Change return type of CongestionController::pacer() method.

webrtc/call/call.cc

 /*
  *  Copyright (c) 2013 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 145 matching lines @@
 
   void UpdateSendHistograms() EXCLUSIVE_LOCKS_REQUIRED(&bitrate_crit_);
   void UpdateReceiveHistograms();
   void UpdateHistograms();
   void UpdateAggregateNetworkState();
 
   Clock* const clock_;
 
   const int num_cpu_cores_;
   const std::unique_ptr<ProcessThread> module_process_thread_;
-  const std::unique_ptr<ProcessThread> pacer_thread_;
   const std::unique_ptr<CallStats> call_stats_;
   const std::unique_ptr<BitrateAllocator> bitrate_allocator_;
   Call::Config config_;
   rtc::ThreadChecker configuration_thread_checker_;
 
   NetworkState audio_network_state_;
   NetworkState video_network_state_;
 
   std::unique_ptr<RWLockWrapper> receive_crit_;
   // Audio, Video, and FlexFEC receive streams are owned by the client that
@@ skipping 75 matching lines @@
 Call* Call::Create(const Call::Config& config) {
   return new internal::Call(config);
 }
 
 namespace internal {
 
 Call::Call(const Call::Config& config)
     : clock_(Clock::GetRealTimeClock()),
       num_cpu_cores_(CpuInfo::DetectNumberOfCores()),
       module_process_thread_(ProcessThread::Create("ModuleProcessThread")),
-      pacer_thread_(ProcessThread::Create("PacerThread")),
       call_stats_(new CallStats(clock_)),
       bitrate_allocator_(new BitrateAllocator(this)),
       config_(config),
       audio_network_state_(kNetworkDown),
       video_network_state_(kNetworkDown),
       receive_crit_(RWLockWrapper::CreateRWLock()),
       send_crit_(RWLockWrapper::CreateRWLock()),
       event_log_(config.event_log),
       first_packet_sent_ms_(-1),
       received_bytes_per_second_counter_(clock_, nullptr, true),
@@ skipping 27 matching lines @@
 
   congestion_controller_->SignalNetworkState(kNetworkDown);
   congestion_controller_->SetBweBitrates(
       config_.bitrate_config.min_bitrate_bps,
       config_.bitrate_config.start_bitrate_bps,
       config_.bitrate_config.max_bitrate_bps);
 
   module_process_thread_->Start();
   module_process_thread_->RegisterModule(call_stats_.get());
   module_process_thread_->RegisterModule(congestion_controller_.get());
-  pacer_thread_->RegisterModule(congestion_controller_->pacer());
-  pacer_thread_->RegisterModule(
-      congestion_controller_->GetRemoteBitrateEstimator(true));
-  pacer_thread_->Start();
 }
 
 Call::~Call() {
   RTC_DCHECK(!remb_.InUse());
   RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
 
   RTC_CHECK(audio_send_ssrcs_.empty());
   RTC_CHECK(video_send_ssrcs_.empty());
   RTC_CHECK(video_send_streams_.empty());
   RTC_CHECK(audio_receive_ssrcs_.empty());
   RTC_CHECK(video_receive_ssrcs_.empty());
   RTC_CHECK(video_receive_streams_.empty());
 
-  pacer_thread_->Stop();

[the sun, 2016/12/15 15:11:32]

Are there any subtle relationship issues between the CongestionController and
Call which may bite us, now that the pacer thread will keep running until after
the explicit dtor code? Do you need to
congestion_controller_.reset(nullptr);
?

[nisse-webrtc, 2016/12/16 09:38:13]

Don't know... Does the call object register any callbacks which are called on
the pacer thread?

[stefan-webrtc, 2016/12/22 09:54:58]

I don't think it does. It calls into rtp modules and transports, but not into
Call.

-  pacer_thread_->DeRegisterModule(congestion_controller_->pacer());
-  pacer_thread_->DeRegisterModule(
-      congestion_controller_->GetRemoteBitrateEstimator(true));
   module_process_thread_->DeRegisterModule(congestion_controller_.get());
   module_process_thread_->DeRegisterModule(call_stats_.get());
   module_process_thread_->Stop();
   call_stats_->DeregisterStatsObserver(congestion_controller_.get());
 
   // Only update histograms after process threads have been shut down, so that
   // they won't try to concurrently update stats.
   {
     rtc::CritScope lock(&bitrate_crit_);
     UpdateSendHistograms();
@@ skipping 781 matching lines @@
   uint32_t ssrc = ByteReader<uint32_t>::ReadBigEndian(&packet[8]);
   ReadLockScoped read_lock(*receive_crit_);
   auto it = video_receive_ssrcs_.find(ssrc);
   if (it == video_receive_ssrcs_.end())
     return false;
   return it->second->OnRecoveredPacket(packet, length);
 }
 
 }  // namespace internal
 }  // namespace webrtc