blob: 7ef0376503d956f83843bbe10af6f80281864142 [file] [log] [blame]
/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef RTC_BASE_ONETIMEEVENT_H_
#define RTC_BASE_ONETIMEEVENT_H_
#include "rtc_base/criticalsection.h"
#include "typedefs.h" // NOLINT(build/include)
namespace webrtc {
// Provides a simple way to perform an operation (such as logging) one
// time in a certain scope.
// Example:
// OneTimeEvent firstFrame;
// ...
// if (firstFrame()) {
// LOG(LS_INFO) << "This is the first frame".
// }
class OneTimeEvent {
public:
OneTimeEvent() {}
bool operator()() {
rtc::CritScope cs(&critsect_);
if (happened_) {
return false;
}
happened_ = true;
return true;
}
private:
bool happened_ = false;
rtc::CriticalSection critsect_;
};
// A non-thread-safe, ligher-weight version of the OneTimeEvent class.
class ThreadUnsafeOneTimeEvent {
public:
ThreadUnsafeOneTimeEvent() {}
bool operator()() {
if (happened_) {
return false;
}
happened_ = true;
return true;
}
private:
bool happened_ = false;
};
} // namespace webrtc
#endif // RTC_BASE_ONETIMEEVENT_H_