Make host_forwarder better handle duplicate forwards.

tools/android/forwarder2/host_forwarder_main.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.
 
 #include <errno.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ skipping 116 matching lines @@
       SendMessage(
           !removed_elements ? "ERROR: could not unmap port" : "OK",
           client_socket.get());
       return;
     }
     int host_port;
     if (!pickle_it.ReadInt(&host_port)) {
       SendMessage("ERROR: missing host port", client_socket.get());
       return;
     }
+    const std::string controller_key = MakeHostControllerMapKey(
+        adb_port, device_port);
+    if (controllers_.find(controller_key) != controllers_.end()) {
+      // The port is already forwarded.

[bulach, 2013/07/08 14:35:36]

nit: maybe expand this a little bit, and add a log to differentiate from 156
below?

// The host already knows about this forward.
// The device side may have been restarted, so
// send the message again to reestablish the link.
LOG(INFO) << "Re-forwarding device port " << device_port << " to host port " <<
host_port;

[Philippe, 2013/07/08 15:47:50]

Note that this wasn't unfortunately doing what your (C++) comment is saying :)
I'm preparing a more robust patch set to follow your comment.

[Philippe, 2013/07/08 17:00:38]

The other patch set I mentioned is a much bigger change. I would like to land
this one before to fix the build downstream if that's ok with you.

[bulach, 2013/07/08 17:40:35]

sgtm.. would you like to add the LOG just in case, so at least we'll have some
information to distinguish the cases?

+      SendMessage(base::StringPrintf("%d:%d", device_port, host_port),
+                  client_socket.get());
+      return;
+    }
     // Create a new host controller.
     scoped_ptr<HostController> host_controller(
         new HostController(device_port, "127.0.0.1", host_port, adb_port,
                            GetExitNotifierFD()));
     if (!host_controller->Connect()) {
       has_failed_ = true;
       SendMessage("ERROR: Connection to device failed.", client_socket.get());
       return;
     }
     // Get the current allocated port.
     device_port = host_controller->device_port();
     LOG(INFO) << "Forwarding device port " << device_port << " to host port "
               << host_port;
     const std::string msg = base::StringPrintf("%d:%d", device_port, host_port);
     if (!SendMessage(msg, client_socket.get()))
       return;
     host_controller->Start();
-    const std::string controller_key = MakeHostControllerMapKey(
-        adb_port, device_port);
     controllers_.insert(
         std::make_pair(controller_key,
                        linked_ptr<HostController>(host_controller.release())));
   }
 
   virtual void OnServerExited() OVERRIDE {
     for (HostControllerMap::iterator it = controllers_.begin();
          it != controllers_.end(); ++it) {
       linked_ptr<HostController> host_controller = it->second;
       host_controller->Join();
@@ skipping 149 matching lines @@
 
   return client_delegate.has_failed() || daemon_delegate.has_failed();
 }
 
 }  // namespace
 }  // namespace forwarder2
 
 int main(int argc, char** argv) {
   return forwarder2::RunHostForwarder(argc, argv);
 }