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

   1 //
   2 // System.Threading.RegisteredWaitHandle.cs
   3 //
   4 // Author:
   5 //   Dick Porter (dick@ximian.com)
   6 //   Lluis Sanchez Gual (lluis@ideary.com)
   7 //
   8 // (C) Ximian, Inc.  http://www.ximian.com
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34
  35 namespace System.Threading
  36 {
  37         public sealed class RegisteredWaitHandle : MarshalByRefObject
  38         {
  39                 WaitHandle _waitObject;
  40                 WaitOrTimerCallback _callback;
  41                 TimeSpan _timeout;
  42                 object _state;
  43                 bool _executeOnlyOnce;
  44                 WaitHandle _finalEvent;
  45                 ManualResetEvent _cancelEvent;
  46                 int _callsInProcess;
  47                 bool _unregistered;
  48
  49                 internal RegisteredWaitHandle (WaitHandle waitObject, WaitOrTimerCallback callback, object state, TimeSpan timeout, bool executeOnlyOnce)
  50                 {
  51                         _waitObject = waitObject;
  52                         _callback = callback;
  53                         _state = state;
  54                         _timeout = timeout;
  55                         _executeOnlyOnce = executeOnlyOnce;
  56                         _finalEvent = null;
  57                         _cancelEvent = new ManualResetEvent (false);
  58                         _callsInProcess = 0;
  59                         _unregistered = false;
  60                 }
  61
  62                 internal void Wait (object state)
  63                 {
  64                         try
  65                         {
  66                                 WaitHandle[] waits = new WaitHandle[] {_waitObject, _cancelEvent};
  67                                 do
  68                                 {
  69                                         int signal = WaitHandle.WaitAny (waits, _timeout, false);
  70                                         if (!_unregistered)
  71                                         {
  72                                                 lock (this) { _callsInProcess++; }
  73                                                 ThreadPool.QueueUserWorkItem (new WaitCallback (DoCallBack), (signal == WaitHandle.WaitTimeout));
  74                                         }
  75                                 }
  76                                 while (!_unregistered && !_executeOnlyOnce);
  77                         }
  78                         catch {}
  79
  80                         lock (this) {
  81                                 _unregistered = true;
  82                                 if (_callsInProcess == 0 && _finalEvent != null)
  83                                         NativeEventCalls.SetEvent_internal (_finalEvent.Handle);
  84                         }
  85                 }
  86
  87                 private void DoCallBack (object timedOut)
  88                 {
  89                         if (_callback != null)
  90                                 _callback (_state, (bool)timedOut);
  91
  92                         lock (this)
  93                         {
  94                                 _callsInProcess--;
  95                                 if (_unregistered && _callsInProcess == 0 && _finalEvent != null)
  96                                         NativeEventCalls.SetEvent_internal (_finalEvent.Handle);
  97                         }
  98                 }
  99
 100                 public bool Unregister(WaitHandle waitObject)
 101                 {
 102                         lock (this)
 103                         {
 104                                 if (_unregistered) return false;
 105                                 _finalEvent = waitObject;
 106                                 _unregistered = true;
 107                                 _cancelEvent.Set();
 108                                 return true;
 109                         }
 110                 }
 111
 112                 [MonoTODO]
 113                 ~RegisteredWaitHandle() {
 114                         // FIXME
 115                 }
 116         }
 117 }