mcs/class/System/System.Net/WebConnectionGroup.cs

   1 //
   2 // System.Net.WebConnectionGroup
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003 Ximian, Inc (http://www.ximian.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.Net.Configuration;
  34 using System.Net.Sockets;
  35
  36 namespace System.Net
  37 {
  38         class WebConnectionGroup
  39         {
  40                 ServicePoint sPoint;
  41                 string name;
  42                 ArrayList connections;
  43                 Random rnd;
  44                 Queue queue;
  45
  46                 public WebConnectionGroup (ServicePoint sPoint, string name)
  47                 {
  48                         this.sPoint = sPoint;
  49                         this.name = name;
  50                         connections = new ArrayList (1);
  51                         queue = new Queue ();
  52                 }
  53
  54                 public WebConnection GetConnection ()
  55                 {
  56                         WebConnection cnc = null;
  57                         lock (connections) {
  58                                 WeakReference cncRef = null;
  59
  60                                 // Remove disposed connections
  61                                 int end = connections.Count;
  62                                 ArrayList removed = null;
  63                                 for (int i = 0; i < end; i++) {
  64                                         cncRef = (WeakReference) connections [i];
  65                                         cnc = cncRef.Target as WebConnection;
  66                                         if (cnc == null) {
  67                                                 if (removed == null)
  68                                                         removed = new ArrayList (1);
  69
  70                                                 removed.Add (i);
  71                                         }
  72                                 }
  73
  74                                 if (removed != null) {
  75                                         for (int i = removed.Count - 1; i >= 0; i--)
  76                                                 connections.RemoveAt ((int) removed [i]);
  77                                 }
  78
  79                                 cnc = CreateOrReuseConnection ();
  80                         }
  81
  82                         return cnc;
  83                 }
  84
  85                 WebConnection CreateOrReuseConnection ()
  86                 {
  87                         // lock is up there.
  88                         WebConnection cnc;
  89                         WeakReference cncRef;
  90
  91                         int count = connections.Count;
  92                         for (int i = 0; i < count; i++) {
  93                                 WeakReference wr = connections [i] as WeakReference;
  94                                 cnc = wr.Target as WebConnection;
  95                                 if (cnc == null) {
  96                                         connections.RemoveAt (i);
  97                                         count--;
  98                                         i--;
  99                                         continue;
 100                                 }
 101
 102                                 if (cnc.Busy)
 103                                         continue;
 104
 105                                 return cnc;
 106                         }
 107
 108                         if (sPoint.ConnectionLimit > count) {
 109                                 cnc = new WebConnection (this, sPoint);
 110                                 connections.Add (new WeakReference (cnc));
 111                                 return cnc;
 112                         }
 113
 114                         if (rnd == null)
 115                                 rnd = new Random ();
 116
 117                         int idx = (count > 1) ? rnd.Next (0, count - 1) : 0;
 118                         cncRef = (WeakReference) connections [idx];
 119                         cnc = cncRef.Target as WebConnection;
 120                         if (cnc == null) {
 121                                 cnc = new WebConnection (this, sPoint);
 122                                 connections.RemoveAt (idx);
 123                                 connections.Add (new WeakReference (cnc));
 124                         }
 125                         return cnc;
 126                 }
 127
 128                 public string Name {
 129                         get { return name; }
 130                 }
 131
 132                 internal Queue Queue {
 133                         get { return queue; }
 134                 }
 135
 136         }
 137 }
 138