/* * * 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_CLOSURE_H #define GRPC_CORE_LIB_IOMGR_CLOSURE_H #include #include #include #include "src/core/lib/iomgr/error.h" #include "src/core/lib/support/mpscq.h" #ifdef __cplusplus extern "C" { #endif struct grpc_closure; typedef struct grpc_closure grpc_closure; #ifndef NDEBUG extern grpc_core::TraceFlag grpc_trace_closure; #endif typedef struct grpc_closure_list { grpc_closure *head; grpc_closure *tail; } grpc_closure_list; /** gRPC Callback definition. * * \param arg Arbitrary input. * \param error GRPC_ERROR_NONE if no error occurred, otherwise some grpc_error * describing what went wrong. * Error contract: it is not the cb's job to unref this error; * the closure scheduler will do that after the cb returns */ typedef void (*grpc_iomgr_cb_func)(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error); typedef struct grpc_closure_scheduler grpc_closure_scheduler; typedef struct grpc_closure_scheduler_vtable { /* NOTE: for all these functions, closure->scheduler == the scheduler that was used to find this vtable */ void (*run)(grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); void (*sched)(grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); const char *name; } grpc_closure_scheduler_vtable; /** Abstract type that can schedule closures for execution */ struct grpc_closure_scheduler { const grpc_closure_scheduler_vtable *vtable; }; /** A closure over a grpc_iomgr_cb_func. */ struct grpc_closure { /** Once queued, next indicates the next queued closure; before then, scratch * space */ union { grpc_closure *next; gpr_mpscq_node atm_next; uintptr_t scratch; } next_data; /** Bound callback. */ grpc_iomgr_cb_func cb; /** Arguments to be passed to "cb". */ void *cb_arg; /** Scheduler to schedule against: NULL to schedule against current execution context */ grpc_closure_scheduler *scheduler; /** Once queued, the result of the closure. Before then: scratch space */ union { grpc_error *error; uintptr_t scratch; } error_data; // extra tracing and debugging for grpc_closure. This incurs a decent amount of // overhead per closure, so it must be enabled at compile time. #ifndef NDEBUG bool scheduled; bool run; // true = run, false = scheduled const char *file_created; int line_created; const char *file_initiated; int line_initiated; #endif }; /** Initializes \a closure with \a cb and \a cb_arg. Returns \a closure. */ #ifndef NDEBUG grpc_closure *grpc_closure_init(const char *file, int line, grpc_closure *closure, grpc_iomgr_cb_func cb, void *cb_arg, grpc_closure_scheduler *scheduler); #define GRPC_CLOSURE_INIT(closure, cb, cb_arg, scheduler) \ grpc_closure_init(__FILE__, __LINE__, closure, cb, cb_arg, scheduler) #else grpc_closure *grpc_closure_init(grpc_closure *closure, grpc_iomgr_cb_func cb, void *cb_arg, grpc_closure_scheduler *scheduler); #define GRPC_CLOSURE_INIT(closure, cb, cb_arg, scheduler) \ grpc_closure_init(closure, cb, cb_arg, scheduler) #endif /* Create a heap allocated closure: try to avoid except for very rare events */ #ifndef NDEBUG grpc_closure *grpc_closure_create(const char *file, int line, grpc_iomgr_cb_func cb, void *cb_arg, grpc_closure_scheduler *scheduler); #define GRPC_CLOSURE_CREATE(cb, cb_arg, scheduler) \ grpc_closure_create(__FILE__, __LINE__, cb, cb_arg, scheduler) #else grpc_closure *grpc_closure_create(grpc_iomgr_cb_func cb, void *cb_arg, grpc_closure_scheduler *scheduler); #define GRPC_CLOSURE_CREATE(cb, cb_arg, scheduler) \ grpc_closure_create(cb, cb_arg, scheduler) #endif #define GRPC_CLOSURE_LIST_INIT \ { NULL, NULL } void grpc_closure_list_init(grpc_closure_list *list); /** add \a closure to the end of \a list and set \a closure's result to \a error Returns true if \a list becomes non-empty */ bool grpc_closure_list_append(grpc_closure_list *list, grpc_closure *closure, grpc_error *error); /** force all success bits in \a list to false */ void grpc_closure_list_fail_all(grpc_closure_list *list, grpc_error *forced_failure); /** append all closures from \a src to \a dst and empty \a src. */ void grpc_closure_list_move(grpc_closure_list *src, grpc_closure_list *dst); /** return whether \a list is empty. */ bool grpc_closure_list_empty(grpc_closure_list list); /** Run a closure directly. Caller ensures that no locks are being held above. * Note that calling this at the end of a closure callback function itself is * by definition safe. */ #ifndef NDEBUG void grpc_closure_run(const char *file, int line, grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); #define GRPC_CLOSURE_RUN(exec_ctx, closure, error) \ grpc_closure_run(__FILE__, __LINE__, exec_ctx, closure, error) #else void grpc_closure_run(grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); #define GRPC_CLOSURE_RUN(exec_ctx, closure, error) \ grpc_closure_run(exec_ctx, closure, error) #endif /** Schedule a closure to be run. Does not need to be run from a safe point. */ #ifndef NDEBUG void grpc_closure_sched(const char *file, int line, grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); #define GRPC_CLOSURE_SCHED(exec_ctx, closure, error) \ grpc_closure_sched(__FILE__, __LINE__, exec_ctx, closure, error) #else void grpc_closure_sched(grpc_exec_ctx *exec_ctx, grpc_closure *closure, grpc_error *error); #define GRPC_CLOSURE_SCHED(exec_ctx, closure, error) \ grpc_closure_sched(exec_ctx, closure, error) #endif /** Schedule all closures in a list to be run. Does not need to be run from a * safe point. */ #ifndef NDEBUG void grpc_closure_list_sched(const char *file, int line, grpc_exec_ctx *exec_ctx, grpc_closure_list *closure_list); #define GRPC_CLOSURE_LIST_SCHED(exec_ctx, closure_list) \ grpc_closure_list_sched(__FILE__, __LINE__, exec_ctx, closure_list) #else void grpc_closure_list_sched(grpc_exec_ctx *exec_ctx, grpc_closure_list *closure_list); #define GRPC_CLOSURE_LIST_SCHED(exec_ctx, closure_list) \ grpc_closure_list_sched(exec_ctx, closure_list) #endif #ifdef __cplusplus } #endif #endif /* GRPC_CORE_LIB_IOMGR_CLOSURE_H */