| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_LIB_IOMGR_EXEC_CTX_H |
| #define GRPC_CORE_LIB_IOMGR_EXEC_CTX_H |
| |
| #include <grpc/support/atm.h> |
| #include <grpc/support/cpu.h> |
| |
| #include "src/core/lib/iomgr/closure.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef gpr_atm grpc_millis; |
| |
| #define GRPC_MILLIS_INF_FUTURE GPR_ATM_MAX |
| #define GRPC_MILLIS_INF_PAST GPR_ATM_MIN |
| |
| /** A workqueue represents a list of work to be executed asynchronously. |
| Forward declared here to avoid a circular dependency with workqueue.h. */ |
| typedef struct grpc_workqueue grpc_workqueue; |
| typedef struct grpc_combiner grpc_combiner; |
| |
| /* This exec_ctx is ready to return: either pre-populated, or cached as soon as |
| the finish_check returns true */ |
| #define GRPC_EXEC_CTX_FLAG_IS_FINISHED 1 |
| /* The exec_ctx's thread is (potentially) owned by a call or channel: care |
| should be given to not delete said call/channel from this exec_ctx */ |
| #define GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP 2 |
| |
| /** Execution context. |
| * A bag of data that collects information along a callstack. |
| * Generally created at public API entry points, and passed down as |
| * pointer to child functions that manipulate it. |
| * |
| * Specific responsibilities (this may grow in the future): |
| * - 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 |
| * heap allocated. |
| * - Instances and pointers to them must always be called exec_ctx. |
| * - Instances are always passed as the first argument to a function that |
| * takes it, and always as a pointer (grpc_exec_ctx is never copied). |
| */ |
| struct grpc_exec_ctx { |
| grpc_closure_list closure_list; |
| /** currently active combiner: updated only via combiner.c */ |
| grpc_combiner* active_combiner; |
| /** last active combiner in the active combiner list */ |
| grpc_combiner* last_combiner; |
| uintptr_t flags; |
| unsigned starting_cpu; |
| void* check_ready_to_finish_arg; |
| bool (*check_ready_to_finish)(grpc_exec_ctx* exec_ctx, void* arg); |
| |
| bool now_is_valid; |
| grpc_millis now; |
| }; |
| |
| /* initializer for grpc_exec_ctx: |
| prefer to use GRPC_EXEC_CTX_INIT whenever possible */ |
| #define GRPC_EXEC_CTX_INITIALIZER(flags, finish_check, finish_check_arg) \ |
| { \ |
| GRPC_CLOSURE_LIST_INIT, NULL, NULL, flags, gpr_cpu_current_cpu(), \ |
| finish_check_arg, finish_check, false, 0 \ |
| } |
| |
| /* initialize an execution context at the top level of an API call into grpc |
| (this is safe to use elsewhere, though possibly not as efficient) */ |
| #define GRPC_EXEC_CTX_INIT \ |
| GRPC_EXEC_CTX_INITIALIZER(GRPC_EXEC_CTX_FLAG_IS_FINISHED, NULL, NULL) |
| |
| extern grpc_closure_scheduler* grpc_schedule_on_exec_ctx; |
| |
| bool grpc_exec_ctx_has_work(grpc_exec_ctx* exec_ctx); |
| |
| /** 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. */ |
| bool grpc_exec_ctx_flush(grpc_exec_ctx* exec_ctx); |
| /** Finish any pending work for a grpc_exec_ctx. Must be called before |
| * the instance is destroyed, or work may be lost. */ |
| void grpc_exec_ctx_finish(grpc_exec_ctx* exec_ctx); |
| /** 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); |
| |
| void grpc_exec_ctx_global_init(void); |
| |
| void grpc_exec_ctx_global_init(void); |
| void grpc_exec_ctx_global_shutdown(void); |
| |
| grpc_millis grpc_exec_ctx_now(grpc_exec_ctx* exec_ctx); |
| void grpc_exec_ctx_invalidate_now(grpc_exec_ctx* exec_ctx); |
| gpr_timespec grpc_millis_to_timespec(grpc_millis millis, gpr_clock_type clock); |
| grpc_millis grpc_timespec_to_millis_round_down(gpr_timespec timespec); |
| grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec timespec); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* GRPC_CORE_LIB_IOMGR_EXEC_CTX_H */ |