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

   1 //
   2 // CancellationToken.cs
   3 //
   4 // Author:
   5 //       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
   6 //
   7 // Copyright (c) 2009 Jérémie "Garuma" Laval
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining a copy
  10 // of this software and associated documentation files (the "Software"), to deal
  11 // in the Software without restriction, including without limitation the rights
  12 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13 // copies of the Software, and to permit persons to whom the Software is
  14 // furnished to do so, subject to the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be included in
  17 // all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25 // THE SOFTWARE.
  26
  27 using System;
  28 using System.Threading;
  29
  30 #if NET_4_0 || BOOTSTRAP_NET_4_0
  31 namespace System.Threading
  32 {
  33         public struct CancellationToken
  34         {
  35                 public CancellationToken (bool canceled)
  36                         : this ()
  37                 {
  38                         // dummy, this is actually set by CancellationTokenSource when the token is created
  39                         Source = null;
  40                 }
  41
  42                 public static CancellationToken None {
  43                         get {
  44                                 return CancellationTokenSource.NoneSource.Token;
  45                         }
  46                 }
  47
  48                 public CancellationTokenRegistration Register (Action callback)
  49                 {
  50                         return Register (callback, false);
  51                 }
  52
  53                 public CancellationTokenRegistration Register (Action callback, bool useSynchronizationContext)
  54                 {
  55                         if (callback == null)
  56                                 throw new ArgumentNullException ("callback");
  57
  58                         return Source.Register (callback, useSynchronizationContext);
  59                 }
  60
  61                 public CancellationTokenRegistration Register (Action<object> callback, object state)
  62                 {
  63                         return Register (callback, state, false);
  64                 }
  65
  66                 public CancellationTokenRegistration Register (Action<object> callback, object state, bool useSynchronizationContext)
  67                 {
  68                         if (callback == null)
  69                                 throw new ArgumentNullException ("callback");
  70
  71                         return Register (() => callback (state), useSynchronizationContext);
  72                 }
  73
  74                 public void ThrowIfCancellationRequested ()
  75                 {
  76                         if (Source.IsCancellationRequested)
  77                                 throw new OperationCanceledException (this);
  78                 }
  79
  80                 public bool Equals (CancellationToken other)
  81                 {
  82                         return this.Source == other.Source;
  83                 }
  84
  85                 public override bool Equals (object obj)
  86                 {
  87                         return (obj is CancellationToken) ? Equals ((CancellationToken)obj) : false;
  88                 }
  89
  90                 public override int GetHashCode ()
  91                 {
  92                         return Source.GetHashCode ();
  93                 }
  94
  95                 public static bool operator == (CancellationToken lhs, CancellationToken rhs)
  96                 {
  97                         return lhs.Equals (rhs);
  98                 }
  99
 100                 public static bool operator != (CancellationToken lhs, CancellationToken rhs)
 101                 {
 102                         return !lhs.Equals (rhs);
 103                 }
 104
 105                 public bool CanBeCanceled {
 106                         get {
 107                                 return true;
 108                         }
 109                 }
 110
 111                 public bool IsCancellationRequested {
 112                         get {
 113                                 return Source.IsCancellationRequested;
 114                         }
 115                 }
 116
 117                 public WaitHandle WaitHandle {
 118                         get {
 119                                 return Source.WaitHandle;
 120                         }
 121                 }
 122
 123                 internal CancellationTokenSource Source {
 124                         get;
 125                         set;
 126                 }
 127         }
 128 }
 129 #endif