spinlock_posix.inc 1.4 KB

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  1. // Copyright 2017 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. // This file is a Posix-specific part of spinlock_wait.cc
  16. #include <sched.h>
  17. #include <atomic>
  18. #include <ctime>
  19. #include "absl/base/internal/errno_saver.h"
  20. #include "absl/base/internal/scheduling_mode.h"
  21. #include "absl/base/port.h"
  22. extern "C" {
  23. ABSL_ATTRIBUTE_WEAK void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockDelay)(
  24. std::atomic<uint32_t>* /* lock_word */, uint32_t /* value */, int loop,
  25. absl::base_internal::SchedulingMode /* mode */) {
  26. absl::base_internal::ErrnoSaver errno_saver;
  27. if (loop == 0) {
  28. } else if (loop == 1) {
  29. sched_yield();
  30. } else {
  31. struct timespec tm;
  32. tm.tv_sec = 0;
  33. tm.tv_nsec = absl::base_internal::SpinLockSuggestedDelayNS(loop);
  34. nanosleep(&tm, nullptr);
  35. }
  36. }
  37. ABSL_ATTRIBUTE_WEAK void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockWake)(
  38. std::atomic<uint32_t>* /* lock_word */, bool /* all */) {}
  39. } // extern "C"