Remove ports that are not used by any channel after timeout

webrtc/p2p/base/port.cc

Index: webrtc/p2p/base/port.cc
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
index b6173ebf45768be331c589631f81f9aee8ccbc80..93d7e351e29fe07366bcc93a8ec8499269410291 100644
--- a/webrtc/p2p/base/port.cc
+++ b/webrtc/p2p/base/port.cc
@@ -198,6 +198,7 @@ void Port::Construct() {
   network_->SignalTypeChanged.connect(this, &Port::OnNetworkTypeChanged);
   network_cost_ = network_->GetCost();
 
+  thread_->PostDelayed(RTC_FROM_HERE, timeout_delay_, this, MSG_CHECK_DEAD);
   LOG_J(LS_INFO, this) << "Port created with network cost " << network_cost_;
 }
 
@@ -644,13 +645,29 @@ void Port::SendBindingErrorResponse(StunMessage* request,
                        << " to " << addr.ToSensitiveString();
 }
 
+void Port::BecomeReady() {
+  // If it is pruned, we won't bring it up again.

[pthatcher1, 2016/07/28 19:35:05]

We should probably RTC_DCHECK(state_ == State::INIT).

[honghaiz3, 2016/07/28 22:51:44]

It may happen that it was pruned first then it become ready, because we don't
stop a session when ICE restart (if it has not been started). 
We could change that behavior, but we should keep it at a separate CL. 

+  if (state_ == State::INIT) {
+    state_ = State::READY;
+  }
+}
+
+void Port::Prune() {
+  state_ = State::PRUNED;
+  thread_->Post(RTC_FROM_HERE, this, MSG_CHECK_DEAD);
+}
+
 void Port::OnMessage(rtc::Message *pmsg) {
-  ASSERT(pmsg->message_id == MSG_DEAD);
+  ASSERT(pmsg->message_id == MSG_CHECK_DEAD);
   if (dead()) {

[pthatcher1, 2016/07/28 19:35:05]

Since there is only one place calling dead() now, I suggest we just inline it.  

[honghaiz3, 2016/07/28 22:51:44]

Done.

     Destroy();
   }
 }
 
+bool Port::dead() const {
+  return state_ != State::READY && connections_.empty();

[pthatcher1, 2016/07/28 19:35:05]

I think (state_ == INIT || state_ == PRUNED) && connections_.empty() would be
more readable, and more careful to adding more states later.

[honghaiz3, 2016/07/28 22:51:44]

Done.

+}
+
 void Port::OnNetworkTypeChanged(const rtc::Network* network) {
   ASSERT(network == network_);
 
@@ -699,12 +716,12 @@ void Port::OnConnectionDestroyed(Connection* conn) {
   connections_.erase(iter);
   HandleConnectionDestroyed(conn);
 
-  // On the controlled side, ports time out after all connections fail.
+  // Ports time out after all connections fail if it is not ready.
   // Note: If a new connection is added after this message is posted, but it
-  // fails and is removed before kPortTimeoutDelay, then this message will
+  // fails and is removed before timeout_delay_, then this message will
   // still cause the Port to be destroyed.
-  if (dead()) {
-    thread_->PostDelayed(RTC_FROM_HERE, timeout_delay_, this, MSG_DEAD);
+  if (connections_.empty()) {
+    thread_->PostDelayed(RTC_FROM_HERE, timeout_delay_, this, MSG_CHECK_DEAD);
   }
 }