diff options
| -rw-r--r-- | absl/synchronization/mutex.cc | 25 | ||||
| -rw-r--r-- | absl/synchronization/mutex.h | 1 |
2 files changed, 4 insertions, 22 deletions
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc index 8148fbde..ad9e2894 100644 --- a/absl/synchronization/mutex.cc +++ b/absl/synchronization/mutex.cc @@ -2325,10 +2325,10 @@ void Mutex::Fer(PerThreadSynch* w) { int c = 0; ABSL_RAW_CHECK(w->waitp->cond == nullptr, "Mutex::Fer while waiting on Condition"); - ABSL_RAW_CHECK(!w->waitp->timeout.has_timeout(), - "Mutex::Fer while in timed wait"); ABSL_RAW_CHECK(w->waitp->cv_word == nullptr, "Mutex::Fer with pending CondVar queueing"); + // The CondVar timeout is not relevant for the Mutex wait. + w->waitp->timeout = {}; for (;;) { intptr_t v = mu_.load(std::memory_order_relaxed); // Note: must not queue if the mutex is unlocked (nobody will wake it). @@ -2571,23 +2571,6 @@ bool CondVar::WaitCommon(Mutex* mutex, KernelTimeout t) { return rc; } -// Wake thread w -// If it was a timed wait, w will be waiting on w->cv -// Otherwise, if it was not a Mutex mutex, w will be waiting on w->sem -// Otherwise, w is transferred to the Mutex mutex via Mutex::Fer(). -void CondVar::Wakeup(PerThreadSynch* w) { - if (w->waitp->timeout.has_timeout()) { - // The waiting thread only needs to observe "w->state == kAvailable" to be - // released, we must cache "cvmu" before clearing "next". - Mutex* mu = w->waitp->cvmu; - w->next = nullptr; - w->state.store(PerThreadSynch::kAvailable, std::memory_order_release); - Mutex::IncrementSynchSem(mu, w); - } else { - w->waitp->cvmu->Fer(w); - } -} - void CondVar::Signal() { SchedulingGuard::ScopedDisable disable_rescheduling; ABSL_TSAN_MUTEX_PRE_SIGNAL(nullptr, 0); @@ -2612,7 +2595,7 @@ void CondVar::Signal() { cv_.store((v & kCvEvent) | reinterpret_cast<intptr_t>(h), std::memory_order_release); if (w != nullptr) { - CondVar::Wakeup(w); // wake waiter, if there was one + w->waitp->cvmu->Fer(w); // wake waiter, if there was one cond_var_tracer("Signal wakeup", this); } if ((v & kCvEvent) != 0) { @@ -2648,7 +2631,7 @@ void CondVar::SignalAll() { do { // for every thread, wake it up w = n; n = n->next; - CondVar::Wakeup(w); + w->waitp->cvmu->Fer(w); } while (w != h); cond_var_tracer("SignalAll wakeup", this); } diff --git a/absl/synchronization/mutex.h b/absl/synchronization/mutex.h index 1fb6cca1..d146b066 100644 --- a/absl/synchronization/mutex.h +++ b/absl/synchronization/mutex.h @@ -974,7 +974,6 @@ class CondVar { private: bool WaitCommon(Mutex* mutex, synchronization_internal::KernelTimeout t); void Remove(base_internal::PerThreadSynch* s); - void Wakeup(base_internal::PerThreadSynch* w); std::atomic<intptr_t> cv_; // Condition variable state. CondVar(const CondVar&) = delete; CondVar& operator=(const CondVar&) = delete; |