class/corlib/System/LocalDataStoreSlot.cs

   1 //
   2 // System.LocalDataStoreSlot.cs
   3 //
   4 // Author:
   5 //   Dick Porter (dick@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Reflection;
  34 using System.Runtime.CompilerServices;
  35 using System.Runtime.InteropServices;
  36
  37 namespace System
  38 {
  39         [ComVisible (true)]
  40         public sealed class LocalDataStoreSlot
  41         {
  42                 internal int slot;
  43                 internal bool thread_local; // false for context-local
  44
  45                 static object lock_obj = new object ();
  46                 static bool[] slot_bitmap_thread;
  47                 static bool[] slot_bitmap_context;
  48
  49                 internal LocalDataStoreSlot (bool in_thread)
  50                 {
  51                         thread_local = in_thread;
  52                         lock (lock_obj) {
  53                                 int i;
  54                                 bool[] slot_bitmap;
  55                                 if (in_thread)
  56                                         slot_bitmap = slot_bitmap_thread;
  57                                 else
  58                                         slot_bitmap = slot_bitmap_context;
  59                                 if (slot_bitmap != null) {
  60                                         for (i = 0; i < slot_bitmap.Length; ++i) {
  61                                                 if (!slot_bitmap [i]) {
  62                                                         slot = i;
  63                                                         slot_bitmap [i] = true;
  64                                                         return;
  65                                                 }
  66                                         }
  67                                         bool[] new_bitmap = new bool [i + 2];
  68                                         slot_bitmap.CopyTo (new_bitmap, 0);
  69                                         slot_bitmap = new_bitmap;
  70                                 } else {
  71                                         slot_bitmap = new bool [2];
  72                                         i = 0;
  73                                 }
  74                                 slot_bitmap [i] = true;
  75                                 slot = i;
  76                                 if (in_thread)
  77                                         slot_bitmap_thread = slot_bitmap;
  78                                 else
  79                                         slot_bitmap_context = slot_bitmap;
  80                         }
  81                 }
  82
  83                 ~LocalDataStoreSlot ()
  84                 {
  85                         /* first remove all the values from the slots and
  86                          * then free the slot itself for reuse.
  87                          */
  88                         System.Threading.Thread.FreeLocalSlotValues (slot, thread_local);
  89                         lock (lock_obj) {
  90                                 if (thread_local)
  91                                         slot_bitmap_thread [slot] = false;
  92                                 else
  93                                         slot_bitmap_context [slot] = false;
  94                         }
  95                 }
  96         }
  97 }