Make the audio channel communicate network state changes to the call.

webrtc/call/call.cc

Index: webrtc/call/call.cc
diff --git a/webrtc/call/call.cc b/webrtc/call/call.cc
index 41ac328eab14f44249a20d7ac0dba85a36bb9d1d..64fcc072e1326891ad2b4298358797213eed6ed8 100644
--- a/webrtc/call/call.cc
+++ b/webrtc/call/call.cc
@@ -86,7 +86,9 @@ class Call : public webrtc::Call, public PacketReceiver,
 
   void SetBitrateConfig(
       const webrtc::Call::Config::BitrateConfig& bitrate_config) override;
-  void SignalNetworkState(NetworkState state) override;
+
+  void SignalChannelNetworkState(MediaType media,
+      ChannelNetworkState state) override;
 
   void OnSentPacket(const rtc::SentPacket& sent_packet) override;
 
@@ -127,7 +129,8 @@ class Call : public webrtc::Call, public PacketReceiver,
   Call::Config config_;
   rtc::ThreadChecker configuration_thread_checker_;
 
-  bool network_enabled_;
+  ChannelNetworkState audio_network_state_;
+  ChannelNetworkState video_network_state_;
 
   rtc::scoped_ptr<RWLockWrapper> receive_crit_;
   // Audio and Video receive streams are owned by the client that creates them.
@@ -178,6 +181,30 @@ Call* Call::Create(const Call::Config& config) {
   return new internal::Call(config);
 }
 
+NetworkState ChannelStateToNetworkState(ChannelNetworkState channelState) {
+  return (channelState == ChannelNetworkState::CHANNEL_NETWORK_DOWN ?
+      kNetworkDown : kNetworkUp);
+}
+
+NetworkState AggregateNetworkState(ChannelNetworkState channelA,
+                                   ChannelNetworkState channelB) {
+  NetworkState aggregateState = kNetworkDown;
+  if (channelA == ChannelNetworkState::CHANNEL_NOT_PRESENT &&
+    channelB == ChannelNetworkState::CHANNEL_NOT_PRESENT) {
+    // When no channels are configured - such as in tests -
+    //  the network is assumed to be up
+    aggregateState = kNetworkUp;
+  } else if (channelA == ChannelNetworkState::CHANNEL_NETWORK_UP ||
+    channelB == ChannelNetworkState::CHANNEL_NETWORK_UP) {
+    // There is at least one channel that reports the network to be up
+    aggregateState = kNetworkUp;
+  } else {
+    // All the channels report that the network is down
+    aggregateState = kNetworkDown;
+  }
+  return aggregateState;
+}
+
 namespace internal {
 
 Call::Call(const Call::Config& config)
@@ -188,7 +215,8 @@ Call::Call(const Call::Config& config)
       call_stats_(new CallStats(clock_)),
       bitrate_allocator_(new BitrateAllocator()),
       config_(config),
-      network_enabled_(true),
+      audio_network_state_(ChannelNetworkState::CHANNEL_NOT_PRESENT),
+      video_network_state_(ChannelNetworkState::CHANNEL_NOT_PRESENT),
       receive_crit_(RWLockWrapper::CreateRWLock()),
       send_crit_(RWLockWrapper::CreateRWLock()),
       received_video_bytes_(0),
@@ -316,8 +344,9 @@ webrtc::AudioSendStream* Call::CreateAudioSendStream(
   RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
   AudioSendStream* send_stream = new AudioSendStream(
       config, config_.audio_state, congestion_controller_.get());
-  if (!network_enabled_)
-    send_stream->SignalNetworkState(kNetworkDown);
+
+  send_stream->SignalNetworkState(
+      ChannelStateToNetworkState(audio_network_state_));
   {
     WriteLockScoped write_lock(*send_crit_);
     RTC_DCHECK(audio_send_ssrcs_.find(config.rtp.ssrc) ==
@@ -397,8 +426,8 @@ webrtc::VideoSendStream* Call::CreateVideoSendStream(
       congestion_controller_.get(), &remb_, bitrate_allocator_.get(), config,
       encoder_config, suspended_video_send_ssrcs_);
 
-  if (!network_enabled_)
-    send_stream->SignalNetworkState(kNetworkDown);
+  send_stream->SignalNetworkState(
+      ChannelStateToNetworkState(video_network_state_));
 
   WriteLockScoped write_lock(*send_crit_);
   for (uint32_t ssrc : config.rtp.ssrcs) {
@@ -468,8 +497,8 @@ webrtc::VideoReceiveStream* Call::CreateVideoReceiveStream(
 
   ConfigureSync(config.sync_group);
 
-  if (!network_enabled_)
-    receive_stream->SignalNetworkState(kNetworkDown);
+  receive_stream->SignalNetworkState(

[the sun, 2016/03/04 12:40:48]

For the send streams, the network state is signaled *before* the streams are
added to the internal data structures, for the video receive stream, the state
is signaled *after*. Unless there is some subtle reason for that I suggest we
make it consistent.

Also, should the network state should be signaled for AudioReceiveStream?

+      ChannelStateToNetworkState(video_network_state_));
 
   if (event_log_)
     event_log_->LogVideoReceiveStreamConfig(config);
@@ -548,23 +577,35 @@ void Call::SetBitrateConfig(
                                          bitrate_config.max_bitrate_bps);
 }
 
-void Call::SignalNetworkState(NetworkState state) {
+void Call::SignalChannelNetworkState(MediaType media,
+                                     ChannelNetworkState state) {
   RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
-  network_enabled_ = state == kNetworkUp;
-  congestion_controller_->SignalNetworkState(state);
+  if (media == MediaType::AUDIO)
+    audio_network_state_ = state;
+  if (media == MediaType::VIDEO)
+    video_network_state_ = state;
+
+  NetworkState aggregateState = AggregateNetworkState(audio_network_state_,
+                                                      video_network_state_);
+  LOG(LS_INFO) << "SignalChannelNetworkState: aggregateState=" <<
+      (aggregateState == kNetworkUp ? "up" : "down");
+  congestion_controller_->SignalNetworkState(aggregateState);
   {
     ReadLockScoped write_lock(*send_crit_);
     for (auto& kv : audio_send_ssrcs_) {
-      kv.second->SignalNetworkState(state);
+      kv.second->SignalNetworkState(
+          ChannelStateToNetworkState(audio_network_state_));
     }
     for (auto& kv : video_send_ssrcs_) {
-      kv.second->SignalNetworkState(state);
+      kv.second->SignalNetworkState(
+          ChannelStateToNetworkState(video_network_state_));
     }
   }
   {
     ReadLockScoped write_lock(*receive_crit_);
     for (auto& kv : video_receive_ssrcs_) {
-      kv.second->SignalNetworkState(state);
+      kv.second->SignalNetworkState(
+          ChannelStateToNetworkState(video_network_state_));
     }
   }
 }