Hibernate the thread if there are no events in the queue. Wake it up when an event is added to the …

webrtc/call/rtc_event_log_helper_thread.h

 /*
  *  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.
  */
 
@@ skipping 49 matching lines @@
       lhs.file.swap(rhs.file);
       swap(lhs.max_size_bytes, rhs.max_size_bytes);
       swap(lhs.start_time, rhs.start_time);
       swap(lhs.stop_time, rhs.stop_time);
     }
   };
 
   RtcEventLogHelperThread(
       SwapQueue<ControlMessage>* message_queue,
       SwapQueue<std::unique_ptr<rtclog::Event>>* event_queue,
-      rtc::Event* wake_up,
-      rtc::Event* file_finished,
       const Clock* const clock);
   ~RtcEventLogHelperThread();
 
+  // This function MUST be called once a STOP_FILE message is added to the
+  // signalling queue. The function will make sure that the output thread
+  // wakes up to read the message, and it blocks until the output thread has
+  // finished writing to the file.
+  void WaitForFileFinished();
+
+  // This fuction MUST be called once an event is added to the event queue.
+  void SignalNewEvent();
+
  private:
   static bool ThreadOutputFunction(void* obj);
 
-  void TerminateThread();
   bool AppendEventToString(rtclog::Event* event);
-  void AppendEventToHistory(const rtclog::Event& event);
-  void LogToMemory();
+  bool LogToMemory();
   void StartLogFile();
-  void LogToFile();
+  bool LogToFile();
   void StopLogFile();
-  void WriteLog();
+  void ProcessEvents();
 
   // Message queues for passing events to the logging thread.
   SwapQueue<ControlMessage>* message_queue_;
   SwapQueue<std::unique_ptr<rtclog::Event>>* event_queue_;
 
   // History containing the most recent events (~ 10 s).
   RingBuffer<std::unique_ptr<rtclog::Event>> history_;
 
   // History containing all past configuration events.
   std::vector<std::unique_ptr<rtclog::Event>> config_history_;
 
   std::unique_ptr<FileWrapper> file_;
   rtc::PlatformThread thread_;
 
   int64_t max_size_bytes_;
   int64_t written_bytes_;
   int64_t start_time_;
   int64_t stop_time_;
 
   bool has_recent_event_;
   std::unique_ptr<rtclog::Event> most_recent_event_;
 
   // Temporary space for serializing profobuf data.
   std::string output_string_;
 
-  rtc::Event* wake_up_;
-  rtc::Event* stopped_;
+  rtc::Event wake_periodically_;
+  rtc::Event wake_from_hibernation_;
+  rtc::Event file_finished_;
 
   const Clock* const clock_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RtcEventLogHelperThread);
 };
 
 }  // namespace webrtc
 
 #endif  // ENABLE_RTC_EVENT_LOG
 
 #endif  // WEBRTC_CALL_RTC_EVENT_LOG_HELPER_THREAD_H_