Merge pull request #6542 from ctiller/ecterm
Let execution contexts signal that they are done
diff --git a/src/core/lib/iomgr/exec_ctx.c b/src/core/lib/iomgr/exec_ctx.c
index 2146c7d..e451479 100644
--- a/src/core/lib/iomgr/exec_ctx.c
+++ b/src/core/lib/iomgr/exec_ctx.c
@@ -39,6 +39,22 @@
#include "src/core/lib/profiling/timers.h"
+bool grpc_exec_ctx_ready_to_finish(grpc_exec_ctx *exec_ctx) {
+ if (!exec_ctx->cached_ready_to_finish) {
+ exec_ctx->cached_ready_to_finish = exec_ctx->check_ready_to_finish(
+ exec_ctx, exec_ctx->check_ready_to_finish_arg);
+ }
+ return exec_ctx->cached_ready_to_finish;
+}
+
+bool grpc_never_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored) {
+ return false;
+}
+
+bool grpc_always_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored) {
+ return true;
+}
+
#ifndef GRPC_EXECUTION_CONTEXT_SANITIZER
bool grpc_exec_ctx_flush(grpc_exec_ctx *exec_ctx) {
bool did_something = 0;
@@ -61,6 +77,7 @@
}
void grpc_exec_ctx_finish(grpc_exec_ctx *exec_ctx) {
+ exec_ctx->cached_ready_to_finish = true;
grpc_exec_ctx_flush(exec_ctx);
}
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index 976cc40..9d47a26 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -53,6 +53,9 @@
* - track a list of work that needs to be delayed until the top of the
* call stack (this provides a convenient mechanism to run callbacks
* without worrying about locking issues)
+ * - provide a decision maker (via grpc_exec_ctx_ready_to_finish) that provides
+ * signal as to whether a borrowed thread should continue to do work or
+ * should actively try to finish up and get this thread back to its owner
*
* CONVENTIONS:
* Instance of this must ALWAYS be constructed on the stack, never
@@ -63,18 +66,26 @@
*/
struct grpc_exec_ctx {
grpc_closure_list closure_list;
+ bool cached_ready_to_finish;
+ void *check_ready_to_finish_arg;
+ bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
};
-#define GRPC_EXEC_CTX_INIT \
- { GRPC_CLOSURE_LIST_INIT }
+#define GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(finish_check, finish_check_arg) \
+ { GRPC_CLOSURE_LIST_INIT, false, finish_check_arg, finish_check }
#else
struct grpc_exec_ctx {
- int unused;
+ bool cached_ready_to_finish;
+ void *check_ready_to_finish_arg;
+ bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
};
-#define GRPC_EXEC_CTX_INIT \
- { 0 }
+#define GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(finish_check, finish_check_arg) \
+ { false, finish_check_arg, finish_check }
#endif
+#define GRPC_EXEC_CTX_INIT \
+ GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(grpc_never_ready_to_finish, NULL)
+
/** Flush any work that has been enqueued onto this grpc_exec_ctx.
* Caller must guarantee that no interfering locks are held.
* Returns true if work was performed, false otherwise. */
@@ -86,6 +97,14 @@
void grpc_exec_ctx_enqueue(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
bool success,
grpc_workqueue *offload_target_or_null);
+/** Returns true if we'd like to leave this execution context as soon as
+ possible: useful for deciding whether to do something more or not depending
+ on outside context */
+bool grpc_exec_ctx_ready_to_finish(grpc_exec_ctx *exec_ctx);
+/** A finish check that is never ready to finish */
+bool grpc_never_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored);
+/** A finish check that is always ready to finish */
+bool grpc_always_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored);
/** Add a list of closures to be executed at the next flush/finish point.
* Leaves \a list empty. */
void grpc_exec_ctx_enqueue_list(grpc_exec_ctx *exec_ctx,