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 226 matching lines @@
           // If stdout, redirect fd to /dev/null.
           int null_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_WRONLY));
           ASSERT(null_fd >= 0);
           VOID_TEMP_FAILURE_RETRY(dup2(null_fd, STDOUT_FILENO));
           VOID_TEMP_FAILURE_RETRY(close(null_fd));
         } else {
           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 187 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)