Add support for cloning server-sockets.

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 820 matching lines @@
       }
     }
     if (!isListening) {
       tokens++;
       returnTokens();
     }
   }
 
   void returnTokens() {
     if (eventPort != null && !isClosing && !isClosed) {
-      if (tokens == 8) {
-        // Return in batches of 8.
+      if (tokens == 2) {

[Søren Gjesse, 2014/04/25 12:24:44]

Please add a constant for this.

[Anders Johnsen, 2014/05/01 11:34:50]

Done.

+        // Return in batches of 2.
         assert(tokens < (1 << FIRST_COMMAND));
         sendToEventHandler((1 << RETURN_TOKEN_COMMAND) | tokens);
         tokens = 0;
       }
     }
   }
 
   void setHandlers({read, write, error, closed, destroyed}) {
     eventHandlers[READ_EVENT] = read;
     eventHandlers[WRITE_EVENT] = write;
@@ skipping 193 matching lines @@
       native "Socket_SendTo";
   nativeCreateConnect(List<int> addr,
                       int port) native "Socket_CreateConnect";
   nativeCreateBindListen(List<int> addr, int port, int backlog, bool v6Only)
       native "ServerSocket_CreateBindListen";
   nativeCreateBindDatagram(List<int> addr, int port, bool reuseAddress)
       native "Socket_CreateBindDatagram";
   nativeAccept(_NativeSocket socket) native "ServerSocket_Accept";
   int nativeGetPort() native "Socket_GetPort";
   List nativeGetRemotePeer() native "Socket_GetRemotePeer";
+  int nativeGetSocketId() native "Socket_GetSocketId";
   OSError nativeGetError() native "Socket_GetError";
   nativeGetOption(int option, int protocol) native "Socket_GetOption";
   bool nativeSetOption(int option, int protocol, value)
       native "Socket_SetOption";
   bool nativeJoinMulticast(
       List<int> addr, List<int> interfaceAddr, int interfaceIndex)
           native "Socket_JoinMulticast";
   bool nativeLeaveMulticast(
       List<int> addr, List<int> interfaceAddr, int interfaceIndex)
       native "Socket_LeaveMulticast";
@@ skipping 74 matching lines @@
     }
   }
 
   void _onPauseStateChange() {
     if (_controller.isPaused) {
       _pause();
     } else {
       _resume();
     }
   }
+
+  RawServerSocketHandle clone() {
+    var port = new ReceivePort();
+    port.first.then((sendPort) {
+      sendPort.send(
+        [_socket.nativeGetSocketId(),
+         _socket.address,
+         _socket.localPort]);
+      port.close();
+    });
+    return new _RawServerSocketHandle(port.sendPort);
+  }
 }
 
 
+class _RawServerSocketHandle implements RawServerSocketHandle {
+  final SendPort _sendPort;
+
+  _RawServerSocketHandle(this._sendPort);
+
+  Future<RawServerSocket> acquire() {
+    var port = new ReceivePort();
+    _sendPort.send(port.sendPort);
+    return port.first.then((args) {
+      port.close();
+      var native = new _NativeSocket.listen();
+      native.nativeSetSocketId(args[0]);
+      native.address = args[1];
+      native.localPort = args[2];
+      return new _RawServerSocket(native);
+    });
+  }
+}
+
+
 class _RawSocket extends Stream<RawSocketEvent>
                  implements RawSocket {
   final _NativeSocket _socket;
   StreamController<RawSocketEvent> _controller;
   bool _readEventsEnabled = true;
   bool _writeEventsEnabled = true;
 
   // Flag to handle Ctrl-D closing of stdio on Mac OS.
   bool _isMacOSTerminalInput = false;
 
@@ skipping 137 matching lines @@
 
 patch class ServerSocket {
   /* patch */ static Future<ServerSocket> bind(address,
                                                int port,
                                                {int backlog: 0,
                                                 bool v6Only: false}) {
     return _ServerSocket.bind(address, port, backlog, v6Only);
   }
 }
 
+
+class _ServerSocketHandle implements ServerSocketHandle {
+  final RawServerSocketHandle _rawHandle;
+
+  _ServerSocketHandle(this._rawHandle);
+
+  Future<ServerSocket> acquire() {
+    return _rawHandle.acquire().then((raw) => new _ServerSocket(raw));
+  }
+}
+
+
 class _ServerSocket extends Stream<Socket>
                     implements ServerSocket {
   final _socket;
 
   static Future<_ServerSocket> bind(address,
                                     int port,
                                     int backlog,
                                     bool v6Only) {
     return _RawServerSocket.bind(address, port, backlog, v6Only)
         .then((socket) => new _ServerSocket(socket));
@@ skipping 10 matching lines @@
         onError: onError,
         onDone: onDone,
         cancelOnError: cancelOnError);
   }
 
   int get port => _socket.port;
 
   InternetAddress get address => _socket.address;
 
   Future close() => _socket.close().then((_) => this);
+
+  ServerSocketHandle clone() {
+    return new _ServerSocketHandle(_socket.clone());
+  }
 }
 
 
 patch class Socket {
   /* patch */ static Future<Socket> connect(host, int port) {
     return RawSocket.connect(host, port).then(
         (socket) => new _Socket(socket));
   }
 }
 
@@ skipping 430 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();