mcs/class/System.Web/System.Web/HttpRuntime.cs

   1 //
   2 // System.Web.HttpRuntime.cs
   3 //
   4 // Authors:
   5 //      Miguel de Icaza (miguel@novell.com)
   6 //      Marek Habersack <mhabersack@novell.com>
   7 //
   8 //
   9 // Copyright (C) 2005-2010 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 //
  32 // TODO: Call HttpRequest.CloseInputStream when we finish a request, as we are using the IntPtr stream.
  33 //
  34 using System.IO;
  35 using System.Text;
  36 using System.Globalization;
  37 using System.Collections;
  38 using System.Collections.Concurrent;
  39 using System.Reflection;
  40 using System.Security;
  41 using System.Security.Permissions;
  42 using System.Web.Caching;
  43 using System.Web.Configuration;
  44 using System.Web.Management;
  45 using System.Web.UI;
  46 using System.Web.Util;
  47 using Mono.Web.Util;
  48 using System.Threading;
  49 #if TARGET_J2EE
  50 using Mainsoft.Web;
  51 #else
  52 using System.CodeDom.Compiler;
  53 using System.Web.Compilation;
  54 #endif
  55
  56 namespace System.Web
  57 {
  58         // CAS - no InheritanceDemand here as the class is sealed
  59         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  60         public sealed class HttpRuntime
  61         {
  62                 static bool domainUnloading;
  63                 static SplitOrderedList <string, string> registeredAssemblies;
  64 #if TARGET_J2EE
  65                 static QueueManager queue_manager { get { return _runtime._queue_manager; } }
  66                 static TraceManager trace_manager { get { return _runtime._trace_manager; } }
  67                 static Cache cache { get { return _runtime._cache; } }
  68                 static Cache internalCache { get { return _runtime._internalCache; } }
  69                 static WaitCallback do_RealProcessRequest;
  70
  71                 QueueManager _queue_manager;
  72                 TraceManager _trace_manager;
  73                 Cache _cache;
  74                 Cache _internalCache;
  75
  76                 public HttpRuntime ()
  77                 {
  78                         WebConfigurationManager.Init ();
  79                         _queue_manager = new QueueManager ();
  80                         _trace_manager = new TraceManager ();
  81                         _cache = new Cache ();
  82                         _internalCache = new Cache();
  83                         _internalCache.DependencyCache = _cache;
  84                 }
  85
  86                 static HttpRuntime _runtimeInstance {
  87                         get {
  88                                 HttpRuntime runtime = (HttpRuntime) AppDomain.CurrentDomain.GetData ("HttpRuntime");
  89                                 if (runtime == null)
  90                                         lock (typeof (HttpRuntime)) {
  91                                                 runtime = (HttpRuntime) AppDomain.CurrentDomain.GetData ("HttpRuntime");
  92                                                 if (runtime == null) {
  93                                                         runtime = new HttpRuntime ();
  94                                                         AppDomain.CurrentDomain.SetData ("HttpRuntime", runtime);
  95                                                 }
  96                                         }
  97                                 return runtime;
  98                         }
  99                 }
 100                 static HttpRuntime _runtime
 101                 {
 102                         get
 103                         {
 104                                 if (HttpContext.Current != null)
 105                                         return HttpContext.Current.HttpRuntimeInstance;
 106                                 else
 107                                         return _runtimeInstance;
 108                         }
 109                 }
 110 #else
 111                 static QueueManager queue_manager;
 112                 static TraceManager trace_manager;
 113                 static Cache cache;
 114                 static Cache internalCache;
 115                 static WaitCallback do_RealProcessRequest;
 116                 static HttpWorkerRequest.EndOfSendNotification end_of_send_cb;
 117                 static Exception initialException;
 118                 static bool firstRun;
 119                 static bool assemblyMappingEnabled;
 120                 static object assemblyMappingLock = new object ();
 121                 static object appOfflineLock = new object ();
 122                 static HttpRuntimeSection runtime_section;
 123
 124                 public HttpRuntime ()
 125                 {
 126
 127                 }
 128 #endif
 129
 130                 static HttpRuntime ()
 131                 {
 132 #if !TARGET_J2EE
 133                         firstRun = true;
 134
 135                         try {
 136                                 WebConfigurationManager.Init ();
 137                                 SettingsMappingManager.Init ();
 138                                 runtime_section = (HttpRuntimeSection) WebConfigurationManager.GetSection ("system.web/httpRuntime");
 139                         } catch (Exception ex) {
 140                                 initialException = ex;
 141                         }
 142
 143                         // The classes in whose constructors exceptions may be thrown, should be handled the same way QueueManager
 144                         // and TraceManager are below. The constructors themselves MUST NOT throw any exceptions - we MUST be sure
 145                         // the objects are created here. The exceptions will be dealt with below, in RealProcessRequest.
 146                         queue_manager = new QueueManager ();
 147                         if (queue_manager.HasException) {
 148                                 if (initialException == null)
 149                                         initialException = queue_manager.InitialException;
 150                                 else {
 151                                         Console.Error.WriteLine ("Exception during QueueManager initialization:");
 152                                         Console.Error.WriteLine (queue_manager.InitialException);
 153                                 }
 154                         }
 155
 156                         trace_manager = new TraceManager ();
 157                         if (trace_manager.HasException) {
 158                                 if (initialException == null)
 159                                         initialException = trace_manager.InitialException;
 160                                 else {
 161                                         Console.Error.WriteLine ("Exception during TraceManager initialization:");
 162                                         Console.Error.WriteLine (trace_manager.InitialException);
 163                                 }
 164                         }
 165
 166                         registeredAssemblies = new SplitOrderedList <string, string> (StringComparer.Ordinal);
 167                         cache = new Cache ();
 168                         internalCache = new Cache ();
 169                         internalCache.DependencyCache = internalCache;
 170 #endif
 171                         do_RealProcessRequest = new WaitCallback (state => {
 172                                 try {
 173                                         RealProcessRequest (state);
 174                                 } catch {}
 175                                 });
 176                         end_of_send_cb = new HttpWorkerRequest.EndOfSendNotification (EndOfSend);
 177                 }
 178
 179                 internal static SplitOrderedList <string, string> RegisteredAssemblies {
 180                         get { return registeredAssemblies; }
 181                 }
 182
 183 #region AppDomain handling
 184                 internal static bool DomainUnloading {
 185                         get { return domainUnloading; }
 186                 }
 187
 188                 [MonoDocumentationNote ("Currently returns path to the application root")]
 189                 public static string AspClientScriptPhysicalPath { get { return AppDomainAppPath; } }
 190
 191                 [MonoDocumentationNote ("Currently returns path to the application root")]
 192                 public static string AspClientScriptVirtualPath { get { return AppDomainAppVirtualPath; } }
 193
 194                 //
 195                 // http://radio.weblogs.com/0105476/stories/2002/07/12/executingAspxPagesWithoutAWebServer.html
 196                 //
 197                 public static string AppDomainAppId {
 198                         [AspNetHostingPermission (SecurityAction.Demand, Level = AspNetHostingPermissionLevel.High)]
 199                         get {
 200                                 //
 201                                 // This value should not change across invocations
 202                                 //
 203                                 string dirname = (string) AppDomain.CurrentDomain.GetData (".appId");
 204                                 if ((dirname != null) && (dirname.Length > 0) && SecurityManager.SecurityEnabled) {
 205                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 206                                 }
 207                                 return dirname;
 208                         }
 209                 }
 210
 211                 // Physical directory for the application
 212                 public static string AppDomainAppPath {
 213                         get {
 214                                 string dirname = (string) AppDomain.CurrentDomain.GetData (".appPath");
 215                                 if (SecurityManager.SecurityEnabled) {
 216                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 217                                 }
 218                                 return dirname;
 219                         }
 220                 }
 221
 222                 public static string AppDomainAppVirtualPath {
 223                         get {
 224                                 return (string) AppDomain.CurrentDomain.GetData (".appVPath");
 225                         }
 226                 }
 227
 228                 public static string AppDomainId {
 229                         [AspNetHostingPermission (SecurityAction.Demand, Level = AspNetHostingPermissionLevel.High)]
 230                         get {
 231                                 return (string) AppDomain.CurrentDomain.GetData (".domainId");
 232                         }
 233                 }
 234
 235                 public static string AspInstallDirectory {
 236                         get {
 237                                 string dirname = (string) AppDomain.CurrentDomain.GetData (".hostingInstallDir");
 238                                 if ((dirname != null) && (dirname.Length > 0) && SecurityManager.SecurityEnabled) {
 239                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 240                                 }
 241                                 return dirname;
 242                         }
 243                 }
 244 #endregion
 245
 246                 static string _actual_bin_directory;
 247                 public static string BinDirectory {
 248                         get {
 249                                 if (_actual_bin_directory == null) {
 250                                         string[] parts = AppDomain.CurrentDomain.SetupInformation.PrivateBinPath.Split (';');
 251                                         string mypath = AppDomainAppPath;
 252                                         string tmp;
 253
 254                                         foreach (string p in parts) {
 255                                                 tmp = Path.Combine (mypath, p);
 256                                                 if (Directory.Exists (tmp)) {
 257                                                         _actual_bin_directory = tmp;
 258                                                         break;
 259                                                 }
 260                                         }
 261
 262                                         if (_actual_bin_directory == null)
 263                                                 _actual_bin_directory = Path.Combine (mypath, "bin");
 264
 265                                         if (_actual_bin_directory [_actual_bin_directory.Length - 1] != Path.DirectorySeparatorChar)
 266                                                 _actual_bin_directory += Path.DirectorySeparatorChar;
 267                                 }
 268
 269                                 if (SecurityManager.SecurityEnabled)
 270                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, _actual_bin_directory).Demand ();
 271
 272                                 return _actual_bin_directory;
 273                         }
 274                 }
 275
 276                 public static Cache Cache {
 277                         get {
 278                                 return cache;
 279                         }
 280                 }
 281
 282                 internal static Cache InternalCache {
 283                         get {
 284                                 return internalCache;
 285                         }
 286                 }
 287
 288                 public static string ClrInstallDirectory {
 289                         get {
 290                                 string dirname = Path.GetDirectoryName (typeof (Object).Assembly.Location);
 291                                 if ((dirname != null) && (dirname.Length > 0) && SecurityManager.SecurityEnabled) {
 292                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 293                                 }
 294                                 return dirname;
 295                         }
 296                 }
 297
 298                 public static string CodegenDir {
 299                         get {
 300                                 string dirname = AppDomain.CurrentDomain.SetupInformation.DynamicBase;
 301                                 if (SecurityManager.SecurityEnabled) {
 302                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 303                                 }
 304                                 return dirname;
 305                         }
 306                 }
 307
 308                 public static bool IsOnUNCShare {
 309                         [AspNetHostingPermission (SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Low)]
 310                         get {
 311                                 return RuntimeHelpers.IsUncShare;
 312                         }
 313                 }
 314
 315                 public static string MachineConfigurationDirectory {
 316                         get {
 317                                 string dirname = Path.GetDirectoryName (ICalls.GetMachineConfigPath ());
 318                                 if ((dirname != null) && (dirname.Length > 0) && SecurityManager.SecurityEnabled) {
 319                                         new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dirname).Demand ();
 320                                 }
 321                                 return dirname;
 322                         }
 323                 }
 324
 325                 internal static HttpRuntimeSection Section { get { return runtime_section; } }
 326
 327                 public static bool UsingIntegratedPipeline { get { return false; } }
 328
 329 #if NET_4_5
 330                 public static Version IISVersion {
 331                         get {
 332                                 // Null means not hosted by IIS
 333                                 return null;
 334                         }
 335                 }
 336
 337                 public static Version TargetFramework {
 338                         get {
 339                                 return runtime_section.TargetFramework;
 340                         }
 341                 }
 342 #endif
 343
 344                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
 345                 public static void Close ()
 346                 {
 347                         // Remove all items from cache.
 348                 }
 349
 350                 internal static HttpWorkerRequest QueuePendingRequest (bool started_internally)
 351                 {
 352                         HttpWorkerRequest next = queue_manager.GetNextRequest (null);
 353                         if (next == null)
 354                                 return null;
 355
 356                         if (!started_internally) {
 357                                 next.StartedInternally = true;
 358                                 ThreadPool.QueueUserWorkItem (do_RealProcessRequest, next);
 359                                 return null;
 360                         }
 361                         return next;
 362                 }
 363
 364 #if !TARGET_J2EE
 365                 static readonly string[] app_offline_files = {"app_offline.htm", "App_Offline.htm", "APP_OFFLINE.HTM"};
 366                 static string app_offline_file;
 367
 368                 static bool AppIsOffline (HttpContext context)
 369                 {
 370                         if (!HttpApplicationFactory.ApplicationDisabled || app_offline_file == null)
 371                                 return false;
 372
 373                         HttpResponse response = context.Response;
 374                         response.Clear ();
 375                         response.ContentType = "text/html";
 376                         response.ExpiresAbsolute = DateTime.UtcNow;
 377                         response.StatusCode = 503;
 378                         response.TransmitFile (app_offline_file, true);
 379
 380                         context.Request.ReleaseResources ();
 381                         context.Response.ReleaseResources ();
 382                         HttpContext.Current = null;
 383                         HttpApplication.requests_total_counter.Increment ();
 384
 385                         return true;
 386                 }
 387
 388                 static void AppOfflineFileRenamed (object sender, RenamedEventArgs args)
 389                 {
 390                         AppOfflineFileChanged (sender, args);
 391                 }
 392
 393                 static void AppOfflineFileChanged (object sender, FileSystemEventArgs args)
 394                 {
 395                         lock (appOfflineLock) {
 396                                 bool offline;
 397
 398                                 switch (args.ChangeType) {
 399                                         case WatcherChangeTypes.Created:
 400                                         case WatcherChangeTypes.Changed:
 401                                                 offline = true;
 402                                                 break;
 403
 404                                         case WatcherChangeTypes.Deleted:
 405                                                 offline = false;
 406                                                 break;
 407
 408                                         case WatcherChangeTypes.Renamed:
 409                                                 RenamedEventArgs rargs = args as RenamedEventArgs;
 410
 411                                                 if (rargs != null &&
 412                                                     String.Compare (rargs.Name, "app_offline.htm", StringComparison.OrdinalIgnoreCase) == 0)
 413                                                         offline = true;
 414                                                 else
 415                                                         offline = false;
 416                                                 break;
 417
 418                                         default:
 419                                                 offline = false;
 420                                                 break;
 421                                 }
 422                                 SetOfflineMode (offline, args.FullPath);
 423                         }
 424                 }
 425
 426                 static void SetOfflineMode (bool offline, string filePath)
 427                 {
 428                         if (!offline) {
 429                                 app_offline_file = null;
 430                                 if (HttpApplicationFactory.ApplicationDisabled)
 431                                         HttpRuntime.UnloadAppDomain ();
 432                         } else {
 433                                 app_offline_file = filePath;
 434                                 HttpApplicationFactory.DisableWatchers ();
 435                                 HttpApplicationFactory.ApplicationDisabled = true;
 436                                 InternalCache.InvokePrivateCallbacks ();
 437                                 HttpApplicationFactory.Dispose ();
 438                         }
 439                 }
 440
 441                 static void SetupOfflineWatch ()
 442                 {
 443                         lock (appOfflineLock) {
 444                                 FileSystemEventHandler seh = new FileSystemEventHandler (AppOfflineFileChanged);
 445                                 RenamedEventHandler reh = new RenamedEventHandler (AppOfflineFileRenamed);
 446
 447                                 string app_dir = AppDomainAppPath;
 448                                 FileSystemWatcher watcher;
 449                                 string offlineFile = null, tmp;
 450
 451                                 foreach (string f in app_offline_files) {
 452                                         watcher = new FileSystemWatcher ();
 453                                         watcher.Path = Path.GetDirectoryName (app_dir);
 454                                         watcher.Filter = Path.GetFileName (f);
 455                                         watcher.NotifyFilter |= NotifyFilters.Size;
 456                                         watcher.Deleted += seh;
 457                                         watcher.Changed += seh;
 458                                         watcher.Created += seh;
 459                                         watcher.Renamed += reh;
 460                                         watcher.EnableRaisingEvents = true;
 461
 462                                         tmp = Path.Combine (app_dir, f);
 463                                         if (File.Exists (tmp))
 464                                                 offlineFile = tmp;
 465                                 }
 466
 467                                 if (offlineFile != null)
 468                                         SetOfflineMode (true, offlineFile);
 469                         }
 470                 }
 471 #endif
 472
 473                 static void RealProcessRequest (object o)
 474                 {
 475                         if (domainUnloading) {
 476                                 Console.Error.WriteLine ("Domain is unloading, not processing the request.");
 477                                 return;
 478                         }
 479
 480                         HttpWorkerRequest req = (HttpWorkerRequest) o;
 481                         bool started_internally = req.StartedInternally;
 482                         do {
 483                                 Process (req);
 484                                 req = QueuePendingRequest (started_internally);
 485                         } while (started_internally && req != null);
 486                 }
 487
 488                 static void Process (HttpWorkerRequest req)
 489                 {
 490                         bool error = false;
 491 #if TARGET_J2EE
 492                         HttpContext context = HttpContext.Current;
 493                         if (context == null)
 494                                 context = new HttpContext (req);
 495                         else
 496                                 context.SetWorkerRequest (req);
 497 #else
 498                         if (firstRun) {
 499                                 firstRun = false;
 500                                 if (initialException != null) {
 501                                         FinishWithException (req, HttpException.NewWithCode ("Initial exception", initialException, WebEventCodes.RuntimeErrorRequestAbort));
 502                                         error = true;
 503                                 }
 504                                 SetupOfflineWatch ();
 505                         }
 506                         HttpContext context = new HttpContext (req);
 507 #endif
 508                         HttpContext.Current = context;
 509 #if !TARGET_J2EE
 510                         if (AppIsOffline (context))
 511                                 return;
 512 #endif
 513
 514                         //
 515                         // Get application instance (create or reuse an instance of the correct class)
 516                         //
 517                         HttpApplication app = null;
 518                         if (!error) {
 519                                 try {
 520                                         app = HttpApplicationFactory.GetApplication (context);
 521                                 } catch (Exception e) {
 522                                         FinishWithException (req, HttpException.NewWithCode (String.Empty, e, WebEventCodes.RuntimeErrorRequestAbort));
 523                                         error = true;
 524                                 }
 525                         }
 526
 527                         if (error) {
 528                                 context.Request.ReleaseResources ();
 529                                 context.Response.ReleaseResources ();
 530                                 HttpContext.Current = null;
 531                         } else {
 532                                 context.ApplicationInstance = app;
 533                                 req.SetEndOfSendNotification (end_of_send_cb, context);
 534
 535                                 //
 536                                 // Ask application to service the request
 537                                 //
 538
 539 #if TARGET_J2EE
 540                                 IHttpAsyncHandler ihah = app;
 541                                 if (context.Handler == null)
 542                                         ihah.BeginProcessRequest (context, new AsyncCallback (request_processed), context);
 543                                 else
 544                                         app.Tick ();
 545                                 //ihh.ProcessRequest (context);
 546                                 IHttpExtendedHandler extHandler = context.Handler as IHttpExtendedHandler;
 547                                 if (extHandler != null && !extHandler.IsCompleted)
 548                                         return;
 549                                 if (context.Error is UnifyRequestException)
 550                                         return;
 551
 552                                 ihah.EndProcessRequest (null);
 553 #else
 554                                 IHttpHandler ihh = app;
 555 //                              IAsyncResult appiar = ihah.BeginProcessRequest (context, new AsyncCallback (request_processed), context);
 556 //                              ihah.EndProcessRequest (appiar);
 557                                 ihh.ProcessRequest (context);
 558 #endif
 559
 560                                 HttpApplicationFactory.Recycle (app);
 561                         }
 562                 }
 563
 564                 static void EndOfSend (HttpWorkerRequest ignored1, object ignored2)
 565                 {
 566                 }
 567
 568                 //
 569                 // ProcessRequest method is executed in the AppDomain of the application
 570                 //
 571                 // Observations:
 572                 //    ProcessRequest does not guarantee that `wr' will be processed synchronously,
 573                 //    the request can be queued and processed later.
 574                 //
 575                 [AspNetHostingPermission (SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Medium)]
 576                 public static void ProcessRequest (HttpWorkerRequest wr)
 577                 {
 578                         if (wr == null)
 579                                 throw new ArgumentNullException ("wr");
 580                         //
 581                         // Queue our request, fetch the next available one from the queue
 582                         //
 583                         HttpWorkerRequest request = queue_manager.GetNextRequest (wr);
 584                         if (request == null)
 585                                 return;
 586
 587                         QueuePendingRequest (false);
 588                         RealProcessRequest (request);
 589                 }
 590
 591 #if TARGET_J2EE
 592                 //
 593                 // Callback to be invoked by IHttpAsyncHandler.BeginProcessRequest
 594                 //
 595                 static void request_processed (IAsyncResult iar)
 596                 {
 597                         HttpContext context = (HttpContext) iar.AsyncState;
 598
 599                         context.Request.ReleaseResources ();
 600                         context.Response.ReleaseResources ();
 601                 }
 602 #endif
 603
 604 #if TARGET_JVM
 605                 [MonoNotSupported ("UnloadAppDomain is not supported")]
 606                 public static void UnloadAppDomain ()
 607                 {
 608                         throw new NotImplementedException ("UnloadAppDomain is not supported");
 609                 }
 610 #else
 611                 //
 612                 // Called when we are shutting down or we need to reload an application
 613                 // that has been modified (touch global.asax)
 614                 //
 615                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
 616                 public static void UnloadAppDomain ()
 617                 {
 618                         //
 619                         // TODO: call ReleaseResources
 620                         //
 621                         domainUnloading = true;
 622                         HttpApplicationFactory.DisableWatchers ();
 623                         ThreadPool.QueueUserWorkItem (delegate {
 624                                 try {
 625                                         ShutdownAppDomain ();
 626                                 } catch (Exception e){
 627                                         Console.Error.WriteLine (e);
 628                                 }
 629                         });
 630                 }
 631 #endif
 632                 //
 633                 // Shuts down the AppDomain
 634                 //
 635                 static void ShutdownAppDomain ()
 636                 {
 637                         queue_manager.Dispose ();
 638                         // This will call Session_End if needed.
 639                         InternalCache.InvokePrivateCallbacks ();
 640                         // Kill our application.
 641                         HttpApplicationFactory.Dispose ();
 642                         ThreadPool.QueueUserWorkItem (delegate {
 643                                 try {
 644                                         DoUnload ();
 645                                 } catch {
 646                                 }});
 647                 }
 648
 649                 static void DoUnload ()
 650                 {
 651 #if TARGET_J2EE
 652                         // No unload support for appdomains under Grasshopper
 653 #else
 654                         AppDomain.Unload (AppDomain.CurrentDomain);
 655 #endif
 656                 }
 657
 658                 static string content503 = "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\n" +
 659                         "<html><head>\n<title>503 Server Unavailable</title>\n</head><body>\n" +
 660                         "<h1>Server Unavailable</h1>\n" +
 661                         "</body></html>\n";
 662
 663                 static void FinishWithException (HttpWorkerRequest wr, HttpException e)
 664                 {
 665                         int code = e.GetHttpCode ();
 666                         wr.SendStatus (code, HttpWorkerRequest.GetStatusDescription (code));
 667                         wr.SendUnknownResponseHeader ("Connection", "close");
 668                         Encoding enc = Encoding.ASCII;
 669                         wr.SendUnknownResponseHeader ("Content-Type", "text/html; charset=" + enc.WebName);
 670                         string msg = e.GetHtmlErrorMessage ();
 671                         byte [] contentBytes = enc.GetBytes (msg);
 672                         wr.SendUnknownResponseHeader ("Content-Length", contentBytes.Length.ToString ());
 673                         wr.SendResponseFromMemory (contentBytes, contentBytes.Length);
 674                         wr.FlushResponse (true);
 675                         wr.CloseConnection ();
 676                         HttpApplication.requests_total_counter.Increment ();
 677                 }
 678
 679                 //
 680                 // This is called from the QueueManager if a request
 681                 // can not be processed (load, no resources, or
 682                 // appdomain unload).
 683                 //
 684                 static internal void FinishUnavailable (HttpWorkerRequest wr)
 685                 {
 686                         wr.SendStatus (503, "Service unavailable");
 687                         wr.SendUnknownResponseHeader ("Connection", "close");
 688                         Encoding enc = Encoding.ASCII;
 689                         wr.SendUnknownResponseHeader ("Content-Type", "text/html; charset=" + enc.WebName);
 690                         byte [] contentBytes = enc.GetBytes (content503);
 691                         wr.SendUnknownResponseHeader ("Content-Length", contentBytes.Length.ToString ());
 692                         wr.SendResponseFromMemory (contentBytes, contentBytes.Length);
 693                         wr.FlushResponse (true);
 694                         wr.CloseConnection ();
 695                         HttpApplication.requests_total_counter.Increment ();
 696                 }
 697
 698                 [AspNetHostingPermissionAttribute(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Unrestricted)]
 699                 [MonoDocumentationNote ("Always returns null on Mono")]
 700                 public static NamedPermissionSet GetNamedPermissionSet ()
 701                 {
 702                         return null;
 703                 }
 704
 705 #if !TARGET_J2EE
 706                 static internal void WritePreservationFile (Assembly asm, string genericNameBase)
 707                 {
 708                         if (asm == null)
 709                                 throw new ArgumentNullException ("asm");
 710                         if (String.IsNullOrEmpty (genericNameBase))
 711                                 throw new ArgumentNullException ("genericNameBase");
 712
 713                         string compiled = Path.Combine (AppDomain.CurrentDomain.SetupInformation.DynamicBase,
 714                                                         genericNameBase + ".compiled");
 715                         PreservationFile pf = new PreservationFile ();
 716                         try {
 717                                 pf.VirtualPath = String.Concat ("/", genericNameBase, "/");
 718
 719                                 AssemblyName an = asm.GetName ();
 720                                 pf.Assembly = an.Name;
 721                                 pf.ResultType = BuildResultTypeCode.TopLevelAssembly;
 722                                 pf.Save (compiled);
 723                         } catch (Exception ex) {
 724                                 throw new HttpException (
 725                                         String.Format ("Failed to write preservation file {0}", genericNameBase + ".compiled"),
 726                                         ex);
 727                         }
 728                 }
 729
 730                 static Assembly ResolveAssemblyHandler(object sender, ResolveEventArgs e)
 731                 {
 732                         AssemblyName an = new AssemblyName (e.Name);
 733                         string dynamic_base = AppDomain.CurrentDomain.SetupInformation.DynamicBase;
 734                         string compiled = Path.Combine (dynamic_base, an.Name + ".compiled");
 735                         string asmPath;
 736
 737                         if (!File.Exists (compiled)) {
 738                                 string fn = an.FullName;
 739                                 if (!RegisteredAssemblies.Find ((uint)fn.GetHashCode (), fn, out asmPath))
 740                                         return null;
 741                         } else {
 742                                 PreservationFile pf;
 743                                 try {
 744                                         pf = new PreservationFile (compiled);
 745                                 } catch (Exception ex) {
 746                                         throw new HttpException (
 747                                                 String.Format ("Failed to read preservation file {0}", an.Name + ".compiled"),
 748                                                 ex);
 749                                 }
 750                                 asmPath = Path.Combine (dynamic_base, pf.Assembly + ".dll");
 751                         }
 752
 753                         if (String.IsNullOrEmpty (asmPath))
 754                                 return null;
 755
 756                         Assembly ret = null;
 757                         try {
 758                                 ret = Assembly.LoadFrom (asmPath);
 759                         } catch (Exception) {
 760                                 // ignore
 761                         }
 762
 763                         return ret;
 764                 }
 765
 766                 internal static void EnableAssemblyMapping (bool enable)
 767                 {
 768                         lock (assemblyMappingLock) {
 769                                 if (assemblyMappingEnabled == enable)
 770                                         return;
 771                                 if (enable)
 772                                         AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler (ResolveAssemblyHandler);
 773                                 else
 774                                         AppDomain.CurrentDomain.AssemblyResolve -= new ResolveEventHandler (ResolveAssemblyHandler);
 775                                 assemblyMappingEnabled = enable;
 776                         }
 777                 }
 778 #endif // #if !TARGET_J2EE
 779
 780                 internal static TraceManager TraceManager {
 781                         get {
 782                                 return trace_manager;
 783                         }
 784                 }
 785         }
 786 }