mcs/class/System.ServiceModel/System.ServiceModel.Dispatcher/ChannelDispatcher.cs

   1 //
   2 // ChannelDispatcher.cs
   3 //
   4 // Author:
   5 //      Atsushi Enomoto <atsushi@ximian.com>
   6 //
   7 // Copyright (C) 2005,2009 Novell, Inc.  http://www.novell.com
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28 using System;
  29 using System.Collections.Generic;
  30 using System.Collections.ObjectModel;
  31 using System.Reflection;
  32 using System.ServiceModel.Channels;
  33 using System.Threading;
  34 using System.Transactions;
  35 using System.ServiceModel;
  36 using System.ServiceModel.Description;
  37
  38 namespace System.ServiceModel.Dispatcher
  39 {
  40         public class ChannelDispatcher : ChannelDispatcherBase
  41         {
  42                 class EndpointDispatcherCollection : SynchronizedCollection<EndpointDispatcher>
  43                 {
  44                         public EndpointDispatcherCollection (ChannelDispatcher owner)
  45                         {
  46                                 this.owner = owner;
  47                         }
  48
  49                         ChannelDispatcher owner;
  50
  51                         protected override void ClearItems ()
  52                         {
  53                                 foreach (var ed in this)
  54                                         ed.ChannelDispatcher = null;
  55                                 base.ClearItems ();
  56                         }
  57
  58                         protected override void InsertItem (int index, EndpointDispatcher item)
  59                         {
  60                                 item.ChannelDispatcher = owner;
  61                                 base.InsertItem (index, item);
  62                         }
  63
  64                         protected override void RemoveItem (int index)
  65                         {
  66                                 if (index < Count)
  67                                         this [index].ChannelDispatcher = null;
  68                                 base.RemoveItem (index);
  69                         }
  70
  71                         protected override void SetItem (int index, EndpointDispatcher item)
  72                         {
  73                                 item.ChannelDispatcher = owner;
  74                                 base.SetItem (index, item);
  75                         }
  76                 }
  77
  78                 ServiceHostBase host;
  79
  80                 string binding_name;
  81                 Collection<IErrorHandler> error_handlers
  82                         = new Collection<IErrorHandler> ();
  83                 IChannelListener listener;
  84                 internal IDefaultCommunicationTimeouts timeouts; // FIXME: remove internal
  85                 MessageVersion message_version;
  86                 bool receive_sync, include_exception_detail_in_faults,
  87                         manual_addressing, is_tx_receive;
  88                 int max_tx_batch_size;
  89                 SynchronizedCollection<IChannelInitializer> initializers
  90                         = new SynchronizedCollection<IChannelInitializer> ();
  91                 IsolationLevel tx_isolation_level;
  92                 TimeSpan tx_timeout;
  93                 ServiceThrottle throttle;
  94
  95                 Guid identifier = Guid.NewGuid ();
  96                 ManualResetEvent async_event = new ManualResetEvent (false);
  97
  98                 ListenerLoopManager loop_manager;
  99                 SynchronizedCollection<EndpointDispatcher> endpoints;
 100
 101                 [MonoTODO ("get binding info from config")]
 102                 public ChannelDispatcher (IChannelListener listener)
 103                         : this (listener, null)
 104                 {
 105                 }
 106
 107                 public ChannelDispatcher (
 108                         IChannelListener listener, string bindingName)
 109                         : this (listener, bindingName, null)
 110                 {
 111                 }
 112
 113                 public ChannelDispatcher (
 114                         IChannelListener listener, string bindingName,
 115                         IDefaultCommunicationTimeouts timeouts)
 116                 {
 117                         if (listener == null)
 118                                 throw new ArgumentNullException ("listener");
 119                         Init (listener, bindingName, timeouts);
 120                 }
 121
 122                 private void Init (IChannelListener listener, string bindingName,
 123                         IDefaultCommunicationTimeouts timeouts)
 124                 {
 125                         this.listener = listener;
 126                         this.binding_name = bindingName;
 127                         // IChannelListener is often a ChannelListenerBase
 128                         // which implements IDefaultCommunicationTimeouts.
 129                         this.timeouts = timeouts ?? listener as IDefaultCommunicationTimeouts ?? DefaultCommunicationTimeouts.Instance;
 130                         endpoints = new EndpointDispatcherCollection (this);
 131                 }
 132
 133                 internal void InitializeServiceEndpoint (Type serviceType, ServiceEndpoint se)
 134                 {
 135                         this.MessageVersion = se.Binding.MessageVersion;
 136                         if (this.MessageVersion == null)
 137                                 this.MessageVersion = MessageVersion.Default;
 138
 139                         //Attach one EndpointDispacher to the ChannelDispatcher
 140                         EndpointDispatcher ed = new EndpointDispatcher (se.Address, se.Contract.Name, se.Contract.Namespace);
 141                         this.Endpoints.Add (ed);
 142                         ed.InitializeServiceEndpoint (false, serviceType, se);
 143                 }
 144
 145                 public string BindingName {
 146                         get { return binding_name; }
 147                 }
 148
 149                 public SynchronizedCollection<IChannelInitializer> ChannelInitializers {
 150                         get { return initializers; }
 151                 }
 152
 153                 protected internal override TimeSpan DefaultCloseTimeout {
 154                         get { return timeouts.CloseTimeout; }
 155                 }
 156
 157                 protected internal override TimeSpan DefaultOpenTimeout {
 158                         get { return timeouts.OpenTimeout; }
 159                 }
 160
 161                 public Collection<IErrorHandler> ErrorHandlers {
 162                         get { return error_handlers; }
 163                 }
 164
 165                 public SynchronizedCollection<EndpointDispatcher> Endpoints {
 166                         get { return endpoints; }
 167                 }
 168
 169                 [MonoTODO]
 170                 public bool IsTransactedAccept {
 171                         get { throw new NotImplementedException (); }
 172                 }
 173
 174                 public bool IsTransactedReceive {
 175                         get { return is_tx_receive; }
 176                         set { is_tx_receive = value; }
 177                 }
 178
 179                 public bool ManualAddressing {
 180                         get { return manual_addressing; }
 181                         set { manual_addressing = value; }
 182                 }
 183
 184                 public int MaxTransactedBatchSize {
 185                         get { return max_tx_batch_size; }
 186                         set { max_tx_batch_size = value; }
 187                 }
 188
 189                 public override ServiceHostBase Host {
 190                         get { return host; }
 191                 }
 192
 193                 public override IChannelListener Listener {
 194                         get { return listener; }
 195                 }
 196
 197                 public MessageVersion MessageVersion {
 198                         get { return message_version; }
 199                         set { message_version = value; }
 200                 }
 201
 202                 public bool ReceiveSynchronously {
 203                         get { return receive_sync; }
 204                         set {
 205                                 ThrowIfDisposedOrImmutable ();
 206                                 receive_sync = value;
 207                         }
 208                 }
 209
 210                 public bool IncludeExceptionDetailInFaults {
 211                         get { return include_exception_detail_in_faults; }
 212                         set { include_exception_detail_in_faults = value; }
 213                 }
 214
 215                 public ServiceThrottle ServiceThrottle {
 216                         get { return throttle; }
 217                         set { throttle = value; }
 218                 }
 219
 220                 public IsolationLevel TransactionIsolationLevel {
 221                         get { return tx_isolation_level; }
 222                         set { tx_isolation_level = value; }
 223                 }
 224
 225                 public TimeSpan TransactionTimeout {
 226                         get { return tx_timeout; }
 227                         set { tx_timeout = value; }
 228                 }
 229
 230                 protected internal override void Attach (ServiceHostBase host)
 231                 {
 232                         this.host = host;
 233                 }
 234
 235                 public override void CloseInput ()
 236                 {
 237                         if (loop_manager != null)
 238                                 loop_manager.CloseInput ();
 239                 }
 240
 241                 protected internal override void Detach (ServiceHostBase host)
 242                 {
 243                         this.host = null;
 244                 }
 245
 246                 protected override void OnAbort ()
 247                 {
 248                         if (loop_manager != null)
 249                                 loop_manager.Stop (TimeSpan.FromTicks (1));
 250                 }
 251
 252                 Action<TimeSpan> open_delegate;
 253                 Action<TimeSpan> close_delegate;
 254
 255                 protected override IAsyncResult OnBeginClose (TimeSpan timeout,
 256                         AsyncCallback callback, object state)
 257                 {
 258                         if (close_delegate == null)
 259                                 close_delegate = new Action<TimeSpan> (OnClose);
 260                         return close_delegate.BeginInvoke (timeout, callback, state);
 261                 }
 262
 263                 protected override IAsyncResult OnBeginOpen (TimeSpan timeout,
 264                         AsyncCallback callback, object state)
 265                 {
 266                         if (open_delegate == null)
 267                                 open_delegate = new Action<TimeSpan> (OnClose);
 268                         return open_delegate.BeginInvoke (timeout, callback, state);
 269                 }
 270
 271                 protected override void OnClose (TimeSpan timeout)
 272                 {
 273                         if (loop_manager != null)
 274                                 loop_manager.Stop (timeout);
 275                 }
 276
 277                 protected override void OnClosed ()
 278                 {
 279                         if (host != null)
 280                                 host.ChannelDispatchers.Remove (this);
 281                         base.OnClosed ();
 282                 }
 283
 284                 protected override void OnEndClose (IAsyncResult result)
 285                 {
 286                         close_delegate.EndInvoke (result);
 287                 }
 288
 289                 protected override void OnEndOpen (IAsyncResult result)
 290                 {
 291                         open_delegate.EndInvoke (result);
 292                 }
 293
 294                 protected override void OnOpen (TimeSpan timeout)
 295                 {
 296                         if (Host == null || MessageVersion == null)
 297                                 throw new InvalidOperationException ("Service host is not attached to this ChannelDispatcher.");
 298
 299                         loop_manager.Setup (timeout);
 300                 }
 301
 302                 protected override void OnOpening ()
 303                 {
 304                         base.OnOpening ();
 305                         loop_manager = new ListenerLoopManager (this);
 306                 }
 307
 308                 protected override void OnOpened ()
 309                 {
 310                         base.OnOpened ();
 311                         StartLoop ();
 312                 }
 313
 314                 void StartLoop ()
 315                 {
 316                         // FIXME: not sure if it should be filled here.
 317                         if (ServiceThrottle == null)
 318                                 ServiceThrottle = new ServiceThrottle ();
 319
 320                         loop_manager.Start ();
 321                 }
 322         }
 323
 324                 // isolated from ChannelDispatcher
 325                 class ListenerLoopManager
 326                 {
 327                         ChannelDispatcher owner;
 328                         AutoResetEvent throttle_wait_handle = new AutoResetEvent (false);
 329                         AutoResetEvent creator_handle = new AutoResetEvent (false);
 330                         ManualResetEvent stop_handle = new ManualResetEvent (false);
 331                         bool loop;
 332                         Thread loop_thread;
 333                         DateTime close_started;
 334                         TimeSpan close_timeout;
 335                         Func<IAsyncResult> channel_acceptor;
 336                         List<IChannel> channels = new List<IChannel> ();
 337
 338                         public ListenerLoopManager (ChannelDispatcher owner)
 339                         {
 340                                 this.owner = owner;
 341                         }
 342
 343                         public void Setup (TimeSpan openTimeout)
 344                         {
 345                                 if (owner.Listener.State != CommunicationState.Opened)
 346                                         owner.Listener.Open (openTimeout);
 347
 348                                 // It is tested at Open(), but strangely it is not instantiated at this point.
 349                                 foreach (var ed in owner.Endpoints)
 350                                         if (ed.DispatchRuntime.InstanceContextProvider == null && (ed.DispatchRuntime.Type == null || ed.DispatchRuntime.Type.GetConstructor (Type.EmptyTypes) == null))
 351                                                 throw new InvalidOperationException ("There is no default constructor for the service Type in the DispatchRuntime");
 352                                 SetupChannelAcceptor ();
 353                         }
 354
 355                         public void Start ()
 356                         {
 357                                 foreach (var ed in owner.Endpoints)
 358                                         if (ed.DispatchRuntime.InstanceContextProvider == null)
 359                                                 ed.DispatchRuntime.InstanceContextProvider = new DefaultInstanceContextProvider ();
 360
 361                                 if (loop_thread == null)
 362                                         loop_thread = new Thread (new ThreadStart (Loop));
 363                                 loop_thread.Start ();
 364                         }
 365
 366                         Func<IAsyncResult> CreateAcceptor<TChannel> (IChannelListener l) where TChannel : class, IChannel
 367                         {
 368                                 IChannelListener<TChannel> r = l as IChannelListener<TChannel>;
 369                                 if (r == null)
 370                                         return null;
 371                                 AsyncCallback callback = delegate (IAsyncResult result) {
 372                                         try {
 373                                                 ChannelAccepted (r.EndAcceptChannel (result));
 374                                         } catch (Exception ex) {
 375                                                 Console.WriteLine ("Exception during finishing channel acceptance.");
 376                                                 Console.WriteLine (ex);
 377                                         }
 378                                 };
 379                                 return delegate {
 380                                         try {
 381                                                 return r.BeginAcceptChannel (callback, null);
 382                                         } catch (Exception ex) {
 383                                                 Console.WriteLine ("Exception during accepting channel.");
 384                                                 Console.WriteLine (ex);
 385                                                 throw;
 386                                         }
 387                                 };
 388                         }
 389
 390                         void SetupChannelAcceptor ()
 391                         {
 392                                 var l = owner.Listener;
 393                                 channel_acceptor =
 394                                         CreateAcceptor<IReplyChannel> (l) ??
 395                                         CreateAcceptor<IReplySessionChannel> (l) ??
 396                                         CreateAcceptor<IInputChannel> (l) ??
 397                                         CreateAcceptor<IInputSessionChannel> (l) ??
 398                                         CreateAcceptor<IDuplexChannel> (l) ??
 399                                         CreateAcceptor<IDuplexSessionChannel> (l);
 400                                 if (channel_acceptor == null)
 401                                         throw new InvalidOperationException (String.Format ("Unrecognized channel listener type: {0}", l.GetType ()));
 402                         }
 403
 404                         public void Stop (TimeSpan timeout)
 405                         {
 406                                 if (loop_thread == null)
 407                                         return;
 408
 409                                 close_started = DateTime.Now;
 410                                 close_timeout = timeout;
 411                                 loop = false;
 412                                 creator_handle.Set ();
 413                                 throttle_wait_handle.Set (); // break primary loop
 414                                 if (stop_handle != null) {
 415                                         stop_handle.WaitOne (timeout > TimeSpan.Zero ? timeout : TimeSpan.FromTicks (1));
 416                                         stop_handle.Close ();
 417                                         stop_handle = null;
 418                                 }
 419                                 if (owner.Listener.State != CommunicationState.Closed)
 420                                         owner.Listener.Abort ();
 421                                 if (loop_thread != null && loop_thread.IsAlive)
 422                                         loop_thread.Abort ();
 423                                 loop_thread = null;
 424                         }
 425
 426                         public void CloseInput ()
 427                         {
 428                                 foreach (var ch in channels.ToArray ()) {
 429                                         if (ch.State == CommunicationState.Closed)
 430                                                 channels.Remove (ch); // zonbie, if exists
 431                                         else {
 432                                                 try {
 433                                                         ch.Close (close_timeout - (DateTime.Now - close_started));
 434                                                 } catch (Exception ex) {
 435                                                         // FIXME: log it.
 436                                                         Console.WriteLine (ex);
 437                                                         ch.Abort ();
 438                                                 }
 439                                         }
 440                                 }
 441                         }
 442
 443                         void Loop ()
 444                         {
 445                                 try {
 446                                         LoopCore ();
 447                                 } catch (Exception ex) {
 448                                         // FIXME: log it
 449                                         Console.WriteLine ("ChannelDispatcher caught an exception inside dispatcher loop, which is likely thrown by the channel listener {0}", owner.Listener);
 450                                         Console.WriteLine (ex);
 451                                 } finally {
 452                                         if (stop_handle != null)
 453                                                 stop_handle.Set ();
 454                                 }
 455                         }
 456
 457                         void LoopCore ()
 458                         {
 459                                 loop = true;
 460
 461                                 // FIXME: use WaitForChannel() for (*only* for) transacted channel listeners.
 462                                 // http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/3faa4a5e-8602-4dbe-a181-73b3f581835e
 463
 464                                 //FIXME: The logic here should be somewhat different as follows:
 465                                 //1. Get the message
 466                                 //2. Get the appropriate EndPointDispatcher that can handle the message
 467                                 //   which is done using the filters (AddressFilter, ContractFilter).
 468                                 //3. Let the appropriate endpoint handle the request.
 469
 470                                 while (loop) {
 471                                         while (loop && channels.Count < owner.ServiceThrottle.MaxConcurrentSessions) {
 472                                                 channel_acceptor ();
 473                                                 creator_handle.WaitOne (); // released by ChannelAccepted()
 474                                         }
 475                                         if (!loop)
 476                                                 break;
 477                                         throttle_wait_handle.WaitOne (); // released by IChannel.Close()
 478                                 }
 479                                 try {
 480                                         owner.Listener.Close ();
 481                                 } finally {
 482                                         // make sure to close both listener and channels.
 483                                         owner.CloseInput ();
 484                                 }
 485                         }
 486
 487                         void ChannelAccepted (IChannel ch)
 488                         {
 489                         try {
 490                                 if (ch == null) // could happen when it was aborted
 491                                         return;
 492                                 if (!loop) {
 493                                         var dis = ch as IDisposable;
 494                                         if (dis != null)
 495                                                 dis.Dispose ();
 496                                         return;
 497                                 }
 498
 499                                 channels.Add (ch);
 500                                 ch.Opened += delegate {
 501                                         ch.Faulted += delegate {
 502                                                 if (channels.Contains (ch))
 503                                                         channels.Remove (ch);
 504                                                 throttle_wait_handle.Set (); // release loop wait lock.
 505                                                 };
 506                                         ch.Closed += delegate {
 507                                                 if (channels.Contains (ch))
 508                                                         channels.Remove (ch);
 509                                                 throttle_wait_handle.Set (); // release loop wait lock.
 510                                                 };
 511                                         };
 512                                 ch.Open ();
 513                         } finally {
 514                                 creator_handle.Set ();
 515                         }
 516
 517                                 ProcessRequestOrInput (ch);
 518                         }
 519
 520                         void ProcessRequestOrInput (IChannel ch)
 521                         {
 522                                 var reply = ch as IReplyChannel;
 523                                 var input = ch as IInputChannel;
 524
 525                                 if (reply != null) {
 526                                         if (owner.ReceiveSynchronously) {
 527                                                 RequestContext rc;
 528                                                 if (reply.TryReceiveRequest (owner.timeouts.ReceiveTimeout, out rc))
 529                                                         ProcessRequest (reply, rc);
 530                                         } else {
 531                                                 reply.BeginTryReceiveRequest (owner.timeouts.ReceiveTimeout, TryReceiveRequestDone, reply);
 532                                         }
 533                                 } else if (input != null) {
 534                                         if (owner.ReceiveSynchronously) {
 535                                                 Message msg;
 536                                                 if (input.TryReceive (owner.timeouts.ReceiveTimeout, out msg))
 537                                                         ProcessInput (input, msg);
 538                                         } else {
 539                                                 input.BeginTryReceive (owner.timeouts.ReceiveTimeout, TryReceiveDone, input);
 540                                         }
 541                                 }
 542                         }
 543
 544                         void TryReceiveRequestDone (IAsyncResult result)
 545                         {
 546                                 RequestContext rc;
 547                                 var reply = (IReplyChannel) result.AsyncState;
 548                                 if (reply.EndTryReceiveRequest (result, out rc))
 549                                         ProcessRequest (reply, rc);
 550                         }
 551
 552                         void TryReceiveDone (IAsyncResult result)
 553                         {
 554                                 Message msg;
 555                                 var input = (IInputChannel) result.AsyncState;
 556                                 if (input.EndTryReceive (result, out msg))
 557                                         ProcessInput (input, msg);
 558                         }
 559
 560                         void SendEndpointNotFound (RequestContext rc, EndpointNotFoundException ex)
 561                         {
 562                                 try {
 563
 564                                         MessageVersion version = rc.RequestMessage.Version;
 565                                         FaultCode fc = new FaultCode ("DestinationUnreachable", version.Addressing.Namespace);
 566                                         Message res = Message.CreateMessage (version, fc, "error occured", rc.RequestMessage.Headers.Action);
 567                                         rc.Reply (res);
 568                                 } catch (Exception e) {
 569                                         // FIXME: log it
 570                                         Console.WriteLine ("Error on sending DestinationUnreachable fault message: " + e);
 571                                 }
 572                         }
 573
 574                         void ProcessRequest (IReplyChannel reply, RequestContext rc)
 575                         {
 576                                 try {
 577                                         EndpointDispatcher candidate = FindEndpointDispatcher (rc.RequestMessage);
 578                                         new InputOrReplyRequestProcessor (candidate.DispatchRuntime, reply).
 579                                                 ProcessReply (rc);
 580                                 } catch (EndpointNotFoundException ex) {
 581                                         SendEndpointNotFound (rc, ex);
 582                                 } catch (Exception ex) {
 583                                         // FIXME: log it.
 584                                         Console.WriteLine (ex);
 585                                 } finally {
 586                                         if (rc != null)
 587                                                 rc.Close ();
 588                                         // unless it is closed by session/call manager, move it back to the loop to receive the next message.
 589                                         if (reply.State != CommunicationState.Closed)
 590                                                 ProcessRequestOrInput (reply);
 591                                 }
 592                         }
 593
 594                         void ProcessInput (IInputChannel input, Message message)
 595                         {
 596                                 try {
 597                                         EndpointDispatcher candidate = null;
 598                                         candidate = FindEndpointDispatcher (message);
 599                                         new InputOrReplyRequestProcessor (candidate.DispatchRuntime, input).
 600                                                 ProcessInput (message);
 601                                 }
 602                                 catch (Exception ex) {
 603                                         // FIXME: log it.
 604                                         Console.WriteLine (ex);
 605                                 } finally {
 606                                         // unless it is closed by session/call manager, move it back to the loop to receive the next message.
 607                                         if (input.State != CommunicationState.Closed)
 608                                                 ProcessRequestOrInput (input);
 609                                 }
 610                         }
 611
 612                         EndpointDispatcher FindEndpointDispatcher (Message message) {
 613                                 EndpointDispatcher candidate = null;
 614                                 for (int i = 0; i < owner.Endpoints.Count; i++) {
 615                                         if (MessageMatchesEndpointDispatcher (message, owner.Endpoints [i])) {
 616                                                 var newdis = owner.Endpoints [i];
 617                                                 if (candidate == null || candidate.FilterPriority < newdis.FilterPriority)
 618                                                         candidate = newdis;
 619                                                 else if (candidate.FilterPriority == newdis.FilterPriority)
 620                                                         throw new MultipleFilterMatchesException ();
 621                                         }
 622                                 }
 623                                 if (candidate == null && owner.Host != null)
 624                                         owner.Host.OnUnknownMessageReceived (message);
 625                                 return candidate;
 626                         }
 627
 628                         bool MessageMatchesEndpointDispatcher (Message req, EndpointDispatcher endpoint)
 629                         {
 630                                 Uri to = req.Headers.To;
 631                                 if (to == null)
 632                                         return false;
 633                                 if (to.AbsoluteUri == Constants.WsaAnonymousUri)
 634                                         return false;
 635                                 return endpoint.AddressFilter.Match (req) && endpoint.ContractFilter.Match (req);
 636                         }
 637                 }
 638 }