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