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                 readonly IProducerConsumerCollection<Task> workQueue;
  34                 readonly ThreadWorker[]        workers;
  35                 readonly EventWaitHandle       pulseHandle = new AutoResetEvent (false);
  36
  37                 public Scheduler ()
  38                         : this (Environment.ProcessorCount, ThreadPriority.Normal)
  39                 {
  40
  41                 }
  42
  43                 public Scheduler (int maxWorker, 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, i, workQueue, 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 (task.IsCompleted)
  65                                 return;
  66
  67                         ParticipateUntil (() => task.IsCompleted);
  68                 }
  69
  70                 public bool ParticipateUntil (Task task, Func<bool> predicate)
  71                 {
  72                         if (task.IsCompleted)
  73                                 return false;
  74
  75                         bool isFromPredicate = false;
  76
  77                         ParticipateUntil (delegate {
  78                                 if (predicate ()) {
  79                                         isFromPredicate = true;
  80                                         return true;
  81                                 }
  82                                 return task.IsCompleted;
  83                         });
  84
  85                         return isFromPredicate;
  86                 }
  87
  88                 // Called with Task.WaitAll(someTasks) or Task.WaitAny(someTasks) so that we can remove ourselves
  89                 // also when our wait condition is ok
  90                 public void ParticipateUntil (Func<bool> predicate)
  91                 {
  92                         ThreadWorker.WorkerMethod (predicate, workQueue, workers);
  93                 }
  94
  95                 public void PulseAll ()
  96                 {
  97                         pulseHandle.Set ();
  98                 }
  99
 100                 public void Dispose ()
 101                 {
 102                         foreach (ThreadWorker w in workers)
 103                                 w.Dispose ();
 104                 }
 105                 #region Scheduler dummy stubs
 106                 protected override System.Collections.Generic.IEnumerable<Task> GetScheduledTasks ()
 107                 {
 108                         throw new System.NotImplementedException();
 109                 }
 110
 111                 protected internal override void QueueTask (Task task)
 112                 {
 113                         throw new System.NotImplementedException();
 114                 }
 115
 116                 protected internal override bool TryDequeue (Task task)
 117                 {
 118                         throw new System.NotImplementedException();
 119                 }
 120
 121                 protected override bool TryExecuteTaskInline (Task task, bool taskWasPreviouslyQueued)
 122                 {
 123                         throw new System.NotImplementedException();
 124                 }
 125
 126                 public override int MaximumConcurrencyLevel {
 127                         get {
 128                                 return base.MaximumConcurrencyLevel;
 129                         }
 130                 }
 131                 #endregion
 132         }
 133 }
 134 #endif