Repo created

TMessagesProj/jni/voip/webrtc/rtc_base/one_time_event.h

@@ -0,0 +1,60 @@
+/*
+ *  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_ONE_TIME_EVENT_H_
+#define RTC_BASE_ONE_TIME_EVENT_H_
+
+#include "rtc_base/synchronization/mutex.h"
+
+namespace webrtc {
+// Provides a simple way to perform an operation (such as logging) one
+// time in a certain scope.
+// Example:
+//   OneTimeEvent firstFrame;
+//   ...
+//   if (firstFrame()) {
+//     RTC_LOG(LS_INFO) << "This is the first frame".
+//   }
+class OneTimeEvent {
+ public:
+  OneTimeEvent() {}
+  bool operator()() {
+    MutexLock lock(&mutex_);
+    if (happened_) {
+      return false;
+    }
+    happened_ = true;
+    return true;
+  }
+
+ private:
+  bool happened_ = false;
+  Mutex mutex_;
+};
+
+// 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_ONE_TIME_EVENT_H_