Fix race on VCM protection callback.

webrtc/video/video_send_stream.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 127 matching lines @@
       module_process_thread_(module_process_thread),
       call_stats_(call_stats),
       congestion_controller_(congestion_controller),
       remb_(remb),
       overuse_detector_(
           Clock::GetRealTimeClock(),
           GetCpuOveruseOptions(config.encoder_settings.full_overuse_time),
           this,
           config.post_encode_callback,
           &stats_proxy_),
-      vie_encoder_(num_cpu_cores,
-                   module_process_thread_,
-                   &stats_proxy_,
-                   config.pre_encode_callback,
-                   &overuse_detector_,
-                   congestion_controller_->pacer(),
-                   &payload_router_,
-                   bitrate_allocator),
-      vcm_(vie_encoder_.vcm()),
       vie_channel_(config.send_transport,
                    module_process_thread_,
                    &payload_router_,
                    nullptr,
                    encoder_feedback_.GetRtcpIntraFrameObserver(),
                    congestion_controller_->GetBitrateController()
                        ->CreateRtcpBandwidthObserver(),
                    congestion_controller_->GetTransportFeedbackObserver(),
                    nullptr,
                    call_stats_->rtcp_rtt_stats(),
                    congestion_controller_->pacer(),
                    congestion_controller_->packet_router(),
                    config_.rtp.ssrcs.size(),
                    true),
       vie_receiver_(vie_channel_.vie_receiver()),
+      vie_encoder_(num_cpu_cores,
+                   module_process_thread_,
+                   &stats_proxy_,
+                   config.pre_encode_callback,
+                   &overuse_detector_,
+                   congestion_controller_->pacer(),
+                   &payload_router_,
+                   bitrate_allocator),
+      vcm_(vie_encoder_.vcm()),
       input_(&vie_encoder_,
              config_.local_renderer,
              &stats_proxy_,
              &overuse_detector_) {
   LOG(LS_INFO) << "VideoSendStream: " << config_.ToString();
 
   RTC_DCHECK(!config_.rtp.ssrcs.empty());
   RTC_DCHECK(module_process_thread_);
   RTC_DCHECK(call_stats_);
   RTC_DCHECK(congestion_controller_);
@@ skipping 76 matching lines @@
   vie_channel_.RegisterSendFrameCountObserver(&stats_proxy_);
 
   module_process_thread_->RegisterModule(&overuse_detector_);
 }
 
 VideoSendStream::~VideoSendStream() {
   LOG(LS_INFO) << "~VideoSendStream: " << config_.ToString();
   Stop();
 
   module_process_thread_->DeRegisterModule(&overuse_detector_);
-  // Remove vcm_protection_callback (part of vie_channel_) before destroying
-  // ViEChannel. vcm_ is owned by ViEEncoder and the registered callback does
-  // not outlive it.
-  vcm_->RegisterProtectionCallback(nullptr);
   vie_channel_.RegisterSendFrameCountObserver(nullptr);
   vie_channel_.RegisterSendBitrateObserver(nullptr);
   vie_channel_.RegisterRtcpPacketTypeCounterObserver(nullptr);
   vie_channel_.RegisterSendChannelRtpStatisticsCallback(nullptr);
   vie_channel_.RegisterSendChannelRtcpStatisticsCallback(nullptr);
 
   vie_encoder_.DeRegisterExternalEncoder(
       config_.encoder_settings.payload_type);
 
   call_stats_->DeregisterStatsObserver(vie_channel_.GetStatsObserver());
@@ skipping 316 matching lines @@
   used_ssrcs.resize(static_cast<size_t>(video_codec.numberOfSimulcastStreams));
   vie_encoder_.SetSsrcs(used_ssrcs);
 
   // Restart the media flow
   vie_encoder_.Restart();
 
   return true;
 }
 }  // namespace internal
 }  // namespace webrtc