Stop a session when a new connection becomes writable.

webrtc/p2p/base/p2ptransportchannel_unittest.cc

 /*
  *  Copyright 2009 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 2141 matching lines @@
   conn2->ReceivedPingResponse();
   EXPECT_EQ_WAIT(conn2, ch.best_connection(), 1000);
   EXPECT_EQ(cricket::TransportChannelState::STATE_CONNECTING, ch.GetState());
 
   // When |conn1| comes back again, |conn2| will be pruned again.
   conn1->ReceivedPingResponse();
   EXPECT_EQ_WAIT(conn1, ch.best_connection(), 1000);
   EXPECT_TRUE_WAIT(!conn2->active(), 1000);
   EXPECT_EQ(cricket::TransportChannelState::STATE_COMPLETED, ch.GetState());
 }
+
+TEST_F(P2PTransportChannelPingTest, TestStopSessions) {

[pthatcher1, 2015/10/24 00:39:04]

Can you leave a comment about what this is testing, and perhaps make
"TestStopSessions"?  Basically, explain that if an ICE restart happens while
we're still writable, we need to stop gathering.

[honghaiz3, 2015/10/26 16:47:46]

Done. Not sure what do you mean by "make TestStopSessions".

+  cricket::FakePortAllocator pa(rtc::Thread::Current(), nullptr);
+  cricket::P2PTransportChannel ch("test channel", 1, nullptr, &pa);
+  PrepareChannel(&ch);
+  ch.SetIceConfig(CreateIceConfig(2000, false));
+  ch.Connect();
+  ch.MaybeStartGathering();
+  ch.AddRemoteCandidate(CreateCandidate("1.1.1.1", 1, 100));
+  cricket::Connection* conn1 = WaitForConnectionTo(&ch, "1.1.1.1", 1);
+  ASSERT_TRUE(conn1 != nullptr);
+  conn1->ReceivedPingResponse();  // Becomes writable and receiving
+  EXPECT_TRUE(!ch.allocator_session()->IsGettingPorts());
+
+  ch.SetIceCredentials(kIceUfrag[1], kIcePwd[1]);
+  ch.MaybeStartGathering();
+  ch.AddRemoteCandidate(CreateCandidate("2.2.2.2", 2, 100));
+  cricket::Connection* conn2 = WaitForConnectionTo(&ch, "2.2.2.2", 2);
+  ASSERT_TRUE(conn2 != nullptr);
+  conn2->ReceivedPingResponse(); // Becomes writable and receiving
+  EXPECT_TRUE(!ch.allocator_session()->IsGettingPorts());
+}