mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/JoinBlock.cs

   1 // JoinBlock.cs
   2 //
   3 // Copyright (c) 2011 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
  26 using System;
  27 using System.Threading.Tasks;
  28 using System.Collections.Generic;
  29 using System.Collections.Concurrent;
  30
  31 namespace System.Threading.Tasks.Dataflow
  32 {
  33         public sealed class JoinBlock<T1, T2> : IReceivableSourceBlock<Tuple<T1, T2>>, ISourceBlock<Tuple<T1, T2>>, IDataflowBlock
  34         {
  35                 static readonly GroupingDataflowBlockOptions defaultOptions = new GroupingDataflowBlockOptions ();
  36
  37                 CompletionHelper compHelper = CompletionHelper.GetNew ();
  38                 GroupingDataflowBlockOptions dataflowBlockOptions;
  39                 TargetBuffer<Tuple<T1, T2>> targets = new TargetBuffer<Tuple<T1, T2>> ();
  40                 MessageVault<Tuple<T1, T2>> vault = new MessageVault<Tuple<T1, T2>> ();
  41                 MessageOutgoingQueue<Tuple<T1, T2>> outgoing;
  42
  43                 JoinTarget<T1> target1;
  44                 JoinTarget<T2> target2;
  45
  46                 DataflowMessageHeader headers;
  47
  48                 public JoinBlock () : this (defaultOptions)
  49                 {
  50
  51                 }
  52
  53                 public JoinBlock (GroupingDataflowBlockOptions dataflowBlockOptions)
  54                 {
  55                         if (dataflowBlockOptions == null)
  56                                 throw new ArgumentNullException ("dataflowBlockOptions");
  57
  58                         this.dataflowBlockOptions = dataflowBlockOptions;
  59                         this.target1 = new JoinTarget<T1> (this, SignalArrivalTarget1, new BlockingCollection<T1> (), compHelper);
  60                         this.target2 = new JoinTarget<T2> (this, SignalArrivalTarget2, new BlockingCollection<T2> (), compHelper);
  61                         this.outgoing = new MessageOutgoingQueue<Tuple<T1, T2>> (compHelper, () => target1.Buffer.IsCompleted || target2.Buffer.IsCompleted);
  62                 }
  63
  64                 public IDisposable LinkTo (ITargetBlock<Tuple<T1, T2>> target, bool unlinkAfterOne)
  65                 {
  66                         var result = targets.AddTarget (target, unlinkAfterOne);
  67                         outgoing.ProcessForTarget (target, this, false, ref headers);
  68                         return result;
  69                 }
  70
  71                 public bool TryReceive (Predicate<Tuple<T1, T2>> filter, out Tuple<T1, T2> item)
  72                 {
  73                         return outgoing.TryReceive (filter, out item);
  74                 }
  75
  76                 public bool TryReceiveAll (out IList<Tuple<T1, T2>> items)
  77                 {
  78                         return outgoing.TryReceiveAll (out items);
  79                 }
  80
  81                 public Tuple<T1, T2> ConsumeMessage (DataflowMessageHeader messageHeader, ITargetBlock<Tuple<T1, T2>> target, out bool messageConsumed)
  82                 {
  83                         return vault.ConsumeMessage (messageHeader, target, out messageConsumed);
  84                 }
  85
  86                 public void ReleaseReservation (DataflowMessageHeader messageHeader, ITargetBlock<Tuple<T1, T2>> target)
  87                 {
  88                         vault.ReleaseReservation (messageHeader, target);
  89                 }
  90
  91                 public bool ReserveMessage (DataflowMessageHeader messageHeader, ITargetBlock<Tuple<T1, T2>> target)
  92                 {
  93                         return vault.ReserveMessage (messageHeader, target);
  94                 }
  95
  96                 public void Complete ()
  97                 {
  98                         outgoing.Complete ();
  99                 }
 100
 101                 public void Fault (Exception ex)
 102                 {
 103                         compHelper.Fault (ex);
 104                 }
 105
 106                 public Task Completion {
 107                         get {
 108                                 return compHelper.Completion;
 109                         }
 110                 }
 111
 112                 void SignalArrivalTarget1 ()
 113                 {
 114                         T2 val2;
 115                         if (target2.Buffer.TryTake (out val2)) {
 116                                 T1 val1 = target1.Buffer.Take ();
 117                                 TriggerMessage (val1, val2);
 118                         }
 119                 }
 120
 121                 void SignalArrivalTarget2 ()
 122                 {
 123                         T1 val1;
 124                         if (target1.Buffer.TryTake (out val1)) {
 125                                 T2 val2 = target2.Buffer.Take ();
 126                                 TriggerMessage (val1, val2);
 127                         }
 128                 }
 129
 130                 void TriggerMessage (T1 val1, T2 val2)
 131                 {
 132                         Tuple<T1, T2> tuple = Tuple.Create (val1, val2);
 133                         ITargetBlock<Tuple<T1, T2>> target = targets.Current;
 134
 135                         if (target == null) {
 136                                 outgoing.AddData (tuple);
 137                         } else {
 138                                 target.OfferMessage (headers.Increment (),
 139                                                      tuple,
 140                                                      this,
 141                                                      false);
 142                         }
 143
 144                         if (!outgoing.IsEmpty && (target = targets.Current) != null)
 145                                 outgoing.ProcessForTarget (target, this, false, ref headers);
 146                 }
 147
 148                 class JoinTarget<TTarget> : MessageBox<TTarget>, ITargetBlock<TTarget>
 149                 {
 150                         JoinBlock<T1, T2> joinBlock;
 151                         BlockingCollection<TTarget> buffer;
 152                         Action signal;
 153
 154                         public JoinTarget (JoinBlock<T1, T2> joinBlock, Action signal, BlockingCollection<TTarget> buffer, CompletionHelper helper)
 155                         : base (buffer, helper, () => joinBlock.outgoing.IsCompleted)
 156                         {
 157                                 this.joinBlock = joinBlock;
 158                                 this.buffer = buffer;
 159                                 this.signal = signal;
 160                         }
 161
 162                         protected override void EnsureProcessing ()
 163                         {
 164                                 signal ();
 165                         }
 166
 167                         public BlockingCollection<TTarget> Buffer {
 168                                 get {
 169                                         return buffer;
 170                                 }
 171                         }
 172
 173                         DataflowMessageStatus ITargetBlock<TTarget>.OfferMessage (DataflowMessageHeader messageHeader,
 174                                                                                   TTarget messageValue,
 175                                                                                   ISourceBlock<TTarget> source,
 176                                                                                   bool consumeToAccept)
 177                         {
 178                                 return OfferMessage (this, messageHeader, messageValue, source, consumeToAccept);
 179                         }
 180
 181                         void IDataflowBlock.Complete ()
 182                         {
 183                                 Complete ();
 184                         }
 185
 186                         Task IDataflowBlock.Completion {
 187                                 get {
 188                                         return joinBlock.Completion;
 189                                 }
 190                         }
 191
 192                         void IDataflowBlock.Fault (Exception e)
 193                         {
 194                                 joinBlock.Fault (e);
 195                         }
 196                 }
 197
 198                 public ITargetBlock<T1> Target1 {
 199                         get {
 200                                 return target1;
 201                         }
 202                 }
 203
 204                 public ITargetBlock<T2> Target2 {
 205                         get {
 206                                 return target2;
 207                         }
 208                 }
 209         }
 210 }
 211