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         internal interface IChannelDispatcherBoundListener
  41         {
  42                 ChannelDispatcher ChannelDispatcher { get; set; }
  43         }
  44
  45         public class ChannelDispatcher : ChannelDispatcherBase
  46         {
  47                 class EndpointDispatcherCollection : SynchronizedCollection<EndpointDispatcher>
  48                 {
  49                         public EndpointDispatcherCollection (ChannelDispatcher owner)
  50                         {
  51                                 this.owner = owner;
  52                         }
  53
  54                         ChannelDispatcher owner;
  55
  56                         protected override void ClearItems ()
  57                         {
  58                                 foreach (var ed in this)
  59                                         ed.ChannelDispatcher = null;
  60                                 base.ClearItems ();
  61                         }
  62
  63                         protected override void InsertItem (int index, EndpointDispatcher item)
  64                         {
  65                                 item.ChannelDispatcher = owner;
  66                                 base.InsertItem (index, item);
  67                         }
  68
  69                         protected override void RemoveItem (int index)
  70                         {
  71                                 if (index < Count)
  72                                         this [index].ChannelDispatcher = null;
  73                                 base.RemoveItem (index);
  74                         }
  75
  76                         protected override void SetItem (int index, EndpointDispatcher item)
  77                         {
  78                                 item.ChannelDispatcher = owner;
  79                                 base.SetItem (index, item);
  80                         }
  81                 }
  82
  83                 ServiceHostBase host;
  84
  85                 string binding_name;
  86                 Collection<IErrorHandler> error_handlers
  87                         = new Collection<IErrorHandler> ();
  88                 IChannelListener listener;
  89                 internal IDefaultCommunicationTimeouts timeouts; // FIXME: remove internal
  90                 MessageVersion message_version;
  91                 bool receive_sync, include_exception_detail_in_faults,
  92                         manual_addressing, is_tx_receive;
  93                 int max_tx_batch_size;
  94                 SynchronizedCollection<IChannelInitializer> initializers
  95                         = new SynchronizedCollection<IChannelInitializer> ();
  96                 IsolationLevel tx_isolation_level;
  97                 TimeSpan tx_timeout;
  98                 ServiceThrottle throttle;
  99
 100                 Guid identifier = Guid.NewGuid ();
 101                 ManualResetEvent async_event = new ManualResetEvent (false);
 102
 103                 ListenerLoopManager loop_manager;
 104                 SynchronizedCollection<EndpointDispatcher> endpoints;
 105
 106                 [MonoTODO ("get binding info from config")]
 107                 public ChannelDispatcher (IChannelListener listener)
 108                         : this (listener, null)
 109                 {
 110                 }
 111
 112                 public ChannelDispatcher (
 113                         IChannelListener listener, string bindingName)
 114                         : this (listener, bindingName, null)
 115                 {
 116                 }
 117
 118                 public ChannelDispatcher (
 119                         IChannelListener listener, string bindingName,
 120                         IDefaultCommunicationTimeouts timeouts)
 121                 {
 122                         if (listener == null)
 123                                 throw new ArgumentNullException ("listener");
 124                         Init (listener, bindingName, timeouts);
 125                 }
 126
 127                 private void Init (IChannelListener listener, string bindingName,
 128                         IDefaultCommunicationTimeouts timeouts)
 129                 {
 130                         this.listener = listener;
 131                         this.binding_name = bindingName;
 132                         // IChannelListener is often a ChannelListenerBase
 133                         // which implements IDefaultCommunicationTimeouts.
 134                         this.timeouts = timeouts ?? listener as IDefaultCommunicationTimeouts ?? DefaultCommunicationTimeouts.Instance;
 135                         endpoints = new EndpointDispatcherCollection (this);
 136                 }
 137
 138                 internal EndpointDispatcher InitializeServiceEndpoint (Type serviceType, ServiceEndpoint se)
 139                 {
 140                         //Attach one EndpointDispacher to the ChannelDispatcher
 141                         EndpointDispatcher ed = new EndpointDispatcher (se.Address, se.Contract.Name, se.Contract.Namespace);
 142                         this.Endpoints.Add (ed);
 143                         ed.InitializeServiceEndpoint (false, serviceType, se);
 144                         return ed;
 145                 }
 146
 147                 public string BindingName {
 148                         get { return binding_name; }
 149                 }
 150
 151                 public SynchronizedCollection<IChannelInitializer> ChannelInitializers {
 152                         get { return initializers; }
 153                 }
 154
 155                 protected internal override TimeSpan DefaultCloseTimeout {
 156                         get { return timeouts.CloseTimeout; }
 157                 }
 158
 159                 protected internal override TimeSpan DefaultOpenTimeout {
 160                         get { return timeouts.OpenTimeout; }
 161                 }
 162
 163                 public Collection<IErrorHandler> ErrorHandlers {
 164                         get { return error_handlers; }
 165                 }
 166
 167                 public SynchronizedCollection<EndpointDispatcher> Endpoints {
 168                         get { return endpoints; }
 169                 }
 170
 171                 [MonoTODO]
 172                 public bool IsTransactedAccept {
 173                         get { throw new NotImplementedException (); }
 174                 }
 175
 176                 public bool IsTransactedReceive {
 177                         get { return is_tx_receive; }
 178                         set { is_tx_receive = value; }
 179                 }
 180
 181                 public bool ManualAddressing {
 182                         get { return manual_addressing; }
 183                         set { manual_addressing = value; }
 184                 }
 185
 186                 public int MaxTransactedBatchSize {
 187                         get { return max_tx_batch_size; }
 188                         set { max_tx_batch_size = value; }
 189                 }
 190
 191                 public override ServiceHostBase Host {
 192                         get { return host; }
 193                 }
 194
 195                 public override IChannelListener Listener {
 196                         get { return listener; }
 197                 }
 198
 199                 public MessageVersion MessageVersion {
 200                         get { return message_version; }
 201                         set { message_version = value; }
 202                 }
 203
 204                 public bool ReceiveSynchronously {
 205                         get { return receive_sync; }
 206                         set {
 207                                 ThrowIfDisposedOrImmutable ();
 208                                 receive_sync = value;
 209                         }
 210                 }
 211
 212                 public bool IncludeExceptionDetailInFaults {
 213                         get { return include_exception_detail_in_faults; }
 214                         set { include_exception_detail_in_faults = value; }
 215                 }
 216
 217                 public ServiceThrottle ServiceThrottle {
 218                         get { return throttle; }
 219                         set { throttle = value; }
 220                 }
 221
 222                 public IsolationLevel TransactionIsolationLevel {
 223                         get { return tx_isolation_level; }
 224                         set { tx_isolation_level = value; }
 225                 }
 226
 227                 public TimeSpan TransactionTimeout {
 228                         get { return tx_timeout; }
 229                         set { tx_timeout = value; }
 230                 }
 231
 232                 protected internal override void Attach (ServiceHostBase host)
 233                 {
 234                         this.host = host;
 235                         var bl = listener as IChannelDispatcherBoundListener;
 236                         if (bl != null)
 237                                 bl.ChannelDispatcher = this;
 238                 }
 239
 240                 public override void CloseInput ()
 241                 {
 242                         if (loop_manager != null)
 243                                 loop_manager.CloseInput ();
 244                 }
 245
 246                 protected internal override void Detach (ServiceHostBase host)
 247                 {
 248                         this.host = null;
 249                 }
 250
 251                 protected override void OnAbort ()
 252                 {
 253                         if (loop_manager != null)
 254                                 loop_manager.Stop (TimeSpan.FromTicks (1));
 255                 }
 256
 257                 Action<TimeSpan> open_delegate;
 258                 Action<TimeSpan> close_delegate;
 259
 260                 protected override IAsyncResult OnBeginClose (TimeSpan timeout,
 261                         AsyncCallback callback, object state)
 262                 {
 263                         if (close_delegate == null)
 264                                 close_delegate = new Action<TimeSpan> (OnClose);
 265                         return close_delegate.BeginInvoke (timeout, callback, state);
 266                 }
 267
 268                 protected override IAsyncResult OnBeginOpen (TimeSpan timeout,
 269                         AsyncCallback callback, object state)
 270                 {
 271                         if (open_delegate == null)
 272                                 open_delegate = new Action<TimeSpan> (OnOpen);
 273                         return open_delegate.BeginInvoke (timeout, callback, state);
 274                 }
 275
 276                 protected override void OnClose (TimeSpan timeout)
 277                 {
 278                         if (loop_manager != null)
 279                                 loop_manager.Stop (timeout);
 280                 }
 281
 282                 protected override void OnClosed ()
 283                 {
 284                         if (host != null)
 285                                 host.ChannelDispatchers.Remove (this);
 286                         base.OnClosed ();
 287                 }
 288
 289                 protected override void OnEndClose (IAsyncResult result)
 290                 {
 291                         close_delegate.EndInvoke (result);
 292                 }
 293
 294                 protected override void OnEndOpen (IAsyncResult result)
 295                 {
 296                         open_delegate.EndInvoke (result);
 297                 }
 298
 299                 protected override void OnOpen (TimeSpan timeout)
 300                 {
 301                         if (Host == null || MessageVersion == null)
 302                                 throw new InvalidOperationException ("Service host is not attached to this ChannelDispatcher.");
 303
 304                         loop_manager.Setup (timeout);
 305                 }
 306
 307                 protected override void OnOpening ()
 308                 {
 309                         base.OnOpening ();
 310                         loop_manager = new ListenerLoopManager (this);
 311                 }
 312
 313                 protected override void OnOpened ()
 314                 {
 315                         base.OnOpened ();
 316                         StartLoop ();
 317                 }
 318
 319                 void StartLoop ()
 320                 {
 321                         // FIXME: not sure if it should be filled here.
 322                         if (ServiceThrottle == null)
 323                                 ServiceThrottle = new ServiceThrottle (this);
 324
 325                         loop_manager.Start ();
 326                 }
 327         }
 328
 329                 // isolated from ChannelDispatcher
 330                 class ListenerLoopManager
 331                 {
 332                         ChannelDispatcher owner;
 333                         AutoResetEvent throttle_wait_handle = new AutoResetEvent (false);
 334                         AutoResetEvent creator_handle = new AutoResetEvent (false);
 335                         ManualResetEvent stop_handle = new ManualResetEvent (false);
 336                         bool loop;
 337                         Thread loop_thread;
 338                         DateTime close_started;
 339                         TimeSpan close_timeout;
 340                         Func<IAsyncResult> channel_acceptor;
 341                         List<IChannel> channels = new List<IChannel> ();
 342                         AddressFilterMode address_filter_mode;
 343
 344                         public ListenerLoopManager (ChannelDispatcher owner)
 345                         {
 346                                 this.owner = owner;
 347                                 var sba = owner.Host != null ? owner.Host.Description.Behaviors.Find<ServiceBehaviorAttribute> () : null;
 348                                 if (sba != null)
 349                                         address_filter_mode = sba.AddressFilterMode;
 350                         }
 351
 352                         public void Setup (TimeSpan openTimeout)
 353                         {
 354                                 if (owner.Listener.State != CommunicationState.Created)
 355                                         throw new InvalidOperationException ("Tried to open the channel listener which is bound to ChannelDispatcher, but it is not at Created state");
 356                                 owner.Listener.Open (openTimeout);
 357
 358                                 // It is tested at Open(), but strangely it is not instantiated at this point.
 359                                 foreach (var ed in owner.Endpoints)
 360                                         if (ed.DispatchRuntime.InstanceContextProvider == null && (ed.DispatchRuntime.Type == null || ed.DispatchRuntime.Type.GetConstructor (Type.EmptyTypes) == null))
 361                                                 throw new InvalidOperationException ("There is no default constructor for the service Type in the DispatchRuntime");
 362                                 SetupChannelAcceptor ();
 363                         }
 364
 365                         public void Start ()
 366                         {
 367                                 if (loop_thread == null)
 368                                         loop_thread = new Thread (new ThreadStart (Loop));
 369                                 loop_thread.Start ();
 370                         }
 371
 372                         Func<IAsyncResult> CreateAcceptor<TChannel> (IChannelListener l) where TChannel : class, IChannel
 373                         {
 374                                 IChannelListener<TChannel> r = l as IChannelListener<TChannel>;
 375                                 if (r == null)
 376                                         return null;
 377                                 AsyncCallback callback = delegate (IAsyncResult result) {
 378                                         try {
 379                                                 ChannelAccepted (r.EndAcceptChannel (result));
 380                                         } catch (Exception ex) {
 381                                                 Console.WriteLine ("Exception during finishing channel acceptance.");
 382                                                 Console.WriteLine (ex);
 383                                                 creator_handle.Set ();
 384                                         }
 385                                 };
 386                                 return delegate {
 387                                         try {
 388                                                 return r.BeginAcceptChannel (callback, null);
 389                                         } catch (Exception ex) {
 390                                                 Console.WriteLine ("Exception during accepting channel.");
 391                                                 Console.WriteLine (ex);
 392                                                 throw;
 393                                         }
 394                                 };
 395                         }
 396
 397                         void SetupChannelAcceptor ()
 398                         {
 399                                 var l = owner.Listener;
 400                                 channel_acceptor =
 401                                         CreateAcceptor<IReplyChannel> (l) ??
 402                                         CreateAcceptor<IReplySessionChannel> (l) ??
 403                                         CreateAcceptor<IInputChannel> (l) ??
 404                                         CreateAcceptor<IInputSessionChannel> (l) ??
 405                                         CreateAcceptor<IDuplexChannel> (l) ??
 406                                         CreateAcceptor<IDuplexSessionChannel> (l);
 407                                 if (channel_acceptor == null)
 408                                         throw new InvalidOperationException (String.Format ("Unrecognized channel listener type: {0}", l.GetType ()));
 409                         }
 410
 411                         public void Stop (TimeSpan timeout)
 412                         {
 413                                 if (loop_thread == null)
 414                                         return;
 415
 416                                 close_started = DateTime.Now;
 417                                 close_timeout = timeout;
 418                                 loop = false;
 419                                 creator_handle.Set ();
 420                                 throttle_wait_handle.Set (); // break primary loop
 421                                 if (stop_handle != null) {
 422                                         stop_handle.WaitOne (timeout > TimeSpan.Zero ? timeout : TimeSpan.FromTicks (1));
 423                                         stop_handle.Close ();
 424                                         stop_handle = null;
 425                                 }
 426                                 if (owner.Listener.State != CommunicationState.Closed) {
 427                                         // FIXME: log it
 428                                         Console.WriteLine ("Channel listener '{0}' is not closed. Aborting.", owner.Listener.GetType ());
 429                                         owner.Listener.Abort ();
 430                                 }
 431                                 if (loop_thread != null && loop_thread.IsAlive)
 432                                         loop_thread.Abort ();
 433                                 loop_thread = null;
 434                         }
 435
 436                         public void CloseInput ()
 437                         {
 438                                 foreach (var ch in channels.ToArray ()) {
 439                                         if (ch.State == CommunicationState.Closed)
 440                                                 channels.Remove (ch); // zonbie, if exists
 441                                         else {
 442                                                 try {
 443                                                         ch.Close (close_timeout - (DateTime.Now - close_started));
 444                                                 } catch (Exception ex) {
 445                                                         // FIXME: log it.
 446                                                         Console.WriteLine (ex);
 447                                                         ch.Abort ();
 448                                                 }
 449                                         }
 450                                 }
 451                         }
 452
 453                         void Loop ()
 454                         {
 455                                 try {
 456                                         LoopCore ();
 457                                 } catch (Exception ex) {
 458                                         // FIXME: log it
 459                                         Console.WriteLine ("ListenerLoopManager caught an exception inside dispatcher loop, which is likely thrown by the channel listener {0}", owner.Listener);
 460                                         Console.WriteLine (ex);
 461                                 } finally {
 462                                         if (stop_handle != null)
 463                                                 stop_handle.Set ();
 464                                 }
 465                         }
 466
 467                         void LoopCore ()
 468                         {
 469                                 loop = true;
 470
 471                                 // FIXME: use WaitForChannel() for (*only* for) transacted channel listeners.
 472                                 // http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/3faa4a5e-8602-4dbe-a181-73b3f581835e
 473
 474                                 while (loop) {
 475                                         // FIXME: take MaxConcurrentCalls into consideration appropriately.
 476                                         while (loop && channels.Count < Math.Min (owner.ServiceThrottle.MaxConcurrentSessions, owner.ServiceThrottle.MaxConcurrentCalls)) {
 477                                                 // FIXME: this should not be required, but saves multi-ChannelDispatcher case (Throttling enabled) for HTTP standalone listener...
 478                                                 Thread.Sleep (100);
 479                                                 channel_acceptor ();
 480                                                 creator_handle.WaitOne (); // released by ChannelAccepted()
 481                                         }
 482                                         if (!loop)
 483                                                 break;
 484                                         throttle_wait_handle.WaitOne (); // released by IChannel.Close()
 485                                 }
 486                                 try {
 487                                         owner.Listener.Close ();
 488                                 } finally {
 489                                         // make sure to close both listener and channels.
 490                                         owner.CloseInput ();
 491                                 }
 492                         }
 493
 494                         void ChannelAccepted (IChannel ch)
 495                         {
 496                         try {
 497                                 if (ch == null) // could happen when it was aborted
 498                                         return;
 499                                 if (!loop) {
 500                                         var dis = ch as IDisposable;
 501                                         if (dis != null)
 502                                                 dis.Dispose ();
 503                                         return;
 504                                 }
 505
 506                                 lock (channels)
 507                                         channels.Add (ch);
 508                                 ch.Opened += delegate {
 509                                         ch.Faulted += delegate {
 510                                                 lock (channels)
 511                                                         if (channels.Contains (ch))
 512                                                                 channels.Remove (ch);
 513                                                 throttle_wait_handle.Set (); // release loop wait lock.
 514                                                 };
 515                                         ch.Closed += delegate {
 516                                                 lock (channels)
 517                                                         if (channels.Contains (ch))
 518                                                                 channels.Remove (ch);
 519                                                 throttle_wait_handle.Set (); // release loop wait lock.
 520                                                 };
 521                                         };
 522                                 ch.Open ();
 523                         } finally {
 524                                 creator_handle.Set ();
 525                         }
 526
 527                                 ProcessRequestOrInput (ch);
 528                         }
 529
 530                         void ProcessRequestOrInput (IChannel ch)
 531                         {
 532                                 var reply = ch as IReplyChannel;
 533                                 var input = ch as IInputChannel;
 534
 535                                 if (reply != null) {
 536                                         if (owner.ReceiveSynchronously) {
 537                                                 RequestContext rc;
 538                                                 if (reply.TryReceiveRequest (owner.timeouts.ReceiveTimeout, out rc))
 539                                                         ProcessRequest (reply, rc);
 540                                         } else {
 541                                                 reply.BeginTryReceiveRequest (owner.timeouts.ReceiveTimeout, TryReceiveRequestDone, reply);
 542                                         }
 543                                 } else if (input != null) {
 544                                         if (owner.ReceiveSynchronously) {
 545                                                 Message msg;
 546                                                 if (input.TryReceive (owner.timeouts.ReceiveTimeout, out msg))
 547                                                         ProcessInput (input, msg);
 548                                         } else {
 549                                                 input.BeginTryReceive (owner.timeouts.ReceiveTimeout, TryReceiveDone, input);
 550                                         }
 551                                 }
 552                         }
 553
 554                         void TryReceiveRequestDone (IAsyncResult result)
 555                         {
 556                                 RequestContext rc;
 557                                 var reply = (IReplyChannel) result.AsyncState;
 558                                 if (reply.EndTryReceiveRequest (result, out rc))
 559                                         ProcessRequest (reply, rc);
 560                                 else
 561                                         reply.Close ();
 562                         }
 563
 564                         void TryReceiveDone (IAsyncResult result)
 565                         {
 566                                 Message msg;
 567                                 var input = (IInputChannel) result.AsyncState;
 568                                 if (input.EndTryReceive (result, out msg))
 569                                         ProcessInput (input, msg);
 570                                 else
 571                                         input.Close ();
 572                         }
 573
 574                         void ProcessRequest (IReplyChannel reply, RequestContext rc)
 575                         {
 576                                 var req = rc.RequestMessage;
 577                                 try {
 578                                         var ed = FindEndpointDispatcher (req);
 579                                         new InputOrReplyRequestProcessor (ed.DispatchRuntime, reply).ProcessReply (rc);
 580                                 } catch (Exception ex) {
 581                                         // FIXME: log it.
 582                                         Console.WriteLine (ex);
 583
 584                                         var conv = reply.GetProperty<FaultConverter> () ?? FaultConverter.GetDefaultFaultConverter (rc.RequestMessage.Version);
 585                                         Message res;
 586                                         if (!conv.TryCreateFaultMessage (ex, out res))
 587                                                 res = Message.CreateMessage (req.Version, new FaultCode ("Receiver"), ex.Message, req.Version.Addressing.FaultNamespace);
 588                                         rc.Reply (res);
 589                                 } finally {
 590                                         if (rc != null)
 591                                                 rc.Close ();
 592                                         // unless it is closed by session/call manager, move it back to the loop to receive the next message.
 593                                         if (loop && reply.State != CommunicationState.Closed)
 594                                                 ProcessRequestOrInput (reply);
 595                                 }
 596                         }
 597
 598                         void ProcessInput (IInputChannel input, Message message)
 599                         {
 600                                 try {
 601                                         EndpointDispatcher candidate = null;
 602                                         candidate = FindEndpointDispatcher (message);
 603                                         new InputOrReplyRequestProcessor (candidate.DispatchRuntime, input).
 604                                                 ProcessInput (message);
 605                                 }
 606                                 catch (Exception ex) {
 607                                         // FIXME: log it.
 608                                         Console.WriteLine (ex);
 609                                 } finally {
 610                                         // unless it is closed by session/call manager, move it back to the loop to receive the next message.
 611                                         if (loop && input.State != CommunicationState.Closed)
 612                                                 ProcessRequestOrInput (input);
 613                                 }
 614                         }
 615
 616                         EndpointDispatcher FindEndpointDispatcher (Message message) {
 617                                 EndpointDispatcher candidate = null;
 618                                 bool hasEndpointMatch = false;
 619                                 foreach (var endpoint in owner.Endpoints) {
 620                                         if (endpoint.AddressFilter.Match (message)) {
 621                                                 hasEndpointMatch = true;
 622                                                 if (!endpoint.ContractFilter.Match (message))
 623                                                         continue;
 624                                                 var newdis = endpoint;
 625                                                 if (candidate == null || candidate.FilterPriority < newdis.FilterPriority)
 626                                                         candidate = newdis;
 627                                                 else if (candidate.FilterPriority == newdis.FilterPriority)
 628                                                         throw new MultipleFilterMatchesException ();
 629                                         }
 630                                 }
 631                                 if (candidate == null && !hasEndpointMatch) {
 632                                         if (owner.Host != null)
 633                                                 owner.Host.OnUnknownMessageReceived (message);
 634                                         // we have to return a fault to the client anyways...
 635                                         throw new EndpointNotFoundException ();
 636                                 }
 637                                 else if (candidate == null)
 638                                         // FIXME: It is not a good place to check, but anyways detach this error from EndpointNotFoundException.
 639                                         throw new ActionNotSupportedException (String.Format ("Action '{0}' did not match any operations in the target contract", message.Headers.Action));
 640
 641                                 return candidate;
 642                         }
 643                 }
 644 }