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, 4 insertions, 8 deletions

diff --git a/src/core/ext/filters/client_channel/subchannel_index.h b/src/core/ext/filters/client_channel/subchannel_index.h
index 05c3878379..9be618e44f 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.h
+++ b/src/core/ext/filters/client_channel/subchannel_index.h
@@ -33,26 +33,22 @@ grpc_subchannel_key *grpc_subchannel_key_create(
     const grpc_subchannel_args *args);
 
 /** Destroy a subchannel key */
-void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
-                                 grpc_subchannel_key *key);
+void grpc_subchannel_key_destroy(grpc_subchannel_key *key);
 
 /** Given a subchannel key, find the subchannel registered for it.
     Returns NULL if no such channel exists.
     Thread-safe. */
-grpc_subchannel *grpc_subchannel_index_find(grpc_exec_ctx *exec_ctx,
-                                            grpc_subchannel_key *key);
+grpc_subchannel *grpc_subchannel_index_find(grpc_subchannel_key *key);
 
 /** Register a subchannel against a key.
     Takes ownership of \a constructed.
     Returns the registered subchannel. This may be different from
     \a constructed in the case of a registration race. */
-grpc_subchannel *grpc_subchannel_index_register(grpc_exec_ctx *exec_ctx,
-                                                grpc_subchannel_key *key,
+grpc_subchannel *grpc_subchannel_index_register(grpc_subchannel_key *key,
                                                 grpc_subchannel *constructed);
 
 /** Remove \a constructed as the registered subchannel for \a key. */
-void grpc_subchannel_index_unregister(grpc_exec_ctx *exec_ctx,
-                                      grpc_subchannel_key *key,
+void grpc_subchannel_index_unregister(grpc_subchannel_key *key,
                                       grpc_subchannel *constructed);
 
 int grpc_subchannel_key_compare(const grpc_subchannel_key *a,