mcs/class/System.Web/System.Web/QueueManager.cs

   1 //
   2 // System.Web.QueueManager
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003,2004 Novell, Inc (http://www.novell.com)
   8 //
   9
  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 using System;
  32 using System.Collections;
  33 using System.Threading;
  34 using System.Web.Configuration;
  35
  36 namespace System.Web
  37 {
  38         class QueueManager
  39         {
  40                 int minFree;
  41                 int minLocalFree;
  42                 int queueLimit;
  43                 Queue queue;
  44                 bool disposing;
  45
  46                 public QueueManager ()
  47                 {
  48 #if NET_2_0
  49                         HttpRuntimeSection config;
  50
  51                         config = (HttpRuntimeSection) WebConfigurationManager.GetSection ("system.web/httpRuntime");
  52 #else
  53                         HttpRuntimeConfig config;
  54
  55                         config = (HttpRuntimeConfig) HttpContext.GetAppConfig ("system.web/httpRuntime");
  56 #endif
  57                         minFree = config.MinFreeThreads;
  58                         minLocalFree = config.MinLocalRequestFreeThreads;
  59                         queueLimit = config.AppRequestQueueLimit;
  60                         queue = new Queue (queueLimit);
  61                 }
  62
  63                 bool CanExecuteRequest (HttpWorkerRequest req)
  64                 {
  65                         if (disposing)
  66                                 return false;
  67
  68 #if TARGET_J2EE
  69                         return true; // The J2EE app server manages the thread pool
  70 #else
  71                         int threads, cports;
  72                         ThreadPool.GetAvailableThreads (out threads, out cports);
  73                         bool local = (req != null && req.GetLocalAddress () == "127.0.0.1");
  74                         return (threads > minFree) || (local && threads > minLocalFree);
  75 #endif
  76                 }
  77
  78                 public HttpWorkerRequest GetNextRequest (HttpWorkerRequest req)
  79                 {
  80                         if (!CanExecuteRequest (req)) {
  81                                 if (!disposing && req != null) {
  82                                         lock (queue) {
  83                                                 Queue (req);
  84                                         }
  85                                 }
  86
  87                                 return null;
  88                         }
  89
  90                         HttpWorkerRequest result;
  91                         lock (queue) {
  92                                 result = Dequeue ();
  93                                 if (result != null) {
  94                                         if (req != null)
  95                                                 Queue (req);
  96                                 } else {
  97                                         result = req;
  98                                 }
  99                         }
 100
 101                         return result;
 102                 }
 103
 104                 void Queue (HttpWorkerRequest wr)
 105                 {
 106                         if (queue.Count < queueLimit) {
 107                                 queue.Enqueue (wr);
 108                                 return;
 109                         }
 110
 111                         HttpRuntime.FinishUnavailable (wr);
 112                 }
 113
 114                 HttpWorkerRequest Dequeue ()
 115                 {
 116                         if (queue.Count > 0)
 117                                 return (HttpWorkerRequest) queue.Dequeue ();
 118
 119                         return null;
 120                 }
 121
 122                 public void Dispose ()
 123                 {
 124                         if (disposing)
 125                                 return;
 126
 127                         disposing = true;
 128                         HttpWorkerRequest wr;
 129                         while ((wr = GetNextRequest (null)) != null)
 130                                 HttpRuntime.FinishUnavailable (wr);
 131
 132                         queue = null;
 133                 }
 134         }
 135 }
 136