Mark handle as invalid, when datagram socket is closed.

runtime/bin/eventhandler_win.cc

 // Copyright (c) 2013, 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 "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/eventhandler.h"
 
 #include <winsock2.h>  // NOLINT
@@ skipping 982 matching lines @@
 bool DatagramSocket::IsClosed() {
   return IsClosing() && !HasPendingRead() && !HasPendingWrite();
 }
 
 
 void DatagramSocket::DoClose() {
   // Just close the socket. This will cause any queued requests to be aborted.
   closesocket(socket());
   MarkClosedRead();
   MarkClosedWrite();
+  handle_ = INVALID_HANDLE_VALUE;
 }
 
 
 void EventHandlerImplementation::HandleInterrupt(InterruptMessage* msg) {
   ASSERT(this != NULL);
   if (msg->id == kTimeoutId) {
     // Change of timeout request. Just set the new timeout and port as the
     // completion thread will use the new timeout value for its next wait.
     timeout_queue_.UpdateTimeout(msg->dart_port, msg->data);
   } else if (msg->id == kShutdownId) {
@@ skipping 351 matching lines @@
 
 
 void EventHandlerImplementation::Shutdown() {
   SendData(kShutdownId, 0, 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)