mcs/class/corlib/System.Runtime.Remoting/RemotingServices.cs

   1 //
   2 // System.Runtime.Remoting.RemotingServices.cs
   3 //
   4 // Authors:
   5 //   Dietmar Maurer (dietmar@ximian.com)
   6 //   Lluis Sanchez Gual (lluis@ideary.com)
   7 //   Patrik Torstensson
   8 //
   9 // (C) 2001 Ximian, Inc.  http://www.ximian.com
  10 //
  11
  12 //
  13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System;
  36 using System.Diagnostics;
  37 using System.Text;
  38 using System.Reflection;
  39 using System.Threading;
  40 using System.Collections;
  41 using System.Runtime.Remoting.Messaging;
  42 using System.Runtime.Remoting.Proxies;
  43 using System.Runtime.Remoting.Channels;
  44 using System.Runtime.Remoting.Contexts;
  45 using System.Runtime.Remoting.Activation;
  46 using System.Runtime.Remoting.Lifetime;
  47 using System.Runtime.CompilerServices;
  48 using System.Runtime.Serialization;
  49 using System.IO;
  50
  51 namespace System.Runtime.Remoting
  52 {
  53         public sealed class RemotingServices
  54         {
  55                 // Holds the identities of the objects, using uri as index
  56                 static Hashtable uri_hash = new Hashtable ();
  57
  58                 internal static string app_id;
  59                 static int next_id = 1;
  60                 static readonly BindingFlags methodBindings = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
  61
  62                 static RemotingServices ()
  63                 {
  64                         RegisterInternalChannels ();
  65                         app_id = Guid.NewGuid().ToString().Replace('-', '_') + "/";
  66                         CreateWellKnownServerIdentity (typeof(RemoteActivator), "RemoteActivationService.rem", WellKnownObjectMode.Singleton);
  67                 }
  68
  69                 private RemotingServices () {}
  70
  71                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  72                 internal extern static object InternalExecute (MonoMethod method, Object obj,
  73                                                                Object[] parameters, out object [] out_args);
  74
  75                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  76                 public extern static bool IsTransparentProxy (object proxy);
  77
  78                 internal static IMethodReturnMessage InternalExecuteMessage (
  79                         MarshalByRefObject target, IMethodCallMessage reqMsg)
  80                 {
  81                         ReturnMessage result;
  82
  83                         MonoMethod method = (MonoMethod) target.GetType().GetMethod(reqMsg.MethodName, BindingFlags.Public|BindingFlags.NonPublic|BindingFlags.Instance, null, (Type[]) reqMsg.MethodSignature, null);
  84                         object oldContext = CallContext.SetCurrentCallContext (reqMsg.LogicalCallContext);
  85
  86                         try
  87                         {
  88                                 object [] out_args;
  89                                 object rval = InternalExecute (method, target, reqMsg.Args, out out_args);
  90
  91                                 // Collect parameters with Out flag from the request message
  92                                 // FIXME: This can be done in the unmanaged side and will be
  93                                 // more efficient
  94
  95                                 ParameterInfo[] parameters = method.GetParameters();
  96                                 object[] returnArgs = new object [parameters.Length];
  97
  98                                 int n = 0;
  99                                 int noa = 0;
 100                                 foreach (ParameterInfo par in parameters)
 101                                 {
 102                                         if (par.IsOut && !par.ParameterType.IsByRef)
 103                                                 returnArgs [n++] = reqMsg.GetArg (par.Position);
 104                                         else if (par.ParameterType.IsByRef)
 105                                                 returnArgs [n++] = out_args [noa++];
 106                                         else
 107                                                 returnArgs [n++] = null;
 108                                 }
 109
 110                                 result = new ReturnMessage (rval, returnArgs, n, CallContext.CreateLogicalCallContext(), reqMsg);
 111                         }
 112                         catch (Exception e)
 113                         {
 114                                 result = new ReturnMessage (e, reqMsg);
 115                         }
 116
 117                         CallContext.RestoreCallContext (oldContext);
 118                         return result;
 119                 }
 120
 121                 public static IMethodReturnMessage ExecuteMessage (
 122                         MarshalByRefObject target, IMethodCallMessage reqMsg)
 123                 {
 124                         if (IsTransparentProxy(target))
 125                         {
 126                                 // Message must go through all chain of sinks
 127                                 RealProxy rp = GetRealProxy (target);
 128                                 return (IMethodReturnMessage) rp.Invoke (reqMsg);
 129                         }
 130                         else    // Direct call
 131                                 return InternalExecuteMessage (target, reqMsg);
 132                 }
 133
 134                 public static object Connect (Type classToProxy, string url)
 135                 {
 136                         ObjRef objRef = new ObjRef (classToProxy, url, null);
 137                         return GetRemoteObject (objRef, classToProxy);
 138                 }
 139
 140                 public static object Connect (Type classToProxy, string url, object data)
 141                 {
 142                         ObjRef objRef = new ObjRef (classToProxy, url, data);
 143                         return GetRemoteObject (objRef, classToProxy);
 144                 }
 145
 146                 public static bool Disconnect (MarshalByRefObject obj)
 147                 {
 148                         if (obj == null) throw new ArgumentNullException ("obj");
 149
 150                         ServerIdentity identity;
 151
 152                         if (IsTransparentProxy (obj))
 153                         {
 154                                 // CBOs are always accessed through a proxy, even in the server, so
 155                                 // for server CBOs it is ok to disconnect a proxy
 156
 157                                 RealProxy proxy = GetRealProxy(obj);
 158                                 if (proxy.GetProxiedType().IsContextful && (proxy.ObjectIdentity is ServerIdentity))
 159                                         identity = proxy.ObjectIdentity as ServerIdentity;
 160                                 else
 161                                         throw new ArgumentException ("The obj parameter is a proxy.");
 162                         }
 163                         else {
 164                                 identity = obj.ObjectIdentity;
 165                                 obj.ObjectIdentity = null;
 166                         }
 167
 168                         if (identity == null || !identity.IsConnected)
 169                                 return false;
 170                         else
 171                         {
 172                                 LifetimeServices.StopTrackingLifetime (identity);
 173                                 DisposeIdentity (identity);
 174                                 return true;
 175                         }
 176                 }
 177
 178                 public static Type GetServerTypeForUri (string uri)
 179                 {
 180                         ServerIdentity ident = GetIdentityForUri (uri) as ServerIdentity;
 181                         if (ident == null) return null;
 182                         return ident.ObjectType;
 183                 }
 184
 185                 public static string GetObjectUri (MarshalByRefObject obj)
 186                 {
 187                         Identity ident = GetObjectIdentity(obj);
 188                         if (ident is ClientIdentity) return ((ClientIdentity)ident).TargetUri;
 189                         else if (ident != null) return ident.ObjectUri;
 190                         else return null;
 191                 }
 192
 193                 public static object Unmarshal (ObjRef objref)
 194                 {
 195                         return Unmarshal(objref, true);
 196                 }
 197
 198                 public static object Unmarshal (ObjRef objref, bool fRefine)
 199                 {
 200                         Type classToProxy = fRefine ? objref.ServerType : typeof (MarshalByRefObject);
 201                         if (classToProxy == null) classToProxy = typeof (MarshalByRefObject);
 202
 203                         if (objref.IsReferenceToWellKnow)
 204                                 return GetRemoteObject(objref, classToProxy);
 205                         else
 206                         {
 207                                 if (classToProxy.IsContextful)
 208                                 {
 209                                         // Look for a ProxyAttribute
 210                                         ProxyAttribute att = (ProxyAttribute) Attribute.GetCustomAttribute (classToProxy, typeof(ProxyAttribute),true);
 211                                         if (att != null)
 212                                                 return att.CreateProxy (objref, classToProxy, null, null).GetTransparentProxy();
 213                                 }
 214                                 return GetProxyForRemoteObject (objref, classToProxy);
 215                         }
 216                 }
 217
 218                 public static ObjRef Marshal (MarshalByRefObject obj)
 219                 {
 220                         return Marshal (obj, null, null);
 221                 }
 222
 223                 public static ObjRef Marshal (MarshalByRefObject obj, string uri)
 224                 {
 225                         return Marshal (obj, uri, null);
 226                 }
 227
 228                 public static ObjRef Marshal (MarshalByRefObject obj, string uri, Type requested_type)
 229                 {
 230                         if (IsTransparentProxy (obj))
 231                         {
 232                                 RealProxy proxy = RemotingServices.GetRealProxy(obj);
 233                                 Identity identity = proxy.ObjectIdentity;
 234
 235                                 if (identity != null)
 236                                 {
 237                                         if (proxy.GetProxiedType().IsContextful && !identity.IsConnected)
 238                                         {
 239                                                 // Unregistered local contextbound object. Register now.
 240                                                 ClientActivatedIdentity cboundIdentity = (ClientActivatedIdentity)identity;
 241                                                 if (uri == null) uri = NewUri();
 242                                                 cboundIdentity.ObjectUri = uri;
 243                                                 RegisterServerIdentity (cboundIdentity);
 244                                                 cboundIdentity.StartTrackingLifetime ((ILease)obj.InitializeLifetimeService());
 245                                                 return cboundIdentity.CreateObjRef(requested_type);
 246                                         }
 247                                         else if (uri != null)
 248                                                 throw new RemotingException ("It is not possible marshal a proxy of a remote object.");
 249
 250                                         return proxy.ObjectIdentity.CreateObjRef(requested_type);
 251                                 }
 252                         }
 253
 254                         if (requested_type == null) requested_type = obj.GetType();
 255
 256                         if (uri == null)
 257                         {
 258                                 if (obj.ObjectIdentity == null)
 259                                 {
 260                                         uri = NewUri();
 261                                         CreateClientActivatedServerIdentity (obj, requested_type, uri);
 262                                 }
 263                         }
 264                         else
 265                         {
 266                                 ClientActivatedIdentity identity = GetIdentityForUri ("/" + uri) as ClientActivatedIdentity;
 267                                 if (identity == null || obj != identity.GetServerObject())
 268                                         CreateClientActivatedServerIdentity (obj, requested_type, uri);
 269                         }
 270
 271                         if (IsTransparentProxy (obj))
 272                                 return RemotingServices.GetRealProxy(obj).ObjectIdentity.CreateObjRef (requested_type);
 273                         else
 274                                 return obj.CreateObjRef(requested_type);
 275                 }
 276
 277                 static string NewUri ()
 278                 {
 279                         int n = Interlocked.Increment (ref next_id);
 280                         return app_id + Environment.TickCount + "_" + n + ".rem";
 281                 }
 282
 283                 public static RealProxy GetRealProxy (object proxy)
 284                 {
 285                         if (!IsTransparentProxy(proxy)) throw new RemotingException("Cannot get the real proxy from an object that is not a transparent proxy.");
 286                         return (RealProxy)((TransparentProxy)proxy)._rp;
 287                 }
 288
 289                 public static MethodBase GetMethodBaseFromMethodMessage(IMethodMessage msg)
 290                 {
 291                         Type type = Type.GetType (msg.TypeName);
 292                         if (type == null)
 293                                 throw new RemotingException ("Type '" + msg.TypeName + "' not found.");
 294
 295                         return GetMethodBaseFromName (type, msg.MethodName, (Type[]) msg.MethodSignature);
 296                 }
 297
 298                 internal static MethodBase GetMethodBaseFromName (Type type, string methodName, Type[] signature)
 299                 {
 300                         if (type.IsInterface) {
 301                                 return FindInterfaceMethod (type, methodName, signature);
 302                         }
 303                         else {
 304                                 MethodBase method = null;
 305                                 if (signature == null)
 306                                         method = type.GetMethod (methodName, methodBindings);
 307                                 else
 308                                         method = type.GetMethod (methodName, methodBindings, null, (Type[]) signature, null);
 309
 310                                 if (method != null)
 311                                         return method;
 312
 313                                 if (signature == null)
 314                                         return type.GetConstructor (methodBindings, null, Type.EmptyTypes, null);
 315                                 else
 316                                         return type.GetConstructor (methodBindings, null, signature, null);
 317                         }
 318                 }
 319
 320                 static MethodBase FindInterfaceMethod (Type type, string methodName, Type[] signature)
 321                 {
 322                         MethodBase method = null;
 323
 324                         if (signature == null)
 325                                 method = type.GetMethod (methodName, methodBindings);
 326                         else
 327                                 method = type.GetMethod (methodName, methodBindings, null, signature, null);
 328
 329                         if (method != null) return method;
 330
 331                         foreach (Type t in type.GetInterfaces ()) {
 332                                 method = FindInterfaceMethod (t, methodName, signature);
 333                                 if (method != null) return method;
 334                         }
 335
 336                         return null;
 337                 }
 338
 339                 public static void GetObjectData(object obj, SerializationInfo info, StreamingContext context)
 340                 {
 341                         if (obj == null) throw new ArgumentNullException ("obj");
 342
 343                         ObjRef oref = Marshal ((MarshalByRefObject)obj);
 344                         oref.GetObjectData (info, context);
 345                 }
 346
 347                 public static ObjRef GetObjRefForProxy(MarshalByRefObject obj)
 348                 {
 349                         Identity ident = GetObjectIdentity(obj);
 350                         if (ident == null) return null;
 351                         else return ident.CreateObjRef(null);
 352                 }
 353
 354                 public static object GetLifetimeService (MarshalByRefObject obj)
 355                 {
 356                         if (obj == null) return null;
 357                         return obj.GetLifetimeService ();
 358                 }
 359
 360                 public static IMessageSink GetEnvoyChainForProxy (MarshalByRefObject obj)
 361                 {
 362                         if (IsTransparentProxy(obj))
 363                                 return ((ClientIdentity)GetRealProxy (obj).ObjectIdentity).EnvoySink;
 364                         else
 365                                 throw new ArgumentException ("obj must be a proxy.","obj");
 366                 }
 367
 368                 [MonoTODO]
 369                 [Conditional ("REMOTING_PERF")]
 370                 public static void LogRemotingStage (int stage)
 371                 {
 372                         throw new NotImplementedException ();
 373                 }
 374
 375                 public static string GetSessionIdForMethodMessage(IMethodMessage msg)
 376                 {
 377                         // It seems that this it what MS returns.
 378                         return msg.Uri;
 379                 }
 380
 381                 public static bool IsMethodOverloaded(IMethodMessage msg)
 382                 {
 383                         // TODO: use internal call for better performance
 384                         Type type = msg.MethodBase.DeclaringType;
 385                         MemberInfo[] members = type.GetMember (msg.MethodName, MemberTypes.Method, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
 386                         return members.Length > 1;
 387                 }
 388
 389                 public static bool IsObjectOutOfAppDomain(object tp)
 390                 {
 391                         // TODO: use internal call for better performance
 392                         Identity ident = GetObjectIdentity((MarshalByRefObject)tp);
 393                         if (ident != null) return !ident.IsFromThisAppDomain;
 394                         else return false;
 395                 }
 396
 397                 public static bool IsObjectOutOfContext(object tp)
 398                 {
 399                         // TODO: use internal call for better performance
 400                         ServerIdentity ident = GetObjectIdentity((MarshalByRefObject)tp) as ServerIdentity;
 401                         if (ident != null) return ident.Context != System.Threading.Thread.CurrentContext;
 402                         else return false;
 403                 }
 404
 405                 public static bool IsOneWay(MethodBase method)
 406                 {
 407                         // TODO: use internal call for better performance
 408                         object[] atts = method.GetCustomAttributes (typeof (OneWayAttribute), false);
 409                         return atts.Length > 0;
 410                 }
 411
 412                 internal static bool IsAsyncMessage(IMessage msg)
 413                 {
 414                         if (! (msg is MonoMethodMessage)) return false;
 415                         else if (((MonoMethodMessage)msg).IsAsync) return true;
 416                         else if (IsOneWay (((MonoMethodMessage)msg).MethodBase)) return true;
 417                         else return false;
 418                 }
 419
 420                 public static void SetObjectUriForMarshal(MarshalByRefObject obj, string uri)
 421                 {
 422                         if (IsTransparentProxy (obj)) throw new RemotingException ("SetObjectUriForMarshal method should only be called for MarshalByRefObjects that exist in the current AppDomain.");
 423                         Marshal (obj, uri);
 424                 }
 425
 426                 #region Internal Methods
 427
 428                 internal static object CreateClientProxy (ActivatedClientTypeEntry entry, object[] activationAttributes)
 429                 {
 430                         if (entry.ContextAttributes != null || activationAttributes != null)
 431                         {
 432                                 ArrayList props = new ArrayList ();
 433                                 if (entry.ContextAttributes != null) props.AddRange (entry.ContextAttributes);
 434                                 if (activationAttributes != null) props.AddRange (activationAttributes);
 435                                 return CreateClientProxy (entry.ObjectType, entry.ApplicationUrl, props.ToArray ());
 436                         }
 437                         else
 438                                 return CreateClientProxy (entry.ObjectType, entry.ApplicationUrl, null);
 439                 }
 440
 441                 internal static object CreateClientProxy (Type objectType, string url, object[] activationAttributes)
 442                 {
 443                         string activationUrl = url + "/RemoteActivationService.rem";
 444
 445                         string objectUri;
 446                         IMessageSink sink = GetClientChannelSinkChain (activationUrl, null, out objectUri);
 447
 448                         RemotingProxy proxy = new RemotingProxy (objectType, activationUrl, activationAttributes);
 449                         return proxy.GetTransparentProxy();
 450                 }
 451
 452                 internal static object CreateClientProxy (WellKnownClientTypeEntry entry)
 453                 {
 454                         return Connect (entry.ObjectType, entry.ObjectUrl, null);
 455                 }
 456
 457                 internal static object CreateClientProxyForContextBound (Type type, object[] activationAttributes)
 458                 {
 459                         if (type.IsContextful)
 460                         {
 461                                 // Look for a ProxyAttribute
 462                                 ProxyAttribute att = (ProxyAttribute) Attribute.GetCustomAttribute (type, typeof(ProxyAttribute), true);
 463                                 if (att != null)
 464                                         return att.CreateInstance (type);
 465                         }
 466                         RemotingProxy proxy = new RemotingProxy (type, ChannelServices.CrossContextUrl, activationAttributes);
 467                         return proxy.GetTransparentProxy();
 468                 }
 469
 470                 internal static Identity GetIdentityForUri (string uri)
 471                 {
 472                         lock (uri_hash)
 473                         {
 474                                 return (Identity)uri_hash [GetNormalizedUri(uri)];
 475                         }
 476                 }
 477
 478                 internal static Identity GetObjectIdentity (MarshalByRefObject obj)
 479                 {
 480                         if (IsTransparentProxy(obj))
 481                                 return GetRealProxy (obj).ObjectIdentity;
 482                         else
 483                                 return obj.ObjectIdentity;
 484                 }
 485
 486                 internal static ClientIdentity GetOrCreateClientIdentity(ObjRef objRef, Type proxyType, out object clientProxy)
 487                 {
 488                         // This method looks for an identity for the given url.
 489                         // If an identity is not found, it creates the identity and
 490                         // assigns it a proxy to the remote object.
 491
 492                         // Creates the client sink chain for the given url or channelData.
 493                         // It will also get the object uri from the url.
 494
 495                         object channelData = objRef.ChannelInfo != null ? objRef.ChannelInfo.ChannelData : null;
 496                         string url = (channelData == null) ? objRef.URI : null;
 497
 498                         string objectUri;
 499                         IMessageSink sink = GetClientChannelSinkChain (url, channelData, out objectUri);
 500
 501                         if (objectUri == null) objectUri = objRef.URI;
 502
 503                         lock (uri_hash)
 504                         {
 505                                 clientProxy = null;
 506                                 string uri = GetNormalizedUri (objRef.URI);
 507
 508                                 ClientIdentity identity = uri_hash [uri] as ClientIdentity;
 509                                 if (identity != null)
 510                                 {
 511                                         // Object already registered
 512                                         clientProxy = identity.ClientProxy;
 513                                         if (clientProxy != null) return identity;
 514
 515                                         // The proxy has just been GCed, so its identity cannot
 516                                         // be reused. Just dispose it.
 517                                         DisposeIdentity (identity);
 518                                 }
 519
 520                                 // Creates an identity and a proxy for the remote object
 521
 522                                 identity = new ClientIdentity (objectUri, objRef);
 523                                 identity.ChannelSink = sink;
 524
 525                                 // Registers the identity
 526                                 uri_hash [uri] = identity;
 527
 528                                 if (proxyType != null)
 529                                 {
 530                                         RemotingProxy proxy = new RemotingProxy (proxyType, identity);
 531                                         clientProxy = proxy.GetTransparentProxy();
 532                                         identity.ClientProxy = (MarshalByRefObject) clientProxy;
 533                                 }
 534
 535                                 return identity;
 536                         }
 537                 }
 538
 539                 static IMessageSink GetClientChannelSinkChain(string url, object channelData, out string objectUri)
 540                 {
 541                         IMessageSink sink = ChannelServices.CreateClientChannelSinkChain (url, channelData, out objectUri);
 542                         if (sink == null)
 543                         {
 544                                 if (url != null)
 545                                 {
 546                                         string msg = String.Format ("Cannot create channel sink to connect to URL {0}. An appropriate channel has probably not been registered.", url);
 547                                         throw new RemotingException (msg);
 548                                 }
 549                                 else
 550                                 {
 551                                         string msg = String.Format ("Cannot create channel sink to connect to the remote object. An appropriate channel has probably not been registered.", url);
 552                                         throw new RemotingException (msg);
 553                                 }
 554                         }
 555                         return sink;
 556                 }
 557
 558                 internal static ClientActivatedIdentity CreateContextBoundObjectIdentity(Type objectType)
 559                 {
 560                         ClientActivatedIdentity identity = new ClientActivatedIdentity (null, objectType);
 561                         identity.ChannelSink = ChannelServices.CrossContextChannel;
 562                         return identity;
 563                 }
 564
 565                 internal static ClientActivatedIdentity CreateClientActivatedServerIdentity(MarshalByRefObject realObject, Type objectType, string objectUri)
 566                 {
 567                         ClientActivatedIdentity identity = new ClientActivatedIdentity (objectUri, objectType);
 568                         identity.AttachServerObject (realObject, Context.DefaultContext);
 569                         RegisterServerIdentity (identity);
 570                         identity.StartTrackingLifetime ((ILease)realObject.InitializeLifetimeService ());
 571                         return identity;
 572                 }
 573
 574                 internal static ServerIdentity CreateWellKnownServerIdentity(Type objectType, string objectUri, WellKnownObjectMode mode)
 575                 {
 576                         ServerIdentity identity;
 577
 578                         if (mode == WellKnownObjectMode.SingleCall)
 579                                 identity = new  SingleCallIdentity(objectUri, Context.DefaultContext, objectType);
 580                         else
 581                                 identity = new  SingletonIdentity(objectUri, Context.DefaultContext, objectType);
 582
 583                         RegisterServerIdentity (identity);
 584                         return identity;
 585                 }
 586
 587                 private static void RegisterServerIdentity(ServerIdentity identity)
 588                 {
 589                         lock (uri_hash)
 590                         {
 591                                 if (uri_hash.ContainsKey (identity.ObjectUri))
 592                                         throw new RemotingException ("Uri already in use: " + identity.ObjectUri + ".");
 593
 594                                 uri_hash[identity.ObjectUri] = identity;
 595                         }
 596                 }
 597
 598                 internal static object GetProxyForRemoteObject (ObjRef objref, Type classToProxy)
 599                 {
 600                         ClientActivatedIdentity identity = GetIdentityForUri (objref.URI) as ClientActivatedIdentity;
 601                         if (identity != null) return identity.GetServerObject ();
 602                         else return GetRemoteObject (objref, classToProxy);
 603                 }
 604
 605                 internal static object GetRemoteObject(ObjRef objRef, Type proxyType)
 606                 {
 607                         object proxy;
 608                         GetOrCreateClientIdentity (objRef, proxyType, out proxy);
 609                         return proxy;
 610                 }
 611
 612                 internal static object GetDomainProxy(AppDomain domain)
 613                 {
 614                         byte[] data = null;
 615
 616                         Context currentContext = Thread.CurrentContext;
 617
 618                         try
 619                         {
 620                                 data = (byte[])AppDomain.InvokeInDomain (domain, typeof (AppDomain).GetMethod ("GetMarshalledDomainObjRef", BindingFlags.Instance|BindingFlags.NonPublic), domain, null);
 621                         }
 622                         finally
 623                         {
 624                                 AppDomain.InternalSetContext (currentContext);
 625                         }
 626
 627                         MemoryStream stream = new MemoryStream (data);
 628                         ObjRef appref = (ObjRef) CADSerializer.DeserializeObject (stream);
 629                         return (AppDomain) RemotingServices.Unmarshal(appref);
 630                 }
 631
 632                 private static void RegisterInternalChannels()
 633                 {
 634                         CrossAppDomainChannel.RegisterCrossAppDomainChannel();
 635                 }
 636
 637                 internal static void DisposeIdentity (Identity ident)
 638                 {
 639                         lock (uri_hash)
 640                         {
 641                                 if (!ident.Disposed) {
 642                                         ClientIdentity clientId = ident as ClientIdentity;
 643                                         if (clientId != null)
 644                                                 uri_hash.Remove (GetNormalizedUri (clientId.TargetUri));
 645                                         else
 646                                                 uri_hash.Remove (ident.ObjectUri);
 647
 648                                         ident.Disposed = true;
 649                                 }
 650                         }
 651                 }
 652
 653                 internal static Identity GetMessageTargetIdentity (IMessage msg)
 654                 {
 655                         // Returns the identity where the message is sent
 656
 657                         if (msg is IInternalMessage)
 658                                 return ((IInternalMessage)msg).TargetIdentity;
 659
 660                         lock (uri_hash)
 661                         {
 662                                 string uri = GetNormalizedUri (((IMethodMessage)msg).Uri);
 663                                 return uri_hash [uri] as ServerIdentity;
 664                         }
 665                 }
 666
 667                 internal static void SetMessageTargetIdentity (IMessage msg, Identity ident)
 668                 {
 669                         if (msg is IInternalMessage)
 670                                 ((IInternalMessage)msg).TargetIdentity = ident;
 671                 }
 672
 673                 internal static bool UpdateOutArgObject (ParameterInfo pi, object local, object remote)
 674                 {
 675                         if (local is StringBuilder)
 676                         {
 677                                 StringBuilder sb = local as StringBuilder;
 678                                 sb.Remove (0, sb.Length);
 679                                 sb.Append (remote.ToString());
 680                                 return true;
 681                         }
 682                         else if (pi.ParameterType.IsArray && ((Array)local).Rank == 1)
 683                         {
 684                                 Array alocal = (Array) local;
 685                                 if (alocal.Rank == 1)
 686                                 {
 687                                         Array.Copy ((Array) remote, alocal, alocal.Length);
 688                                         return true;
 689                                 }
 690                                 else
 691                                 {
 692                                         // TODO
 693                                 }
 694                         }
 695                         return false;
 696                 }
 697
 698                 static string GetNormalizedUri (string uri)
 699                 {
 700                         if (uri.StartsWith ("/")) return uri.Substring (1);
 701                         else return uri;
 702                 }
 703
 704                 #endregion
 705         }
 706 }