3 // Copyright (c) 2011 Jérémie "garuma" Laval
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:
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
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
28 using System.Threading.Tasks;
29 using System.Collections;
30 using System.Collections.Generic;
31 using System.Collections.Concurrent;
33 namespace System.Threading.Tasks.Dataflow
35 internal class TargetBuffer<T> : IEnumerable<ITargetBlock<T>>
37 ConcurrentQueue<TargetWaiter> targetWaiters = new ConcurrentQueue<TargetWaiter> ();
39 class TargetWaiter : IDisposable
41 public volatile bool Disabled;
42 public readonly ITargetBlock<T> Target;
43 public readonly bool UnlinkAfterOne;
45 ConcurrentQueue<TargetWaiter> queue;
46 AtomicBooleanValue removed;
48 public TargetWaiter (ITargetBlock<T> target, bool unlinkAfterOne, ConcurrentQueue<TargetWaiter> queue)
51 UnlinkAfterOne = unlinkAfterOne;
55 public void Dispose ()
60 Thread.MemoryBarrier ();
62 if (queue.TryPeek (out t) && t == this && removed.TryRelaxedSet ()) {
63 queue.TryDequeue (out t);
65 SpinWait wait = new SpinWait ();
66 while (queue.TryPeek (out t) && t == this)
72 public IDisposable AddTarget (ITargetBlock<T> block, bool unlinkAfterOne)
74 TargetWaiter w = new TargetWaiter (block, unlinkAfterOne, targetWaiters);
75 targetWaiters.Enqueue (w);
80 public ITargetBlock<T> Current {
85 if (!targetWaiters.TryPeek (out w))
88 if (w.Disabled == true) {
91 } else if (w.UnlinkAfterOne) {
100 public IEnumerator<ITargetBlock<T>> GetEnumerator ()
102 return targetWaiters.Select (w => w.Target).GetEnumerator ();
105 IEnumerator IEnumerable.GetEnumerator ()
107 return targetWaiters.Select (w => w.Target).GetEnumerator ();