1 // Copyright 2023 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #include "absl/synchronization/internal/waiter_base.h" 16 17 #include "absl/base/config.h" 18 #include "absl/base/internal/thread_identity.h" 19 20 namespace absl { 21 ABSL_NAMESPACE_BEGIN 22 namespace synchronization_internal { 23 24 #ifdef ABSL_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL 25 constexpr int WaiterBase::kIdlePeriods; 26 #endif 27 MaybeBecomeIdle()28void WaiterBase::MaybeBecomeIdle() { 29 base_internal::ThreadIdentity *identity = 30 base_internal::CurrentThreadIdentityIfPresent(); 31 assert(identity != nullptr); 32 const bool is_idle = identity->is_idle.load(std::memory_order_relaxed); 33 const int ticker = identity->ticker.load(std::memory_order_relaxed); 34 const int wait_start = identity->wait_start.load(std::memory_order_relaxed); 35 if (!is_idle && ticker - wait_start > kIdlePeriods) { 36 identity->is_idle.store(true, std::memory_order_relaxed); 37 } 38 } 39 40 } // namespace synchronization_internal 41 ABSL_NAMESPACE_END 42 } // namespace absl 43