Fix posix IPC channel hanging problem.

ipc/ipc_channel_posix_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // These tests are POSIX only.
 
 #include "ipc/ipc_channel_posix.h"
 
 #include <fcntl.h>
 #include <sys/socket.h>
@@ skipping 210 matching lines @@
   channel.Close();
   ASSERT_TRUE(HANDLE_EINTR(close(pipe_fds[1])) == 0);
 
   // Make sure that we can use the socket that is created for us by
   // a standard channel.
   IPC::Channel channel2(socket_name, IPC::Channel::MODE_SERVER, NULL);
   ASSERT_TRUE(channel2.Connect());
   ASSERT_FALSE(channel2.AcceptsConnections());
 }
 
+// If a connection closes right before a Send() call, we may end up closing
+// the connection without notifying the listener, which can cause hangs in
+// sync_message_filter and others. Make sure the listener is notified.
+TEST_F(IPCChannelPosixTest, SendHangTest) {
+  IPCChannelPosixTestListener out_listener(true);
+  IPCChannelPosixTestListener in_listener(true);
+  IPC::ChannelHandle in_handle("IN");
+  IPC::Channel in_chan(in_handle, IPC::Channel::MODE_SERVER, &in_listener);
+  base::FileDescriptor out_fd(in_chan.TakeClientFileDescriptor(), false);
+  IPC::ChannelHandle out_handle("OUT", out_fd);
+  IPC::Channel out_chan(out_handle, IPC::Channel::MODE_CLIENT, &out_listener);
+  ASSERT_TRUE(in_chan.Connect());
+  ASSERT_TRUE(out_chan.Connect());
+  in_chan.Close();  // simulate remote process dying at an unforunate time.
+  // Send will fail, because it cannot write the message.
+  ASSERT_FALSE(out_chan.Send(new IPC::Message(
+      0,  // routing_id
+      kQuitMessage,  // message type
+      IPC::Message::PRIORITY_NORMAL)));
+  ASSERT_EQ(IPCChannelPosixTestListener::CHANNEL_ERROR, out_listener.status());
+}
+
 TEST_F(IPCChannelPosixTest, AdvancedConnected) {
   // Test creating a connection to an external process.
   IPCChannelPosixTestListener listener(false);
   IPC::ChannelHandle chan_handle(GetConnectionSocketName());
   SetUpSocket(&chan_handle, IPC::Channel::MODE_NAMED_SERVER);
   IPC::Channel channel(chan_handle, IPC::Channel::MODE_NAMED_SERVER, &listener);
   ASSERT_TRUE(channel.Connect());
   ASSERT_TRUE(channel.AcceptsConnections());
   ASSERT_FALSE(channel.HasAcceptedConnection());
 
@@ skipping 176 matching lines @@
   if (connected) {
     IPCChannelPosixTest::SpinRunLoop(TestTimeouts::action_max_timeout());
     EXPECT_EQ(IPCChannelPosixTestListener::CHANNEL_ERROR, listener.status());
   } else {
     EXPECT_EQ(IPCChannelPosixTestListener::DISCONNECTED, listener.status());
   }
   return 0;
 }
 
 }  // namespace