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, 15 insertions, 17 deletions

diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.cc b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
index 6410a6043d..b23c58d1c6 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
@@ -34,21 +34,19 @@ static void client_channel_factory_ref(
     grpc_client_channel_factory *cc_factory) {}
 
 static void client_channel_factory_unref(
-    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {}
+    grpc_client_channel_factory *cc_factory) {}
 
 static grpc_subchannel *client_channel_factory_create_subchannel(
-    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
-    const grpc_subchannel_args *args) {
+    grpc_client_channel_factory *cc_factory, const grpc_subchannel_args *args) {
   grpc_connector *connector = grpc_chttp2_connector_create();
-  grpc_subchannel *s = grpc_subchannel_create(exec_ctx, connector, args);
-  grpc_connector_unref(exec_ctx, connector);
+  grpc_subchannel *s = grpc_subchannel_create(connector, args);
+  grpc_connector_unref(connector);
   return s;
 }
 
 static grpc_channel *client_channel_factory_create_channel(
-    grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
-    const char *target, grpc_client_channel_type type,
-    const grpc_channel_args *args) {
+    grpc_client_channel_factory *cc_factory, const char *target,
+    grpc_client_channel_type type, const grpc_channel_args *args) {
   if (target == NULL) {
     gpr_log(GPR_ERROR, "cannot create channel with NULL target name");
     return NULL;
@@ -56,14 +54,14 @@ static grpc_channel *client_channel_factory_create_channel(
   // Add channel arg containing the server URI.
   grpc_arg arg = grpc_channel_arg_string_create(
       (char *)GRPC_ARG_SERVER_URI,
-      grpc_resolver_factory_add_default_prefix_if_needed(exec_ctx, target));
+      grpc_resolver_factory_add_default_prefix_if_needed(target));
   const char *to_remove[] = {GRPC_ARG_SERVER_URI};
   grpc_channel_args *new_args =
       grpc_channel_args_copy_and_add_and_remove(args, to_remove, 1, &arg, 1);
   gpr_free(arg.value.string);
-  grpc_channel *channel = grpc_channel_create(exec_ctx, target, new_args,
-                                              GRPC_CLIENT_CHANNEL, NULL);
-  grpc_channel_args_destroy(exec_ctx, new_args);
+  grpc_channel *channel =
+      grpc_channel_create(target, new_args, GRPC_CLIENT_CHANNEL, NULL);
+  grpc_channel_args_destroy(new_args);
   return channel;
 }
 
@@ -82,7 +80,7 @@ static grpc_client_channel_factory client_channel_factory = {
 grpc_channel *grpc_insecure_channel_create(const char *target,
                                            const grpc_channel_args *args,
                                            void *reserved) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  ExecCtx _local_exec_ctx;
   GRPC_API_TRACE(
       "grpc_insecure_channel_create(target=%s, args=%p, reserved=%p)", 3,
       (target, args, reserved));
@@ -93,11 +91,11 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
   grpc_channel_args *new_args = grpc_channel_args_copy_and_add(args, &arg, 1);
   // Create channel.
   grpc_channel *channel = client_channel_factory_create_channel(
-      &exec_ctx, &client_channel_factory, target,
-      GRPC_CLIENT_CHANNEL_TYPE_REGULAR, new_args);
+      &client_channel_factory, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR,
+      new_args);
   // Clean up.
-  grpc_channel_args_destroy(&exec_ctx, new_args);
-  grpc_exec_ctx_finish(&exec_ctx);
+  grpc_channel_args_destroy(new_args);
+  grpc_exec_ctx_finish();
   return channel != NULL ? channel : grpc_lame_client_channel_create(
                                          target, GRPC_STATUS_INTERNAL,
                                          "Failed to create client channel");