Removing instances of exec_ctx being passed around in functions in

src/core. exec_ctx is now a thread_local pointer of type ExecCtx instead of
grpc_exec_ctx which is initialized whenever ExecCtx is instantiated. ExecCtx
also keeps track of the previous exec_ctx so that nesting of exec_ctx is
allowed. This means that there is only one exec_ctx being used at any
time. Also, grpc_exec_ctx_finish is called in the destructor of the
object, and the previous exec_ctx is restored to avoid breaking current
functionality. The code still explicitly calls grpc_exec_ctx_finish
because removing all such instances causes the code to break.

1 files changed, 31 insertions, 44 deletions

diff --git a/src/core/ext/filters/client_channel/subchannel.h b/src/core/ext/filters/client_channel/subchannel.h
index 46b29f1fe0..63d3353b7d 100644
--- a/src/core/ext/filters/client_channel/subchannel.h
+++ b/src/core/ext/filters/client_channel/subchannel.h
@@ -46,36 +46,34 @@ typedef struct grpc_subchannel_key grpc_subchannel_key;
   grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) \
   grpc_subchannel_ref_from_weak_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_SUBCHANNEL_UNREF(cl, p, r) \
-  grpc_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_UNREF(p, r) \
+  grpc_subchannel_unref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_WEAK_REF(p, r) \
   grpc_subchannel_weak_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
-  grpc_subchannel_weak_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(p, r) \
+  grpc_subchannel_weak_unref((p), __FILE__, __LINE__, (r))
 #define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) \
   grpc_connected_subchannel_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
-  grpc_connected_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(p, r) \
+  grpc_connected_subchannel_unref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) \
   grpc_subchannel_call_ref((p), __FILE__, __LINE__, (r))
-#define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
-  grpc_subchannel_call_unref((cl), (p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) \
+  grpc_subchannel_call_unref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_REF_EXTRA_ARGS \
   , const char *file, int line, const char *reason
 #else
 #define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
 #define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) \
   grpc_subchannel_ref_from_weak_ref((p))
-#define GRPC_SUBCHANNEL_UNREF(cl, p, r) grpc_subchannel_unref((cl), (p))
+#define GRPC_SUBCHANNEL_UNREF(p, r) grpc_subchannel_unref((p))
 #define GRPC_SUBCHANNEL_WEAK_REF(p, r) grpc_subchannel_weak_ref((p))
-#define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
-  grpc_subchannel_weak_unref((cl), (p))
+#define GRPC_SUBCHANNEL_WEAK_UNREF(p, r) grpc_subchannel_weak_unref((p))
 #define GRPC_CONNECTED_SUBCHANNEL_REF(p, r) grpc_connected_subchannel_ref((p))
-#define GRPC_CONNECTED_SUBCHANNEL_UNREF(cl, p, r) \
-  grpc_connected_subchannel_unref((cl), (p))
+#define GRPC_CONNECTED_SUBCHANNEL_UNREF(p, r) \
+  grpc_connected_subchannel_unref((p))
 #define GRPC_SUBCHANNEL_CALL_REF(p, r) grpc_subchannel_call_ref((p))
-#define GRPC_SUBCHANNEL_CALL_UNREF(cl, p, r) \
-  grpc_subchannel_call_unref((cl), (p))
+#define GRPC_SUBCHANNEL_CALL_UNREF(p, r) grpc_subchannel_call_unref((p))
 #define GRPC_SUBCHANNEL_REF_EXTRA_ARGS
 #endif
 
@@ -83,24 +81,20 @@ grpc_subchannel *grpc_subchannel_ref(
     grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 grpc_subchannel *grpc_subchannel_ref_from_weak_ref(
     grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_subchannel_unref(grpc_exec_ctx *exec_ctx,
-                           grpc_subchannel *channel
-                               GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_unref(
+    grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 grpc_subchannel *grpc_subchannel_weak_ref(
     grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_subchannel_weak_unref(grpc_exec_ctx *exec_ctx,
-                                grpc_subchannel *channel
-                                    GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_weak_unref(
+    grpc_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 grpc_connected_subchannel *grpc_connected_subchannel_ref(
     grpc_connected_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_connected_subchannel_unref(grpc_exec_ctx *exec_ctx,
-                                     grpc_connected_subchannel *channel
-                                         GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_connected_subchannel_unref(
+    grpc_connected_subchannel *channel GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 void grpc_subchannel_call_ref(
     grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
-void grpc_subchannel_call_unref(grpc_exec_ctx *exec_ctx,
-                                grpc_subchannel_call *call
-                                    GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
+void grpc_subchannel_call_unref(
+    grpc_subchannel_call *call GRPC_SUBCHANNEL_REF_EXTRA_ARGS);
 
 /** construct a subchannel call */
 typedef struct {
@@ -114,14 +108,13 @@ typedef struct {
 } grpc_connected_subchannel_call_args;
 
 grpc_error *grpc_connected_subchannel_create_call(
-    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *connected_subchannel,
+    grpc_connected_subchannel *connected_subchannel,
     const grpc_connected_subchannel_call_args *args,
     grpc_subchannel_call **subchannel_call);
 
 /** process a transport level op */
 void grpc_connected_subchannel_process_transport_op(
-    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *subchannel,
-    grpc_transport_op *op);
+    grpc_connected_subchannel *subchannel, grpc_transport_op *op);
 
 /** poll the current connectivity state of a channel */
 grpc_connectivity_state grpc_subchannel_check_connectivity(
@@ -130,15 +123,12 @@ grpc_connectivity_state grpc_subchannel_check_connectivity(
 /** call notify when the connectivity state of a channel changes from *state.
     Updates *state with the new state of the channel */
 void grpc_subchannel_notify_on_state_change(
-    grpc_exec_ctx *exec_ctx, grpc_subchannel *channel,
-    grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
-    grpc_closure *notify);
+    grpc_subchannel *channel, grpc_pollset_set *interested_parties,
+    grpc_connectivity_state *state, grpc_closure *notify);
 void grpc_connected_subchannel_notify_on_state_change(
-    grpc_exec_ctx *exec_ctx, grpc_connected_subchannel *channel,
-    grpc_pollset_set *interested_parties, grpc_connectivity_state *state,
-    grpc_closure *notify);
-void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx,
-                                    grpc_connected_subchannel *channel,
+    grpc_connected_subchannel *channel, grpc_pollset_set *interested_parties,
+    grpc_connectivity_state *state, grpc_closure *notify);
+void grpc_connected_subchannel_ping(grpc_connected_subchannel *channel,
                                     grpc_closure *notify);
 
 /** retrieve the grpc_connected_subchannel - or NULL if called before
@@ -151,8 +141,7 @@ const grpc_subchannel_key *grpc_subchannel_get_key(
     const grpc_subchannel *subchannel);
 
 /** continue processing a transport op */
-void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
-                                     grpc_subchannel_call *subchannel_call,
+void grpc_subchannel_call_process_op(grpc_subchannel_call *subchannel_call,
                                      grpc_transport_stream_op_batch *op);
 
 /** Must be called once per call. Sets the 'then_schedule_closure' argument for
@@ -176,13 +165,11 @@ struct grpc_subchannel_args {
 };
 
 /** create a subchannel given a connector */
-grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
-                                        grpc_connector *connector,
+grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
                                         const grpc_subchannel_args *args);
 
 /// Sets \a addr from \a args.
-void grpc_get_subchannel_address_arg(grpc_exec_ctx *exec_ctx,
-                                     const grpc_channel_args *args,
+void grpc_get_subchannel_address_arg(const grpc_channel_args *args,
                                      grpc_resolved_address *addr);
 
 /// Returns the URI string for the address to connect to.