Very simple version of Isolates.

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 188 matching lines @@
   // Socket close state
   bool isClosed = false;
   bool isClosing = false;
   bool isClosedRead = false;
   bool isClosedWrite = false;
   Completer closeCompleter = new Completer();
 
   // Handlers and receive port for socket events from the event handler.
   int eventMask = 0;
   List eventHandlers;
-  ReceivePort eventPort;
+  RawReceivePort eventPort;
 
   // Indicates if native interrupts can be activated.
   bool canActivateEvents = true;
 
   // The type flags for this socket.
   final int typeFlags;
 
   // Holds the port of the socket, null if not known.
   int localPort;
 
@@ skipping 361 matching lines @@
   }
 
   void sendToEventHandler(int data) {
     connectToEventHandler();
     assert(!isClosed);
     _EventHandler._sendData(this, eventPort, data);
   }
 
   void connectToEventHandler() {
     if (eventPort == null) {
-      eventPort = new ReceivePort();
-      eventPort.receive ((var message, _) => multiplex(message));
+      eventPort = new RawReceivePort(multiplex);
     }
   }
 
   void disconnectFromEventHandler() {
     if (eventPort != null) {
       eventPort.close();
       eventPort = null;
     }
   }
 
@@ skipping 612 matching lines @@
     if (_detachReady != null) {
       _detachReady.complete(null);
     } else {
       if (_raw != null) {
         _raw.shutdown(SocketDirection.SEND);
         _disableWriteEvent();
       }
     }
   }
 }