Keep track of when a socket has been destroyed

sdk/lib/io/socket.dart

 // 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.
 
 part of dart.io;
 
 
 /**
  * [InternetAddressType] is the type an [InternetAddress]. Currently,
  * IP version 4 (IPv4) and IP version 6 (IPv6) are supported.
@@ skipping 239 matching lines @@
                                             int port,
                                             {int backlog: 0,
                                              bool v6Only: false});
 
   /**
    * Returns the port used by this socket.
    */
   int get port;
 
   /**
-   * Closes the socket.
+   * Closes the socket. The returned future completes when the socket
+   * is fully closed and is no longer bound.
    */
-  void close();
+  Future close();
 }
 
 /**
  * The [SocketDirection] is used as a parameter to [Socket.close] and
  * [RawSocket.close] to close a socket in the specified direction(s).
  */
 class SocketDirection {
   static const SocketDirection RECEIVE = const SocketDirection._(0);
   static const SocketDirection SEND = const SocketDirection._(1);
   static const SocketDirection BOTH = const SocketDirection._(2);
@@ skipping 20 matching lines @@
   final _value;
 }
 
 /**
  * Events for the [RawSocket].
  */
 class RawSocketEvent {
   static const RawSocketEvent READ = const RawSocketEvent._(0);
   static const RawSocketEvent WRITE = const RawSocketEvent._(1);
   static const RawSocketEvent READ_CLOSED = const RawSocketEvent._(2);
+  static const RawSocketEvent CLOSED = const RawSocketEvent._(3);
   const RawSocketEvent._(this._value);
   final int _value;
   String toString() {
     return ['RawSocketEvent:READ',
             'RawSocketEvent:WRITE',
-            'RawSocketEvent:READ_CLOSED'][_value];
+            'RawSocketEvent:READ_CLOSED',
+            'RawSocketEvent:CLOSED'][_value];
   }
 }
 
 /**
  * The [RawSocket] is a low-level interface to a socket, exposing the raw
  * events signaled by the system. It's a [Stream] of [RawSocketEvent]s.
  */
 abstract class RawSocket implements Stream<RawSocketEvent> {
   /**
    * Creates a new socket connection to the host and port and returns a [Future]
@@ skipping 175 matching lines @@
       } else {
         sb.write(", address = ${address.address}");
       }
     }
     if (port != null) {
       sb.write(", port = $port");
     }
     return sb.toString();
   }
 }