mcs/class/System.Windows.Forms/System.Windows.Forms/AsyncMethodResult.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2004 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Jackson Harper (jackson@ximian.com)
  24
  25
  26 using System;
  27 using System.Threading;
  28
  29 namespace System.Windows.Forms {
  30
  31         internal class AsyncMethodResult : IAsyncResult {
  32
  33                 private ManualResetEvent handle;
  34                 private object state;
  35                 private bool completed;
  36                 private object return_value;
  37                 private Exception exception;
  38
  39                 public AsyncMethodResult ()
  40                 {
  41                         handle = new ManualResetEvent (false);
  42                 }
  43
  44                 public virtual WaitHandle AsyncWaitHandle {
  45                         get {
  46                                 lock (this) {
  47                                         return handle;
  48                                 }
  49                         }
  50                 }
  51
  52                 public object AsyncState {
  53                         get { return state; }
  54                         set { state = value; }
  55                 }
  56
  57                 public bool CompletedSynchronously {
  58                         get { return false; }
  59                 }
  60
  61                 public bool IsCompleted {
  62                         get {
  63                                 lock (this) {
  64                                         return completed;
  65                                 }
  66                         }
  67                 }
  68
  69                 public object EndInvoke ()
  70                 {
  71                         lock (this) {
  72                                 if (completed) {
  73                                         if (exception == null)
  74                                                 return return_value;
  75                                         else
  76                                                 throw exception;
  77                                 }
  78                         }
  79                         handle.WaitOne ();
  80
  81                         if (exception != null)
  82                                 throw exception;
  83
  84                         return return_value;
  85                 }
  86
  87                 public void Complete (object result)
  88                 {
  89                         lock (this) {
  90                                 completed = true;
  91                                 return_value = result;
  92                                 handle.Set ();
  93                         }
  94                 }
  95
  96                 public void CompleteWithException (Exception ex)
  97                 {
  98                         lock (this) {
  99                                 completed = true;
 100                                 exception = ex;
 101                                 handle.Set ();
 102                         }
 103                 }
 104         }
 105
 106 }
 107
 108