SIGQUIT toggles VM service HTTP server

runtime/bin/vmservice/server.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.
 
 part of vmservice_io;
 
 class WebSocketClient extends Client {
   static const int PARSE_ERROR_CODE = 4000;
   static const int BINARY_MESSAGE_ERROR_CODE = 4001;
   static const int NOT_MAP_ERROR_CODE = 4002;
@@ skipping 62 matching lines @@
   dynamic toJson() {
     Map map = super.toJson();
     map['type'] = 'HttpRequestClient';
     map['request'] = '$request';
     return map;
   }
 }
 
 class Server {
   static const WEBSOCKET_PATH = '/ws';
-  String defaultPath = '/index.html';
-  int port;
+  static const SLASH_PATH = '/index.html';
 
-  final VMService service;
+  final VMService _service;
+  final int _port;
+  bool _displayStatusMessages;
+
   HttpServer _server;
+  var _subscription;
 
-  Server(this.service, this.port);
+  bool get running => _server != null;
+
+  Server(this._service, int port) : _port = port,
+                                    _displayStatusMessages = (port == 0);
 
   void _requestHandler(HttpRequest request) {
     // Allow cross origin requests.
     request.response.headers.add('Access-Control-Allow-Origin', '*');
 
     final String path =
-          request.uri.path == '/' ? defaultPath : request.uri.path;
+          request.uri.path == '/' ? SLASH_PATH : request.uri.path;
 
     var resource = Resource.resources[path];
     if (resource != null) {
       // Serving up a static resource (e.g. .css, .html, .png).
       request.response.headers.contentType =
           ContentType.parse(resource.mimeType);
       request.response.add(resource.data);
       request.response.close();
       return;
     }
 
     if (path == WEBSOCKET_PATH) {
       WebSocketTransformer.upgrade(request).then((WebSocket webSocket) {
-        new WebSocketClient(webSocket, service);
+        new WebSocketClient(webSocket, _service);
       });
       return;
     }
 
     var message = new Message.fromUri(request.uri);
-    var client = new HttpRequestClient(request, service);
+    var client = new HttpRequestClient(request, _service);
     client.onMessage(null, message);
   }
 
-  Future startServer() {
-    return HttpServer.bind(InternetAddress.LOOPBACK_IP_V4, port).then((s) {
-      // Only display message when port is automatically selected.
-      var display_message = (port == 0);
-      // Retrieve port.
-      port = s.port;
+  Future startup() {
+    return HttpServer.bind(InternetAddress.LOOPBACK_IP_V4, _port).then((s) {
       _server = s;
-      _server.listen(_requestHandler);
-      if (display_message) {
-        print('VMService listening on port $port');
+      _subscription = _server.listen(_requestHandler);
+      if (_displayStatusMessages) {
+        print('VMService listening on port ${_server.port}');
       }
       return s;
     });
   }
+
+  void shutdown() {
+    // Force displaying of status messages if we are forcibly shutdown.
+    _displayStatusMessages = true;

[Ivan Posva, 2014/04/14 16:12:58]

Shouldn't the fact whether you are forced to shutdown be a parameter?

[Cutch, 2014/04/15 17:42:07]

Done.

+    // Shutdown HTTP server and subscription.
+    var closedPort = _server.port;
+    _server.close(force: true);
+    _server = null;
+    _subscription.cancel();
+    _subscription = null;
+    if (_displayStatusMessages) {
+      print('VMService is no longer listening on port $closedPort');
+    }
+  }
 }