Start better error reporting for sockets

runtime/bin/http_impl.dart

 // Copyright (c) 2012, 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.
 
 class _HttpRequestResponseBase {
   _HttpRequestResponseBase(_HttpConnectionBase this._httpConnection)
       : _contentLength = -1,
         _keepAlive = false,
         _headers = new Map();
 
@@ skipping 491 matching lines @@
       // Client closed socket for writing. Socket should still be open
       // for writing the response.
       _closing = true;
     } else {
       // The connection is currently not used by any request just close it.
       _socket.close();
     }
     if (_onDisconnectCallback != null) _onDisconnectCallback();
   }
 
-  void _onError() {
+  void _onError(Exception e) {
     // If an error occours, treat the socket as closed.
     _onClosed();
     if (_onErrorCallback != null) {
-      _onErrorCallback("Connection closed while sending data to client.");
+      _onErrorCallback("Connection closed while sending data to client ($e).");
     }
   }
 
   void set onDisconnect(void callback()) {
     _onDisconnectCallback = callback;
   }
 
   void set onError(void callback(String errorMessage)) {
     _onErrorCallback = callback;
   }
@@ skipping 536 matching lines @@
     Queue socketConnections = _openSockets[_connectionKey(host, port)];
     if (socketConnections == null || socketConnections.isEmpty()) {
       Socket socket = new Socket(host, port);
       socket.onConnect = () {
         socket.onError = null;
         _SocketConnection socketConn =
             new _SocketConnection(host, port, socket);
         _activeSockets.add(socketConn);
         _connectionOpened(socketConn, connection);
       };
-      socket.onError = () {
+      socket.onError = (Exception e) {
         if (_onError !== null) {
           _onError(HttpStatus.NETWORK_CONNECT_TIMEOUT_ERROR);

[Mads Ager (google), 2012/03/14 12:51:51]

Do interpolation as above? Or doens't it make sense here?

[Søren Gjesse, 2012/03/19 10:05:43]

For some odd reason this onError currently takes a HttpStatus. This will be
changed in an upcoming change.

         }
       };
     } else {
       _SocketConnection socketConn = socketConnections.removeFirst();
       _activeSockets.add(socketConn);
       new Timer(0, (ignored) => _connectionOpened(socketConn, connection));
 
       // Get rid of eviction timer if there are no more active connections.
       if (socketConnections.isEmpty()) {
         _evictionTimer.cancel();
@@ skipping 52 matching lines @@
     _onError = callback;
   }
 
   Function _onOpen;
   Function _onError;
   Map<String, Queue<_SocketConnection>> _openSockets;
   Set<_SocketConnection> _activeSockets;
   Timer _evictionTimer;
   bool _shutdown;  // Has this HTTP client been shutdown?
 }