Version 1.3.4

dart/runtime/bin/socket_patch.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.
 
 patch class RawServerSocket {
   /* patch */ static Future<RawServerSocket> bind(address,
                                                   int port,
                                                   {int backlog: 0,
                                                    bool v6Only: false}) {
     return _RawServerSocket.bind(address, port, backlog, v6Only);
@@ skipping 1050 matching lines @@
                                        int port,
                                        int backlog,
                                        bool v6Only) {
     if (port < 0 || port > 0xFFFF)
       throw new ArgumentError("Invalid port $port");
     if (backlog < 0) throw new ArgumentError("Invalid backlog $backlog");
     return _NativeSocket.bind(address, port, backlog, v6Only)
         .then((socket) => new _RawServerSocket(socket));
   }
 
-  _RawServerSocket(this._socket) {
+  _RawServerSocket(this._socket);
+
+  StreamSubscription<RawSocket> listen(void onData(RawSocket event),
+                                       {Function onError,
+                                        void onDone(),
+                                        bool cancelOnError}) {
+    if (_controller != null) {
+      throw new StateError("Stream was already listened to");
+    }
     var zone = Zone.current;
     _controller = new StreamController(sync: true,
         onListen: _onSubscriptionStateChange,
         onCancel: _onSubscriptionStateChange,
         onPause: _onPauseStateChange,
         onResume: _onPauseStateChange);
     _socket.setHandlers(
       read: zone.bindCallback(() {
         do {
           var socket = _socket.accept();
           if (socket == null) return;
           _controller.add(new _RawSocket(socket));
         } while (!_controller.isPaused);
       }),
       error: zone.bindUnaryCallback((e) {
         _controller.addError(e);
         _controller.close();
       }),
-      destroyed: _controller.close
-    );
-  }
-
-  StreamSubscription<RawSocket> listen(void onData(RawSocket event),
-                                       {Function onError,
-                                        void onDone(),
-                                        bool cancelOnError}) {
+      destroyed: _controller.close);
     return _controller.stream.listen(
         onData,
         onError: onError,
         onDone: onDone,
         cancelOnError: cancelOnError);
   }
 
   int get port => _socket.port;
 
   InternetAddress get address => _socket.address;
@@ skipping 656 matching lines @@
                        String address,
                        List<int> in_addr,
                        int port) {
   return new Datagram(
       data,
       new _InternetAddress(address, null, in_addr),
       port);
 }
 
 String _socketsStats() => _SocketsObservatory.toJSON();