class/corlib/System.Threading/ManualResetEventSlim.cs

   1 #if NET_4_0
   2 // ManuelResetEventSlim.cs
   3 //
   4 // Copyright (c) 2008 Jérémie "Garuma" Laval
   5 //
   6 // Permission is hereby granted, free of charge, to any person obtaining a copy
   7 // of this software and associated documentation files (the "Software"), to deal
   8 // in the Software without restriction, including without limitation the rights
   9 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 // copies of the Software, and to permit persons to whom the Software is
  11 // furnished to do so, subject to the following conditions:
  12 //
  13 // The above copyright notice and this permission notice shall be included in
  14 // all copies or substantial portions of the Software.
  15 //
  16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 // THE SOFTWARE.
  23 //
  24 //
  25
  26 using System;
  27 using System.Diagnostics;
  28
  29 namespace System.Threading
  30 {
  31         public class ManualResetEventSlim : IDisposable
  32         {
  33                 const int defaultSpinCount = 20;
  34                 const int isSet    = 1;
  35                 const int isNotSet = 0;
  36                 readonly int spinCount;
  37                 readonly SpinWait sw = new SpinWait ();
  38
  39                 int state;
  40
  41
  42                 public ManualResetEventSlim () : this(false, 20)
  43                 {
  44                 }
  45
  46                 public ManualResetEventSlim (bool initState) : this (initState, 20)
  47                 {
  48                 }
  49
  50                 public ManualResetEventSlim (bool initState, int spinCount)
  51                 {
  52                         this.state = initState ? isSet : isNotSet;
  53                         this.spinCount = spinCount;
  54                 }
  55
  56                 public bool IsSet {
  57                         get {
  58                                 return state == isSet;
  59                         }
  60                 }
  61
  62                 public int SpinCount {
  63                         get {
  64                                 return spinCount;
  65                         }
  66                 }
  67
  68                 public void Reset ()
  69                 {
  70                         Interlocked.Exchange (ref state, isNotSet);
  71                 }
  72
  73                 public void Set ()
  74                 {
  75                         Interlocked.Exchange (ref state, isSet);
  76                 }
  77
  78                 public void Wait ()
  79                 {
  80                         // First spin
  81                         for (int i = 0; i < spinCount && state == isNotSet; i++)
  82                                 sw.SpinOnce ();
  83
  84                         // Then, fallback to classic Sleep's yielding
  85                         while (state == isNotSet)
  86                                 Thread.Sleep (0);
  87                 }
  88
  89                 public bool Wait (int millisecondsTimeout)
  90                 {
  91                         if (millisecondsTimeout < -1)
  92                                 throw new ArgumentOutOfRangeException ("millisecondsTimeout",
  93                                                                        "millisecondsTimeout is a negative number other than -1");
  94
  95                         if (millisecondsTimeout == -1) {
  96                                 Wait ();
  97                                 return true;
  98                         }
  99
 100                         Watch s = Watch.StartNew ();
 101
 102                         // First spin
 103                         for (int i = 0; i < spinCount && state == isNotSet; i++) {
 104                                 if (s.ElapsedMilliseconds >= millisecondsTimeout)
 105                                         return false;
 106
 107                                 sw.SpinOnce ();
 108                         }
 109
 110                         // Then, fallback to classic Sleep's yielding
 111                         while (state == isNotSet) {
 112                                 if (s.ElapsedMilliseconds >= millisecondsTimeout)
 113                                         return false;
 114
 115                                 sw.SpinOnce ();
 116                         }
 117
 118                         return true;
 119                 }
 120
 121                 public bool Wait (TimeSpan ts)
 122                 {
 123                         return Wait ((int)ts.TotalMilliseconds);
 124                 }
 125
 126                 [MonoTODO]
 127                 public WaitHandle WaitHandle {
 128                         get {
 129                                 return null;
 130                         }
 131                 }
 132
 133                 #region IDisposable implementation
 134                 public void Dispose ()
 135                 {
 136                         Dispose(true);
 137                 }
 138
 139                 protected virtual void Dispose(bool managedRes)
 140                 {
 141
 142                 }
 143                 #endregion
 144
 145         }
 146 }
 147 #endif