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

   1 #if NET_4_0 || BOOTSTRAP_NET_4_0
   2 // Scheduler.cs
   3 //
   4 // Copyright (c) 2008 Jérémie "Garuma" Laval
   5 //
   6 // Permission is hereby granted, free of charge, to any person obtaining a copy
   7 // of this software and associated documentation files (the "Software"), to deal
   8 // in the Software without restriction, including without limitation the rights
   9 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 // copies of the Software, and to permit persons to whom the Software is
  11 // furnished to do so, subject to the following conditions:
  12 //
  13 // The above copyright notice and this permission notice shall be included in
  14 // all copies or substantial portions of the Software.
  15 //
  16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 // THE SOFTWARE.
  23 //
  24 //
  25
  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                 bool                  isPulsable = true;
  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);
  50                         }
  51                 }
  52
  53                 public void AddWork (Task t)
  54                 {
  55                         // Add to the shared work pool
  56                         workQueue.TryAdd (t);
  57                         // Wake up some worker if they were asleep
  58                         PulseAll ();
  59                 }
  60
  61                 public void ParticipateUntil (Task task)
  62                 {
  63                         if (AreTasksFinished (task))
  64                                 return;
  65
  66                         ParticipateUntil (delegate {
  67                                 return AreTasksFinished (task);
  68                         });
  69                 }
  70
  71                 public bool ParticipateUntil (Task task, Func<bool> predicate)
  72                 {
  73                         if (AreTasksFinished (task))
  74                                 return false;
  75
  76                         bool isFromPredicate = false;
  77
  78                         ParticipateUntil (delegate {
  79                                 if (predicate ()) {
  80                                         isFromPredicate = true;
  81                                         return true;
  82                                 }
  83                                 return AreTasksFinished (task);
  84                         });
  85
  86                         return isFromPredicate;
  87                 }
  88
  89                 // Called with Task.WaitAll(someTasks) or Task.WaitAny(someTasks) so that we can remove ourselves
  90                 // also when our wait condition is ok
  91                 public void ParticipateUntil (Func<bool> predicate)
  92                 {
  93                         ThreadWorker.WorkerMethod (predicate, workQueue, workers);
  94                 }
  95
  96                 public void PulseAll ()
  97                 {
  98                         if (isPulsable) {
  99                                 foreach (ThreadWorker worker in workers) {
 100                                         if (worker != null)
 101                                                 worker.Pulse ();
 102                                 }
 103                         }
 104                 }
 105
 106                 public void InhibitPulse ()
 107                 {
 108                         isPulsable = false;
 109                 }
 110
 111                 public void UnInhibitPulse ()
 112                 {
 113                         isPulsable = true;
 114                 }
 115
 116                 public void Dispose ()
 117                 {
 118                         foreach (ThreadWorker w in workers) {
 119                                 w.Dispose ();
 120                         }
 121                 }
 122
 123                 bool AreTasksFinished (Task parent)
 124                 {
 125                         return parent.IsCompleted;
 126                 }
 127
 128                 #region Scheduler dummy stubs
 129                 protected override System.Collections.Generic.IEnumerable<Task> GetScheduledTasks ()
 130                 {
 131                         throw new System.NotImplementedException();
 132                 }
 133
 134                 protected internal override void QueueTask (Task task)
 135                 {
 136                         throw new System.NotImplementedException();
 137                 }
 138
 139                 protected internal override bool TryDequeue (Task task)
 140                 {
 141                         throw new System.NotImplementedException();
 142                 }
 143
 144                 protected override bool TryExecuteTaskInline (Task task, bool taskWasPreviouslyQueued)
 145                 {
 146                         throw new System.NotImplementedException();
 147                 }
 148
 149                 public override int MaximumConcurrencyLevel {
 150                         get {
 151                                 return base.MaximumConcurrencyLevel;
 152                         }
 153                 }
 154                 #endregion
 155         }
 156 }
 157 #endif