1 /* 2 * 3 * Copyright 2017 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_GPRPP_ATOMIC_WITH_ATM_H 20 #define GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_ATM_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <grpc/support/atm.h> 25 26 namespace grpc_core { 27 28 enum MemoryOrderRelaxed { memory_order_relaxed }; 29 30 template <class T> 31 class atomic; 32 33 template <> 34 class atomic<bool> { 35 public: atomic()36 atomic() { gpr_atm_no_barrier_store(&x_, static_cast<gpr_atm>(false)); } atomic(bool x)37 explicit atomic(bool x) { 38 gpr_atm_no_barrier_store(&x_, static_cast<gpr_atm>(x)); 39 } 40 compare_exchange_strong(bool & expected,bool update,MemoryOrderRelaxed,MemoryOrderRelaxed)41 bool compare_exchange_strong(bool& expected, bool update, MemoryOrderRelaxed, 42 MemoryOrderRelaxed) { 43 if (!gpr_atm_no_barrier_cas(&x_, static_cast<gpr_atm>(expected), 44 static_cast<gpr_atm>(update))) { 45 expected = gpr_atm_no_barrier_load(&x_) != 0; 46 return false; 47 } 48 return true; 49 } 50 51 private: 52 gpr_atm x_; 53 }; 54 55 } // namespace grpc_core 56 57 #endif /* GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_ATM_H */ 58