class/System/System.ComponentModel/AsyncOperation.cs

   1 //
   2 // AsyncOperation.cs
   3 //
   4 // Authors:
   5 //      Atsushi Enomoto <atsushi@ximian.com>
   6 //
   7 // Copyright (C) 2006 Novell, Inc.
   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 #if NET_2_0
  31 using System.Threading;
  32
  33 namespace System.ComponentModel
  34 {
  35         public sealed class AsyncOperation
  36         {
  37                 internal AsyncOperation (SynchronizationContext ctx,
  38                                          object state)
  39                 {
  40                         this.ctx = ctx;
  41                         this.state = state;
  42
  43                         ctx.OperationStarted ();
  44                 }
  45
  46                 ~AsyncOperation ()
  47                 {
  48                         if (!done && ctx != null)
  49                                 ctx.OperationCompleted ();
  50                 }
  51
  52                 SynchronizationContext ctx;
  53                 object state;
  54                 bool done;
  55
  56                 public SynchronizationContext SynchronizationContext {
  57                         get { return ctx; }
  58                 }
  59
  60                 public object UserSuppliedState {
  61                         get { return state; }
  62                 }
  63
  64                 public void OperationCompleted ()
  65                 {
  66                         if (done)
  67                                 throw new InvalidOperationException ("This task is already completed. Multiple call to OperationCompleted is not allowed.");
  68
  69                         ctx.OperationCompleted ();
  70
  71                         done = true;
  72                 }
  73
  74                 public void Post (SendOrPostCallback d, object arg)
  75                 {
  76                         if (done)
  77                                 throw new InvalidOperationException ("This task is already completed. Multiple call to Post is not allowed.");
  78
  79                         ctx.Post (d, arg);
  80                 }
  81
  82                 public void PostOperationCompleted (
  83                         SendOrPostCallback d, object arg)
  84                 {
  85                         if (done)
  86                                 throw new InvalidOperationException ("This task is already completed. Multiple call to PostOperationCompleted is not allowed.");
  87
  88                         Post (d, arg);
  89                         OperationCompleted ();
  90                 }
  91         }
  92 }
  93 #endif