Put delivering of parsed http-requests at the end of the message-queue.

sdk/lib/io/http_impl.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 dart.io;
 
 const int _OUTGOING_BUFFER_SIZE = 8 * 1024;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
@@ skipping 2172 matching lines @@
 
   InternetAddress get address {
     if (closed) throw new HttpException("HttpServer is not bound to a socket");
     return _serverSocket.address;
   }
 
   set sessionTimeout(int timeout) {
     _sessionManager.sessionTimeout = timeout;
   }
 
-  void _handleRequest(HttpRequest request) => _controller.add(request);
+  void _handleRequest(_HttpRequest request) {
+    // Delay the request until the isolate's message-queue is handled.
+    // This greatly improves scheduling when a lot of requests are active.
+    Timer.run(() {
+      if (!closed) {
+        _controller.add(request);
+      } else {
+        request._httpConnection.destroy();
+      }
+    });
+  }
 
   void _handleError(error) {
     if (!closed) _controller.addError(error);
   }
 
   void _connectionClosed(_HttpConnection connection) {
     // Remove itself from either idle or active connections.
     connection.unlink();
     _maybePerformCleanup();
   }
@@ skipping 486 matching lines @@
   const _RedirectInfo(this.statusCode, this.method, this.location);
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }