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

   1 // ManuelResetEventSlim.cs
   2 //
   3 // Copyright (c) 2008 Jérémie "Garuma" Laval
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining a copy
   6 // of this software and associated documentation files (the "Software"), to deal
   7 // in the Software without restriction, including without limitation the rights
   8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 // copies of the Software, and to permit persons to whom the Software is
  10 // furnished to do so, subject to the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be included in
  13 // all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 // THE SOFTWARE.
  22 //
  23 //
  24
  25 #if NET_4_0 || MOBILE
  26
  27 using System;
  28
  29 namespace System.Threading
  30 {
  31         [System.Diagnostics.DebuggerDisplayAttribute ("Set = {IsSet}")]
  32         public class ManualResetEventSlim : IDisposable
  33         {
  34                 const int isSet    = 1;
  35                 const int isNotSet = 0;
  36                 const int defaultSpinCount = 100;
  37
  38                 int state;
  39                 readonly int spinCount;
  40
  41                 ManualResetEvent handle;
  42
  43                 readonly static Watch sw = Watch.StartNew ();
  44
  45                 public ManualResetEventSlim () : this (false, defaultSpinCount)
  46                 {
  47                 }
  48
  49                 public ManualResetEventSlim (bool initialState) : this (initialState, defaultSpinCount)
  50                 {
  51                 }
  52
  53                 public ManualResetEventSlim (bool initialState, int spinCount)
  54                 {
  55                         if (spinCount < 0)
  56                                 throw new ArgumentOutOfRangeException ("spinCount is less than 0", "spinCount");
  57
  58                         this.state = initialState ? isSet : isNotSet;
  59                         this.spinCount = spinCount;
  60                 }
  61
  62                 public bool IsSet {
  63                         get {
  64                                 return state == isSet;
  65                         }
  66                 }
  67
  68                 public int SpinCount {
  69                         get {
  70                                 return spinCount;
  71                         }
  72                 }
  73
  74                 public void Reset ()
  75                 {
  76                         state = isNotSet;
  77                         if (handle != null)
  78                                 handle.Reset ();
  79                 }
  80
  81                 public void Set ()
  82                 {
  83                         state = isSet;
  84                         if (handle != null)
  85                                 handle.Set ();
  86                 }
  87
  88                 public void Wait ()
  89                 {
  90                         Wait (CancellationToken.None);
  91                 }
  92
  93                 public bool Wait (int millisecondsTimeout)
  94                 {
  95                         return Wait (millisecondsTimeout, CancellationToken.None);
  96                 }
  97
  98                 public bool Wait (TimeSpan timeout)
  99                 {
 100                         return Wait ((int)timeout.TotalMilliseconds, CancellationToken.None);
 101                 }
 102
 103                 public void Wait (CancellationToken cancellationToken)
 104                 {
 105                         Wait (-1, cancellationToken);
 106                 }
 107
 108                 public bool Wait (int millisecondsTimeout, CancellationToken cancellationToken)
 109                 {
 110                         if (millisecondsTimeout < -1)
 111                                 throw new ArgumentOutOfRangeException ("millisecondsTimeout",
 112                                                                        "millisecondsTimeout is a negative number other than -1");
 113
 114                         long start = millisecondsTimeout == -1 ? 0 : sw.ElapsedMilliseconds;
 115                         SpinWait wait = new SpinWait ();
 116
 117                         while (state == isNotSet) {
 118                                 cancellationToken.ThrowIfCancellationRequested ();
 119
 120                                 if (millisecondsTimeout > -1 && (sw.ElapsedMilliseconds - start) > millisecondsTimeout)
 121                                         return false;
 122
 123                                 if (wait.Count < spinCount) {
 124                                         wait.SpinOnce ();
 125                                 } else {
 126                                         int waitTime = millisecondsTimeout == -1 ? -1 : Math.Max (millisecondsTimeout - (int)(sw.ElapsedMilliseconds - start) , 1);
 127                                         WaitHandle handle = WaitHandle;
 128                                         if (state == isSet)
 129                                                 return true;
 130                                         if (WaitHandle.WaitAny (new[] { handle, cancellationToken.WaitHandle }, waitTime, false) == 0)
 131                                                 return true;
 132                                 }
 133                         }
 134
 135                         return true;
 136                 }
 137
 138                 public bool Wait (TimeSpan timeout, CancellationToken cancellationToken)
 139                 {
 140                         return Wait ((int)timeout.TotalMilliseconds, cancellationToken);
 141                 }
 142
 143                 public WaitHandle WaitHandle {
 144                         get {
 145                                 if (handle != null)
 146                                         return handle;
 147                                 return LazyInitializer.EnsureInitialized (ref handle,
 148                                                                           () => new ManualResetEvent (state == isSet ? true : false));
 149                         }
 150                 }
 151
 152                 #region IDisposable implementation
 153                 public void Dispose ()
 154                 {
 155                         Dispose(true);
 156                 }
 157
 158                 protected virtual void Dispose (bool disposing)
 159                 {
 160
 161                 }
 162                 #endregion
 163
 164         }
 165 }
 166 #endif