mcs/class/corlib/System.Threading.Tasks/SchedulerProxy.cs

   1 //
   2 // SchedulerProxy.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 #if NET_4_0 || MOBILE
  28 using System;
  29 using System.Threading;
  30 using System.Reflection;
  31
  32 namespace System.Threading.Tasks
  33 {
  34         internal class SchedulerProxy
  35         {
  36                 TaskScheduler scheduler;
  37
  38                 Action<Task> participateUntil1;
  39                 Func<Task, ManualResetEventSlim, int, bool> participateUntil2;
  40
  41                 public SchedulerProxy (TaskScheduler scheduler)
  42                 {
  43                         this.scheduler = scheduler;
  44                         FindMonoSpecificImpl ();
  45                 }
  46
  47                 void FindMonoSpecificImpl ()
  48                 {
  49                         // participateUntil1
  50                         FetchMethod<Action<Task>> ("MonoParticipateUntil",
  51                                                    new[] { typeof(Task) },
  52                                                    ref participateUntil1);
  53                         // participateUntil2
  54                         FetchMethod<Func<Task, ManualResetEventSlim, int, bool>> ("MonoParticipateUntil",
  55                                                                                   new[] { typeof(Task), typeof(ManualResetEventSlim), typeof(int) },
  56                                                                                   ref participateUntil2);
  57                 }
  58
  59                 void FetchMethod<TDelegate> (string name, Type[] types, ref TDelegate field) where TDelegate : class
  60                 {
  61                         var method = scheduler.GetType ().GetMethod (name,
  62                                                                      BindingFlags.Instance | BindingFlags.Public,
  63                                                                      null,
  64                                                                      types,
  65                                                                      null);
  66                         if (method == null)
  67                                 return;
  68                         field = Delegate.CreateDelegate (typeof(TDelegate), scheduler, method) as TDelegate;
  69                         Console.WriteLine ("Created delegate for " + name);
  70                 }
  71
  72                 public void ParticipateUntil (Task task)
  73                 {
  74                         if (participateUntil1 != null) {
  75                                 participateUntil1 (task);
  76                                 return;
  77                         }
  78
  79                         if (task.Status == TaskStatus.WaitingToRun)
  80                                 task.Execute (null);
  81
  82                         if (task.IsCompleted)
  83                                 return;
  84
  85                         ManualResetEventSlim evt = new ManualResetEventSlim (false);
  86                         task.ContinueWith (_ => evt.Set (), TaskContinuationOptions.ExecuteSynchronously);
  87
  88                         ParticipateUntil (evt, -1);
  89                 }
  90
  91                 public bool ParticipateUntil (Task task, ManualResetEventSlim evt, int millisecondsTimeout)
  92                 {
  93                         if (task.IsCompleted)
  94                                 return false;
  95
  96                         if (participateUntil2 != null)
  97                                 return participateUntil2 (task, evt, millisecondsTimeout);
  98
  99                         bool fromPredicate = true;
 100                         task.ContinueWith (_ => { fromPredicate = false; evt.Set (); }, TaskContinuationOptions.ExecuteSynchronously);
 101
 102                         ParticipateUntil (evt, millisecondsTimeout);
 103
 104                         return fromPredicate;
 105                 }
 106
 107                 void ParticipateUntil (ManualResetEventSlim evt, int millisecondsTimeout)
 108                 {
 109                         evt.Wait (millisecondsTimeout);
 110                 }
 111
 112                 public void PulseAll ()
 113                 {
 114
 115                 }
 116         }
 117 }
 118 #endif