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.cc

 /*
  *  Copyright (c) 2015 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 85 matching lines @@
   void LogRtcpPacket(PacketDirection direction,
                      MediaType media_type,
                      const uint8_t* packet,
                      size_t length) override;
   void LogAudioPlayout(uint32_t ssrc) override;
   void LogBwePacketLossEvent(int32_t bitrate,
                              uint8_t fraction_loss,
                              int32_t total_packets) override;
 
  private:
+  void StoreEvent(std::unique_ptr<rtclog::Event>* event);
+
   // Message queue for passing control messages to the logging thread.
   SwapQueue<RtcEventLogHelperThread::ControlMessage> message_queue_;
 
   // Message queue for passing events to the logging thread.
   SwapQueue<std::unique_ptr<rtclog::Event> > event_queue_;
 
   rtc::Event wake_up_;
+  rtc::Event end_hibernation_;
   rtc::Event stopped_;
 
   const Clock* const clock_;
 
   RtcEventLogHelperThread helper_thread_;
   rtc::ThreadChecker thread_checker_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RtcEventLogImpl);
 };
 
@@ skipping 36 matching lines @@
 static const int kEventsPerSecond = 1000;
 static const int kControlMessagesPerSecond = 10;
 }  // namespace
 
 // RtcEventLogImpl member functions.
 RtcEventLogImpl::RtcEventLogImpl(const Clock* clock)
     // Allocate buffers for roughly one second of history.
     : message_queue_(kControlMessagesPerSecond),
       event_queue_(kEventsPerSecond),
       wake_up_(false, false),
+      end_hibernation_(false, false),
       stopped_(false, false),
       clock_(clock),
       helper_thread_(&message_queue_,
                      &event_queue_,
                      &wake_up_,
+                     &end_hibernation_,
                      &stopped_,
                      clock),
       thread_checker_() {
   thread_checker_.DetachFromThread();
 }
 
 RtcEventLogImpl::~RtcEventLogImpl() {
   // The RtcEventLogHelperThread destructor closes the file
   // and waits for the thread to terminate.
 }
@@ skipping 10 matching lines @@
   message.stop_time = std::numeric_limits<int64_t>::max();
   message.file.reset(FileWrapper::Create());
   if (message.file->OpenFile(file_name.c_str(), false) != 0) {
     LOG(LS_ERROR) << "Can't open file. WebRTC event log not started.";
     return false;
   }
   if (!message_queue_.Insert(&message)) {
     LOG(LS_ERROR) << "Message queue full. Can't start logging.";
     return false;
   }
+  end_hibernation_.Set();
   LOG(LS_INFO) << "Starting WebRTC event log.";
   return true;
 }
 
 bool RtcEventLogImpl::StartLogging(rtc::PlatformFile platform_file,
                                    int64_t max_size_bytes) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   RtcEventLogHelperThread::ControlMessage message;
   message.message_type = RtcEventLogHelperThread::ControlMessage::START_FILE;
   message.max_size_bytes = max_size_bytes <= 0
@@ skipping 13 matching lines @@
     return false;
   }
   if (message.file->OpenFromFileHandle(file_handle, true, false) != 0) {
     LOG(LS_ERROR) << "Can't open file. WebRTC event log not started.";
     return false;
   }
   if (!message_queue_.Insert(&message)) {
     LOG(LS_ERROR) << "Message queue full. Can't start logging.";
     return false;
   }
+  end_hibernation_.Set();
   LOG(LS_INFO) << "Starting WebRTC event log.";
   return true;
 }
 
 void RtcEventLogImpl::StopLogging() {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   RtcEventLogHelperThread::ControlMessage message;
   message.message_type = RtcEventLogHelperThread::ControlMessage::STOP_FILE;
   message.stop_time = clock_->TimeInMicroseconds();
   while (!message_queue_.Insert(&message)) {
     // TODO(terelius): We would like to have a blocking Insert function in the
     // SwapQueue, but for the time being we will just clear any previous
     // messages.
     // Since StopLogging waits for the thread, it is essential that we don't
     // clear any STOP_FILE messages. To ensure that there is only one call at a
     // time, we require that all calls to StopLogging are made on the same
     // thread.
     LOG(LS_ERROR) << "Message queue full. Clearing queue to stop logging.";
     message_queue_.Clear();
   }
   LOG(LS_INFO) << "Stopping WebRTC event log.";
+  end_hibernation_.Set();

[pbos-webrtc, 2016/06/03 08:54:25]

Should the last three lines here be replaced with something like
logging_thread_.Stop() which would do the appropriate sets and waits? I think
some shared events between the classes could be avoidable.

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

Done. Note that this only reduces the number of shared events between the
classes. It does not change the number of shared events between the threads.

   wake_up_.Set();                       // Request the output thread to wake up.
   stopped_.Wait(rtc::Event::kForever);  // Wait for the log to stop.
 }
 
 void RtcEventLogImpl::LogVideoReceiveStreamConfig(
     const VideoReceiveStream::Config& config) {
   std::unique_ptr<rtclog::Event> event(new rtclog::Event());
   event->set_timestamp_us(clock_->TimeInMicroseconds());
   event->set_type(rtclog::Event::VIDEO_RECEIVER_CONFIG_EVENT);
 
@@ skipping 17 matching lines @@
         receiver_config->add_header_extensions();
     extension->set_name(e.uri);
     extension->set_id(e.id);
   }
 
   for (const auto& d : config.decoders) {
     rtclog::DecoderConfig* decoder = receiver_config->add_decoders();
     decoder->set_name(d.payload_name);
     decoder->set_payload_type(d.payload_type);
   }
-  if (!event_queue_.Insert(&event)) {
-    LOG(LS_ERROR) << "Config queue full. Not logging config event.";
-  }
+  StoreEvent(&event);
 }
 
 void RtcEventLogImpl::LogVideoSendStreamConfig(
     const VideoSendStream::Config& config) {
   std::unique_ptr<rtclog::Event> event(new rtclog::Event());
   event->set_timestamp_us(clock_->TimeInMicroseconds());
   event->set_type(rtclog::Event::VIDEO_SENDER_CONFIG_EVENT);
 
   rtclog::VideoSendConfig* sender_config = event->mutable_video_sender_config();
 
   for (const auto& ssrc : config.rtp.ssrcs) {
     sender_config->add_ssrcs(ssrc);
   }
 
   for (const auto& e : config.rtp.extensions) {
     rtclog::RtpHeaderExtension* extension =
         sender_config->add_header_extensions();
     extension->set_name(e.uri);
     extension->set_id(e.id);
   }
 
   for (const auto& rtx_ssrc : config.rtp.rtx.ssrcs) {
     sender_config->add_rtx_ssrcs(rtx_ssrc);
   }
   sender_config->set_rtx_payload_type(config.rtp.rtx.payload_type);
 
   rtclog::EncoderConfig* encoder = sender_config->mutable_encoder();
   encoder->set_name(config.encoder_settings.payload_name);
   encoder->set_payload_type(config.encoder_settings.payload_type);
-  if (!event_queue_.Insert(&event)) {
-    LOG(LS_ERROR) << "Config queue full. Not logging config event.";
-  }
+  StoreEvent(&event);
 }
 
 void RtcEventLogImpl::LogRtpHeader(PacketDirection direction,
                                    MediaType media_type,
                                    const uint8_t* header,
                                    size_t packet_length) {
   // Read header length (in bytes) from packet data.
   if (packet_length < 12u) {
     return;  // Don't read outside the packet.
   }
   const bool x = (header[0] & 0x10) != 0;
   const uint8_t cc = header[0] & 0x0f;
   size_t header_length = 12u + cc * 4u;
 
   if (x) {
     if (packet_length < 12u + cc * 4u + 4u) {
       return;  // Don't read outside the packet.
     }
     size_t x_len = ByteReader<uint16_t>::ReadBigEndian(header + 14 + cc * 4);
     header_length += (x_len + 1) * 4;
   }
 
   std::unique_ptr<rtclog::Event> rtp_event(new rtclog::Event());
   rtp_event->set_timestamp_us(clock_->TimeInMicroseconds());
   rtp_event->set_type(rtclog::Event::RTP_EVENT);
   rtp_event->mutable_rtp_packet()->set_incoming(direction == kIncomingPacket);
   rtp_event->mutable_rtp_packet()->set_type(ConvertMediaType(media_type));
   rtp_event->mutable_rtp_packet()->set_packet_length(packet_length);
   rtp_event->mutable_rtp_packet()->set_header(header, header_length);
-  if (!event_queue_.Insert(&rtp_event)) {
-    LOG(LS_ERROR) << "RTP queue full. Not logging RTP packet.";
-  }
+  StoreEvent(&rtp_event);
 }
 
 void RtcEventLogImpl::LogRtcpPacket(PacketDirection direction,
                                     MediaType media_type,
                                     const uint8_t* packet,
                                     size_t length) {
   std::unique_ptr<rtclog::Event> rtcp_event(new rtclog::Event());
   rtcp_event->set_timestamp_us(clock_->TimeInMicroseconds());
   rtcp_event->set_type(rtclog::Event::RTCP_EVENT);
   rtcp_event->mutable_rtcp_packet()->set_incoming(direction == kIncomingPacket);
@@ skipping 37 matching lines @@
         FALLTHROUGH();
       default:
         // We don't log sender descriptions, application defined messages
         // or message blocks of unknown type.
         break;
     }
 
     block_begin += block_size;
   }
   rtcp_event->mutable_rtcp_packet()->set_packet_data(buffer, buffer_length);
-  if (!event_queue_.Insert(&rtcp_event)) {
-    LOG(LS_ERROR) << "RTCP queue full. Not logging RTCP packet.";
-  }
+  StoreEvent(&rtcp_event);
 }
 
 void RtcEventLogImpl::LogAudioPlayout(uint32_t ssrc) {
   std::unique_ptr<rtclog::Event> event(new rtclog::Event());
   event->set_timestamp_us(clock_->TimeInMicroseconds());
   event->set_type(rtclog::Event::AUDIO_PLAYOUT_EVENT);
   auto playout_event = event->mutable_audio_playout_event();
   playout_event->set_local_ssrc(ssrc);
-  if (!event_queue_.Insert(&event)) {
-    LOG(LS_ERROR) << "Playout queue full. Not logging ACM playout.";
-  }
+  StoreEvent(&event);
 }
 
 void RtcEventLogImpl::LogBwePacketLossEvent(int32_t bitrate,
                                             uint8_t fraction_loss,
                                             int32_t total_packets) {
   std::unique_ptr<rtclog::Event> event(new rtclog::Event());
   event->set_timestamp_us(clock_->TimeInMicroseconds());
   event->set_type(rtclog::Event::BWE_PACKET_LOSS_EVENT);
   auto bwe_event = event->mutable_bwe_packet_loss_event();
   bwe_event->set_bitrate(bitrate);
   bwe_event->set_fraction_loss(fraction_loss);
   bwe_event->set_total_packets(total_packets);
-  if (!event_queue_.Insert(&event)) {
-    LOG(LS_ERROR) << "BWE loss queue full. Not logging BWE update.";
+  StoreEvent(&event);
+}
+
+void RtcEventLogImpl::StoreEvent(std::unique_ptr<rtclog::Event>* event) {
+  if (!event_queue_.Insert(event)) {
+    LOG(LS_ERROR) << "WebRTC event log queue full. Dropping event.";
   }
+  end_hibernation_.Set();
 }
 
 bool RtcEventLog::ParseRtcEventLog(const std::string& file_name,
                                    rtclog::EventStream* result) {
   char tmp_buffer[1024];
   int bytes_read = 0;
   std::unique_ptr<FileWrapper> dump_file(FileWrapper::Create());
   if (dump_file->OpenFile(file_name.c_str(), true) != 0) {
     return false;
   }
@@ skipping 10 matching lines @@
 // RtcEventLog member functions.
 std::unique_ptr<RtcEventLog> RtcEventLog::Create(const Clock* clock) {
 #ifdef ENABLE_RTC_EVENT_LOG
   return std::unique_ptr<RtcEventLog>(new RtcEventLogImpl(clock));
 #else
   return std::unique_ptr<RtcEventLog>(new RtcEventLogNullImpl());
 #endif  // ENABLE_RTC_EVENT_LOG
 }
 
 }  // namespace webrtc