Add Observatory test of io.

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 268 matching lines @@
   // Socket close state
   bool isClosed = false;
   bool isClosing = false;
   bool isClosedRead = false;
   bool isClosedWrite = false;
   Completer closeCompleter = new Completer.sync();
 
   // Handlers and receive port for socket events from the event handler.
   final List eventHandlers = new List(EVENT_COUNT + 1);
   RawReceivePort eventPort;
+  bool flagsSent = false;
 
   // The type flags for this socket.
   final int typeFlags;
 
   // Holds the port of the socket, 0 if not known.
   int localPort = 0;
 
   // Holds the address used to connect or bind the socket.
   InternetAddress address;
 
@@ skipping 151 matching lines @@
                                                      port,
                                                      backlog,
                                                      v6Only);
           if (result is OSError) {
             throw new SocketException("Failed to create server socket",
                                       osError: result,
                                       address: address,
                                       port: port);
           }
           if (port != 0) socket.localPort = port;
+          socket.connectToEventHandler();
           return socket;
         });
   }
 
   static Future<_NativeSocket> bindDatagram(
       host, int port, bool reuseAddress) {
     return new Future.value(host)
         .then((host) {
           if (host is _InternetAddress) return host;
           return lookup(host)
@@ skipping 282 matching lines @@
         }
       }
     }
     if (!isListening) {
       tokens++;
       returnTokens(NORMAL_TOKEN_BATCH_SIZE);
     }
   }
 
   void returnTokens(int tokenBatchSize) {
-    if (eventPort != null && !isClosing && !isClosed) {
+    if (!isClosing && !isClosed) {
+      assert(eventPort != null);
       // Return in batches.
       if (tokens == tokenBatchSize) {
         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;
     eventHandlers[ERROR_EVENT] = error;
     eventHandlers[CLOSED_EVENT] = closed;
     eventHandlers[DESTROYED_EVENT] = destroyed;
   }
 
   void setListening({read: true, write: true}) {
     sendReadEvents = read;
     sendWriteEvents = write;
     if (read) issueReadEvent();
     if (write) issueWriteEvent();
-    if (eventPort == null && !isClosing) {
+    if (!flagsSent && !isClosing) {
+      flagsSent = true;
       int flags = typeFlags & TYPE_TYPE_MASK;
       if (!isClosedRead) flags |= 1 << READ_EVENT;
       if (!isClosedWrite) flags |= 1 << WRITE_EVENT;
       sendToEventHandler(flags);
     }
   }
 
   Future close() {
     if (!isClosing && !isClosed) {
       sendToEventHandler(1 << CLOSE_COMMAND);
@@ skipping 1102 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();