AsymmetricMemoryBarrier.h 1002 B

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  1. /*
  2. * Copyright 2016-present Facebook, Inc.
  3. *
  4. * Licensed under the Apache License, Version 2.0 (the "License");
  5. * you may not use this file except in compliance with the License.
  6. * You may obtain a copy of the License at
  7. *
  8. * http://www.apache.org/licenses/LICENSE-2.0
  9. *
  10. * Unless required by applicable law or agreed to in writing, software
  11. * distributed under the License is distributed on an "AS IS" BASIS,
  12. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. * See the License for the specific language governing permissions and
  14. * limitations under the License.
  15. */
  16. #pragma once
  17. #include <atomic>
  18. #include <folly/portability/Asm.h>
  19. namespace folly {
  20. enum class AMBFlags {
  21. NORMAL,
  22. EXPEDITED,
  23. };
  24. FOLLY_ALWAYS_INLINE void asymmetricLightBarrier() {
  25. if (kIsLinux) {
  26. asm_volatile_memory();
  27. } else {
  28. std::atomic_thread_fence(std::memory_order_seq_cst);
  29. }
  30. }
  31. void asymmetricHeavyBarrier(AMBFlags flags = AMBFlags::EXPEDITED);
  32. } // namespace folly