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

   1 // Scheduler.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 || BOOTSTRAP_NET_4_0
  26 using System;
  27 using System.Collections.Concurrent;
  28
  29 namespace System.Threading.Tasks
  30 {
  31         internal class Scheduler: TaskScheduler, IScheduler
  32         {
  33                 IProducerConsumerCollection<Task> workQueue;
  34                 ThreadWorker[]        workers;
  35                 EventWaitHandle       pulseHandle = new AutoResetEvent (false);
  36
  37                 public Scheduler ()
  38                         : this (Environment.ProcessorCount, 0, ThreadPriority.Normal)
  39                 {
  40
  41                 }
  42
  43                 public Scheduler (int maxWorker, int maxStackSize, ThreadPriority priority)
  44                 {
  45                         workQueue = new ConcurrentQueue<Task> ();
  46                         workers = new ThreadWorker [maxWorker];
  47
  48                         for (int i = 0; i < maxWorker; i++) {
  49                                 workers [i] = new ThreadWorker (this, workers, workQueue, maxStackSize, priority, pulseHandle);
  50                                 workers [i].Pulse ();
  51                         }
  52                 }
  53
  54                 public void AddWork (Task t)
  55                 {
  56                         // Add to the shared work pool
  57                         workQueue.TryAdd (t);
  58                         // Wake up some worker if they were asleep
  59                         PulseAll ();
  60                 }
  61
  62                 public void ParticipateUntil (Task task)
  63                 {
  64                         if (AreTasksFinished (task))
  65                                 return;
  66
  67                         ParticipateUntil (delegate {
  68                                 return AreTasksFinished (task);
  69                         });
  70                 }
  71
  72                 public bool ParticipateUntil (Task task, Func<bool> predicate)
  73                 {
  74                         if (AreTasksFinished (task))
  75                                 return false;
  76
  77                         bool isFromPredicate = false;
  78
  79                         ParticipateUntil (delegate {
  80                                 if (predicate ()) {
  81                                         isFromPredicate = true;
  82                                         return true;
  83                                 }
  84                                 return AreTasksFinished (task);
  85                         });
  86
  87                         return isFromPredicate;
  88                 }
  89
  90                 // Called with Task.WaitAll(someTasks) or Task.WaitAny(someTasks) so that we can remove ourselves
  91                 // also when our wait condition is ok
  92                 public void ParticipateUntil (Func<bool> predicate)
  93                 {
  94                         ThreadWorker.WorkerMethod (predicate, workQueue, workers);
  95                 }
  96
  97                 public void PulseAll ()
  98                 {
  99                         pulseHandle.Set ();
 100                 }
 101
 102                 public void Dispose ()
 103                 {
 104                         foreach (ThreadWorker w in workers) {
 105                                 w.Dispose ();
 106                         }
 107                 }
 108
 109                 bool AreTasksFinished (Task parent)
 110                 {
 111                         return parent.IsCompleted;
 112                 }
 113
 114                 #region Scheduler dummy stubs
 115                 protected override System.Collections.Generic.IEnumerable<Task> GetScheduledTasks ()
 116                 {
 117                         throw new System.NotImplementedException();
 118                 }
 119
 120                 protected internal override void QueueTask (Task task)
 121                 {
 122                         throw new System.NotImplementedException();
 123                 }
 124
 125                 protected internal override bool TryDequeue (Task task)
 126                 {
 127                         throw new System.NotImplementedException();
 128                 }
 129
 130                 protected override bool TryExecuteTaskInline (Task task, bool taskWasPreviouslyQueued)
 131                 {
 132                         throw new System.NotImplementedException();
 133                 }
 134
 135                 public override int MaximumConcurrencyLevel {
 136                         get {
 137                                 return base.MaximumConcurrencyLevel;
 138                         }
 139                 }
 140                 #endregion
 141         }
 142 }
 143 #endif