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

Index: webrtc/call/rtc_event_log_helper_thread.h
diff --git a/webrtc/call/rtc_event_log_helper_thread.h b/webrtc/call/rtc_event_log_helper_thread.h
index 60ed912b65163a22971272c8b9ab05cd4fcc5e89..c506f2843331c3788008a6cbbc47d4a9a2acba7a 100644
--- a/webrtc/call/rtc_event_log_helper_thread.h
+++ b/webrtc/call/rtc_event_log_helper_thread.h
@@ -68,6 +68,7 @@ class RtcEventLogHelperThread final {
       SwapQueue<ControlMessage>* message_queue,
       SwapQueue<std::unique_ptr<rtclog::Event>>* event_queue,
       rtc::Event* wake_up,
+      rtc::Event* end_hibernation,
       rtc::Event* file_finished,
       const Clock* const clock);
   ~RtcEventLogHelperThread();
@@ -75,14 +76,12 @@ class RtcEventLogHelperThread final {
  private:
   static bool ThreadOutputFunction(void* obj);
 
-  void TerminateThread();
   bool AppendEventToString(rtclog::Event* event);
-  void AppendEventToHistory(const rtclog::Event& event);
-  void LogToMemory();
+  int LogToMemory();

[pbos-webrtc, 2016/06/03 08:56:15]

size_t or preferably just a bool for whether it succeeds or not.

[terelius, 2016/06/08 11:47:29]

Changed to bool.

   void StartLogFile();
-  void LogToFile();
+  int LogToFile();
   void StopLogFile();
-  void WriteLog();
+  void ProcessEvents();
 
   // Message queues for passing events to the logging thread.
   SwapQueue<ControlMessage>* message_queue_;
@@ -109,6 +108,7 @@ class RtcEventLogHelperThread final {
   std::string output_string_;
 
   rtc::Event* wake_up_;
+  rtc::Event* end_hibernation_;

[pbos-webrtc, 2016/06/03 08:51:06]

Shouldn't the wake_up_ event be sufficient to signal that we should wake up? Or
is the wake_up_ event really just a timer that can be awoken in the destructor?
If this is the case then wake_up_ should preferably be renamed something like
batch_timer_ or something.

[terelius, 2016/06/08 11:47:29]

Both are needed. I renamed them wake_periodically_ and wake_from_hibernation_.

   rtc::Event* stopped_;
 
   const Clock* const clock_;