Keep track of when a socket has been destroyed

runtime/bin/eventhandler_macos.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 "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 220 matching lines @@
         sd->ShutdownWrite();
         UpdateKqueue(kqueue_fd_, sd);
       } else if ((msg.data & (1 << kCloseCommand)) != 0) {
         ASSERT(msg.data == (1 << kCloseCommand));
         // Close the socket and free system resources.
         RemoveFromKqueue(kqueue_fd_, sd);
         intptr_t fd = sd->fd();
         sd->Close();
         socket_map_.Remove(GetHashmapKeyFromFd(fd), GetHashmapHashFromFd(fd));
         delete sd;
+        DartUtils::PostInt32(msg.dart_port, 1 << kDestroyedEvent);
       } else {
         if ((msg.data & (1 << kInEvent)) != 0 && sd->IsClosedRead()) {
           DartUtils::PostInt32(msg.dart_port, 1 << kCloseEvent);
         } else {
           // Setup events to wait for.
           sd->SetPortAndMask(msg.dart_port, msg.data);
           UpdateKqueue(kqueue_fd_, sd);
         }
       }
     }
@@ skipping 184 matching lines @@
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)