diff options
Diffstat (limited to 'absl/base/internal/spinlock_wait.h')
-rw-r--r-- | absl/base/internal/spinlock_wait.h | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/absl/base/internal/spinlock_wait.h b/absl/base/internal/spinlock_wait.h index 169bc749..9a1adcda 100644 --- a/absl/base/internal/spinlock_wait.h +++ b/absl/base/internal/spinlock_wait.h @@ -39,22 +39,22 @@ struct SpinLockWaitTransition { // satisfying 0<=i<n && trans[i].done, atomically make the transition, // then return the old value of *w. Make any other atomic transitions // where !trans[i].done, but continue waiting. +// +// Wakeups for threads blocked on SpinLockWait do not respect priorities. uint32_t SpinLockWait(std::atomic<uint32_t> *w, int n, const SpinLockWaitTransition trans[], SchedulingMode scheduling_mode); -// If possible, wake some thread that has called SpinLockDelay(w, ...). If -// "all" is true, wake all such threads. This call is a hint, and on some -// systems it may be a no-op; threads calling SpinLockDelay() will always wake -// eventually even if SpinLockWake() is never called. +// If possible, wake some thread that has called SpinLockDelay(w, ...). If `all` +// is true, wake all such threads. On some systems, this may be a no-op; on +// those systems, threads calling SpinLockDelay() will always wake eventually +// even if SpinLockWake() is never called. void SpinLockWake(std::atomic<uint32_t> *w, bool all); // Wait for an appropriate spin delay on iteration "loop" of a // spin loop on location *w, whose previously observed value was "value". // SpinLockDelay() may do nothing, may yield the CPU, may sleep a clock tick, -// or may wait for a delay that can be truncated by a call to SpinLockWake(w). -// In all cases, it must return in bounded time even if SpinLockWake() is not -// called. +// or may wait for a call to SpinLockWake(w). void SpinLockDelay(std::atomic<uint32_t> *w, uint32_t value, int loop, base_internal::SchedulingMode scheduling_mode); @@ -73,21 +73,23 @@ ABSL_NAMESPACE_END // By changing our extension points to be extern "C", we dodge this // check. extern "C" { -void AbslInternalSpinLockWake(std::atomic<uint32_t> *w, bool all); -void AbslInternalSpinLockDelay( +void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockWake)(std::atomic<uint32_t> *w, + bool all); +void ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockDelay)( std::atomic<uint32_t> *w, uint32_t value, int loop, absl::base_internal::SchedulingMode scheduling_mode); } inline void absl::base_internal::SpinLockWake(std::atomic<uint32_t> *w, bool all) { - AbslInternalSpinLockWake(w, all); + ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockWake)(w, all); } inline void absl::base_internal::SpinLockDelay( std::atomic<uint32_t> *w, uint32_t value, int loop, absl::base_internal::SchedulingMode scheduling_mode) { - AbslInternalSpinLockDelay(w, value, loop, scheduling_mode); + ABSL_INTERNAL_C_SYMBOL(AbslInternalSpinLockDelay) + (w, value, loop, scheduling_mode); } #endif // ABSL_BASE_INTERNAL_SPINLOCK_WAIT_H_ |