waiter_base.cc 1.5 KB

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  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. #include "absl/synchronization/internal/waiter_base.h"
  15. #include "absl/base/config.h"
  16. #include "absl/base/internal/thread_identity.h"
  17. namespace absl {
  18. ABSL_NAMESPACE_BEGIN
  19. namespace synchronization_internal {
  20. #ifdef ABSL_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL
  21. constexpr int WaiterBase::kIdlePeriods;
  22. #endif
  23. void WaiterBase::MaybeBecomeIdle() {
  24. base_internal::ThreadIdentity *identity =
  25. base_internal::CurrentThreadIdentityIfPresent();
  26. assert(identity != nullptr);
  27. const bool is_idle = identity->is_idle.load(std::memory_order_relaxed);
  28. const int ticker = identity->ticker.load(std::memory_order_relaxed);
  29. const int wait_start = identity->wait_start.load(std::memory_order_relaxed);
  30. if (!is_idle && ticker - wait_start > kIdlePeriods) {
  31. identity->is_idle.store(true, std::memory_order_relaxed);
  32. }
  33. }
  34. } // namespace synchronization_internal
  35. ABSL_NAMESPACE_END
  36. } // namespace absl