mcs/class/corlib/System.Threading/CompressedStack.cs

   1 //
   2 // System.Threading.Thread.cs
   3 //
   4 // Authors:
   5 //      Zoltan Varga (vargaz@freemail.hu)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System.Collections;
  31 using System.Diagnostics;
  32 using System.Reflection;
  33 using System.Runtime.InteropServices;
  34 using System.Runtime.Serialization;
  35 using System.Security;
  36 using System.Security.Permissions;
  37
  38 namespace System.Threading {
  39
  40         [Serializable]
  41         public sealed class CompressedStack : ISerializable {
  42                 private ArrayList _list;
  43
  44                 internal CompressedStack (int length)
  45                 {
  46                         if (length > 0)
  47                                 _list = new ArrayList (length);
  48                 }
  49
  50                 internal CompressedStack (CompressedStack cs)
  51                 {
  52                         if ((cs != null) && (cs._list != null))
  53                                 _list = (ArrayList) cs._list.Clone ();
  54                 }
  55
  56                 [ComVisibleAttribute (false)]
  57                 public CompressedStack CreateCopy ()
  58                 {
  59                         return new CompressedStack (this);
  60                 }
  61
  62                 public static CompressedStack Capture ()
  63                 {
  64 #if !FEATURE_COMPRESSEDSTACK
  65                         throw new NotSupportedException ();
  66 #else
  67                         CompressedStack cs = new CompressedStack (0);
  68                         cs._list = new ArrayList ();
  69
  70                         // include any current CompressedStack inside the new Capture
  71                         CompressedStack currentCs = Thread.CurrentThread.ExecutionContext.SecurityContext.CompressedStack;
  72                         if (currentCs != null) {
  73                                 for (int i=0; i < currentCs._list.Count; i++)
  74                                         cs._list.Add (currentCs._list [i]);
  75                         }
  76                         return cs;
  77 #endif
  78                 }
  79
  80                 // NOTE: This method doesn't show in the class library status page because
  81                 // it cannot be "found" with the StrongNameIdentityPermission for ECMA key.
  82                 // But it's there!
  83                 [SecurityCritical]
  84                 static public CompressedStack GetCompressedStack ()
  85                 {
  86 #if !FEATURE_COMPRESSEDSTACK
  87                         throw new NotSupportedException ();
  88 #else
  89                         // Note: CompressedStack.GetCompressedStack doesn't return null
  90                         // like Thread.CurrentThread.GetCompressedStack if no compressed
  91                         // stack is present.
  92
  93             CompressedStack cs = Thread.CurrentThread.ExecutionContext.SecurityContext.CompressedStack;
  94                         if (cs == null || cs.IsEmpty ()) {
  95                                 cs = CompressedStack.Capture ();
  96                         } else {
  97                                 cs = cs.CreateCopy ();
  98                                 // merge the existing compressed stack (from a previous Thread) with the current
  99                                 // Thread stack so we can assign "all of it" to yet another Thread
 100                                 CompressedStack newstack = CompressedStack.Capture ();
 101                                 for (int i=0; i < newstack._list.Count; i++)
 102                                         cs._list.Add (newstack._list [i]);
 103                         }
 104                         return cs;
 105 #endif
 106                 }
 107
 108                 [MonoTODO ("incomplete")]
 109                 [SecurityCritical]
 110                 public void GetObjectData (SerializationInfo info, StreamingContext context)
 111                 {
 112                         if (info == null)
 113                                 throw new ArgumentNullException ("info");
 114                 }
 115
 116                 [SecurityCritical]
 117                 static public void Run (CompressedStack compressedStack, ContextCallback callback, object state)
 118                 {
 119 #if !FEATURE_COMPRESSEDSTACK
 120                         throw new NotSupportedException ();
 121 #else
 122                         if (compressedStack == null)
 123                                 throw new ArgumentException ("compressedStack");
 124
 125                         Thread t = Thread.CurrentThread;
 126                         CompressedStack original = null;
 127                         try {
 128                                 original = t.ExecutionContext.SecurityContext.CompressedStack;
 129                                 t.ExecutionContext.SecurityContext.CompressedStack = compressedStack;
 130                                 callback (state);
 131                         }
 132                         finally {
 133                                 if (original != null)
 134                                         t.ExecutionContext.SecurityContext.CompressedStack = original;
 135                         }
 136 #endif
 137                 }
 138
 139                 // internal stuff
 140                 internal bool Equals (CompressedStack cs)
 141                 {
 142                         if (IsEmpty ())
 143                                 return cs.IsEmpty ();
 144                         if (cs.IsEmpty ())
 145                                 return false;
 146                         if (_list.Count != cs._list.Count)
 147                                 return false;
 148
 149                         return true;
 150                 }
 151
 152                 internal bool IsEmpty ()
 153                 {
 154                         return ((_list == null) || (_list.Count == 0));
 155                 }
 156
 157                 internal IList List {
 158                         get { return _list; }
 159                 }
 160         }
 161 }