Let debug target pick the debugger port

runtime/bin/dbg_connection.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/dbg_connection.h"
 #include "bin/dbg_message.h"
 #include "bin/dartutils.h"
 #include "bin/log.h"
 #include "bin/socket.h"
 #include "bin/thread.h"
@@ skipping 260 matching lines @@
   }
   if (msgbuf_ != NULL) {
     delete msgbuf_;
     msgbuf_ = NULL;
   }
   // TODO(hausner): Need to tell the VM debugger object to remove all
   // breakpoints.
 }
 
 
-void DebuggerConnectionHandler::StartHandler(const char* address,
-                                             int port_number) {
+int DebuggerConnectionHandler::StartHandler(const char* address,
+                                            int port_number) {
   ASSERT(handler_lock_ != NULL);
   MonitorLocker ml(handler_lock_);
   if (listener_fd_ != -1) {
-    return;  // The debugger connection handler was already started.
+    // The debugger connection handler was already started.
+    return Socket::GetPort(listener_fd_);
   }
 
   // First setup breakpoint, exception and delayed breakpoint handlers.
   DbgMsgQueueList::Initialize();
 
   // Initialize the socket implementation.
   if (!Socket::Initialize()) {
     FATAL("Failed initializing socket implementation.");
   }
 
   // Now setup a listener socket and start a thread which will
   // listen, accept connections from debuggers, read and handle/dispatch
   // debugger commands received on these connections.
   ASSERT(listener_fd_ == -1);
-
   OSError *os_error;
   SocketAddresses* addresses = Socket::LookupAddress(address, -1, &os_error);
   listener_fd_ = ServerSocket::CreateBindListen(
       addresses->GetAt(0)->addr(), port_number, 1);
+  port_number = Socket::GetPort(listener_fd_);
   DebuggerConnectionImpl::StartHandler(port_number);
+  return port_number;
 }
 
 
 void DebuggerConnectionHandler::WaitForConnection() {
   ASSERT(handler_lock_ != NULL);
   MonitorLocker ml(handler_lock_);
   while (!IsConnected()) {
     dart::Monitor::WaitResult res = ml.Wait();
     ASSERT(res == dart::Monitor::kNotified);
   }
@@ skipping 133 matching lines @@
 
 
 bool DebuggerConnectionHandler::IsConnected() {
   // TODO(asiva): Support multiple debugger connections.
   // Return true if a connection has been established.
   return singleton_handler != NULL;
 }
 
 }  // namespace bin
 }  // namespace dart