1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPC_CORE_LIB_GPR_SPINLOCK_H 20 #define GRPC_CORE_LIB_GPR_SPINLOCK_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <grpc/support/atm.h> 25 26 /* Simple spinlock. No backoff strategy, gpr_spinlock_lock is almost always 27 a concurrency code smell. */ 28 typedef struct { 29 gpr_atm atm; 30 } gpr_spinlock; 31 32 #ifdef __cplusplus 33 #define GPR_SPINLOCK_INITIALIZER (gpr_spinlock{0}) 34 #else 35 #define GPR_SPINLOCK_INITIALIZER ((gpr_spinlock){0}) 36 #endif 37 #define GPR_SPINLOCK_STATIC_INITIALIZER \ 38 { 0 } 39 40 #define gpr_spinlock_trylock(lock) (gpr_atm_acq_cas(&(lock)->atm, 0, 1)) 41 #define gpr_spinlock_unlock(lock) (gpr_atm_rel_store(&(lock)->atm, 0)) 42 #define gpr_spinlock_lock(lock) \ 43 do { \ 44 } while (!gpr_spinlock_trylock((lock))) 45 46 #endif /* GRPC_CORE_LIB_GPR_SPINLOCK_H */ 47
