61 lines
1.4 KiB
C++
61 lines
1.4 KiB
C++
/*
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* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef RTC_BASE_ONE_TIME_EVENT_H_
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#define RTC_BASE_ONE_TIME_EVENT_H_
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#include "rtc_base/synchronization/mutex.h"
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namespace webrtc {
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// Provides a simple way to perform an operation (such as logging) one
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// time in a certain scope.
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// Example:
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// OneTimeEvent firstFrame;
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// ...
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// if (firstFrame()) {
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// RTC_LOG(LS_INFO) << "This is the first frame".
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// }
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class OneTimeEvent {
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public:
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OneTimeEvent() {}
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bool operator()() {
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MutexLock lock(&mutex_);
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if (happened_) {
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return false;
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}
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happened_ = true;
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return true;
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}
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private:
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bool happened_ = false;
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Mutex mutex_;
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};
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// A non-thread-safe, ligher-weight version of the OneTimeEvent class.
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class ThreadUnsafeOneTimeEvent {
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public:
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ThreadUnsafeOneTimeEvent() {}
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bool operator()() {
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if (happened_) {
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return false;
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}
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happened_ = true;
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return true;
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}
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private:
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bool happened_ = false;
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};
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} // namespace webrtc
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#endif // RTC_BASE_ONE_TIME_EVENT_H_
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