@ tcp_read (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, gpr_slice_buffer * incom
   if (tcp->finished_edge)
     {
       tcp->finished_edge = 0;
-      grpc_fd_notify_on_read (tcp->em_fd, &tcp->read_closure, closure_list);
+      grpc_fd_notify_on_read (exec_ctx, tcp->em_fd, &tcp->read_closure);
     }
   else
     {
@@ -412,8 +412,8 @@ tcp_handle_write (void *arg /* grpc_tcp */ , int success,
     {
       cb = tcp->write_cb;
       tcp->write_cb = NULL;
-      cb->cb (cb->cb_arg, 0, closure_list);
-      TCP_UNREF (tcp, "write", closure_list);
+      cb->cb (exec_ctx, cb->cb_arg, 0);
+      TCP_UNREF (exec_ctx, tcp, "write");
       return;
     }
 
@@ -421,14 +421,14 @@ tcp_handle_write (void *arg /* grpc_tcp */ , int success,
   status = tcp_flush (tcp);
   if (status == FLUSH_PENDING)
     {
-      grpc_fd_notify_on_write (tcp->em_fd, &tcp->write_closure, closure_list);
+      grpc_fd_notify_on_write (exec_ctx, tcp->em_fd, &tcp->write_closure);
     }
   else
     {
       cb = tcp->write_cb;
       tcp->write_cb = NULL;
-      cb->cb (cb->cb_arg, status == FLUSH_DONE, closure_list);
-      TCP_UNREF (tcp, "write", closure_list);
+      cb->cb (exec_ctx, cb->cb_arg, status == FLUSH_DONE);
+      TCP_UNREF (exec_ctx, tcp, "write");
     }
   GRPC_TIMER_END (GRPC_PTAG_TCP_CB_WRITE, 0);
 }
@@ -469,7 +469,7 @@ tcp_write (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, gpr_slice_buffer * buf,
     {
       TCP_REF (tcp, "write");
       tcp->write_cb = cb;
-      grpc_fd_notify_on_write (tcp->em_fd, &tcp->write_closure, closure_list);
+      grpc_fd_notify_on_write (exec_ctx, tcp->em_fd, &tcp->write_closure);
     }
   else
     {
@@ -483,14 +483,14 @@ static void
 tcp_add_to_pollset (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, grpc_pollset * pollset)
 {
   grpc_tcp *tcp = (grpc_tcp *) ep;
-  grpc_pollset_add_fd (pollset, tcp->em_fd, closure_list);
+  grpc_pollset_add_fd (exec_ctx, pollset, tcp->em_fd);
 }
 
 static void
 tcp_add_to_pollset_set (grpc_exec_ctx * exec_ctx, grpc_endpoint * ep, grpc_pollset_set * pollset_set)
 {
   grpc_tcp *tcp = (grpc_tcp *) ep;
-  grpc_pollset_set_add_fd (pollset_set, tcp->em_fd, closure_list);
+  grpc_pollset_set_add_fd (exec_ctx, pollset_set, tcp->em_fd);
 }
 
 static char *
diff --git a/src/core/iomgr/tcp_server_posix.c b/src/core/iomgr/tcp_server_posix.c
index ee462aabd4..2d42e03ce0 100644
--- a/src/core/iomgr/tcp_server_posix.c
+++ b/src/core/iomgr/tcp_server_posix.c
@@ -168,7 +168,7 @@ destroyed_port (grpc_exec_ctx * exec_ctx, void *server, int success)
   if (s->destroyed_ports == s->nports)
     {
       gpr_mu_unlock (&s->mu);
-      finish_shutdown (s, closure_list);
+      finish_shutdown (exec_ctx, s);
     }
   else
     {
@@ -205,14 +205,14 @@ deactivated_all_ports (grpc_exec_ctx * exec_ctx, grpc_tcp_server * s)
 	    }
 	  sp->destroyed_closure.cb = destroyed_port;
 	  sp->destroyed_closure.cb_arg = s;
-	  grpc_fd_orphan (sp->emfd, &sp->destroyed_closure, "tcp_listener_shutdown", closure_list);
+	  grpc_fd_orphan (exec_ctx, sp->emfd, &sp->destroyed_closure, "tcp_listener_shutdown");
 	}
       gpr_mu_unlock (&s->mu);
     }
   else
     {
       gpr_mu_unlock (&s->mu);
-      finish_shutdown (s, closure_list);
+      finish_shutdown (exec_ctx, s);
     }
 }
 
@@ -232,14 +232,14 @@ grpc_tcp_server_destroy (grpc_exec_ctx * exec_ctx, grpc_tcp_server * s, grpc_clo
     {
       for (i = 0; i < s->nports; i++)
 	{
-	  grpc_fd_shutdown (s->ports[i].emfd, closure_list);
+	  grpc_fd_shutdown (exec_ctx, s->ports[i].emfd);
 	}
       gpr_mu_unlock (&s->mu);
     }
   else
     {
       gpr_mu_unlock (&s->mu);
-      deactivated_all_ports (s, closure_list);
+      deactivated_all_ports (exec_ctx, s);
     }
 }
 
@@ -361,7 +361,7 @@ on_read (grpc_exec_ctx * exec_ctx, void *arg, int success)
 	    case EINTR:
 	      continue;
 	    case EAGAIN:
-	      grpc_fd_notify_on_read (sp->emfd, &sp->read_closure, closure_list);
+	      grpc_fd_notify_on_read (exec_ctx, sp->emfd, &sp->read_closure);
 	      return;
 	    default:
 	      gpr_log (GPR_ERROR, "Failed accept4: %s", strerror (errno));
@@ -385,9 +385,9 @@ on_read (grpc_exec_ctx * exec_ctx, void *arg, int success)
          incoming channel to every pollset owned by the server */
       for (i = 0; i < sp->server->pollset_count; i++)
 	{
-	  grpc_pollset_add_fd (sp->server->pollsets[i], fdobj, closure_list);
+	  grpc_pollset_add_fd (exec_ctx, sp->server->pollsets[i], fdobj);
 	}
-      sp->server->on_accept_cb (sp->server->on_accept_cb_arg, grpc_tcp_create (fdobj, GRPC_TCP_DEFAULT_READ_SLICE_SIZE, addr_str), closure_list);
+      sp->server->on_accept_cb (sp->server->on_accept_cb_arg, grpc_tcp_create (exec_ctx, fdobj, GRPC_TCP_DEFAULT_READ_SLICE_SIZE, addr_str));
 
       gpr_free (name);
       gpr_free (addr_str);
@@ -400,7 +400,7 @@ error:
   if (0 == --sp->server->active_ports)
     {
       gpr_mu_unlock (&sp->server->mu);
-      deactivated_all_ports (sp->server, closure_list);
+      deactivated_all_ports (exec_ctx, sp->server);
     }
   else
     {
@@ -557,11 +557,11 @@ grpc_tcp_server_start (grpc_exec_ctx * exec_ctx, grpc_tcp_server * s, grpc_polls
     {
       for (j = 0; j < pollset_count; j++)
 	{
-	  grpc_pollset_add_fd (pollsets[j], s->ports[i].emfd, closure_list);
+	  grpc_pollset_add_fd (exec_ctx, pollsets[j], s->ports[i].emfd);
 	}
       s->ports[i].read_closure.cb = on_read;
       s->ports[i].read_closure.cb_arg = &s->ports[i];
-      grpc_fd_notify_on_read (s->ports[i].emfd, &s->ports[i].read_closure, closure_list);
+      grpc_fd_notify_on_read (exec_ctx, s->ports[i].emfd, &s->ports[i].read_closure);
       s->active_ports++;
     }
   gpr_mu_unlock (&s->mu);
diff --git a/src/core/iomgr/udp_server.c b/src/core/iomgr/udp_server.c
index 2f45011a89..80b8748ea5 100644
--- a/src/core/iomgr/udp_server.c
+++ b/src/core/iomgr/udp_server.c
@@ -162,7 +162,7 @@ destroyed_port (grpc_exec_ctx * exec_ctx, void *server, int success)
   if (s->destroyed_ports == s->nports)
     {
       gpr_mu_unlock (&s->mu);
-      finish_shutdown (s, closure_list);
+      finish_shutdown (exec_ctx, s);
     }
   else
     {
@@ -198,14 +198,14 @@ deactivated_all_ports (grpc_exec_ctx * exec_ctx, grpc_udp_server * s)
 	    }
 	  sp->destroyed_closure.cb = destroyed_port;
 	  sp->destroyed_closure.cb_arg = s;
-	  grpc_fd_orphan (sp->emfd, &sp->destroyed_closure, "udp_listener_shutdown", closure_list);
+	  grpc_fd_orphan (exec_ctx, sp->emfd, &sp->destroyed_closure, "udp_listener_shutdown");
 	}
       gpr_mu_unlock (&s->mu);
     }
   else
     {
       gpr_mu_unlock (&s->mu);
-      finish_shutdown (s, closure_list);
+      finish_shutdown (exec_ctx, s);
     }
 }
 
@@ -225,14 +225,14 @@ grpc_udp_server_destroy (grpc_exec_ctx * exec_ctx, grpc_udp_server * s, grpc_clo
     {
       for (i = 0; i < s->nports; i++)
 	{
-	  grpc_fd_shutdown (s->ports[i].emfd, closure_list);
+	  grpc_fd_shutdown (exec_ctx, s->ports[i].emfd);
 	}
       gpr_mu_unlock (&s->mu);
     }
   else
     {
       gpr_mu_unlock (&s->mu);
-      deactivated_all_ports (s, closure_list);
+      deactivated_all_ports (exec_ctx, s);
     }
 }
 
@@ -302,7 +302,7 @@ on_read (grpc_exec_ctx * exec_ctx, void *arg, int success)
       if (0 == --sp->server->active_ports)
 	{
 	  gpr_mu_unlock (&sp->server->mu);
-	  deactivated_all_ports (sp->server, closure_list);
+	  deactivated_all_ports (exec_ctx, sp->server);
 	}
       else
 	{
@@ -316,7 +316,7 @@ on_read (grpc_exec_ctx * exec_ctx, void *arg, int success)
   sp->read_cb (sp->fd);
 
   /* Re-arm the notification event so we get another chance to read. */
-  grpc_fd_notify_on_read (sp->emfd, &sp->read_closure, closure_list);
+  grpc_fd_notify_on_read (exec_ctx, sp->emfd, &sp->read_closure);
 }
 
 static int
@@ -461,11 +461,11 @@ grpc_udp_server_start (grpc_exec_ctx * exec_ctx, grpc_udp_server * s, grpc_polls
     {
       for (j = 0; j < pollset_count; j++)
 	{
-	  grpc_pollset_add_fd (pollsets[j], s->ports[i].emfd, closure_list);
+	  grpc_pollset_add_fd (exec_ctx, pollsets[j], s->ports[i].emfd);
 	}
       s->ports[i].read_closure.cb = on_read;
       s->ports[i].read_closure.cb_arg = &s->ports[i];
-      grpc_fd_notify_on_read (s->ports[i].emfd, &s->ports[i].read_closure, closure_list);
+      grpc_fd_notify_on_read (exec_ctx, s->ports[i].emfd, &s->ports[i].read_closure);
       s->active_ports++;
     }
   gpr_mu_unlock (&s->mu);
diff --git a/src/core/iomgr/workqueue_posix.c b/src/core/iomgr/workqueue_posix.c
index 1aadaa4028..a407fb61a4 100644
--- a/src/core/iomgr/workqueue_posix.c
+++ b/src/core/iomgr/workqueue_posix.c
@@ -59,7 +59,7 @@ grpc_workqueue_create (grpc_closure_list * closure_list)
   sprintf (name, "workqueue:%p", (void *) workqueue);
   workqueue->wakeup_read_fd = grpc_fd_create (GRPC_WAKEUP_FD_GET_READ_FD (&workqueue->wakeup_fd), name);
   grpc_closure_init (&workqueue->read_closure, on_readable, workqueue);
-  grpc_fd_notify_on_read (workqueue->wakeup_read_fd, &workqueue->read_closure, closure_list);
+  grpc_fd_notify_on_read (exec_ctx, workqueue->wakeup_read_fd, &workqueue->read_closure);
   return workqueue;
 }
 
@@ -67,7 +67,7 @@ static void
 workqueue_destroy (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
 {
   GPR_ASSERT (grpc_closure_list_empty (workqueue->closure_list));
-  grpc_fd_shutdown (workqueue->wakeup_read_fd, closure_list);
+  grpc_fd_shutdown (exec_ctx, workqueue->wakeup_read_fd);
 }
 
 #ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
@@ -95,21 +95,21 @@ grpc_workqueue_unref (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
 #endif
   if (gpr_unref (&workqueue->refs))
     {
-      workqueue_destroy (workqueue, closure_list);
+      workqueue_destroy (exec_ctx, workqueue);
     }
 }
 
 void
 grpc_workqueue_add_to_pollset (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue, grpc_pollset * pollset)
 {
-  grpc_pollset_add_fd (pollset, workqueue->wakeup_read_fd, closure_list);
+  grpc_pollset_add_fd (exec_ctx, pollset, workqueue->wakeup_read_fd);
 }
 
 void
 grpc_workqueue_flush (grpc_exec_ctx * exec_ctx, grpc_workqueue * workqueue)
 {
   gpr_mu_lock (&workqueue->mu);
-  grpc_closure_list_move (&workqueue->closure_list, closure_list);
+  grpc_closure_list_move (exec_ctx, &workqueue->closure_list);
   gpr_mu_unlock (&workqueue->mu);
 }
 
@@ -124,16 +124,16 @@ on_readable (grpc_exec_ctx * exec_ctx, void *arg, int success)
       /* HACK: let wakeup_fd code know that we stole the fd */
       workqueue->wakeup_fd.read_fd = 0;
       grpc_wakeup_fd_destroy (&workqueue->wakeup_fd);
-      grpc_fd_orphan (workqueue->wakeup_read_fd, NULL, "destroy", closure_list);
+      grpc_fd_orphan (exec_ctx, workqueue->wakeup_read_fd, NULL, "destroy");
       gpr_free (workqueue);
     }
   else
     {
       gpr_mu_lock (&workqueue->mu);
-      grpc_closure_list_move (&workqueue->closure_list, closure_list);
+      grpc_closure_list_move (exec_ctx, &workqueue->closure_list);
       grpc_wakeup_fd_consume_wakeup (&workqueue->wakeup_fd);
       gpr_mu_unlock (&workqueue->mu);
-      grpc_fd_notify_on_read (workqueue->wakeup_read_fd, &workqueue->read_closure, closure_list);
+      grpc_fd_notify_on_read (exec_ctx, workqueue->wakeup_read_fd, &workqueue->read_closure);
     }
 }
 
diff --git a/src/core/security/client_auth_filter.c b/src/core/security/client_auth_filter.c
index 89ac3f464f..33f2e8093a 100644
--- a/src/core/security/client_auth_filter.c
+++ b/src/core/security/client_auth_filter.c
@@ -94,7 +94,7 @@ bubble_up_error (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_status
   call_data *calld = elem->call_data;
   gpr_log (GPR_ERROR, "Client side authentication failure: %s", error_msg);
   grpc_transport_stream_op_add_cancellation (&calld->op, status);
-  grpc_call_next_op (elem, &calld->op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, &calld->op);
 }
 
 static void
@@ -109,7 +109,7 @@ on_credentials_metadata (grpc_exec_ctx * exec_ctx, void *user_data, grpc_credent
   reset_service_url (calld);
   if (status != GRPC_CREDENTIALS_OK)
     {
-      bubble_up_error (elem, GRPC_STATUS_UNAUTHENTICATED, "Credentials failed to get metadata.", closure_list);
+      bubble_up_error (exec_ctx, elem, GRPC_STATUS_UNAUTHENTICATED, "Credentials failed to get metadata.");
       return;
     }
   GPR_ASSERT (num_md <= MAX_CREDENTIALS_METADATA_COUNT);
@@ -119,7 +119,7 @@ on_credentials_metadata (grpc_exec_ctx * exec_ctx, void *user_data, grpc_credent
     {
       grpc_metadata_batch_add_tail (mdb, &calld->md_links[i], grpc_mdelem_from_slices (chand->md_ctx, gpr_slice_ref (md_elems[i].key), gpr_slice_ref (md_elems[i].value)));
     }
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 void
@@ -161,7 +161,7 @@ send_security_metadata (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc
   if (!channel_creds_has_md && !call_creds_has_md)
     {
       /* Skip sending metadata altogether. */
-      grpc_call_next_op (elem, op, closure_list);
+      grpc_call_next_op (exec_ctx, elem, op);
       return;
     }
 
@@ -170,7 +170,7 @@ send_security_metadata (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc
       calld->creds = grpc_composite_credentials_create (channel_creds, ctx->creds, NULL);
       if (calld->creds == NULL)
 	{
-	  bubble_up_error (elem, GRPC_STATUS_INVALID_ARGUMENT, "Incompatible credentials set on channel and call.", closure_list);
+	  bubble_up_error (exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, "Incompatible credentials set on channel and call.");
 	  return;
 	}
     }
@@ -182,7 +182,7 @@ send_security_metadata (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc
   build_service_url (chand->security_connector->base.url_scheme, calld);
   calld->op = *op;		/* Copy op (originates from the caller's stack). */
   GPR_ASSERT (calld->pollset);
-  grpc_credentials_get_request_metadata (calld->creds, calld->pollset, calld->service_url, on_credentials_metadata, elem, closure_list);
+  grpc_credentials_get_request_metadata (exec_ctx, calld->creds, calld->pollset, calld->service_url, on_credentials_metadata, elem);
 }
 
 static void
@@ -193,13 +193,13 @@ on_host_checked (grpc_exec_ctx * exec_ctx, void *user_data, grpc_security_status
 
   if (status == GRPC_SECURITY_OK)
     {
-      send_security_metadata (elem, &calld->op, closure_list);
+      send_security_metadata (exec_ctx, elem, &calld->op);
     }
   else
     {
       char *error_msg;
       gpr_asprintf (&error_msg, "Invalid host %s set in :authority metadata.", grpc_mdstr_as_c_string (calld->host));
-      bubble_up_error (elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg, closure_list);
+      bubble_up_error (exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg);
       gpr_free (error_msg);
     }
 }
@@ -272,26 +272,26 @@ auth_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grp
 	      grpc_security_status status;
 	      const char *call_host = grpc_mdstr_as_c_string (calld->host);
 	      calld->op = *op;	/* Copy op (originates from the caller's stack). */
-	      status = grpc_channel_security_connector_check_call_host (chand->security_connector, call_host, on_host_checked, elem, closure_list);
+	      status = grpc_channel_security_connector_check_call_host (exec_ctx, chand->security_connector, call_host, on_host_checked, elem);
 	      if (status != GRPC_SECURITY_OK)
 		{
 		  if (status == GRPC_SECURITY_ERROR)
 		    {
 		      char *error_msg;
 		      gpr_asprintf (&error_msg, "Invalid host %s set in :authority metadata.", call_host);
-		      bubble_up_error (elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg, closure_list);
+		      bubble_up_error (exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg);
 		      gpr_free (error_msg);
 		    }
 		  return;	/* early exit */
 		}
 	    }
-	  send_security_metadata (elem, op, closure_list);
+	  send_security_metadata (exec_ctx, elem, op);
 	  return;		/* early exit */
 	}
     }
 
   /* pass control down the stack */
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/security/credentials.c b/src/core/security/credentials.c
index caf3d6f885..7c444f6ac9 100644
--- a/src/core/security/credentials.c
+++ b/src/core/security/credentials.c
@@ -126,11 +126,11 @@ grpc_credentials_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credential
     {
       if (cb != NULL)
 	{
-	  cb (user_data, NULL, 0, GRPC_CREDENTIALS_OK, closure_list);
+	  cb (exec_ctx, user_data, NULL, 0, GRPC_CREDENTIALS_OK);
 	}
       return;
     }
-  creds->vtable->get_request_metadata (creds, pollset, service_url, cb, user_data, closure_list);
+  creds->vtable->get_request_metadata (exec_ctx, creds, pollset, service_url, cb, user_data);
 }
 
 grpc_security_status
@@ -460,12 +460,12 @@ jwt_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * creds, gr
 
   if (jwt_md != NULL)
     {
-      cb (user_data, jwt_md->entries, jwt_md->num_entries, GRPC_CREDENTIALS_OK, closure_list);
+      cb (exec_ctx, user_data, jwt_md->entries, jwt_md->num_entries, GRPC_CREDENTIALS_OK);
       grpc_credentials_md_store_unref (jwt_md);
     }
   else
     {
-      cb (user_data, NULL, 0, GRPC_CREDENTIALS_ERROR, closure_list);
+      cb (exec_ctx, user_data, NULL, 0, GRPC_CREDENTIALS_ERROR);
     }
 }
 
@@ -644,12 +644,12 @@ on_oauth2_token_fetcher_http_response (grpc_exec_ctx * exec_ctx, void *user_data
   if (status == GRPC_CREDENTIALS_OK)
     {
       c->token_expiration = gpr_time_add (gpr_now (GPR_CLOCK_REALTIME), token_lifetime);
-      r->cb (r->user_data, c->access_token_md->entries, c->access_token_md->num_entries, status, closure_list);
+      r->cb (exec_ctx, r->user_data, c->access_token_md->entries, c->access_token_md->num_entries, status);
     }
   else
     {
       c->token_expiration = gpr_inf_past (GPR_CLOCK_REALTIME);
-      r->cb (r->user_data, NULL, 0, status, closure_list);
+      r->cb (exec_ctx, r->user_data, NULL, 0, status);
     }
   gpr_mu_unlock (&c->mu);
   grpc_credentials_metadata_request_destroy (r);
@@ -671,12 +671,12 @@ oauth2_token_fetcher_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_creden
   }
   if (cached_access_token_md != NULL)
     {
-      cb (user_data, cached_access_token_md->entries, cached_access_token_md->num_entries, GRPC_CREDENTIALS_OK, closure_list);
+      cb (exec_ctx, user_data, cached_access_token_md->entries, cached_access_token_md->num_entries, GRPC_CREDENTIALS_OK);
       grpc_credentials_md_store_unref (cached_access_token_md);
     }
   else
     {
-      c->fetch_func (grpc_credentials_metadata_request_create (creds, cb, user_data), &c->httpcli_context, pollset, on_oauth2_token_fetcher_http_response, gpr_time_add (gpr_now (GPR_CLOCK_REALTIME), refresh_threshold), closure_list);
+      c->fetch_func (grpc_credentials_metadata_request_create (creds, cb, user_data), &c->httpcli_context, pollset, on_oauth2_token_fetcher_http_response, gpr_time_add (gpr_now (exec_ctx, GPR_CLOCK_REALTIME), refresh_threshold));
     }
 }
 
@@ -710,7 +710,7 @@ compute_engine_fetch_oauth2 (grpc_exec_ctx * exec_ctx, grpc_credentials_metadata
   request.path = GRPC_COMPUTE_ENGINE_METADATA_TOKEN_PATH;
   request.hdr_count = 1;
   request.hdrs = &header;
-  grpc_httpcli_get (httpcli_context, pollset, &request, deadline, response_cb, metadata_req, closure_list);
+  grpc_httpcli_get (exec_ctx, httpcli_context, pollset, &request, deadline, response_cb, metadata_req);
 }
 
 grpc_credentials *
@@ -755,7 +755,7 @@ refresh_token_fetch_oauth2 (grpc_exec_ctx * exec_ctx, grpc_credentials_metadata_
   request.hdr_count = 1;
   request.hdrs = &header;
   request.handshaker = &grpc_httpcli_ssl;
-  grpc_httpcli_post (httpcli_context, pollset, &request, body, strlen (body), deadline, response_cb, metadata_req, closure_list);
+  grpc_httpcli_post (httpcli_context, pollset, &request, body, strlen (exec_ctx, body), deadline, response_cb, metadata_req);
   gpr_free (body);
 }
 
@@ -828,7 +828,7 @@ md_only_test_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials *
     }
   else
     {
-      cb (user_data, c->md_store->entries, 1, GRPC_CREDENTIALS_OK, closure_list);
+      cb (exec_ctx, user_data, c->md_store->entries, 1, GRPC_CREDENTIALS_OK);
     }
 }
 
@@ -877,7 +877,7 @@ static void
 access_token_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * creds, grpc_pollset * pollset, const char *service_url, grpc_credentials_metadata_cb cb, void *user_data)
 {
   grpc_access_token_credentials *c = (grpc_access_token_credentials *) creds;
-  cb (user_data, c->access_token_md->entries, 1, GRPC_CREDENTIALS_OK, closure_list);
+  cb (exec_ctx, user_data, c->access_token_md->entries, 1, GRPC_CREDENTIALS_OK);
 }
 
 static grpc_credentials_vtable access_token_vtable = {
@@ -1047,7 +1047,7 @@ composite_metadata_cb (grpc_exec_ctx * exec_ctx, void *user_data, grpc_credentia
   grpc_composite_credentials_metadata_context *ctx = (grpc_composite_credentials_metadata_context *) user_data;
   if (status != GRPC_CREDENTIALS_OK)
     {
-      ctx->cb (ctx->user_data, NULL, 0, status, closure_list);
+      ctx->cb (exec_ctx, ctx->user_data, NULL, 0, status);
       return;
     }
 
@@ -1067,13 +1067,13 @@ composite_metadata_cb (grpc_exec_ctx * exec_ctx, void *user_data, grpc_credentia
       grpc_credentials *inner_creds = ctx->composite_creds->inner.creds_array[ctx->creds_index++];
       if (grpc_credentials_has_request_metadata (inner_creds))
 	{
-	  grpc_credentials_get_request_metadata (inner_creds, ctx->pollset, ctx->service_url, composite_metadata_cb, ctx, closure_list);
+	  grpc_credentials_get_request_metadata (exec_ctx, inner_creds, ctx->pollset, ctx->service_url, composite_metadata_cb, ctx);
 	  return;
 	}
     }
 
   /* We're done!. */
-  ctx->cb (ctx->user_data, ctx->md_elems->entries, ctx->md_elems->num_entries, GRPC_CREDENTIALS_OK, closure_list);
+  ctx->cb (exec_ctx, ctx->user_data, ctx->md_elems->entries, ctx->md_elems->num_entries, GRPC_CREDENTIALS_OK);
   composite_md_context_destroy (ctx);
   grpc_closure_list_run (closure_list);
 }
@@ -1085,7 +1085,7 @@ composite_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * cre
   grpc_composite_credentials_metadata_context *ctx;
   if (!grpc_credentials_has_request_metadata (creds))
     {
-      cb (user_data, NULL, 0, GRPC_CREDENTIALS_OK, closure_list);
+      cb (exec_ctx, user_data, NULL, 0, GRPC_CREDENTIALS_OK);
       return;
     }
   ctx = gpr_malloc (sizeof (grpc_composite_credentials_metadata_context));
@@ -1101,7 +1101,7 @@ composite_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * cre
       grpc_credentials *inner_creds = c->inner.creds_array[ctx->creds_index++];
       if (grpc_credentials_has_request_metadata (inner_creds))
 	{
-	  grpc_credentials_get_request_metadata (inner_creds, pollset, service_url, composite_metadata_cb, ctx, closure_list);
+	  grpc_credentials_get_request_metadata (exec_ctx, inner_creds, pollset, service_url, composite_metadata_cb, ctx);
 	  return;
 	}
     }
@@ -1262,7 +1262,7 @@ static void
 iam_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * creds, grpc_pollset * pollset, const char *service_url, grpc_credentials_metadata_cb cb, void *user_data)
 {
   grpc_google_iam_credentials *c = (grpc_google_iam_credentials *) creds;
-  cb (user_data, c->iam_md->entries, c->iam_md->num_entries, GRPC_CREDENTIALS_OK, closure_list);
+  cb (exec_ctx, user_data, c->iam_md->entries, c->iam_md->num_entries, GRPC_CREDENTIALS_OK);
 }
 
 static grpc_credentials_vtable iam_vtable = {
@@ -1373,7 +1373,7 @@ plugin_get_request_metadata (grpc_exec_ctx * exec_ctx, grpc_credentials * creds,
     }
   else
     {
-      cb (user_data, NULL, 0, GRPC_CREDENTIALS_OK, closure_list);
+      cb (exec_ctx, user_data, NULL, 0, GRPC_CREDENTIALS_OK);
     }
 }
 
diff --git a/src/core/security/handshake.c b/src/core/security/handshake.c
index 7951f34943..687cc575a7 100644
--- a/src/core/security/handshake.c
+++ b/src/core/security/handshake.c
@@ -68,20 +68,20 @@ security_handshake_done (grpc_exec_ctx * exec_ctx, grpc_security_handshake * h,
 {
   if (is_success)
     {
-      h->cb (h->user_data, GRPC_SECURITY_OK, h->wrapped_endpoint, h->secure_endpoint, closure_list);
+      h->cb (exec_ctx, h->user_data, GRPC_SECURITY_OK, h->wrapped_endpoint, h->secure_endpoint);
     }
   else
     {
       if (h->secure_endpoint != NULL)
 	{
-	  grpc_endpoint_shutdown (h->secure_endpoint, closure_list);
-	  grpc_endpoint_destroy (h->secure_endpoint, closure_list);
+	  grpc_endpoint_shutdown (exec_ctx, h->secure_endpoint);
+	  grpc_endpoint_destroy (exec_ctx, h->secure_endpoint);
 	}
       else
 	{
-	  grpc_endpoint_destroy (h->wrapped_endpoint, closure_list);
+	  grpc_endpoint_destroy (exec_ctx, h->wrapped_endpoint);
 	}
-      h->cb (h->user_data, GRPC_SECURITY_ERROR, h->wrapped_endpoint, NULL, closure_list);
+      h->cb (exec_ctx, h->user_data, GRPC_SECURITY_ERROR, h->wrapped_endpoint, NULL);
     }
   if (h->handshaker != NULL)
     tsi_handshaker_destroy (h->handshaker);
@@ -103,20 +103,20 @@ on_peer_checked (grpc_exec_ctx * exec_ctx, void *user_data, grpc_security_status
   if (status != GRPC_SECURITY_OK)
     {
       gpr_log (GPR_ERROR, "Error checking peer.");
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
   result = tsi_handshaker_create_frame_protector (h->handshaker, NULL, &protector);
   if (result != TSI_OK)
     {
       gpr_log (GPR_ERROR, "Frame protector creation failed with error %s.", tsi_result_to_string (result));
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
   h->secure_endpoint = grpc_secure_endpoint_create (protector, h->wrapped_endpoint, h->left_overs.slices, h->left_overs.count);
   h->left_overs.count = 0;
   h->left_overs.length = 0;
-  security_handshake_done (h, 1, closure_list);
+  security_handshake_done (exec_ctx, h, 1);
   return;
 }
 
@@ -130,19 +130,19 @@ check_peer (grpc_exec_ctx * exec_ctx, grpc_security_handshake * h)
   if (result != TSI_OK)
     {
       gpr_log (GPR_ERROR, "Peer extraction failed with error %s", tsi_result_to_string (result));
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
   peer_status = grpc_security_connector_check_peer (h->connector, peer, on_peer_checked, h);
   if (peer_status == GRPC_SECURITY_ERROR)
     {
       gpr_log (GPR_ERROR, "Peer check failed.");
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
   else if (peer_status == GRPC_SECURITY_OK)
     {
-      on_peer_checked (h, peer_status, closure_list);
+      on_peer_checked (exec_ctx, h, peer_status);
     }
 }
 
@@ -169,7 +169,7 @@ send_handshake_bytes_to_peer (grpc_exec_ctx * exec_ctx, grpc_security_handshake
   if (result != TSI_OK)
     {
       gpr_log (GPR_ERROR, "Handshake failed with error %s", tsi_result_to_string (result));
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
 
@@ -178,7 +178,7 @@ send_handshake_bytes_to_peer (grpc_exec_ctx * exec_ctx, grpc_security_handshake
   gpr_slice_buffer_add (&h->outgoing, to_send);
   /* TODO(klempner,jboeuf): This should probably use the client setup
      deadline */
-  grpc_endpoint_write (h->wrapped_endpoint, &h->outgoing, &h->on_handshake_data_sent_to_peer, closure_list);
+  grpc_endpoint_write (exec_ctx, h->wrapped_endpoint, &h->outgoing, &h->on_handshake_data_sent_to_peer);
 }
 
 static void
@@ -194,7 +194,7 @@ on_handshake_data_received_from_peer (grpc_exec_ctx * exec_ctx, void *handshake,
   if (!success)
     {
       gpr_log (GPR_ERROR, "Read failed.");
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
 
@@ -211,12 +211,12 @@ on_handshake_data_received_from_peer (grpc_exec_ctx * exec_ctx, void *handshake,
       /* We may need more data. */
       if (result == TSI_INCOMPLETE_DATA)
 	{
-	  grpc_endpoint_read (h->wrapped_endpoint, &h->incoming, &h->on_handshake_data_received_from_peer, closure_list);
+	  grpc_endpoint_read (exec_ctx, h->wrapped_endpoint, &h->incoming, &h->on_handshake_data_received_from_peer);
 	  return;
 	}
       else
 	{
-	  send_handshake_bytes_to_peer (h, closure_list);
+	  send_handshake_bytes_to_peer (exec_ctx, h);
 	  return;
 	}
     }
@@ -224,7 +224,7 @@ on_handshake_data_received_from_peer (grpc_exec_ctx * exec_ctx, void *handshake,
   if (result != TSI_OK)
     {
       gpr_log (GPR_ERROR, "Handshake failed with error %s", tsi_result_to_string (result));
-      security_handshake_done (h, 0, closure_list);
+      security_handshake_done (exec_ctx, h, 0);
       return;
     }
 
@@ -233,7 +233,7 @@ on_handshake_data_received_from_peer (grpc_exec_ctx * exec_ctx, void *handshake,
   num_left_overs = (has_left_overs_in_current_slice ? 1 : 0) + h->incoming.count - i - 1;
   if (num_left_overs == 0)
     {
-      check_peer (h, closure_list);
+      check_peer (exec_ctx, h);
       return;
     }
 
@@ -244,7 +244,7 @@ on_handshake_data_received_from_peer (grpc_exec_ctx * exec_ctx, void *handshake,
       gpr_slice_unref (h->incoming.slices[i]);	/* split_tail above increments refcount. */
     }
   gpr_slice_buffer_addn (&h->left_overs, &h->incoming.slices[i + 1], num_left_overs - (size_t) has_left_overs_in_current_slice);
-  check_peer (h, closure_list);
+  check_peer (exec_ctx, h);
 }
 
 /* If handshake is NULL, the handshake is done. */
@@ -258,7 +258,7 @@ on_handshake_data_sent_to_peer (grpc_exec_ctx * exec_ctx, void *handshake, int s
     {
       gpr_log (GPR_ERROR, "Write failed.");
       if (handshake != NULL)
-	security_handshake_done (h, 0, closure_list);
+	security_handshake_done (exec_ctx, h, 0);
       return;
     }
 
@@ -267,11 +267,11 @@ on_handshake_data_sent_to_peer (grpc_exec_ctx * exec_ctx, void *handshake, int s
     {
       /* TODO(klempner,jboeuf): This should probably use the client setup
          deadline */
-      grpc_endpoint_read (h->wrapped_endpoint, &h->incoming, &h->on_handshake_data_received_from_peer, closure_list);
+      grpc_endpoint_read (exec_ctx, h->wrapped_endpoint, &h->incoming, &h->on_handshake_data_received_from_peer);
     }
   else
     {
-      check_peer (h, closure_list);
+      check_peer (exec_ctx, h);
     }
 }
 
@@ -292,5 +292,5 @@ grpc_do_security_handshake (grpc_exec_ctx * exec_ctx, tsi_handshaker * handshake
   gpr_slice_buffer_init (&h->left_overs);
   gpr_slice_buffer_init (&h->outgoing);
   gpr_slice_buffer_init (&h->incoming);
-  send_handshake_bytes_to_peer (h, closure_list);
+  send_handshake_bytes_to_peer (exec_ctx, h);
 }
diff --git a/src/core/security/jwt_verifier.c b/src/core/security/jwt_verifier.c
index dcc751f143..7a45ff9343 100644
--- a/src/core/security/jwt_verifier.c
+++ b/src/core/security/jwt_verifier.c
@@ -774,7 +774,7 @@ on_openid_config_retrieved (grpc_exec_ctx * exec_ctx, void *user_data, const grp
     {
       *(req.host + (req.path - jwks_uri)) = '\0';
     }
-  grpc_httpcli_get (&ctx->verifier->http_ctx, ctx->pollset, &req, gpr_time_add (gpr_now (GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay), on_keys_retrieved, ctx, closure_list);
+  grpc_httpcli_get (&ctx->verifier->http_ctx, ctx->pollset, &req, gpr_time_add (gpr_now (exec_ctx, GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay), on_keys_retrieved, ctx);
   grpc_json_destroy (json);
   gpr_free (req.host);
   return;
@@ -893,7 +893,7 @@ retrieve_key_and_verify (grpc_exec_ctx * exec_ctx, verifier_cb_ctx * ctx)
       http_cb = on_openid_config_retrieved;
     }
 
-  grpc_httpcli_get (&ctx->verifier->http_ctx, ctx->pollset, &req, gpr_time_add (gpr_now (GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay), http_cb, ctx, closure_list);
+  grpc_httpcli_get (&ctx->verifier->http_ctx, ctx->pollset, &req, gpr_time_add (gpr_now (exec_ctx, GPR_CLOCK_REALTIME), grpc_jwt_verifier_max_delay), http_cb, ctx);
   gpr_free (req.host);
   gpr_free (req.path);
   return;
@@ -943,7 +943,7 @@ grpc_jwt_verifier_verify (grpc_exec_ctx * exec_ctx, grpc_jwt_verifier * verifier
   signature = grpc_base64_decode (cur, 1);
   if (GPR_SLICE_IS_EMPTY (signature))
     goto error;
-  retrieve_key_and_verify (verifier_cb_ctx_create (verifier, pollset, header, claims, audience, signature, jwt, signed_jwt_len, user_data, cb), closure_list);
+  retrieve_key_and_verify (verifier_cb_ctx_create (exec_ctx, verifier, pollset, header, claims, audience, signature, jwt, signed_jwt_len, user_data, cb));
   return;
 
 error:
diff --git a/src/core/security/secure_endpoint.c b/src/core/security/secure_endpoint.c
index 966dfbb666..7dee1c1edb 100644
--- a/src/core/security/secure_endpoint.c
+++ b/src/core/security/secure_endpoint.c
@@ -72,7 +72,7 @@ static void
 destroy (grpc_exec_ctx * exec_ctx, secure_endpoint * secure_ep)
 {
   secure_endpoint *ep = secure_ep;
-  grpc_endpoint_destroy (ep->wrapped_ep, closure_list);
+  grpc_endpoint_destroy (exec_ctx, ep->wrapped_ep);
   tsi_frame_protector_destroy (ep->protector);
   gpr_slice_buffer_destroy (&ep->leftover_bytes);
   gpr_slice_unref (ep->read_staging_buffer);
@@ -95,7 +95,7 @@ secure_endpoint_unref (secure_endpoint * ep, grpc_closure_list * closure_list, c
   gpr_log (file, line, GPR_LOG_SEVERITY_DEBUG, "SECENDP unref %p : %s %d -> %d", ep, reason, ep->ref.count, ep->ref.count - 1);
   if (gpr_unref (&ep->ref))
     {
-      destroy (ep, closure_list);
+      destroy (exec_ctx, ep);
     }
 }
 
@@ -113,7 +113,7 @@ secure_endpoint_unref (grpc_exec_ctx * exec_ctx, secure_endpoint * ep)
 {
   if (gpr_unref (&ep->ref))
     {
-      destroy (ep, closure_list);
+      destroy (exec_ctx, ep);
     }
 }
 
@@ -149,7 +149,7 @@ call_read_cb (grpc_exec_ctx * exec_ctx, secure_endpoint * ep, int success)
     }
   ep->read_buffer = NULL;
   grpc_closure_list_add (closure_list, ep->read_cb, success);
-  SECURE_ENDPOINT_UNREF (ep, "read", closure_list);
+  SECURE_ENDPOINT_UNREF (exec_ctx, ep, "read");
 }
 
 static void
@@ -165,7 +165,7 @@ on_read (grpc_exec_ctx * exec_ctx, void *user_data, int success)
   if (!success)
     {
       gpr_slice_buffer_reset_and_unref (ep->read_buffer);
-      call_read_cb (ep, 0, closure_list);
+      call_read_cb (exec_ctx, ep, 0);
       return;
     }
 
@@ -226,11 +226,11 @@ on_read (grpc_exec_ctx * exec_ctx, void *user_data, int success)
   if (result != TSI_OK)
     {
       gpr_slice_buffer_reset_and_unref (ep->read_buffer);
-      call_read_cb (ep, 0, closure_list);
+      call_read_cb (exec_ctx, ep, 0);
       return;
     }
 
-  call_read_cb (ep, 1, closure_list);
+  call_read_cb (exec_ctx, ep, 1);
 }
 
 static void
@@ -246,11 +246,11 @@ endpoint_read (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep, gpr_slice_bu
     {
       gpr_slice_buffer_swap (&ep->leftover_bytes, &ep->source_buffer);
       GPR_ASSERT (ep->leftover_bytes.count == 0);
-      on_read (ep, 1, closure_list);
+      on_read (exec_ctx, ep, 1);
       return;
     }
 
-  grpc_endpoint_read (ep->wrapped_ep, &ep->source_buffer, &ep->on_read, closure_list);
+  grpc_endpoint_read (exec_ctx, ep->wrapped_ep, &ep->source_buffer, &ep->on_read);
 }
 
 static void
@@ -344,35 +344,35 @@ endpoint_write (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep, gpr_slice_b
       return;
     }
 
-  grpc_endpoint_write (ep->wrapped_ep, &ep->output_buffer, cb, closure_list);
+  grpc_endpoint_write (exec_ctx, ep->wrapped_ep, &ep->output_buffer, cb);
 }
 
 static void
 endpoint_shutdown (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep)
 {
   secure_endpoint *ep = (secure_endpoint *) secure_ep;
-  grpc_endpoint_shutdown (ep->wrapped_ep, closure_list);
+  grpc_endpoint_shutdown (exec_ctx, ep->wrapped_ep);
 }
 
 static void
 endpoint_destroy (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep)
 {
   secure_endpoint *ep = (secure_endpoint *) secure_ep;
-  SECURE_ENDPOINT_UNREF (ep, "destroy", closure_list);
+  SECURE_ENDPOINT_UNREF (exec_ctx, ep, "destroy");
 }
 
 static void
 endpoint_add_to_pollset (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep, grpc_pollset * pollset)
 {
   secure_endpoint *ep = (secure_endpoint *) secure_ep;
-  grpc_endpoint_add_to_pollset (ep->wrapped_ep, pollset, closure_list);
+  grpc_endpoint_add_to_pollset (exec_ctx, ep->wrapped_ep, pollset);
 }
 
 static void
 endpoint_add_to_pollset_set (grpc_exec_ctx * exec_ctx, grpc_endpoint * secure_ep, grpc_pollset_set * pollset_set)
 {
   secure_endpoint *ep = (secure_endpoint *) secure_ep;
-  grpc_endpoint_add_to_pollset_set (ep->wrapped_ep, pollset_set, closure_list);
+  grpc_endpoint_add_to_pollset_set (exec_ctx, ep->wrapped_ep, pollset_set);
 }
 
 static char *
diff --git a/src/core/security/security_connector.c b/src/core/security/security_connector.c
index 91462c52cd..729de29d49 100644
--- a/src/core/security/security_connector.c
+++ b/src/core/security/security_connector.c
@@ -114,11 +114,11 @@ grpc_security_connector_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_co
 {
   if (sc == NULL || nonsecure_endpoint == NULL)
     {
-      cb (user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL, closure_list);
+      cb (exec_ctx, user_data, GRPC_SECURITY_ERROR, nonsecure_endpoint, NULL);
     }
   else
     {
-      sc->vtable->do_handshake (sc, nonsecure_endpoint, cb, user_data, closure_list);
+      sc->vtable->do_handshake (exec_ctx, sc, nonsecure_endpoint, cb, user_data);
     }
 }
 
@@ -138,7 +138,7 @@ grpc_channel_security_connector_check_call_host (grpc_exec_ctx * exec_ctx, grpc_
 {
   if (sc == NULL || sc->check_call_host == NULL)
     return GRPC_SECURITY_ERROR;
-  return sc->check_call_host (sc, host, cb, user_data, closure_list);
+  return sc->check_call_host (exec_ctx, sc, host, cb, user_data);
 }
 
 #ifdef GRPC_SECURITY_CONNECTOR_REFCOUNT_DEBUG
@@ -303,7 +303,7 @@ fake_channel_check_call_host (grpc_exec_ctx * exec_ctx, grpc_channel_security_co
   grpc_fake_channel_security_connector *c = (grpc_fake_channel_security_connector *) sc;
   if (c->call_host_check_is_async)
     {
-      cb (user_data, GRPC_SECURITY_OK, closure_list);
+      cb (exec_ctx, user_data, GRPC_SECURITY_OK);
       return GRPC_SECURITY_PENDING;
     }
   else
@@ -315,13 +315,13 @@ fake_channel_check_call_host (grpc_exec_ctx * exec_ctx, grpc_channel_security_co
 static void
 fake_channel_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_connector * sc, grpc_endpoint * nonsecure_endpoint, grpc_security_handshake_done_cb cb, void *user_data)
 {
-  grpc_do_security_handshake (tsi_create_fake_handshaker (1), sc, nonsecure_endpoint, cb, user_data, closure_list);
+  grpc_do_security_handshake (tsi_create_fake_handshaker (exec_ctx, 1), sc, nonsecure_endpoint, cb, user_data);
 }
 
 static void
 fake_server_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_connector * sc, grpc_endpoint * nonsecure_endpoint, grpc_security_handshake_done_cb cb, void *user_data)
 {
-  grpc_do_security_handshake (tsi_create_fake_handshaker (0), sc, nonsecure_endpoint, cb, user_data, closure_list);
+  grpc_do_security_handshake (tsi_create_fake_handshaker (exec_ctx, 0), sc, nonsecure_endpoint, cb, user_data);
 }
 
 static grpc_security_connector_vtable fake_channel_vtable = {
@@ -432,11 +432,11 @@ ssl_channel_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_connector * sc
 						       &handshaker);
   if (status != GRPC_SECURITY_OK)
     {
-      cb (user_data, status, nonsecure_endpoint, NULL, closure_list);
+      cb (exec_ctx, user_data, status, nonsecure_endpoint, NULL);
     }
   else
     {
-      grpc_do_security_handshake (handshaker, sc, nonsecure_endpoint, cb, user_data, closure_list);
+      grpc_do_security_handshake (exec_ctx, handshaker, sc, nonsecure_endpoint, cb, user_data);
     }
 }
 
@@ -448,11 +448,11 @@ ssl_server_do_handshake (grpc_exec_ctx * exec_ctx, grpc_security_connector * sc,
   grpc_security_status status = ssl_create_handshaker (c->handshaker_factory, 0, NULL, &handshaker);
   if (status != GRPC_SECURITY_OK)
     {
-      cb (user_data, status, nonsecure_endpoint, NULL, closure_list);
+      cb (exec_ctx, user_data, status, nonsecure_endpoint, NULL);
     }
   else
     {
-      grpc_do_security_handshake (handshaker, sc, nonsecure_endpoint, cb, user_data, closure_list);
+      grpc_do_security_handshake (exec_ctx, handshaker, sc, nonsecure_endpoint, cb, user_data);
     }
 }
 
diff --git a/src/core/security/server_auth_filter.c b/src/core/security/server_auth_filter.c
index 86a5f9cb3e..77239e782e 100644
--- a/src/core/security/server_auth_filter.c
+++ b/src/core/security/server_auth_filter.c
@@ -175,7 +175,7 @@ auth_on_recv (grpc_exec_ctx * exec_ctx, void *user_data, int success)
 	  return;
 	}
     }
-  calld->on_done_recv->cb (calld->on_done_recv->cb_arg, success, closure_list);
+  calld->on_done_recv->cb (exec_ctx, calld->on_done_recv->cb_arg, success);
 }
 
 static void
@@ -202,7 +202,7 @@ static void
 auth_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, grpc_transport_stream_op * op)
 {
   set_recv_ops_md_callbacks (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 /* Constructor for call_data */
diff --git a/src/core/security/server_secure_chttp2.c b/src/core/security/server_secure_chttp2.c
index b11cf1079a..5b67f51b7d 100644
--- a/src/core/security/server_secure_chttp2.c
+++ b/src/core/security/server_secure_chttp2.c
@@ -104,7 +104,7 @@ setup_transport (grpc_exec_ctx * exec_ctx, void *statep, grpc_transport * transp
   args_to_add[0] = grpc_security_connector_to_arg (state->sc);
   args_to_add[1] = grpc_auth_metadata_processor_to_arg (&state->creds->processor);
   args_copy = grpc_channel_args_copy_and_add (grpc_server_get_channel_args (state->server), args_to_add, GPR_ARRAY_SIZE (args_to_add));
-  grpc_server_setup_transport (state->server, transport, extra_filters, GPR_ARRAY_SIZE (extra_filters), mdctx, args_copy, closure_list);
+  grpc_server_setup_transport (state->server, transport, extra_filters, GPR_ARRAY_SIZE (exec_ctx, extra_filters), mdctx, args_copy);
   grpc_channel_args_destroy (args_copy);
 }
 
@@ -146,15 +146,15 @@ on_secure_handshake_done (grpc_exec_ctx * exec_ctx, void *statep, grpc_security_
       if (!state->is_shutdown)
 	{
 	  mdctx = grpc_mdctx_create ();
-	  transport = grpc_create_chttp2_transport (grpc_server_get_channel_args (state->server), secure_endpoint, mdctx, 0, closure_list);
-	  setup_transport (state, transport, mdctx, closure_list);
-	  grpc_chttp2_transport_start_reading (transport, NULL, 0, closure_list);
+	  transport = grpc_create_chttp2_transport (grpc_server_get_channel_args (exec_ctx, state->server), secure_endpoint, mdctx, 0);
+	  setup_transport (exec_ctx, state, transport, mdctx);
+	  grpc_chttp2_transport_start_reading (exec_ctx, transport, NULL, 0);
 	}
       else
 	{
 	  /* We need to consume this here, because the server may already have gone
 	   * away. */
-	  grpc_endpoint_destroy (secure_endpoint, closure_list);
+	  grpc_endpoint_destroy (exec_ctx, secure_endpoint);
 	}
       gpr_mu_unlock (&state->mu);
     }
@@ -180,7 +180,7 @@ on_accept (grpc_exec_ctx * exec_ctx, void *statep, grpc_endpoint * tcp)
   node->next = state->handshaking_tcp_endpoints;
   state->handshaking_tcp_endpoints = node;
   gpr_mu_unlock (&state->mu);
-  grpc_security_connector_do_handshake (state->sc, tcp, on_secure_handshake_done, state, closure_list);
+  grpc_security_connector_do_handshake (exec_ctx, state->sc, tcp, on_secure_handshake_done, state);
 }
 
 /* Server callback: start listening on our ports */
@@ -188,18 +188,18 @@ static void
 start (grpc_exec_ctx * exec_ctx, grpc_server * server, void *statep, grpc_pollset ** pollsets, size_t pollset_count)
 {
   grpc_server_secure_state *state = statep;
-  grpc_tcp_server_start (state->tcp, pollsets, pollset_count, on_accept, state, closure_list);
+  grpc_tcp_server_start (exec_ctx, state->tcp, pollsets, pollset_count, on_accept, state);
 }
 
 static void
 destroy_done (grpc_exec_ctx * exec_ctx, void *statep, int success)
 {
   grpc_server_secure_state *state = statep;
-  state->destroy_callback->cb (state->destroy_callback->cb_arg, success, closure_list);
+  state->destroy_callback->cb (exec_ctx, state->destroy_callback->cb_arg, success);
   gpr_mu_lock (&state->mu);
   while (state->handshaking_tcp_endpoints != NULL)
     {
-      grpc_endpoint_shutdown (state->handshaking_tcp_endpoints->tcp_endpoint, closure_list);
+      grpc_endpoint_shutdown (exec_ctx, state->handshaking_tcp_endpoints->tcp_endpoint);
       remove_tcp_from_list_locked (state, state->handshaking_tcp_endpoints->tcp_endpoint);
     }
   gpr_mu_unlock (&state->mu);
@@ -219,7 +219,7 @@ destroy (grpc_exec_ctx * exec_ctx, grpc_server * server, void *statep, grpc_clos
   tcp = state->tcp;
   gpr_mu_unlock (&state->mu);
   grpc_closure_init (&state->destroy_closure, destroy_done, state);
-  grpc_tcp_server_destroy (tcp, &state->destroy_closure, closure_list);
+  grpc_tcp_server_destroy (exec_ctx, tcp, &state->destroy_closure);
 }
 
 int
diff --git a/src/core/surface/call.c b/src/core/surface/call.c
index 5360abdfa9..de47bc3808 100644
--- a/src/core/surface/call.c
+++ b/src/core/surface/call.c
@@ -417,7 +417,7 @@ grpc_call_set_completion_queue (grpc_exec_ctx * exec_ctx, grpc_call * call, grpc
     {
       GRPC_CQ_INTERNAL_REF (cq, "bind");
     }
-  unlock (call, closure_list);
+  unlock (exec_ctx, call);
 }
 
 grpc_completion_queue *
@@ -452,7 +452,7 @@ done_completion (grpc_exec_ctx * exec_ctx, void *call, grpc_cq_completion * comp
   gpr_mu_lock (&c->completion_mu);
   c->allocated_completions &= (gpr_uint8) ~ (1u << (completion - c->completions));
   gpr_mu_unlock (&c->completion_mu);
-  GRPC_CALL_INTERNAL_UNREF (c, "completion", closure_list);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, c, "completion");
 }
 
 #ifdef GRPC_CALL_REF_COUNT_DEBUG
@@ -473,8 +473,8 @@ destroy_call (grpc_exec_ctx * exec_ctx, grpc_call * call)
 {
   size_t i;
   grpc_call *c = call;
-  grpc_call_stack_destroy (CALL_STACK_FROM_CALL (c), closure_list);
-  GRPC_CHANNEL_INTERNAL_UNREF (c->channel, "call", closure_list);
+  grpc_call_stack_destroy (CALL_STACK_FROM_CALL (exec_ctx, c));
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, c->channel, "call");
   gpr_mu_destroy (&c->mu);
   gpr_mu_destroy (&c->completion_mu);
   for (i = 0; i < STATUS_SOURCE_COUNT; i++)
@@ -527,7 +527,7 @@ grpc_call_internal_unref (grpc_exec_ctx * exec_ctx, grpc_call * c)
 #endif
   if (gpr_unref (&c->internal_refcount))
     {
-      destroy_call (c, closure_list);
+      destroy_call (exec_ctx, c);
     }
 }
 
@@ -715,19 +715,19 @@ unlock (grpc_exec_ctx * exec_ctx, grpc_call * call)
 
   if (start_op)
     {
-      execute_op (call, &op, closure_list);
+      execute_op (exec_ctx, call, &op);
     }
 
   if (completing_requests > 0)
     {
       for (i = 0; i < completing_requests; i++)
 	{
-	  completed_requests[i].on_complete (call, completed_requests[i].success, completed_requests[i].user_data, closure_list);
+	  completed_requests[i].on_complete (exec_ctx, call, completed_requests[i].success, completed_requests[i].user_data);
 	}
       lock (call);
       call->completing = 0;
-      unlock (call, closure_list);
-      GRPC_CALL_INTERNAL_UNREF (call, "completing", closure_list);
+      unlock (exec_ctx, call);
+      GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "completing");
     }
 }
 
@@ -917,8 +917,8 @@ call_on_done_send (grpc_exec_ctx * exec_ctx, void *pc, int success)
   call->send_ops.nops = 0;
   call->last_send_contains = 0;
   call->sending = 0;
-  unlock (call, closure_list);
-  GRPC_CALL_INTERNAL_UNREF (call, "sending", closure_list);
+  unlock (exec_ctx, call);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "sending");
 }
 
 static void
@@ -1055,7 +1055,7 @@ call_on_done_recv (grpc_exec_ctx * exec_ctx, void *pc, int success)
 	    case GRPC_NO_OP:
 	      break;
 	    case GRPC_OP_METADATA:
-	      recv_metadata (call, &op->data.metadata, closure_list);
+	      recv_metadata (exec_ctx, call, &op->data.metadata);
 	      break;
 	    case GRPC_OP_BEGIN_MESSAGE:
 	      success = begin_message (call, op->data.begin_message);
@@ -1080,7 +1080,7 @@ call_on_done_recv (grpc_exec_ctx * exec_ctx, void *pc, int success)
 	  call->read_state = READ_STATE_STREAM_CLOSED;
 	  if (call->have_alarm)
 	    {
-	      grpc_alarm_cancel (&call->alarm, closure_list);
+	      grpc_alarm_cancel (exec_ctx, &call->alarm);
 	    }
 	  /* propagate cancellation to any interested children */
 	  child_call = call->first_child;
@@ -1093,13 +1093,13 @@ call_on_done_recv (grpc_exec_ctx * exec_ctx, void *pc, int success)
 		    {
 		      GRPC_CALL_INTERNAL_REF (child_call, "propagate_cancel");
 		      grpc_call_cancel (child_call, NULL);
-		      GRPC_CALL_INTERNAL_UNREF (child_call, "propagate_cancel", closure_list);
+		      GRPC_CALL_INTERNAL_UNREF (exec_ctx, child_call, "propagate_cancel");
 		    }
 		  child_call = next_child_call;
 		}
 	      while (child_call != call->first_child);
 	    }
-	  GRPC_CALL_INTERNAL_UNREF (call, "closed", closure_list);
+	  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "closed");
 	}
       finish_read_ops (call);
     }
@@ -1113,9 +1113,9 @@ call_on_done_recv (grpc_exec_ctx * exec_ctx, void *pc, int success)
       finish_ioreq_op (call, GRPC_IOREQ_RECV_STATUS_DETAILS, 0);
     }
   call->recv_ops.nops = 0;
-  unlock (call, closure_list);
+  unlock (exec_ctx, call);
 
-  GRPC_CALL_INTERNAL_UNREF (call, "receiving", closure_list);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "receiving");
   GRPC_TIMER_END (GRPC_PTAG_CALL_ON_DONE_RECV, 0);
 }
 
@@ -1386,7 +1386,7 @@ grpc_call_start_ioreq_and_call_back (grpc_exec_ctx * exec_ctx, grpc_call * call,
   grpc_call_error err;
   lock (call);
   err = start_ioreq (call, reqs, nreqs, on_complete, user_data);
-  unlock (call, closure_list);
+  unlock (exec_ctx, call);
   return err;
 }
 
@@ -1467,7 +1467,7 @@ cancel_with_status (grpc_call * c, grpc_status_code status, const char *descript
 static void
 finished_loose_op (grpc_exec_ctx * exec_ctx, void *call, int success_ignored)
 {
-  GRPC_CALL_INTERNAL_UNREF (call, "loose-op", closure_list);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "loose-op");
 }
 
 typedef struct
@@ -1480,7 +1480,7 @@ static void
 finished_loose_op_allocated (grpc_exec_ctx * exec_ctx, void *alloc, int success)
 {
   finished_loose_op_allocated_args *args = alloc;
-  finished_loose_op (args->call, success, closure_list);
+  finished_loose_op (exec_ctx, args->call, success);
   gpr_free (args);
 }
 
@@ -1508,7 +1508,7 @@ execute_op (grpc_exec_ctx * exec_ctx, grpc_call * call, grpc_transport_stream_op
 
   elem = CALL_ELEM_FROM_CALL (call, 0);
   op->context = call->context;
-  elem->filter->start_transport_stream_op (elem, op, closure_list);
+  elem->filter->start_transport_stream_op (exec_ctx, elem, op);
 }
 
 char *
@@ -1538,8 +1538,8 @@ call_alarm (grpc_exec_ctx * exec_ctx, void *arg, int success)
       cancel_with_status (call, GRPC_STATUS_DEADLINE_EXCEEDED, "Deadline Exceeded");
     }
   finish_read_ops (call);
-  unlock (call, closure_list);
-  GRPC_CALL_INTERNAL_UNREF (call, "alarm", closure_list);
+  unlock (exec_ctx, call);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "alarm");
 }
 
 static void
@@ -1554,7 +1554,7 @@ set_deadline_alarm (grpc_exec_ctx * exec_ctx, grpc_call * call, gpr_timespec dea
   GRPC_CALL_INTERNAL_REF (call, "alarm");
   call->have_alarm = 1;
   call->send_deadline = gpr_convert_clock_type (deadline, GPR_CLOCK_MONOTONIC);
-  grpc_alarm_init (&call->alarm, call->send_deadline, call_alarm, call, gpr_now (GPR_CLOCK_MONOTONIC), closure_list);
+  grpc_alarm_init (&call->alarm, call->send_deadline, call_alarm, call, gpr_now (exec_ctx, GPR_CLOCK_MONOTONIC));
 }
 
 /* we offset status by a small amount when storing it into transport metadata
@@ -1669,7 +1669,7 @@ recv_metadata (grpc_exec_ctx * exec_ctx, grpc_call * call, grpc_metadata_batch *
     }
   if (gpr_time_cmp (md->deadline, gpr_inf_future (md->deadline.clock_type)) != 0 && !call->is_client)
     {
-      set_deadline_alarm (call, md->deadline, closure_list);
+      set_deadline_alarm (exec_ctx, call, md->deadline);
     }
   if (!is_trailing)
     {
@@ -1714,13 +1714,13 @@ set_cancelled_value (grpc_status_code status, void *dest)
 static void
 finish_batch (grpc_exec_ctx * exec_ctx, grpc_call * call, int success, void *tag)
 {
-  grpc_cq_end_op (call->cq, tag, success, done_completion, call, allocate_completion (call), closure_list);
+  grpc_cq_end_op (call->cq, tag, success, done_completion, call, allocate_completion (exec_ctx, call));
 }
 
 static void
 finish_batch_with_close (grpc_exec_ctx * exec_ctx, grpc_call * call, int success, void *tag)
 {
-  grpc_cq_end_op (call->cq, tag, 1, done_completion, call, allocate_completion (call), closure_list);
+  grpc_cq_end_op (call->cq, tag, 1, done_completion, call, allocate_completion (exec_ctx, call));
 }
 
 static int
diff --git a/src/core/surface/call.h b/src/core/surface/call.h
index 29a3e11354..b1f3be8521 100644
--- a/src/core/surface/call.h
+++ b/src/core/surface/call.h
@@ -107,14 +107,14 @@ extern "C"
   void grpc_call_internal_unref (grpc_exec_ctx * exec_ctx, grpc_call * call, const char *reason);
 #define GRPC_CALL_INTERNAL_REF(call, reason) \
   grpc_call_internal_ref(call, reason)
-#define GRPC_CALL_INTERNAL_UNREF(call, reason, closure_list) \
-  grpc_call_internal_unref(call, reason, closure_list)
+#define GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, reason) \
+  grpc_call_internal_unref(exec_ctx, call, reason)
 #else
   void grpc_call_internal_ref (grpc_call * call);
   void grpc_call_internal_unref (grpc_exec_ctx * exec_ctx, grpc_call * call);
 #define GRPC_CALL_INTERNAL_REF(call, reason) grpc_call_internal_ref(call)
-#define GRPC_CALL_INTERNAL_UNREF(call, reason, closure_list) \
-  grpc_call_internal_unref(call, closure_list)
+#define GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, reason) \
+  grpc_call_internal_unref(exec_ctx, call)
 #endif
 
   grpc_call_error grpc_call_start_ioreq_and_call_back (grpc_exec_ctx * exec_ctx, grpc_call * call, const grpc_ioreq * reqs, size_t nreqs, grpc_ioreq_completion_func on_complete, void *user_data);
diff --git a/src/core/surface/channel.c b/src/core/surface/channel.c
index 82a463dd75..2d120cf807 100644
--- a/src/core/surface/channel.c
+++ b/src/core/surface/channel.c
@@ -187,7 +187,7 @@ grpc_channel_create_from_filters (grpc_exec_ctx * exec_ctx, const char *target,
       gpr_free (default_authority);
     }
 
-  grpc_channel_stack_init (filters, num_filters, channel, args, channel->metadata_context, CHANNEL_STACK_FROM_CHANNEL (channel), closure_list);
+  grpc_channel_stack_init (filters, num_filters, channel, args, channel->metadata_context, CHANNEL_STACK_FROM_CHANNEL (exec_ctx, channel));
 
   return channel;
 }
@@ -265,7 +265,7 @@ static void
 destroy_channel (grpc_exec_ctx * exec_ctx, grpc_channel * channel)
 {
   size_t i;
-  grpc_channel_stack_destroy (CHANNEL_STACK_FROM_CHANNEL (channel), closure_list);
+  grpc_channel_stack_destroy (CHANNEL_STACK_FROM_CHANNEL (exec_ctx, channel));
   for (i = 0; i < NUM_CACHED_STATUS_ELEMS; i++)
     {
       GRPC_MDELEM_UNREF (channel->grpc_status_elem[i]);
@@ -309,7 +309,7 @@ grpc_channel_internal_unref (grpc_exec_ctx * exec_ctx, grpc_channel * channel)
 #endif
   if (gpr_unref (&channel->refs))
     {
-      destroy_channel (channel, closure_list);
+      destroy_channel (exec_ctx, channel);
     }
 }
 
diff --git a/src/core/surface/channel.h b/src/core/surface/channel.h
index 982986e966..678aa5ba56 100644
--- a/src/core/surface/channel.h
+++ b/src/core/surface/channel.h
@@ -61,15 +61,15 @@ void grpc_channel_internal_ref (grpc_channel * channel, const char *reason);
 void grpc_channel_internal_unref (grpc_exec_ctx * exec_ctx, grpc_channel * channel, const char *reason);
 #define GRPC_CHANNEL_INTERNAL_REF(channel, reason) \
   grpc_channel_internal_ref(channel, reason)
-#define GRPC_CHANNEL_INTERNAL_UNREF(channel, reason, closure_list) \
-  grpc_channel_internal_unref(channel, reason, closure_list)
+#define GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, reason) \
+  grpc_channel_internal_unref(exec_ctx, channel, reason)
 #else
 void grpc_channel_internal_ref (grpc_channel * channel);
 void grpc_channel_internal_unref (grpc_exec_ctx * exec_ctx, grpc_channel * channel);
 #define GRPC_CHANNEL_INTERNAL_REF(channel, reason) \
   grpc_channel_internal_ref(channel)
-#define GRPC_CHANNEL_INTERNAL_UNREF(channel, reason, closure_list) \
-  grpc_channel_internal_unref(channel, closure_list)
+#define GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, reason) \
+  grpc_channel_internal_unref(exec_ctx, channel)
 #endif
 
 #endif /* GRPC_INTERNAL_CORE_SURFACE_CHANNEL_H */
diff --git a/src/core/surface/channel_connectivity.c b/src/core/surface/channel_connectivity.c
index 7c174aa47f..b72be303d1 100644
--- a/src/core/surface/channel_connectivity.c
+++ b/src/core/surface/channel_connectivity.c
@@ -83,7 +83,7 @@ typedef struct
 static void
 delete_state_watcher (grpc_exec_ctx * exec_ctx, state_watcher * w)
 {
-  GRPC_CHANNEL_INTERNAL_UNREF (w->channel, "watch_connectivity", closure_list);
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, w->channel, "watch_connectivity");
   gpr_mu_destroy (&w->mu);
   gpr_free (w);
 }
@@ -112,7 +112,7 @@ finished_completion (grpc_exec_ctx * exec_ctx, void *pw, grpc_cq_completion * ig
 
   if (delete)
     {
-      delete_state_watcher (w, closure_list);
+      delete_state_watcher (exec_ctx, w);
     }
 }
 
@@ -127,7 +127,7 @@ partly_done (grpc_exec_ctx * exec_ctx, state_watcher * w, int due_to_completion)
     {
       w->removed = 1;
       client_channel_elem = grpc_channel_stack_last_element (grpc_channel_get_channel_stack (w->channel));
-      grpc_client_channel_del_interested_party (client_channel_elem, grpc_cq_pollset (w->cq), closure_list);
+      grpc_client_channel_del_interested_party (client_channel_elem, grpc_cq_pollset (exec_ctx, w->cq));
     }
   gpr_mu_unlock (&w->mu);
   if (due_to_completion)
@@ -135,7 +135,7 @@ partly_done (grpc_exec_ctx * exec_ctx, state_watcher * w, int due_to_completion)
       gpr_mu_lock (&w->mu);
       w->success = 1;
       gpr_mu_unlock (&w->mu);
-      grpc_alarm_cancel (&w->alarm, closure_list);
+      grpc_alarm_cancel (exec_ctx, &w->alarm);
     }
 
   gpr_mu_lock (&w->mu);
@@ -143,7 +143,7 @@ partly_done (grpc_exec_ctx * exec_ctx, state_watcher * w, int due_to_completion)
     {
     case WAITING:
       w->phase = CALLING_BACK;
-      grpc_cq_end_op (w->cq, w->tag, w->success, finished_completion, w, &w->completion_storage, closure_list);
+      grpc_cq_end_op (exec_ctx, w->cq, w->tag, w->success, finished_completion, w, &w->completion_storage);
       break;
     case CALLING_BACK:
       w->phase = CALLING_BACK_AND_FINISHED;
@@ -160,20 +160,20 @@ partly_done (grpc_exec_ctx * exec_ctx, state_watcher * w, int due_to_completion)
 
   if (delete)
     {
-      delete_state_watcher (w, closure_list);
+      delete_state_watcher (exec_ctx, w);
     }
 }
 
 static void
 watch_complete (grpc_exec_ctx * exec_ctx, void *pw, int success)
 {
-  partly_done (pw, 1, closure_list);
+  partly_done (exec_ctx, pw, 1);
 }
 
 static void
 timeout_complete (grpc_exec_ctx * exec_ctx, void *pw, int success)
 {
-  partly_done (pw, 0, closure_list);
+  partly_done (exec_ctx, pw, 0);
 }
 
 void
diff --git a/src/core/surface/channel_create.c b/src/core/surface/channel_create.c
index a8c9f1749f..2f597563ab 100644
--- a/src/core/surface/channel_create.c
+++ b/src/core/surface/channel_create.c
@@ -90,8 +90,8 @@ connected (grpc_exec_ctx * exec_ctx, void *arg, int success)
   grpc_endpoint *tcp = c->tcp;
   if (tcp != NULL)
     {
-      c->result->transport = grpc_create_chttp2_transport (c->args.channel_args, tcp, c->mdctx, 1, closure_list);
-      grpc_chttp2_transport_start_reading (c->result->transport, NULL, 0, closure_list);
+      c->result->transport = grpc_create_chttp2_transport (exec_ctx, c->args.channel_args, tcp, c->mdctx, 1);
+      grpc_chttp2_transport_start_reading (exec_ctx, c->result->transport, NULL, 0);
       GPR_ASSERT (c->result->transport);
       c->result->filters = gpr_malloc (sizeof (grpc_channel_filter *));
       c->result->filters[0] = &grpc_http_client_filter;
@@ -103,7 +103,7 @@ connected (grpc_exec_ctx * exec_ctx, void *arg, int success)
     }
   notify = c->notify;
   c->notify = NULL;
-  notify->cb (notify->cb_arg, 1, closure_list);
+  notify->cb (exec_ctx, notify->cb_arg, 1);
 }
 
 static void
@@ -122,7 +122,7 @@ connector_connect (grpc_exec_ctx * exec_ctx, grpc_connector * con, const grpc_co
   c->result = result;
   c->tcp = NULL;
   grpc_closure_init (&c->connected, connected, c);
-  grpc_tcp_client_connect (&c->connected, &c->tcp, args->interested_parties, args->addr, args->addr_len, args->deadline, closure_list);
+  grpc_tcp_client_connect (exec_ctx, &c->connected, &c->tcp, args->interested_parties, args->addr, args->addr_len, args->deadline);
 }
 
 static const grpc_connector_vtable connector_vtable = {
@@ -151,7 +151,7 @@ subchannel_factory_unref (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * sc
   subchannel_factory *f = (subchannel_factory *) scf;
   if (gpr_unref (&f->refs))
     {
-      GRPC_CHANNEL_INTERNAL_UNREF (f->master, "subchannel_factory", closure_list);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, f->master, "subchannel_factory");
       grpc_channel_args_destroy (f->merge_args);
       grpc_mdctx_unref (f->mdctx);
       gpr_free (f);
@@ -174,7 +174,7 @@ subchannel_factory_create_subchannel (grpc_exec_ctx * exec_ctx, grpc_subchannel_
   args->args = final_args;
   args->master = f->master;
   s = grpc_subchannel_create (&c->base, args);
-  grpc_connector_unref (&c->base, closure_list);
+  grpc_connector_unref (exec_ctx, &c->base);
   grpc_channel_args_destroy (final_args);
   return s;
 }
diff --git a/src/core/surface/completion_queue.c b/src/core/surface/completion_queue.c
index 2410ad6fb5..5cc07261bf 100644
--- a/src/core/surface/completion_queue.c
+++ b/src/core/surface/completion_queue.c
@@ -181,7 +181,7 @@ grpc_cq_end_op (grpc_completion_queue * cc, void *tag, int success, void (*done)
       GPR_ASSERT (cc->shutdown_called);
       cc->shutdown = 1;
       gpr_mu_unlock (GRPC_POLLSET_MU (&cc->pollset));
-      grpc_pollset_shutdown (&cc->pollset, &cc->pollset_destroy_done, closure_list);
+      grpc_pollset_shutdown (exec_ctx, &cc->pollset, &cc->pollset_destroy_done);
     }
 }
 
diff --git a/src/core/surface/lame_client.c b/src/core/surface/lame_client.c
index be3a308f0f..e2a8e191ad 100644
--- a/src/core/surface/lame_client.c
+++ b/src/core/surface/lame_client.c
@@ -65,7 +65,7 @@ lame_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * el
   if (op->send_ops != NULL)
     {
       grpc_stream_ops_unref_owned_objects (op->send_ops->ops, op->send_ops->nops);
-      op->on_done_send->cb (op->on_done_send->cb_arg, 0, closure_list);
+      op->on_done_send->cb (exec_ctx, op->on_done_send->cb_arg, 0);
     }
   if (op->recv_ops != NULL)
     {
@@ -83,11 +83,11 @@ lame_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element * el
       mdb.deadline = gpr_inf_future (GPR_CLOCK_REALTIME);
       grpc_sopb_add_metadata (op->recv_ops, mdb);
       *op->recv_state = GRPC_STREAM_CLOSED;
-      op->on_done_recv->cb (op->on_done_recv->cb_arg, 1, closure_list);
+      op->on_done_recv->cb (exec_ctx, op->on_done_recv->cb_arg, 1);
     }
   if (op->on_consumed != NULL)
     {
-      op->on_consumed->cb (op->on_consumed->cb_arg, 0, closure_list);
+      op->on_consumed->cb (exec_ctx, op->on_consumed->cb_arg, 0);
     }
 }
 
@@ -105,11 +105,11 @@ lame_start_transport_op (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem,
     {
       GPR_ASSERT (*op->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE);
       *op->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE;
-      op->on_connectivity_state_change->cb (op->on_connectivity_state_change->cb_arg, 1, closure_list);
+      op->on_connectivity_state_change->cb (exec_ctx, op->on_connectivity_state_change->cb_arg, 1);
     }
   if (op->on_consumed != NULL)
     {
-      op->on_consumed->cb (op->on_consumed->cb_arg, 1, closure_list);
+      op->on_consumed->cb (exec_ctx, op->on_consumed->cb_arg, 1);
     }
 }
 
@@ -118,7 +118,7 @@ init_call_elem (grpc_exec_ctx * exec_ctx, grpc_call_element * elem, const void *
 {
   if (initial_op)
     {
-      grpc_transport_stream_op_finish_with_failure (initial_op, closure_list);
+      grpc_transport_stream_op_finish_with_failure (exec_ctx, initial_op);
     }
 }
 
diff --git a/src/core/surface/secure_channel_create.c b/src/core/surface/secure_channel_create.c
index b65b03a002..1290308992 100644
--- a/src/core/surface/secure_channel_create.c
+++ b/src/core/surface/secure_channel_create.c
@@ -113,8 +113,8 @@ on_secure_handshake_done (grpc_exec_ctx * exec_ctx, void *arg, grpc_security_sta
       GPR_ASSERT (c->connecting_endpoint == wrapped_endpoint);
       c->connecting_endpoint = NULL;
       gpr_mu_unlock (&c->mu);
-      c->result->transport = grpc_create_chttp2_transport (c->args.channel_args, secure_endpoint, c->mdctx, 1, closure_list);
-      grpc_chttp2_transport_start_reading (c->result->transport, NULL, 0, closure_list);
+      c->result->transport = grpc_create_chttp2_transport (exec_ctx, c->args.channel_args, secure_endpoint, c->mdctx, 1);
+      grpc_chttp2_transport_start_reading (exec_ctx, c->result->transport, NULL, 0);
       c->result->filters = gpr_malloc (sizeof (grpc_channel_filter *) * 2);
       c->result->filters[0] = &grpc_http_client_filter;
       c->result->filters[1] = &grpc_client_auth_filter;
@@ -122,7 +122,7 @@ on_secure_handshake_done (grpc_exec_ctx * exec_ctx, void *arg, grpc_security_sta
     }
   notify = c->notify;
   c->notify = NULL;
-  notify->cb (notify->cb_arg, 1, closure_list);
+  notify->cb (exec_ctx, notify->cb_arg, 1);
 }
 
 static void
@@ -137,14 +137,14 @@ connected (grpc_exec_ctx * exec_ctx, void *arg, int success)
       GPR_ASSERT (c->connecting_endpoint == NULL);
       c->connecting_endpoint = tcp;
       gpr_mu_unlock (&c->mu);
-      grpc_security_connector_do_handshake (&c->security_connector->base, tcp, on_secure_handshake_done, c, closure_list);
+      grpc_security_connector_do_handshake (exec_ctx, &c->security_connector->base, tcp, on_secure_handshake_done, c);
     }
   else
     {
       memset (c->result, 0, sizeof (*c->result));
       notify = c->notify;
       c->notify = NULL;
-      notify->cb (notify->cb_arg, 1, closure_list);
+      notify->cb (exec_ctx, notify->cb_arg, 1);
     }
 }
 
@@ -159,7 +159,7 @@ connector_shutdown (grpc_exec_ctx * exec_ctx, grpc_connector * con)
   gpr_mu_unlock (&c->mu);
   if (ep)
     {
-      grpc_endpoint_shutdown (ep, closure_list);
+      grpc_endpoint_shutdown (exec_ctx, ep);
     }
 }
 
@@ -176,7 +176,7 @@ connector_connect (grpc_exec_ctx * exec_ctx, grpc_connector * con, const grpc_co
   GPR_ASSERT (c->connecting_endpoint == NULL);
   gpr_mu_unlock (&c->mu);
   grpc_closure_init (&c->connected_closure, connected, c);
-  grpc_tcp_client_connect (&c->connected_closure, &c->newly_connecting_endpoint, args->interested_parties, args->addr, args->addr_len, args->deadline, closure_list);
+  grpc_tcp_client_connect (exec_ctx, &c->connected_closure, &c->newly_connecting_endpoint, args->interested_parties, args->addr, args->addr_len, args->deadline);
 }
 
 static const grpc_connector_vtable connector_vtable = {
@@ -207,7 +207,7 @@ subchannel_factory_unref (grpc_exec_ctx * exec_ctx, grpc_subchannel_factory * sc
   if (gpr_unref (&f->refs))
     {
       GRPC_SECURITY_CONNECTOR_UNREF (&f->security_connector->base, "subchannel_factory");
-      GRPC_CHANNEL_INTERNAL_UNREF (f->master, "subchannel_factory", closure_list);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, f->master, "subchannel_factory");
       grpc_channel_args_destroy (f->merge_args);
       grpc_mdctx_unref (f->mdctx);
       gpr_free (f);
@@ -231,7 +231,7 @@ subchannel_factory_create_subchannel (grpc_exec_ctx * exec_ctx, grpc_subchannel_
   args->master = f->master;
   args->mdctx = f->mdctx;
   s = grpc_subchannel_create (&c->base, args);
-  grpc_connector_unref (&c->base, closure_list);
+  grpc_connector_unref (exec_ctx, &c->base);
   grpc_channel_args_destroy (final_args);
   return s;
 }
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index 793d485dfb..fac93beaa4 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -302,7 +302,7 @@ send_shutdown (grpc_exec_ctx * exec_ctx, grpc_channel * channel, int send_goaway
   op.on_consumed = &sc->closure;
 
   elem = grpc_channel_stack_element (grpc_channel_get_channel_stack (channel), 0);
-  elem->filter->start_transport_op (elem, &op, closure_list);
+  elem->filter->start_transport_op (exec_ctx, elem, &op);
 }
 
 static void
@@ -312,8 +312,8 @@ channel_broadcaster_shutdown (grpc_exec_ctx * exec_ctx, channel_broadcaster * cb
 
   for (i = 0; i < cb->num_channels; i++)
     {
-      send_shutdown (cb->channels[i], send_goaway, force_disconnect, closure_list);
-      GRPC_CHANNEL_INTERNAL_UNREF (cb->channels[i], "broadcast", closure_list);
+      send_shutdown (exec_ctx, cb->channels[i], send_goaway, force_disconnect);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, cb->channels[i], "broadcast");
     }
   gpr_free (cb->channels);
 }
@@ -363,7 +363,7 @@ request_matcher_kill_requests (grpc_exec_ctx * exec_ctx, grpc_server * server, r
   int request_id;
   while ((request_id = gpr_stack_lockfree_pop (rm->requests)) != -1)
     {
-      fail_call (server, &server->requested_calls[request_id], closure_list);
+      fail_call (exec_ctx, server, &server->requested_calls[request_id]);
     }
 }
 
@@ -412,7 +412,7 @@ server_unref (grpc_exec_ctx * exec_ctx, grpc_server * server)
 {
   if (gpr_unref (&server->internal_refcount))
     {
-      server_delete (server, closure_list);
+      server_delete (exec_ctx, server);
     }
 }
 
@@ -436,8 +436,8 @@ finish_destroy_channel (grpc_exec_ctx * exec_ctx, void *cd, int success)
   channel_data *chand = cd;
   grpc_server *server = chand->server;
   gpr_log (GPR_DEBUG, "finish_destroy_channel: %p", chand->channel);
-  GRPC_CHANNEL_INTERNAL_UNREF (chand->channel, "server", closure_list);
-  server_unref (server, closure_list);
+  GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, chand->channel, "server");
+  server_unref (exec_ctx, server);
 }
 
 static void
@@ -448,7 +448,7 @@ destroy_channel (grpc_exec_ctx * exec_ctx, channel_data * chand)
   GPR_ASSERT (chand->server != NULL);
   orphan_channel (chand);
   server_ref (chand->server);
-  maybe_finish_shutdown (chand->server, closure_list);
+  maybe_finish_shutdown (exec_ctx, chand->server);
   chand->finish_destroy_channel_closure.cb = finish_destroy_channel;
   chand->finish_destroy_channel_closure.cb_arg = chand;
   grpc_closure_list_add (closure_list, &chand->finish_destroy_channel_closure, 1);
@@ -494,7 +494,7 @@ finish_start_new_rpc (grpc_exec_ctx * exec_ctx, grpc_server * server, grpc_call_
       gpr_mu_lock (&calld->mu_state);
       calld->state = ACTIVATED;
       gpr_mu_unlock (&calld->mu_state);
-      begin_call (server, calld, &server->requested_calls[request_id], closure_list);
+      begin_call (exec_ctx, server, calld, &server->requested_calls[request_id]);
     }
 }
 
@@ -522,7 +522,7 @@ start_new_rpc (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
 	    continue;
 	  if (rm->method != calld->path)
 	    continue;
-	  finish_start_new_rpc (server, elem, &rm->server_registered_method->request_matcher, closure_list);
+	  finish_start_new_rpc (exec_ctx, server, elem, &rm->server_registered_method->request_matcher);
 	  return;
 	}
       /* check for a wildcard method definition (no host set) */
@@ -536,11 +536,11 @@ start_new_rpc (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
 	    continue;
 	  if (rm->method != calld->path)
 	    continue;
-	  finish_start_new_rpc (server, elem, &rm->server_registered_method->request_matcher, closure_list);
+	  finish_start_new_rpc (exec_ctx, server, elem, &rm->server_registered_method->request_matcher);
 	  return;
 	}
     }
-  finish_start_new_rpc (server, elem, &server->unregistered_request_matcher, closure_list);
+  finish_start_new_rpc (exec_ctx, server, elem, &server->unregistered_request_matcher);
 }
 
 static int
@@ -558,7 +558,7 @@ num_listeners (grpc_server * server)
 static void
 done_shutdown_event (grpc_exec_ctx * exec_ctx, void *server, grpc_cq_completion * completion)
 {
-  server_unref (server, closure_list);
+  server_unref (exec_ctx, server);
 }
 
 static int
@@ -577,12 +577,12 @@ static void
 kill_pending_work_locked (grpc_exec_ctx * exec_ctx, grpc_server * server)
 {
   registered_method *rm;
-  request_matcher_kill_requests (server, &server->unregistered_request_matcher, closure_list);
-  request_matcher_zombify_all_pending_calls (&server->unregistered_request_matcher, closure_list);
+  request_matcher_kill_requests (exec_ctx, server, &server->unregistered_request_matcher);
+  request_matcher_zombify_all_pending_calls (exec_ctx, &server->unregistered_request_matcher);
   for (rm = server->registered_methods; rm; rm = rm->next)
     {
-      request_matcher_kill_requests (server, &rm->request_matcher, closure_list);
-      request_matcher_zombify_all_pending_calls (&rm->request_matcher, closure_list);
+      request_matcher_kill_requests (exec_ctx, server, &rm->request_matcher);
+      request_matcher_zombify_all_pending_calls (exec_ctx, &rm->request_matcher);
     }
 }
 
@@ -595,7 +595,7 @@ maybe_finish_shutdown (grpc_exec_ctx * exec_ctx, grpc_server * server)
       return;
     }
 
-  kill_pending_work_locked (server, closure_list);
+  kill_pending_work_locked (exec_ctx, server);
 
   if (server->root_channel_data.next != &server->root_channel_data || server->listeners_destroyed < num_listeners (server))
     {
@@ -610,7 +610,7 @@ maybe_finish_shutdown (grpc_exec_ctx * exec_ctx, grpc_server * server)
   for (i = 0; i < server->num_shutdown_tags; i++)
     {
       server_ref (server);
-      grpc_cq_end_op (server->shutdown_tags[i].cq, server->shutdown_tags[i].tag, 1, done_shutdown_event, server, &server->shutdown_tags[i].completion, closure_list);
+      grpc_cq_end_op (exec_ctx, server->shutdown_tags[i].cq, server->shutdown_tags[i].tag, 1, done_shutdown_event, server, &server->shutdown_tags[i].completion);
     }
 }
 
@@ -659,7 +659,7 @@ server_on_recv (grpc_exec_ctx * exec_ctx, void *ptr, int success)
 	  if (calld->host && calld->path)
 	    {
 	      calld->got_initial_metadata = 1;
-	      start_new_rpc (elem, closure_list);
+	      start_new_rpc (exec_ctx, elem);
 	    }
 	  break;
 	}
@@ -708,7 +708,7 @@ server_on_recv (grpc_exec_ctx * exec_ctx, void *ptr, int success)
       break;
     }
 
-  calld->on_done_recv->cb (calld->on_done_recv->cb_arg, success, closure_list);
+  calld->on_done_recv->cb (exec_ctx, calld->on_done_recv->cb_arg, success);
 }
 
 static void
@@ -731,7 +731,7 @@ server_start_transport_stream_op (grpc_exec_ctx * exec_ctx, grpc_call_element *
 {
   GRPC_CALL_LOG_OP (GPR_INFO, elem, op);
   server_mutate_op (elem, op);
-  grpc_call_next_op (elem, op, closure_list);
+  grpc_call_next_op (exec_ctx, elem, op);
 }
 
 static void
@@ -752,14 +752,14 @@ channel_connectivity_changed (grpc_exec_ctx * exec_ctx, void *cd, int iomgr_stat
       grpc_transport_op op;
       memset (&op, 0, sizeof (op));
       op.on_connectivity_state_change = &chand->channel_connectivity_changed, op.connectivity_state = &chand->connectivity_state;
-      grpc_channel_next_op (grpc_channel_stack_element (grpc_channel_get_channel_stack (chand->channel), 0), &op, closure_list);
+      grpc_channel_next_op (grpc_channel_stack_element (grpc_channel_get_channel_stack (exec_ctx, chand->channel), 0), &op);
     }
   else
     {
       gpr_mu_lock (&server->mu_global);
-      destroy_channel (chand, closure_list);
+      destroy_channel (exec_ctx, chand);
       gpr_mu_unlock (&server->mu_global);
-      GRPC_CHANNEL_INTERNAL_UNREF (chand->channel, "connectivity", closure_list);
+      GRPC_CHANNEL_INTERNAL_UNREF (exec_ctx, chand->channel, "connectivity");
     }
 }
 
@@ -800,7 +800,7 @@ destroy_call_elem (grpc_exec_ctx * exec_ctx, grpc_call_element * elem)
 
   gpr_mu_destroy (&calld->mu_state);
 
-  server_unref (chand->server, closure_list);
+  server_unref (exec_ctx, chand->server);
 }
 
 static void
@@ -845,11 +845,11 @@ destroy_channel_elem (grpc_exec_ctx * exec_ctx, grpc_channel_element * elem)
       chand->next->prev = chand->prev;
       chand->prev->next = chand->next;
       chand->next = chand->prev = chand;
-      maybe_finish_shutdown (chand->server, closure_list);
+      maybe_finish_shutdown (exec_ctx, chand->server);
       gpr_mu_unlock (&chand->server->mu_global);
       GRPC_MDSTR_UNREF (chand->path_key);
       GRPC_MDSTR_UNREF (chand->authority_key);
-      server_unref (chand->server, closure_list);
+      server_unref (exec_ctx, chand->server);
     }
 }
 
@@ -1031,10 +1031,10 @@ grpc_server_setup_transport (grpc_exec_ctx * exec_ctx, grpc_server * s, grpc_tra
     {
       memset (&op, 0, sizeof (op));
       op.bind_pollset = grpc_cq_pollset (s->cqs[i]);
-      grpc_transport_perform_op (transport, &op, closure_list);
+      grpc_transport_perform_op (exec_ctx, transport, &op);
     }
 
-  channel = grpc_channel_create_from_filters (NULL, filters, num_filters, args, mdctx, 0, closure_list);
+  channel = grpc_channel_create_from_filters (exec_ctx, NULL, filters, num_filters, args, mdctx, 0);
   chand = (channel_data *) grpc_channel_stack_element (grpc_channel_get_channel_stack (channel), 0)->channel_data;
   chand->server = s;
   server_ref (s);
@@ -1089,7 +1089,7 @@ grpc_server_setup_transport (grpc_exec_ctx * exec_ctx, grpc_server * s, grpc_tra
   op.on_connectivity_state_change = &chand->channel_connectivity_changed;
   op.connectivity_state = &chand->connectivity_state;
   op.disconnect = gpr_atm_acq_load (&s->shutdown_flag) != 0;
-  grpc_transport_perform_op (transport, &op, closure_list);
+  grpc_transport_perform_op (exec_ctx, transport, &op);
 }
 
 void
@@ -1105,7 +1105,7 @@ listener_destroy_done (grpc_exec_ctx * exec_ctx, void *s, int success)
   grpc_server *server = s;
   gpr_mu_lock (&server->mu_global);
   server->listeners_destroyed++;
-  maybe_finish_shutdown (server, closure_list);
+  maybe_finish_shutdown (exec_ctx, server);
   gpr_mu_unlock (&server->mu_global);
 }
 
@@ -1220,14 +1220,14 @@ queue_call_request (grpc_exec_ctx * exec_ctx, grpc_server * server, requested_ca
   int request_id;
   if (gpr_atm_acq_load (&server->shutdown_flag))
     {
-      fail_call (server, rc, closure_list);
+      fail_call (exec_ctx, server, rc);
       return GRPC_CALL_OK;
     }
   request_id = gpr_stack_lockfree_pop (server->request_freelist);
   if (request_id == -1)
     {
       /* out of request ids: just fail this one */
-      fail_call (server, rc, closure_list);
+      fail_call (exec_ctx, server, rc);
       return GRPC_CALL_OK;
     }
   switch (rc->type)
@@ -1265,7 +1265,7 @@ queue_call_request (grpc_exec_ctx * exec_ctx, grpc_server * server, requested_ca
 	      GPR_ASSERT (calld->state == PENDING);
 	      calld->state = ACTIVATED;
 	      gpr_mu_unlock (&calld->mu_state);
-	      begin_call (server, calld, &server->requested_calls[request_id], closure_list);
+	      begin_call (exec_ctx, server, calld, &server->requested_calls[request_id]);
 	    }
 	  gpr_mu_lock (&server->mu_call);
 	}
@@ -1367,7 +1367,7 @@ begin_call (grpc_exec_ctx * exec_ctx, grpc_server * server, call_data * calld, r
      fill in the metadata array passed by the client, we need to perform
      an ioreq op, that should complete immediately. */
 
-  grpc_call_set_completion_queue (calld->call, rc->cq_bound_to_call, closure_list);
+  grpc_call_set_completion_queue (exec_ctx, calld->call, rc->cq_bound_to_call);
   *rc->call = calld->call;
   calld->cq_new = rc->cq_for_notification;
   switch (rc->type)
@@ -1402,7 +1402,7 @@ begin_call (grpc_exec_ctx * exec_ctx, grpc_server * server, call_data * calld, r
     }
 
   GRPC_CALL_INTERNAL_REF (calld->call, "server");
-  grpc_call_start_ioreq_and_call_back (calld->call, req, (size_t) (r - req), publish, rc, closure_list);
+  grpc_call_start_ioreq_and_call_back (calld->call, req, (size_t) (exec_ctx, r - req), publish, rc);
 }
 
 static void
@@ -1421,7 +1421,7 @@ done_request_event (grpc_exec_ctx * exec_ctx, void *req, grpc_cq_completion * c)
       gpr_free (req);
     }
 
-  server_unref (server, closure_list);
+  server_unref (exec_ctx, server);
 }
 
 static void
@@ -1438,7 +1438,7 @@ fail_call (grpc_exec_ctx * exec_ctx, grpc_server * server, requested_call * rc)
       break;
     }
   server_ref (server);
-  grpc_cq_end_op (rc->cq_for_notification, rc->tag, 0, done_request_event, rc, &rc->completion, closure_list);
+  grpc_cq_end_op (exec_ctx, rc->cq_for_notification, rc->tag, 0, done_request_event, rc, &rc->completion);
 }
 
 static void
@@ -1449,8 +1449,8 @@ publish_registered_or_batch (grpc_exec_ctx * exec_ctx, grpc_call * call, int suc
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   server_ref (chand->server);
-  grpc_cq_end_op (calld->cq_new, rc->tag, success, done_request_event, rc, &rc->completion, closure_list);
-  GRPC_CALL_INTERNAL_UNREF (call, "server", closure_list);
+  grpc_cq_end_op (exec_ctx, calld->cq_new, rc->tag, success, done_request_event, rc, &rc->completion);
+  GRPC_CALL_INTERNAL_UNREF (exec_ctx, call, "server");
 }
 
 const grpc_channel_args *
diff --git a/src/core/surface/server_chttp2.c b/src/core/surface/server_chttp2.c
index aa4eb9b05b..438ac385b4 100644
--- a/src/core/surface/server_chttp2.c
+++ b/src/core/surface/server_chttp2.c
@@ -48,7 +48,7 @@ setup_transport (grpc_exec_ctx * exec_ctx, void *server, grpc_transport * transp
   static grpc_channel_filter const *extra_filters[] = {
     &grpc_http_server_filter
   };
-  grpc_server_setup_transport (server, transport, extra_filters, GPR_ARRAY_SIZE (extra_filters), mdctx, grpc_server_get_channel_args (server), closure_list);
+  grpc_server_setup_transport (server, transport, extra_filters, GPR_ARRAY_SIZE (extra_filters), mdctx, grpc_server_get_channel_args (exec_ctx, server));
 }
 
 static void
@@ -62,9 +62,9 @@ new_transport (grpc_exec_ctx * exec_ctx, void *server, grpc_endpoint * tcp)
    * case.
    */
   grpc_mdctx *mdctx = grpc_mdctx_create ();
-  grpc_transport *transport = grpc_create_chttp2_transport (grpc_server_get_channel_args (server), tcp, mdctx, 0, closure_list);
-  setup_transport (server, transport, mdctx, closure_list);
-  grpc_chttp2_transport_start_reading (transport, NULL, 0, closure_list);
+  grpc_transport *transport = grpc_create_chttp2_transport (grpc_server_get_channel_args (exec_ctx, server), tcp, mdctx, 0);
+  setup_transport (exec_ctx, server, transport, mdctx);
+  grpc_chttp2_transport_start_reading (exec_ctx, transport, NULL, 0);
 }
 
 /* Server callback: start listening on our ports */
@@ -72,7 +72,7 @@ static void
 start (grpc_exec_ctx * exec_ctx, grpc_server * server, void *tcpp, grpc_pollset ** pollsets, size_t pollset_count)
 {
   grpc_tcp_server *tcp = tcpp;
-  grpc_tcp_server_start (tcp, pollsets, pollset_count, new_transport, server, closure_list);
+  grpc_tcp_server_start (exec_ctx, tcp, pollsets, pollset_count, new_transport, server);
 }
 
 /* Server callback: destroy the tcp listener (so we don't generate further
@@ -81,7 +81,7 @@ static void
 destroy (grpc_exec_ctx * exec_ctx, grpc_server * server, void *tcpp, grpc_closure * destroy_done)
 {
   grpc_tcp_server *tcp = tcpp;
-  grpc_tcp_server_destroy (tcp, destroy_done, closure_list);
+  grpc_tcp_server_destroy (exec_ctx, tcp, destroy_done);
 }
 
 int
diff --git a/src/core/transport/chttp2/parsing.c b/src/core/transport/chttp2/parsing.c
index 8e1dfc9d36..5b55147677 100644
--- a/src/core/transport/chttp2/parsing.c
+++ b/src/core/transport/chttp2/parsing.c
@@ -119,7 +119,7 @@ grpc_chttp2_publish_reads (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_globa
      published later */
   if (transport_parsing->goaway_received)
     {
-      grpc_chttp2_add_incoming_goaway (transport_global, (gpr_uint32) transport_parsing->goaway_error, transport_parsing->goaway_text, closure_list);
+      grpc_chttp2_add_incoming_goaway (transport_global, (exec_ctx, gpr_uint32) transport_parsing->goaway_error, transport_parsing->goaway_text);
       transport_parsing->goaway_text = gpr_empty_slice ();
       transport_parsing->goaway_received = 0;
     }
@@ -339,7 +339,7 @@ grpc_chttp2_perform_read (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_parsin
 	}
       if (transport_parsing->incoming_frame_size == 0)
 	{
-	  if (!parse_frame_slice (transport_parsing, gpr_empty_slice (), 1, closure_list))
+	  if (!parse_frame_slice (transport_parsing, gpr_empty_slice (exec_ctx, ), 1))
 	    {
 	      return 0;
 	    }
@@ -360,7 +360,7 @@ grpc_chttp2_perform_read (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_parsin
       GPR_ASSERT (cur < end);
       if ((gpr_uint32) (end - cur) == transport_parsing->incoming_frame_size)
 	{
-	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (slice, (size_t) (cur - beg), (size_t) (end - beg)), 1, closure_list))
+	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (slice, (size_t) (cur - beg), (size_t) (exec_ctx, end - beg)), 1))
 	    {
 	      return 0;
 	    }
@@ -371,7 +371,7 @@ grpc_chttp2_perform_read (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_parsin
       else if ((gpr_uint32) (end - cur) > transport_parsing->incoming_frame_size)
 	{
 	  size_t cur_offset = (size_t) (cur - beg);
-	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (slice, cur_offset, cur_offset + transport_parsing->incoming_frame_size), 1, closure_list))
+	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (exec_ctx, slice, cur_offset, cur_offset + transport_parsing->incoming_frame_size), 1))
 	    {
 	      return 0;
 	    }
@@ -381,7 +381,7 @@ grpc_chttp2_perform_read (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_parsin
 	}
       else
 	{
-	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (slice, (size_t) (cur - beg), (size_t) (end - beg)), 0, closure_list))
+	  if (!parse_frame_slice (transport_parsing, gpr_slice_sub_no_ref (slice, (size_t) (cur - beg), (size_t) (exec_ctx, end - beg)), 0))
 	    {
 	      return 0;
 	    }
@@ -757,7 +757,7 @@ static int
 parse_frame_slice (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_parsing * transport_parsing, gpr_slice slice, int is_last)
 {
   grpc_chttp2_stream_parsing *stream_parsing = transport_parsing->incoming_stream;
-  switch (transport_parsing->parser (transport_parsing->parser_data, transport_parsing, stream_parsing, slice, is_last, closure_list))
+  switch (transport_parsing->parser (exec_ctx, transport_parsing->parser_data, transport_parsing, stream_parsing, slice, is_last))
     {
     case GRPC_CHTTP2_PARSE_OK:
       if (stream_parsing)
diff --git a/src/core/transport/chttp2/writing.c b/src/core/transport/chttp2/writing.c
index 6c4f0102f7..6c051f5b47 100644
--- a/src/core/transport/chttp2/writing.c
+++ b/src/core/transport/chttp2/writing.c
@@ -150,7 +150,7 @@ grpc_chttp2_perform_writes (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_writ
   GPR_ASSERT (transport_writing->outbuf.count > 0);
   GPR_ASSERT (endpoint);
 
-  grpc_endpoint_write (endpoint, &transport_writing->outbuf, &transport_writing->done_cb, closure_list);
+  grpc_endpoint_write (exec_ctx, endpoint, &transport_writing->outbuf, &transport_writing->done_cb);
 }
 
 static void
diff --git a/src/core/transport/chttp2_transport.c b/src/core/transport/chttp2_transport.c
index bef7d03300..d880a1b9db 100644
--- a/src/core/transport/chttp2_transport.c
+++ b/src/core/transport/chttp2_transport.c
@@ -147,7 +147,7 @@ destruct_transport (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
 
   grpc_chttp2_stream_map_destroy (&t->parsing_stream_map);
   grpc_chttp2_stream_map_destroy (&t->new_stream_map);
-  grpc_connectivity_state_destroy (&t->channel_callback.state_tracker, closure_list);
+  grpc_connectivity_state_destroy (exec_ctx, &t->channel_callback.state_tracker);
 
   gpr_mu_unlock (&t->mu);
   gpr_mu_destroy (&t->mu);
@@ -178,7 +178,7 @@ unref_transport (grpc_chttp2_transport * t, grpc_closure_list * closure_list, co
   gpr_log (GPR_DEBUG, "chttp2:unref:%p %d->%d %s [%s:%d]", t, t->refs.count, t->refs.count - 1, reason, file, line);
   if (!gpr_unref (&t->refs))
     return;
-  destruct_transport (t, closure_list);
+  destruct_transport (exec_ctx, t);
 }
 
 static void
@@ -195,7 +195,7 @@ unref_transport (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
 {
   if (!gpr_unref (&t->refs))
     return;
-  destruct_transport (t, closure_list);
+  destruct_transport (exec_ctx, t);
 }
 
 static void
@@ -333,10 +333,10 @@ destroy_transport (grpc_exec_ctx * exec_ctx, grpc_transport * gt)
 
   lock (t);
   t->destroying = 1;
-  drop_connection (t, closure_list);
-  unlock (t, closure_list);
+  drop_connection (exec_ctx, t);
+  unlock (exec_ctx, t);
 
-  UNREF_TRANSPORT (t, "destroy", closure_list);
+  UNREF_TRANSPORT (exec_ctx, t, "destroy");
 }
 
 /** block grpc_endpoint_shutdown being called until a paired
@@ -355,7 +355,7 @@ allow_endpoint_shutdown_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport
     {
       if (t->ep)
 	{
-	  grpc_endpoint_shutdown (t->ep, closure_list);
+	  grpc_endpoint_shutdown (exec_ctx, t->ep);
 	}
     }
 }
@@ -368,7 +368,7 @@ allow_endpoint_shutdown_unlocked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transpor
       gpr_mu_lock (&t->mu);
       if (t->ep)
 	{
-	  grpc_endpoint_shutdown (t->ep, closure_list);
+	  grpc_endpoint_shutdown (exec_ctx, t->ep);
 	}
       gpr_mu_unlock (&t->mu);
     }
@@ -377,10 +377,10 @@ allow_endpoint_shutdown_unlocked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transpor
 static void
 destroy_endpoint (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
 {
-  grpc_endpoint_destroy (t->ep, closure_list);
+  grpc_endpoint_destroy (exec_ctx, t->ep);
   t->ep = NULL;
   /* safe because we'll still have the ref for write */
-  UNREF_TRANSPORT (t, "disconnect", closure_list);
+  UNREF_TRANSPORT (exec_ctx, t, "disconnect");
 }
 
 static void
@@ -389,10 +389,10 @@ close_transport_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
   if (!t->closed)
     {
       t->closed = 1;
-      connectivity_state_set (&t->global, GRPC_CHANNEL_FATAL_FAILURE, "close_transport", closure_list);
+      connectivity_state_set (exec_ctx, &t->global, GRPC_CHANNEL_FATAL_FAILURE, "close_transport");
       if (t->ep)
 	{
-	  allow_endpoint_shutdown_locked (t, closure_list);
+	  allow_endpoint_shutdown_locked (exec_ctx, t);
 	}
     }
 }
@@ -427,8 +427,8 @@ init_stream (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_stream * gs, co
     }
 
   if (initial_op)
-    perform_stream_op_locked (&t->global, &s->global, initial_op, closure_list);
-  unlock (t, closure_list);
+    perform_stream_op_locked (exec_ctx, &t->global, &s->global, initial_op);
+  unlock (exec_ctx, t);
 
   return 0;
 }
@@ -446,7 +446,7 @@ destroy_stream (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_stream * gs)
   GPR_ASSERT (!s->global.in_stream_map);
   if (grpc_chttp2_unregister_stream (t, s) && t->global.sent_goaway)
     {
-      close_transport_locked (t, closure_list);
+      close_transport_locked (exec_ctx, t);
     }
   if (!t->parsing_active && s->global.id)
     {
@@ -476,7 +476,7 @@ destroy_stream (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_stream * gs)
   grpc_chttp2_incoming_metadata_buffer_destroy (&s->global.incoming_metadata);
   grpc_chttp2_incoming_metadata_live_op_buffer_end (&s->global.outstanding_metadata);
 
-  UNREF_TRANSPORT (t, "stream", closure_list);
+  UNREF_TRANSPORT (exec_ctx, t, "stream");
 }
 
 grpc_chttp2_stream_parsing *
@@ -518,7 +518,7 @@ lock (grpc_chttp2_transport * t)
 static void
 unlock (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
 {
-  unlock_check_read_write_state (t, closure_list);
+  unlock_check_read_write_state (exec_ctx, t);
   if (!t->writing_active && !t->closed && grpc_chttp2_unlocking_check_writes (&t->global, &t->writing))
     {
       t->writing_active = 1;
@@ -558,34 +558,34 @@ grpc_chttp2_terminate_writing (grpc_exec_ctx * exec_ctx, void *transport_writing
 
   lock (t);
 
-  allow_endpoint_shutdown_locked (t, closure_list);
+  allow_endpoint_shutdown_locked (exec_ctx, t);
 
   if (!success)
     {
-      drop_connection (t, closure_list);
+      drop_connection (exec_ctx, t);
     }
 
   /* cleanup writing related jazz */
-  grpc_chttp2_cleanup_writing (&t->global, &t->writing, closure_list);
+  grpc_chttp2_cleanup_writing (exec_ctx, &t->global, &t->writing);
 
   /* leave the writing flag up on shutdown to prevent further writes in unlock()
      from starting */
   t->writing_active = 0;
   if (t->ep && !t->endpoint_reading)
     {
-      destroy_endpoint (t, closure_list);
+      destroy_endpoint (exec_ctx, t);
     }
 
-  unlock (t, closure_list);
+  unlock (exec_ctx, t);
 
-  UNREF_TRANSPORT (t, "writing", closure_list);
+  UNREF_TRANSPORT (exec_ctx, t, "writing");
 }
 
 static void
 writing_action (grpc_exec_ctx * exec_ctx, void *gt, int iomgr_success_ignored)
 {
   grpc_chttp2_transport *t = gt;
-  grpc_chttp2_perform_writes (&t->writing, t->ep, closure_list);
+  grpc_chttp2_perform_writes (exec_ctx, &t->writing, t->ep);
 }
 
 void
@@ -596,7 +596,7 @@ grpc_chttp2_add_incoming_goaway (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport
   gpr_free (msg);
   gpr_slice_unref (goaway_text);
   transport_global->seen_goaway = 1;
-  connectivity_state_set (transport_global, GRPC_CHANNEL_FATAL_FAILURE, "got_goaway", closure_list);
+  connectivity_state_set (exec_ctx, transport_global, GRPC_CHANNEL_FATAL_FAILURE, "got_goaway");
 }
 
 static void
@@ -615,7 +615,7 @@ maybe_start_some_streams (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_global
 
       if (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID)
 	{
-	  connectivity_state_set (transport_global, GRPC_CHANNEL_TRANSIENT_FAILURE, "no_more_stream_ids", closure_list);
+	  connectivity_state_set (exec_ctx, transport_global, GRPC_CHANNEL_TRANSIENT_FAILURE, "no_more_stream_ids");
 	}
 
       stream_global->outgoing_window = transport_global->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
@@ -663,7 +663,7 @@ perform_stream_op_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_global
 	    {
 	      GRPC_CHTTP2_IF_TRACING (gpr_log (GPR_DEBUG, "HTTP:%s: New grpc_chttp2_stream %p waiting for concurrency", transport_global->is_client ? "CLI" : "SVR", stream_global));
 	      grpc_chttp2_list_add_waiting_for_concurrency (transport_global, stream_global);
-	      maybe_start_some_streams (transport_global, closure_list);
+	      maybe_start_some_streams (exec_ctx, transport_global);
 	    }
 	  else if (stream_global->outgoing_window > 0)
 	    {
@@ -704,7 +704,7 @@ perform_stream_op_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_global
 
   if (op->bind_pollset)
     {
-      add_to_pollset_locked (TRANSPORT_FROM_GLOBAL (transport_global), op->bind_pollset, closure_list);
+      add_to_pollset_locked (TRANSPORT_FROM_GLOBAL (exec_ctx, transport_global), op->bind_pollset);
     }
 
   grpc_closure_list_add (closure_list, op->on_consumed, 1);
@@ -717,8 +717,8 @@ perform_stream_op (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_stream *
   grpc_chttp2_stream *s = (grpc_chttp2_stream *) gs;
 
   lock (t);
-  perform_stream_op_locked (&t->global, &s->global, op, closure_list);
-  unlock (t, closure_list);
+  perform_stream_op_locked (exec_ctx, &t->global, &s->global, op);
+  unlock (exec_ctx, t);
 }
 
 static void
@@ -752,7 +752,7 @@ perform_transport_op (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_transp
 
   if (op->on_connectivity_state_change)
     {
-      grpc_connectivity_state_notify_on_state_change (&t->channel_callback.state_tracker, op->connectivity_state, op->on_connectivity_state_change, closure_list);
+      grpc_connectivity_state_notify_on_state_change (exec_ctx, &t->channel_callback.state_tracker, op->connectivity_state, op->on_connectivity_state_change);
     }
 
   if (op->send_goaway)
@@ -770,12 +770,12 @@ perform_transport_op (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_transp
 
   if (op->bind_pollset)
     {
-      add_to_pollset_locked (t, op->bind_pollset, closure_list);
+      add_to_pollset_locked (exec_ctx, t, op->bind_pollset);
     }
 
   if (op->bind_pollset_set)
     {
-      add_to_pollset_set_locked (t, op->bind_pollset_set, closure_list);
+      add_to_pollset_set_locked (exec_ctx, t, op->bind_pollset_set);
     }
 
   if (op->send_ping)
@@ -785,16 +785,16 @@ perform_transport_op (grpc_exec_ctx * exec_ctx, grpc_transport * gt, grpc_transp
 
   if (op->disconnect)
     {
-      close_transport_locked (t, closure_list);
+      close_transport_locked (exec_ctx, t);
     }
 
-  unlock (t, closure_list);
+  unlock (exec_ctx, t);
 
   if (close_transport)
     {
       lock (t);
-      close_transport_locked (t, closure_list);
-      unlock (t, closure_list);
+      close_transport_locked (exec_ctx, t);
+      unlock (exec_ctx, t);
     }
 }
 
@@ -833,7 +833,7 @@ remove_stream (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t, gpr_uint32 i
     }
   if (grpc_chttp2_unregister_stream (t, s) && t->global.sent_goaway)
     {
-      close_transport_locked (t, closure_list);
+      close_transport_locked (exec_ctx, t);
     }
 
   new_stream_count = grpc_chttp2_stream_map_size (&t->parsing_stream_map) + grpc_chttp2_stream_map_size (&t->new_stream_map);
@@ -841,7 +841,7 @@ remove_stream (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t, gpr_uint32 i
   if (new_stream_count != t->global.concurrent_stream_count)
     {
       t->global.concurrent_stream_count = (gpr_uint32) new_stream_count;
-      maybe_start_some_streams (&t->global, closure_list);
+      maybe_start_some_streams (exec_ctx, &t->global);
     }
 }
 
@@ -862,7 +862,7 @@ unlock_check_read_write_state (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport *
 	  GPR_ASSERT (stream_global->in_stream_map);
 	  GPR_ASSERT (stream_global->write_state != GRPC_WRITE_STATE_OPEN);
 	  GPR_ASSERT (stream_global->read_closed);
-	  remove_stream (t, stream_global->id, closure_list);
+	  remove_stream (exec_ctx, t, stream_global->id);
 	  grpc_chttp2_list_add_read_write_state_changed (transport_global, stream_global);
 	}
     }
@@ -911,7 +911,7 @@ unlock_check_read_write_state (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport *
 	    }
 	  else
 	    {
-	      remove_stream (t, stream_global->id, closure_list);
+	      remove_stream (exec_ctx, t, stream_global->id);
 	    }
 	}
       if (!stream_global->publish_sopb)
@@ -1072,7 +1072,7 @@ end_all_the_calls (grpc_chttp2_transport * t)
 static void
 drop_connection (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
 {
-  close_transport_locked (t, closure_list);
+  close_transport_locked (exec_ctx, t);
   end_all_the_calls (t);
 }
 
@@ -1104,7 +1104,7 @@ read_error_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t)
   t->endpoint_reading = 0;
   if (!t->writing_active && t->ep)
     {
-      destroy_endpoint (t, closure_list);
+      destroy_endpoint (exec_ctx, t);
     }
 }
 
@@ -1126,12 +1126,12 @@ recv_data (grpc_exec_ctx * exec_ctx, void *tp, int success)
       grpc_chttp2_stream_map_move_into (&t->new_stream_map, &t->parsing_stream_map);
       grpc_chttp2_prepare_to_read (&t->global, &t->parsing);
       gpr_mu_unlock (&t->mu);
-      for (; i < t->read_buffer.count && grpc_chttp2_perform_read (&t->parsing, t->read_buffer.slices[i], closure_list); i++)
+      for (; i < t->read_buffer.count && grpc_chttp2_perform_read (exec_ctx, &t->parsing, t->read_buffer.slices[i]); i++)
 	;
       gpr_mu_lock (&t->mu);
       if (i != t->read_buffer.count)
 	{
-	  drop_connection (t, closure_list);
+	  drop_connection (exec_ctx, t);
 	}
       /* merge stream lists */
       grpc_chttp2_stream_map_move_into (&t->new_stream_map, &t->parsing_stream_map);
@@ -1142,13 +1142,13 @@ recv_data (grpc_exec_ctx * exec_ctx, void *tp, int success)
 	  t->parsing.initial_window_update = 0;
 	}
       /* handle higher level things */
-      grpc_chttp2_publish_reads (&t->global, &t->parsing, closure_list);
+      grpc_chttp2_publish_reads (exec_ctx, &t->global, &t->parsing);
       t->parsing_active = 0;
     }
   if (!success || i != t->read_buffer.count)
     {
-      drop_connection (t, closure_list);
-      read_error_locked (t, closure_list);
+      drop_connection (exec_ctx, t);
+      read_error_locked (exec_ctx, t);
     }
   else if (!t->closed)
     {
@@ -1157,17 +1157,17 @@ recv_data (grpc_exec_ctx * exec_ctx, void *tp, int success)
       prevent_endpoint_shutdown (t);
     }
   gpr_slice_buffer_reset_and_unref (&t->read_buffer);
-  unlock (t, closure_list);
+  unlock (exec_ctx, t);
 
   if (keep_reading)
     {
-      grpc_endpoint_read (t->ep, &t->read_buffer, &t->recv_data, closure_list);
-      allow_endpoint_shutdown_unlocked (t, closure_list);
-      UNREF_TRANSPORT (t, "keep_reading", closure_list);
+      grpc_endpoint_read (exec_ctx, t->ep, &t->read_buffer, &t->recv_data);
+      allow_endpoint_shutdown_unlocked (exec_ctx, t);
+      UNREF_TRANSPORT (exec_ctx, t, "keep_reading");
     }
   else
     {
-      UNREF_TRANSPORT (t, "recv_data", closure_list);
+      UNREF_TRANSPORT (exec_ctx, t, "recv_data");
     }
 }
 
@@ -1179,7 +1179,7 @@ static void
 connectivity_state_set (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport_global * transport_global, grpc_connectivity_state state, const char *reason)
 {
   GRPC_CHTTP2_IF_TRACING (gpr_log (GPR_DEBUG, "set connectivity_state=%d", state));
-  grpc_connectivity_state_set (&TRANSPORT_FROM_GLOBAL (transport_global)->channel_callback.state_tracker, state, reason, closure_list);
+  grpc_connectivity_state_set (&TRANSPORT_FROM_GLOBAL (exec_ctx, transport_global)->channel_callback.state_tracker, state, reason);
 }
 
 /*
@@ -1191,7 +1191,7 @@ add_to_pollset_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t, grpc
 {
   if (t->ep)
     {
-      grpc_endpoint_add_to_pollset (t->ep, pollset, closure_list);
+      grpc_endpoint_add_to_pollset (exec_ctx, t->ep, pollset);
     }
 }
 
@@ -1200,7 +1200,7 @@ add_to_pollset_set_locked (grpc_exec_ctx * exec_ctx, grpc_chttp2_transport * t,
 {
   if (t->ep)
     {
-      grpc_endpoint_add_to_pollset_set (t->ep, pollset_set, closure_list);
+      grpc_endpoint_add_to_pollset_set (exec_ctx, t->ep, pollset_set);
     }
 }
 
@@ -1256,7 +1256,7 @@ grpc_transport *
 grpc_create_chttp2_transport (grpc_exec_ctx * exec_ctx, const grpc_channel_args * channel_args, grpc_endpoint * ep, grpc_mdctx * mdctx, int is_client)
 {
   grpc_chttp2_transport *t = gpr_malloc (sizeof (grpc_chttp2_transport));
-  init_transport (t, channel_args, ep, mdctx, is_client != 0, closure_list);
+  init_transport (exec_ctx, t, channel_args, ep, mdctx, is_client != 0);
   return &t->base;
 }
 
@@ -1266,5 +1266,5 @@ grpc_chttp2_transport_start_reading (grpc_exec_ctx * exec_ctx, grpc_transport *
   grpc_chttp2_transport *t = (grpc_chttp2_transport *) transport;
   REF_TRANSPORT (t, "recv_data");	/* matches unref inside recv_data */
   gpr_slice_buffer_addn (&t->read_buffer, slices, nslices);
-  recv_data (t, 1, closure_list);
+  recv_data (exec_ctx, t, 1);
 }
diff --git a/src/core/transport/transport.c b/src/core/transport/transport.c
index ca04d34b3f..e41481aa64 100644
--- a/src/core/transport/transport.c
+++ b/src/core/transport/transport.c
@@ -45,37 +45,37 @@ grpc_transport_stream_size (grpc_transport * transport)
 void
 grpc_transport_destroy (grpc_exec_ctx * exec_ctx, grpc_transport * transport)
 {
-  transport->vtable->destroy (transport, closure_list);
+  transport->vtable->destroy (exec_ctx, transport);
 }
 
 int
 grpc_transport_init_stream (grpc_exec_ctx * exec_ctx, grpc_transport * transport, grpc_stream * stream, const void *server_data, grpc_transport_stream_op * initial_op)
 {
-  return transport->vtable->init_stream (transport, stream, server_data, initial_op, closure_list);
+  return transport->vtable->init_stream (exec_ctx, transport, stream, server_data, initial_op);
 }
 
 void
 grpc_transport_perform_stream_op (grpc_exec_ctx * exec_ctx, grpc_transport * transport, grpc_stream * stream, grpc_transport_stream_op * op)
 {
-  transport->vtable->perform_stream_op (transport, stream, op, closure_list);
+  transport->vtable->perform_stream_op (exec_ctx, transport, stream, op);
 }
 
 void
 grpc_transport_perform_op (grpc_exec_ctx * exec_ctx, grpc_transport * transport, grpc_transport_op * op)
 {
-  transport->vtable->perform_op (transport, op, closure_list);
+  transport->vtable->perform_op (exec_ctx, transport, op);
 }
 
 void
 grpc_transport_destroy_stream (grpc_exec_ctx * exec_ctx, grpc_transport * transport, grpc_stream * stream)
 {
-  transport->vtable->destroy_stream (transport, stream, closure_list);
+  transport->vtable->destroy_stream (exec_ctx, transport, stream);
 }
 
 char *
 grpc_transport_get_peer (grpc_exec_ctx * exec_ctx, grpc_transport * transport)
 {
-  return transport->vtable->get_peer (transport, closure_list);
+  return transport->vtable->get_peer (exec_ctx, transport);
 }
 
 void
@@ -119,7 +119,7 @@ free_message (grpc_exec_ctx * exec_ctx, void *p, int iomgr_success)
   gpr_slice_unref (cmd->message);
   if (cmd->then_call != NULL)
     {
-      cmd->then_call->cb (cmd->then_call->cb_arg, iomgr_success, closure_list);
+      cmd->then_call->cb (exec_ctx, cmd->then_call->cb_arg, iomgr_success);
     }
   gpr_free (cmd);
 }
diff --git a/test/core/iomgr/endpoint_tests.c b/test/core/iomgr/endpoint_tests.c
index bea0371053..32d08a7c6a 100644
--- a/test/core/iomgr/endpoint_tests.c
+++ b/test/core/iomgr/endpoint_tests.c
@@ -153,7 +153,7 @@ read_and_write_test_read_handler (grpc_exec_ctx * exec_ctx, void *data, int succ
     }
   else if (success)
     {
-      grpc_endpoint_read (state->read_ep, &state->incoming, &state->done_read, closure_list);
+      grpc_endpoint_read (exec_ctx, state->read_ep, &state->incoming, &state->done_read);
     }
 }
 
@@ -176,7 +176,7 @@ read_and_write_test_write_handler (grpc_exec_ctx * exec_ctx, void *data, int suc
 	  slices = allocate_blocks (state->current_write_size, 8192, &nslices, &state->current_write_data);
 	  gpr_slice_buffer_reset_and_unref (&state->outgoing);
 	  gpr_slice_buffer_addn (&state->outgoing, slices, nslices);
-	  grpc_endpoint_write (state->write_ep, &state->outgoing, &state->done_write, closure_list);
+	  grpc_endpoint_write (exec_ctx, state->write_ep, &state->outgoing, &state->done_write);
 	  free (slices);
 	  return;
 	}
diff --git a/test/core/iomgr/fd_posix_test.c b/test/core/iomgr/fd_posix_test.c
index d8b4032162..82d6206c86 100644
--- a/test/core/iomgr/fd_posix_test.c
+++ b/test/core/iomgr/fd_posix_test.c
@@ -129,10 +129,10 @@ session_shutdown_cb (void *arg,	/*session */
 {
   session *se = arg;
   server *sv = se->sv;
-  grpc_fd_orphan (se->em_fd, NULL, "a", closure_list);
+  grpc_fd_orphan (exec_ctx, se->em_fd, NULL, "a");
   gpr_free (se);
   /* Start to shutdown listen fd. */
-  grpc_fd_shutdown (sv->em_fd, closure_list);
+  grpc_fd_shutdown (exec_ctx, sv->em_fd);
 }
 
 /* Called when data become readable in a session. */
@@ -148,7 +148,7 @@ session_read_cb (void *arg,	/*session */
 
   if (!success)
     {
-      session_shutdown_cb (arg, 1, closure_list);
+      session_shutdown_cb (exec_ctx, arg, 1);
       return;
     }
 
@@ -167,7 +167,7 @@ session_read_cb (void *arg,	/*session */
      been drained, In such a case, read() returns -1 and set errno to EAGAIN. */
   if (read_once == 0)
     {
-      session_shutdown_cb (arg, 1, closure_list);
+      session_shutdown_cb (exec_ctx, arg, 1);
     }
   else if (read_once == -1)
     {
@@ -181,7 +181,7 @@ session_read_cb (void *arg,	/*session */
 	     TODO(chenw): in multi-threaded version, callback and polling can be
 	     run in different threads. polling may catch a persist read edge event
 	     before notify_on_read is called.  */
-	  grpc_fd_notify_on_read (se->em_fd, &se->session_read_closure, closure_list);
+	  grpc_fd_notify_on_read (exec_ctx, se->em_fd, &se->session_read_closure);
 	}
       else
 	{
@@ -199,7 +199,7 @@ listen_shutdown_cb (void *arg /*server */ , int success,
 {
   server *sv = arg;
 
-  grpc_fd_orphan (sv->em_fd, NULL, "b", closure_list);
+  grpc_fd_orphan (exec_ctx, sv->em_fd, NULL, "b");
 
   gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
   sv->done = 1;
@@ -222,7 +222,7 @@ listen_cb (void *arg,		 /*=sv_arg*/
 
   if (!success)
     {
-      listen_shutdown_cb (arg, 1, closure_list);
+      listen_shutdown_cb (exec_ctx, arg, 1);
       return;
     }
 
@@ -234,12 +234,12 @@ listen_cb (void *arg,		 /*=sv_arg*/
   se = gpr_malloc (sizeof (*se));
   se->sv = sv;
   se->em_fd = grpc_fd_create (fd, "listener");
-  grpc_pollset_add_fd (&g_pollset, se->em_fd, closure_list);
+  grpc_pollset_add_fd (exec_ctx, &g_pollset, se->em_fd);
   se->session_read_closure.cb = session_read_cb;
   se->session_read_closure.cb_arg = se;
-  grpc_fd_notify_on_read (se->em_fd, &se->session_read_closure, closure_list);
+  grpc_fd_notify_on_read (exec_ctx, se->em_fd, &se->session_read_closure);
 
-  grpc_fd_notify_on_read (listen_em_fd, &sv->listen_closure, closure_list);
+  grpc_fd_notify_on_read (exec_ctx, listen_em_fd, &sv->listen_closure);
 }
 
 /* Max number of connections pending to be accepted by listen(). */
@@ -265,11 +265,11 @@ server_start (grpc_exec_ctx * exec_ctx, server * sv)
   GPR_ASSERT (listen (fd, MAX_NUM_FD) == 0);
 
   sv->em_fd = grpc_fd_create (fd, "server");
-  grpc_pollset_add_fd (&g_pollset, sv->em_fd, closure_list);
+  grpc_pollset_add_fd (exec_ctx, &g_pollset, sv->em_fd);
   /* Register to be interested in reading from listen_fd. */
   sv->listen_closure.cb = listen_cb;
   sv->listen_closure.cb_arg = sv;
-  grpc_fd_notify_on_read (sv->em_fd, &sv->listen_closure, closure_list);
+  grpc_fd_notify_on_read (exec_ctx, sv->em_fd, &sv->listen_closure);
 
   return port;
 }
@@ -327,7 +327,7 @@ client_session_shutdown_cb (void *arg /*client */ , int success,
 			    grpc_closure_list * closure_list)
 {
   client *cl = arg;
-  grpc_fd_orphan (cl->em_fd, NULL, "c", closure_list);
+  grpc_fd_orphan (exec_ctx, cl->em_fd, NULL, "c");
   cl->done = 1;
   grpc_pollset_kick (&g_pollset, NULL);
 }
@@ -344,7 +344,7 @@ client_session_write (void *arg,	/*client */
   if (!success)
     {
       gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
-      client_session_shutdown_cb (arg, 1, closure_list);
+      client_session_shutdown_cb (exec_ctx, arg, 1);
       gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
       return;
     }
@@ -364,12 +364,12 @@ client_session_write (void *arg,	/*client */
 	{
 	  cl->write_closure.cb = client_session_write;
 	  cl->write_closure.cb_arg = cl;
-	  grpc_fd_notify_on_write (cl->em_fd, &cl->write_closure, closure_list);
+	  grpc_fd_notify_on_write (exec_ctx, cl->em_fd, &cl->write_closure);
 	  cl->client_write_cnt++;
 	}
       else
 	{
-	  client_session_shutdown_cb (arg, 1, closure_list);
+	  client_session_shutdown_cb (exec_ctx, arg, 1);
 	}
       gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
     }
@@ -409,9 +409,9 @@ client_start (grpc_exec_ctx * exec_ctx, client * cl, int port)
     }
 
   cl->em_fd = grpc_fd_create (fd, "client");
-  grpc_pollset_add_fd (&g_pollset, cl->em_fd, closure_list);
+  grpc_pollset_add_fd (exec_ctx, &g_pollset, cl->em_fd);
 
-  client_session_write (cl, 1, closure_list);
+  client_session_write (exec_ctx, cl, 1);
 }
 
 /* Wait for the signal to shutdown a client. */
diff --git a/test/core/iomgr/tcp_client_posix_test.c b/test/core/iomgr/tcp_client_posix_test.c
index b93b9a5725..6dcdf9ee25 100644
--- a/test/core/iomgr/tcp_client_posix_test.c
+++ b/test/core/iomgr/tcp_client_posix_test.c
@@ -72,8 +72,8 @@ must_succeed (grpc_exec_ctx * exec_ctx, void *arg, int success)
 {
   GPR_ASSERT (g_connecting != NULL);
   GPR_ASSERT (success);
-  grpc_endpoint_shutdown (g_connecting, closure_list);
-  grpc_endpoint_destroy (g_connecting, closure_list);
+  grpc_endpoint_shutdown (exec_ctx, g_connecting);
+  grpc_endpoint_destroy (exec_ctx, g_connecting);
   g_connecting = NULL;
   finish_connection ();
 }
diff --git a/test/core/iomgr/tcp_posix_test.c b/test/core/iomgr/tcp_posix_test.c
index af338249c5..168fc87d16 100644
--- a/test/core/iomgr/tcp_posix_test.c
+++ b/test/core/iomgr/tcp_posix_test.c
@@ -176,7 +176,7 @@ read_cb (grpc_exec_ctx * exec_ctx, void *user_data, int success)
     }
   else
     {
-      grpc_endpoint_read (state->ep, &state->incoming, &state->read_cb, closure_list);
+      grpc_endpoint_read (exec_ctx, state->ep, &state->incoming, &state->read_cb);
       gpr_mu_unlock (GRPC_POLLSET_MU (&g_pollset));
     }
 }
diff --git a/test/core/iomgr/tcp_server_posix_test.c b/test/core/iomgr/tcp_server_posix_test.c
index 8467e937ee..e59e45a8b2 100644
--- a/test/core/iomgr/tcp_server_posix_test.c
+++ b/test/core/iomgr/tcp_server_posix_test.c
@@ -51,8 +51,8 @@ static int g_nconnects = 0;
 static void
 on_connect (grpc_exec_ctx * exec_ctx, void *arg, grpc_endpoint * tcp)
 {
-  grpc_endpoint_shutdown (tcp, closure_list);
-  grpc_endpoint_destroy (tcp, closure_list);
+  grpc_endpoint_shutdown (exec_ctx, tcp);
+  grpc_endpoint_destroy (exec_ctx, tcp);
 
   gpr_mu_lock (GRPC_POLLSET_MU (&g_pollset));
   g_nconnects++;
diff --git a/test/core/security/credentials_test.c b/test/core/security/credentials_test.c
index 281f14f3b7..3facb9556f 100644
--- a/test/core/security/credentials_test.c
+++ b/test/core/security/credentials_test.c
@@ -461,7 +461,7 @@ compute_engine_httpcli_get_success_override (grpc_exec_ctx * exec_ctx, const grp
 {
   grpc_httpcli_response response = http_response (200, valid_oauth2_json_response);
   validate_compute_engine_http_request (request);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   return 1;
 }
 
@@ -470,7 +470,7 @@ compute_engine_httpcli_get_failure_override (grpc_exec_ctx * exec_ctx, const grp
 {
   grpc_httpcli_response response = http_response (403, "Not Authorized.");
   validate_compute_engine_http_request (request);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   return 1;
 }
 
@@ -548,7 +548,7 @@ refresh_token_httpcli_post_success (grpc_exec_ctx * exec_ctx, const grpc_httpcli
 {
   grpc_httpcli_response response = http_response (200, valid_oauth2_json_response);
   validate_refresh_token_http_request (request, body, body_size);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   return 1;
 }
 
@@ -557,7 +557,7 @@ refresh_token_httpcli_post_failure (grpc_exec_ctx * exec_ctx, const grpc_httpcli
 {
   grpc_httpcli_response response = http_response (403, "Not Authorized.");
   validate_refresh_token_http_request (request, body, body_size);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   return 1;
 }
 
diff --git a/test/core/security/jwt_verifier_test.c b/test/core/security/jwt_verifier_test.c
index 506918d27c..8832dca817 100644
--- a/test/core/security/jwt_verifier_test.c
+++ b/test/core/security/jwt_verifier_test.c
@@ -203,7 +203,7 @@ httpcli_get_google_keys_for_email (grpc_exec_ctx * exec_ctx, const grpc_httpcli_
   GPR_ASSERT (request->handshaker == &grpc_httpcli_ssl);
   GPR_ASSERT (strcmp (request->host, "www.googleapis.com") == 0);
   GPR_ASSERT (strcmp (request->path, "/robot/v1/metadata/x509/" "777-abaslkan11hlb6nmim3bpspl31ud@developer." "gserviceaccount.com") == 0);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   gpr_free (response.body);
   return 1;
 }
@@ -246,7 +246,7 @@ httpcli_get_custom_keys_for_email (grpc_exec_ctx * exec_ctx, const grpc_httpcli_
   GPR_ASSERT (request->handshaker == &grpc_httpcli_ssl);
   GPR_ASSERT (strcmp (request->host, "keys.bar.com") == 0);
   GPR_ASSERT (strcmp (request->path, "/jwk/foo@bar.com") == 0);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   gpr_free (response.body);
   return 1;
 }
@@ -279,7 +279,7 @@ httpcli_get_jwk_set (grpc_exec_ctx * exec_ctx, const grpc_httpcli_request * requ
   GPR_ASSERT (request->handshaker == &grpc_httpcli_ssl);
   GPR_ASSERT (strcmp (request->host, "www.googleapis.com") == 0);
   GPR_ASSERT (strcmp (request->path, "/oauth2/v3/certs") == 0);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   gpr_free (response.body);
   return 1;
 }
@@ -292,7 +292,7 @@ httpcli_get_openid_config (grpc_exec_ctx * exec_ctx, const grpc_httpcli_request
   GPR_ASSERT (strcmp (request->host, "accounts.google.com") == 0);
   GPR_ASSERT (strcmp (request->path, GRPC_OPENID_CONFIG_URL_SUFFIX) == 0);
   grpc_httpcli_set_override (httpcli_get_jwk_set, httpcli_post_should_not_be_called);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   gpr_free (response.body);
   return 1;
 }
@@ -331,7 +331,7 @@ httpcli_get_bad_json (grpc_exec_ctx * exec_ctx, const grpc_httpcli_request * req
 {
   grpc_httpcli_response response = http_response (200, gpr_strdup ("{\"bad\": \"stuff\"}"));
   GPR_ASSERT (request->handshaker == &grpc_httpcli_ssl);
-  on_response (user_data, &response, closure_list);
+  on_response (exec_ctx, user_data, &response);
   gpr_free (response.body);
   return 1;
 }
diff --git a/test/core/util/port_posix.c b/test/core/util/port_posix.c
index 670b19e28c..a1893375ec 100644
--- a/test/core/util/port_posix.c
+++ b/test/core/util/port_posix.c
@@ -247,7 +247,7 @@ got_port_from_server (grpc_exec_ctx * exec_ctx, void *arg, const grpc_httpcli_re
       req.path = "/get";
       gpr_log (GPR_DEBUG, "failed port pick from server: retrying");
       sleep (1);
-      grpc_httpcli_get (pr->ctx, &pr->pollset, &req, GRPC_TIMEOUT_SECONDS_TO_DEADLINE (10), got_port_from_server, pr, closure_list);
+      grpc_httpcli_get (pr->ctx, &pr->pollset, &req, GRPC_TIMEOUT_SECONDS_TO_DEADLINE (exec_ctx, 10), got_port_from_server, pr);
       return;
     }
   GPR_ASSERT (response);
diff --git a/test/core/util/reconnect_server.c b/test/core/util/reconnect_server.c
index 4d1ef62e17..f3a7df1f69 100644
--- a/test/core/util/reconnect_server.c
+++ b/test/core/util/reconnect_server.c
@@ -75,8 +75,8 @@ on_connect (grpc_exec_ctx * exec_ctx, void *arg, grpc_endpoint * tcp)
   gpr_timespec now = gpr_now (GPR_CLOCK_REALTIME);
   timestamp_list *new_tail;
   peer = grpc_endpoint_get_peer (tcp);
-  grpc_endpoint_shutdown (tcp, closure_list);
-  grpc_endpoint_destroy (tcp, closure_list);
+  grpc_endpoint_shutdown (exec_ctx, tcp);
+  grpc_endpoint_destroy (exec_ctx, tcp);
   if (peer)
     {
       last_colon = strrchr (peer, ':');