Reland of TransportController refactoring.

talk/session/media/channel.cc

Index: talk/session/media/channel.cc
diff --git a/talk/session/media/channel.cc b/talk/session/media/channel.cc
index 294681ef1449aa94033112e8e5315cec5048a0f7..7b5809855f632f4db59876a6d6e05142548254eb 100644
--- a/talk/session/media/channel.cc
+++ b/talk/session/media/channel.cc
@@ -170,15 +170,17 @@
 }
 
 BaseChannel::BaseChannel(rtc::Thread* thread,
-                         MediaChannel* media_channel, BaseSession* session,
-                         const std::string& content_name, bool rtcp)
+                         MediaChannel* media_channel,
+                         TransportController* transport_controller,
+                         const std::string& content_name,
+                         bool rtcp)
     : worker_thread_(thread),
-      session_(session),
+      transport_controller_(transport_controller),
       media_channel_(media_channel),
       content_name_(content_name),
-      rtcp_(rtcp),
-      transport_channel_(NULL),
-      rtcp_transport_channel_(NULL),
+      rtcp_transport_enabled_(rtcp),
+      transport_channel_(nullptr),
+      rtcp_transport_channel_(nullptr),
       enabled_(false),
       writable_(false),
       rtp_ready_to_send_(false),
@@ -204,20 +206,31 @@
   // the media channel may try to send on the dead transport channel. NULLing
   // is not an effective strategy since the sends will come on another thread.
   delete media_channel_;
-  set_transport_channel(nullptr);
-  set_rtcp_transport_channel(nullptr);
+  // Note that we don't just call set_transport_channel(nullptr) because that
+  // would call a pure virtual method which we can't do from a destructor.
+  if (transport_channel_) {
+    DisconnectFromTransportChannel(transport_channel_);
+    transport_controller_->DestroyTransportChannel_w(
+        transport_name_, cricket::ICE_CANDIDATE_COMPONENT_RTP);
+  }
+  if (rtcp_transport_channel_) {
+    DisconnectFromTransportChannel(rtcp_transport_channel_);
+    transport_controller_->DestroyTransportChannel_w(
+        transport_name_, cricket::ICE_CANDIDATE_COMPONENT_RTCP);
+  }
   LOG(LS_INFO) << "Destroyed channel";
 }
 
 bool BaseChannel::Init() {
-  if (!SetTransportChannels(session(), rtcp())) {
+  if (!SetTransport(content_name())) {
     return false;
   }
 
   if (!SetDtlsSrtpCiphers(transport_channel(), false)) {
     return false;
   }
-  if (rtcp() && !SetDtlsSrtpCiphers(rtcp_transport_channel(), true)) {
+  if (rtcp_transport_enabled() &&
+      !SetDtlsSrtpCiphers(rtcp_transport_channel(), true)) {
     return false;
   }
 
@@ -231,29 +244,35 @@
   media_channel_->SetInterface(NULL);
 }
 
-bool BaseChannel::SetTransportChannels(BaseSession* session, bool rtcp) {
-  return worker_thread_->Invoke<bool>(Bind(
-      &BaseChannel::SetTransportChannels_w, this, session, rtcp));
-}
-
-bool BaseChannel::SetTransportChannels_w(BaseSession* session, bool rtcp) {
+bool BaseChannel::SetTransport(const std::string& transport_name) {
+  return worker_thread_->Invoke<bool>(
+      Bind(&BaseChannel::SetTransport_w, this, transport_name));
+}
+
+bool BaseChannel::SetTransport_w(const std::string& transport_name) {
   ASSERT(worker_thread_ == rtc::Thread::Current());
 
-  set_transport_channel(session->CreateChannel(
-      content_name(), cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  if (transport_name == transport_name_) {
+    // Nothing to do if transport name isn't changing
+    return true;
+  }
+
+  set_transport_channel(transport_controller_->CreateTransportChannel_w(
+      transport_name, cricket::ICE_CANDIDATE_COMPONENT_RTP));
   if (!transport_channel()) {
     return false;
   }
-  if (rtcp) {
-    set_rtcp_transport_channel(session->CreateChannel(
-        content_name(), cricket::ICE_CANDIDATE_COMPONENT_RTCP));
+  if (rtcp_transport_enabled()) {
+    LOG(LS_INFO) << "Create RTCP TransportChannel for " << content_name()
+                 << " on " << transport_name << " transport ";
+    set_rtcp_transport_channel(transport_controller_->CreateTransportChannel_w(
+        transport_name, cricket::ICE_CANDIDATE_COMPONENT_RTCP));
     if (!rtcp_transport_channel()) {
       return false;
     }
-  } else {
-    set_rtcp_transport_channel(nullptr);
-  }
-
+  }
+
+  transport_name_ = transport_name;
   return true;
 }
 
@@ -261,42 +280,62 @@
   ASSERT(worker_thread_ == rtc::Thread::Current());
 
   TransportChannel* old_tc = transport_channel_;
-
-  if (old_tc == new_tc) {
+  if (!old_tc && !new_tc) {
+    // Nothing to do
     return;
   }
+  ASSERT(old_tc != new_tc);
+
   if (old_tc) {
     DisconnectFromTransportChannel(old_tc);
-    session()->DestroyChannel(
-        content_name(), cricket::ICE_CANDIDATE_COMPONENT_RTP);
+    transport_controller_->DestroyTransportChannel_w(
+        transport_name_, cricket::ICE_CANDIDATE_COMPONENT_RTP);
   }
 
   transport_channel_ = new_tc;
 
   if (new_tc) {
     ConnectToTransportChannel(new_tc);
-  }
+    for (const auto& pair : socket_options_) {
+      new_tc->SetOption(pair.first, pair.second);
+    }
+  }
+
+  // Update aggregate writable/ready-to-send state between RTP and RTCP upon
+  // setting new channel
+  UpdateWritableState_w();
+  SetReadyToSend(false, new_tc && new_tc->writable());
 }
 
 void BaseChannel::set_rtcp_transport_channel(TransportChannel* new_tc) {
   ASSERT(worker_thread_ == rtc::Thread::Current());
 
   TransportChannel* old_tc = rtcp_transport_channel_;
-
-  if (old_tc == new_tc) {
+  if (!old_tc && !new_tc) {
+    // Nothing to do
     return;
   }
+  ASSERT(old_tc != new_tc);
+
   if (old_tc) {
     DisconnectFromTransportChannel(old_tc);
-    session()->DestroyChannel(
-        content_name(), cricket::ICE_CANDIDATE_COMPONENT_RTCP);
+    transport_controller_->DestroyTransportChannel_w(
+        transport_name_, cricket::ICE_CANDIDATE_COMPONENT_RTCP);
   }
 
   rtcp_transport_channel_ = new_tc;
 
   if (new_tc) {
     ConnectToTransportChannel(new_tc);
-  }
+    for (const auto& pair : rtcp_socket_options_) {
+      new_tc->SetOption(pair.first, pair.second);
+    }
+  }
+
+  // Update aggregate writable/ready-to-send state between RTP and RTCP upon
+  // setting new channel
+  UpdateWritableState_w();
+  SetReadyToSend(true, new_tc && new_tc->writable());
 }
 
 void BaseChannel::ConnectToTransportChannel(TransportChannel* tc) {
@@ -407,9 +446,13 @@
   switch (type) {
     case ST_RTP:
       channel = transport_channel_;
+      socket_options_.push_back(
+          std::pair<rtc::Socket::Option, int>(opt, value));
       break;
     case ST_RTCP:
       channel = rtcp_transport_channel_;
+      rtcp_socket_options_.push_back(
+          std::pair<rtc::Socket::Option, int>(opt, value));
       break;
   }
   return channel ? channel->SetOption(opt, value) : -1;
@@ -417,12 +460,7 @@
 
 void BaseChannel::OnWritableState(TransportChannel* channel) {
   ASSERT(channel == transport_channel_ || channel == rtcp_transport_channel_);
-  if (transport_channel_->writable()
-      && (!rtcp_transport_channel_ || rtcp_transport_channel_->writable())) {
-    ChannelWritable_w();
-  } else {
-    ChannelNotWritable_w();
-  }
+  UpdateWritableState_w();
 }
 
 void BaseChannel::OnChannelRead(TransportChannel* channel,
@@ -440,26 +478,25 @@
 }
 
 void BaseChannel::OnReadyToSend(TransportChannel* channel) {
-  SetReadyToSend(channel, true);
-}
-
-void BaseChannel::SetReadyToSend(TransportChannel* channel, bool ready) {
   ASSERT(channel == transport_channel_ || channel == rtcp_transport_channel_);
-  if (channel == transport_channel_) {
+  SetReadyToSend(channel == rtcp_transport_channel_, true);
+}
+
+void BaseChannel::SetReadyToSend(bool rtcp, bool ready) {
+  if (rtcp) {
+    rtcp_ready_to_send_ = ready;
+  } else {
     rtp_ready_to_send_ = ready;
   }
-  if (channel == rtcp_transport_channel_) {
-    rtcp_ready_to_send_ = ready;
-  }
-
-  if (!ready) {
+
+  if (rtp_ready_to_send_ &&
+      // In the case of rtcp mux |rtcp_transport_channel_| will be null.
+      (rtcp_ready_to_send_ || !rtcp_transport_channel_)) {
+    // Notify the MediaChannel when both rtp and rtcp channel can send.
+    media_channel_->OnReadyToSend(true);
+  } else {
     // Notify the MediaChannel when either rtp or rtcp channel can't send.
     media_channel_->OnReadyToSend(false);
-  } else if (rtp_ready_to_send_ &&
-             // In the case of rtcp mux |rtcp_transport_channel_| will be null.
-             (rtcp_ready_to_send_ || !rtcp_transport_channel_)) {
-    // Notify the MediaChannel when both rtp and rtcp channel can send.
-    media_channel_->OnReadyToSend(true);
   }
 }
 
@@ -581,7 +618,7 @@
   if (ret != static_cast<int>(packet->size())) {
     if (channel->GetError() == EWOULDBLOCK) {
       LOG(LS_WARNING) << "Got EWOULDBLOCK from socket.";
-      SetReadyToSend(channel, false);
+      SetReadyToSend(rtcp, false);
     }
     return false;
   }
@@ -715,14 +752,21 @@
   ChangeState();
 }
 
+void BaseChannel::UpdateWritableState_w() {
+  if (transport_channel_ && transport_channel_->writable() &&
+      (!rtcp_transport_channel_ || rtcp_transport_channel_->writable())) {
+    ChannelWritable_w();
+  } else {
+    ChannelNotWritable_w();
+  }
+}
+
 void BaseChannel::ChannelWritable_w() {
   ASSERT(worker_thread_ == rtc::Thread::Current());
   if (writable_)
     return;
 
-  LOG(LS_INFO) << "Channel socket writable ("
-               << transport_channel_->content_name() << ", "
-               << transport_channel_->component() << ")"
+  LOG(LS_INFO) << "Channel writable (" << content_name_ << ")"
                << (was_ever_writable_ ? "" : " for the first time");
 
   std::vector<ConnectionInfo> infos;
@@ -739,13 +783,13 @@
   // If we're doing DTLS-SRTP, now is the time.
   if (!was_ever_writable_ && ShouldSetupDtlsSrtp()) {
     if (!SetupDtlsSrtp(false)) {
-      SignalDtlsSetupFailure(this, false);
+      SignalDtlsSetupFailure_w(false);
       return;
     }
 
     if (rtcp_transport_channel_) {
       if (!SetupDtlsSrtp(true)) {
-        SignalDtlsSetupFailure(this, true);
+        SignalDtlsSetupFailure_w(true);
         return;
       }
     }
@@ -788,8 +832,8 @@
 bool BaseChannel::SetupDtlsSrtp(bool rtcp_channel) {
   bool ret = false;
 
-  TransportChannel *channel = rtcp_channel ?
-      rtcp_transport_channel_ : transport_channel_;
+  TransportChannel* channel =
+      rtcp_channel ? rtcp_transport_channel_ : transport_channel_;
 
   // No DTLS
   if (!channel->IsDtlsActive())
@@ -884,9 +928,7 @@
   if (!writable_)
     return;
 
-  LOG(LS_INFO) << "Channel socket not writable ("
-               << transport_channel_->content_name() << ", "
-               << transport_channel_->component() << ")";
+  LOG(LS_INFO) << "Channel not writable (" << content_name_ << ")";
   writable_ = false;
   ChangeState();
 }
@@ -985,7 +1027,8 @@
 void BaseChannel::ActivateRtcpMux_w() {
   if (!rtcp_mux_filter_.IsActive()) {
     rtcp_mux_filter_.SetActive();
-    set_rtcp_transport_channel(NULL);
+    set_rtcp_transport_channel(nullptr);
+    rtcp_transport_enabled_ = false;
   }
 }
 
@@ -1004,7 +1047,11 @@
       ret = rtcp_mux_filter_.SetAnswer(enable, src);
       if (ret && rtcp_mux_filter_.IsActive()) {
         // We activated RTCP mux, close down the RTCP transport.
-        set_rtcp_transport_channel(NULL);
+        LOG(LS_INFO) << "Enabling rtcp-mux for " << content_name()
+                     << " by destroying RTCP transport channel for "
+                     << transport_name();
+        set_rtcp_transport_channel(nullptr);
+        rtcp_transport_enabled_ = false;
       }
       break;
     case CA_UPDATE:
@@ -1231,14 +1278,16 @@
 VoiceChannel::VoiceChannel(rtc::Thread* thread,
                            MediaEngineInterface* media_engine,
                            VoiceMediaChannel* media_channel,
-                           BaseSession* session,
+                           TransportController* transport_controller,
                            const std::string& content_name,
                            bool rtcp)
-    : BaseChannel(thread, media_channel, session, content_name,
+    : BaseChannel(thread,
+                  media_channel,
+                  transport_controller,
+                  content_name,
                   rtcp),
       media_engine_(media_engine),
-      received_media_(false) {
-}
+      received_media_(false) {}
 
 VoiceChannel::~VoiceChannel() {
   StopAudioMonitor();
@@ -1264,11 +1313,12 @@
                              media_channel(), ssrc, renderer));
 }
 
-bool VoiceChannel::SetAudioSend(uint32 ssrc, bool mute,
+bool VoiceChannel::SetAudioSend(uint32 ssrc,
+                                bool mute,
                                 const AudioOptions* options,
                                 AudioRenderer* renderer) {
-  return InvokeOnWorker(Bind(&VoiceMediaChannel::SetAudioSend,
-                             media_channel(), ssrc, mute, options, renderer));
+  return InvokeOnWorker(Bind(&VoiceMediaChannel::SetAudioSend, media_channel(),
+                             ssrc, mute, options, renderer));
 }
 
 bool VoiceChannel::SetRingbackTone(const void* buf, int len) {
@@ -1607,14 +1657,16 @@
 
 VideoChannel::VideoChannel(rtc::Thread* thread,
                            VideoMediaChannel* media_channel,
-                           BaseSession* session,
+                           TransportController* transport_controller,
                            const std::string& content_name,
                            bool rtcp)
-    : BaseChannel(thread, media_channel, session, content_name,
+    : BaseChannel(thread,
+                  media_channel,
+                  transport_controller,
+                  content_name,
                   rtcp),
       renderer_(NULL),
-      previous_we_(rtc::WE_CLOSE) {
-}
+      previous_we_(rtc::WE_CLOSE) {}
 
 bool VideoChannel::Init() {
   if (!BaseChannel::Init()) {
@@ -1707,10 +1759,11 @@
   return true;
 }
 
-bool VideoChannel::SetVideoSend(uint32 ssrc, bool mute,
+bool VideoChannel::SetVideoSend(uint32 ssrc,
+                                bool mute,
                                 const VideoOptions* options) {
-  return InvokeOnWorker(Bind(&VideoMediaChannel::SetVideoSend,
-                             media_channel(), ssrc, mute, options));
+  return InvokeOnWorker(Bind(&VideoMediaChannel::SetVideoSend, media_channel(),
+                             ssrc, mute, options));
 }
 
 void VideoChannel::ChangeState() {
@@ -2045,13 +2098,16 @@
 
 DataChannel::DataChannel(rtc::Thread* thread,
                          DataMediaChannel* media_channel,
-                         BaseSession* session,
+                         TransportController* transport_controller,
                          const std::string& content_name,
                          bool rtcp)
-    : BaseChannel(thread, media_channel, session, content_name, rtcp),
+    : BaseChannel(thread,
+                  media_channel,
+                  transport_controller,
+                  content_name,
+                  rtcp),
       data_channel_type_(cricket::DCT_NONE),
-      ready_to_send_data_(false) {
-}
+      ready_to_send_data_(false) {}
 
 DataChannel::~DataChannel() {
   StopMediaMonitor();