notification.cc (2778B)
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 #include "absl/synchronization/notification.h" 16 17 #include <atomic> 18 19 #include "absl/base/internal/raw_logging.h" 20 #include "absl/base/internal/tracing.h" 21 #include "absl/synchronization/mutex.h" 22 #include "absl/time/time.h" 23 24 namespace absl { 25 ABSL_NAMESPACE_BEGIN 26 27 void Notification::Notify() { 28 base_internal::TraceSignal(this, TraceObjectKind()); 29 MutexLock l(&this->mutex_); 30 31 #ifndef NDEBUG 32 if (ABSL_PREDICT_FALSE(notified_yet_.load(std::memory_order_relaxed))) { 33 ABSL_RAW_LOG( 34 FATAL, 35 "Notify() method called more than once for Notification object %p", 36 static_cast<void *>(this)); 37 } 38 #endif 39 40 notified_yet_.store(true, std::memory_order_release); 41 } 42 43 Notification::~Notification() { 44 // Make sure that the thread running Notify() exits before the object is 45 // destructed. 46 MutexLock l(&this->mutex_); 47 } 48 49 void Notification::WaitForNotification() const { 50 base_internal::TraceWait(this, TraceObjectKind()); 51 if (!HasBeenNotifiedInternal(&this->notified_yet_)) { 52 this->mutex_.LockWhen( 53 Condition(&HasBeenNotifiedInternal, &this->notified_yet_)); 54 this->mutex_.Unlock(); 55 } 56 base_internal::TraceContinue(this, TraceObjectKind()); 57 } 58 59 bool Notification::WaitForNotificationWithTimeout( 60 absl::Duration timeout) const { 61 base_internal::TraceWait(this, TraceObjectKind()); 62 bool notified = HasBeenNotifiedInternal(&this->notified_yet_); 63 if (!notified) { 64 notified = this->mutex_.LockWhenWithTimeout( 65 Condition(&HasBeenNotifiedInternal, &this->notified_yet_), timeout); 66 this->mutex_.Unlock(); 67 } 68 base_internal::TraceContinue(notified ? this : nullptr, TraceObjectKind()); 69 return notified; 70 } 71 72 bool Notification::WaitForNotificationWithDeadline(absl::Time deadline) const { 73 base_internal::TraceWait(this, TraceObjectKind()); 74 bool notified = HasBeenNotifiedInternal(&this->notified_yet_); 75 if (!notified) { 76 notified = this->mutex_.LockWhenWithDeadline( 77 Condition(&HasBeenNotifiedInternal, &this->notified_yet_), deadline); 78 this->mutex_.Unlock(); 79 } 80 base_internal::TraceContinue(notified ? this : nullptr, TraceObjectKind()); 81 return notified; 82 } 83 84 ABSL_NAMESPACE_END 85 } // namespace absl