Fix wrong pointer arithmetic when extending the file descripter list in the eventhandler

runtime/tests/dart/src/SocketManyConnectionsTest.dart

+// Copyright (c) 2011, 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.
+//
+// Test creating a large number of socket connections.
+
+final SERVERINIT = 0;
+final SERVERSHUTDOWN = -1;
+final CONNECTIONS = 200;
+final HOST = "127.0.0.1";
+
+class SocketManyConnectionsTest {
+
+  SocketManyConnectionsTest.start()
+      : _receivePort = new ReceivePort(),
+        _sendPort = null,
+        _connections = 0,
+        _sockets = new List<Socket>(CONNECTIONS) {
+    new TestServer().spawn().then((SendPort port) {
+      _sendPort = port;
+      start();
+    });
+  }
+
+  void run() {
+
+    void connectHandler() {
+      _connections++;
+      if (_connections == CONNECTIONS) {
+        for (int i = 0; i < CONNECTIONS; i++) {
+          _sockets[i].close();
+        }
+        shutdown();
+      }
+    }
+
+    for (int i = 0; i < CONNECTIONS; i++) {
+      _sockets[i] = new Socket(HOST, _port);
+      if (_sockets[i] !== null) {
+        _sockets[i].setConnectHandler(connectHandler);
+      } else {
+        Expect.fail("socket creation failed");
+      }
+    }
+  }
+
+  void start() {
+    _receivePort.receive((var message, SendPort replyTo) {
+      _port = message;
+      run();
+    });
+    _sendPort.send(SERVERINIT, _receivePort.toSendPort());
+  }
+
+  void shutdown() {
+    _sendPort.send(SERVERSHUTDOWN, _receivePort.toSendPort());
+    _receivePort.close();
+  }
+
+  int _port;
+  ReceivePort _receivePort;
+  SendPort _sendPort;
+  List<Socket> _sockets;
+  int _connections;
+}
+
+class TestServer extends Isolate {
+
+  void main() {
+
+    void connectionHandler() {
+      Socket _client;
+
+      void closeHandler() {
+        _client.close();
+      }
+
+      void errorHandler() {
+        print("Socket error");
+        _client.close();
+      }
+
+      _client = _server.accept();
+      _connections++;
+      _client.setCloseHandler(closeHandler);
+      _client.setErrorHandler(errorHandler);
+    }
+
+    void errorHandlerServer() {
+      print("Server socket error");
+      _server.close();
+    }
+
+    this.port.receive((message, SendPort replyTo) {
+      if (message == SERVERINIT) {
+        _server = new ServerSocket(HOST, 0, 10);
+        Expect.equals(true, _server !== null);
+        _server.setConnectionHandler(connectionHandler);
+        _server.setErrorHandler(errorHandlerServer);
+        replyTo.send(_server.port, null);
+      } else if (message == SERVERSHUTDOWN) {
+        _server.close();
+        this.port.close();
+      }
+    });
+  }
+
+  ServerSocket _server;
+  int _connections = 0;
+}
+
+main() {
+  SocketManyConnectionsTest test = new SocketManyConnectionsTest.start();
+}