Free SCTP data channels asynchronously in PeerConnection.

talk/app/webrtc/peerconnection.cc

Index: talk/app/webrtc/peerconnection.cc
diff --git a/talk/app/webrtc/peerconnection.cc b/talk/app/webrtc/peerconnection.cc
index f0db1397aa7941612612ea3be8cb010b0b09c854..566ca619e9c6ffb8b20850616ef27b5b068d260c 100644
--- a/talk/app/webrtc/peerconnection.cc
+++ b/talk/app/webrtc/peerconnection.cc
@@ -106,6 +106,7 @@ enum {
   MSG_SET_SESSIONDESCRIPTION_FAILED,
   MSG_CREATE_SESSIONDESCRIPTION_FAILED,
   MSG_GETSTATS,
+  MSG_FREE_DATACHANNEL,
 };
 
 struct SetSessionDescriptionMsg : public rtc::MessageData {
@@ -1313,6 +1314,13 @@ void PeerConnection::OnMessage(rtc::Message* msg) {
       delete param;
       break;
     }
+    case MSG_FREE_DATACHANNEL: {
+      auto param =
+          static_cast<rtc::TypedMessageData<rtc::scoped_refptr<DataChannel>>*>(
+              msg->pdata);
+      delete param;

[pthatcher1, 2015/12/03 19:45:15]

Does "delete msg->pdata" not work without the cast?

+      break;
+    }
     default:
       RTC_DCHECK(false && "Not implemented");
       break;
@@ -1900,6 +1908,11 @@ void PeerConnection::OnSctpDataChannelClosed(DataChannel* channel) {
       if (channel->id() >= 0) {
         sid_allocator_.ReleaseSid(channel->id());
       }
+      // Since this method is triggered by a signal from the DataChannel,
+      // we can't free it directly here; we need to free it asynchronously.
+      signaling_thread()->Post(
+          this, MSG_FREE_DATACHANNEL,

[pthatcher1, 2015/12/03 19:45:15]

If you don't need the type cast, you could just call this MSG_DELETE. 

[Taylor Brandstetter, 2015/12/04 19:27:45]

Good point. Done.

+          new rtc::TypedMessageData<rtc::scoped_refptr<DataChannel>>(channel));
       sctp_data_channels_.erase(it);
       return;
     }