mcs/class/System/System.Threading/Barrier.cs

   1 //
   2 // Barrier.cs
   3 //
   4 // Author:
   5 //       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
   6 //
   7 // Copyright (c) 2009 Jérémie "Garuma" Laval
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining a copy
  10 // of this software and associated documentation files (the "Software"), to deal
  11 // in the Software without restriction, including without limitation the rights
  12 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13 // copies of the Software, and to permit persons to whom the Software is
  14 // furnished to do so, subject to the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be included in
  17 // all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25 // THE SOFTWARE.
  26
  27 #if NET_4_0 || BOOTSTRAP_NET_4_0
  28
  29 using System;
  30
  31 namespace System.Threading
  32 {
  33         public class Barrier : IDisposable
  34         {
  35                 const int MaxParticipants = 32767;
  36                 Action<Barrier> postPhaseAction;
  37
  38                 int participants;
  39                 bool cleaned;
  40                 CountdownEvent cntd;
  41                 ManualResetEventSlim postPhaseEvt = new ManualResetEventSlim ();
  42                 long phase;
  43
  44                 public Barrier (int participants) : this (participants, null)
  45                 {
  46                 }
  47
  48                 public Barrier (int participants, Action<Barrier> postPhaseAction)
  49                 {
  50                         if (participants < 0 || participants > MaxParticipants)
  51                                 throw new ArgumentOutOfRangeException ("participants");
  52
  53                         this.participants = participants;
  54                         this.postPhaseAction = postPhaseAction;
  55
  56                         InitCountdownEvent ();
  57                 }
  58
  59                 public void Dispose ()
  60                 {
  61                         Dispose (true);
  62                 }
  63
  64                 protected virtual void Dispose (bool disposing)
  65                 {
  66                         if (disposing){
  67                                 if (cntd != null){
  68                                         cntd.Dispose ();
  69                                         cntd = null;
  70                                 }
  71                                 postPhaseAction = null;
  72                                 cleaned = true;
  73                         }
  74                 }
  75
  76                 void InitCountdownEvent ()
  77                 {
  78                         postPhaseEvt = new ManualResetEventSlim (false);
  79                         cntd = new CountdownEvent (participants);
  80                 }
  81
  82                 public long AddParticipant ()
  83                 {
  84                         return AddParticipants (1);
  85                 }
  86
  87                 static Exception GetDisposed ()
  88                 {
  89                         return new ObjectDisposedException ("Barrier");
  90                 }
  91
  92                 public long AddParticipants (int participantCount)
  93                 {
  94                         if (cleaned)
  95                                 throw GetDisposed ();
  96
  97                         if (participantCount < 0)
  98                                 throw new InvalidOperationException ();
  99
 100                         // Basically, we try to add ourselves and return
 101                         // the phase. If the call return false, we repeatdly try
 102                         // to add ourselves for the next phase
 103                         do {
 104                                 if (cntd.TryAddCount (participantCount)) {
 105                                         Interlocked.Add (ref participants, participantCount);
 106                                         return phase;
 107                                 }
 108                         } while (true);
 109                 }
 110
 111                 public void RemoveParticipant ()
 112                 {
 113                         RemoveParticipants (1);
 114                 }
 115
 116                 public void RemoveParticipants (int participantCount)
 117                 {
 118                         if (cleaned)
 119                                 throw GetDisposed ();
 120                         if (participantCount < 0)
 121                                 throw new ArgumentOutOfRangeException ("participantCount");
 122
 123                         if (cntd.Signal (participantCount))
 124                                 PostPhaseAction (postPhaseEvt);
 125
 126                         Interlocked.Add (ref participants, -participantCount);
 127                 }
 128
 129                 public void SignalAndWait ()
 130                 {
 131                         if (cleaned)
 132                                 throw GetDisposed ();
 133                         SignalAndWait ((c) => { c.Wait (); return true; });
 134                 }
 135
 136                 public void SignalAndWait (CancellationToken token)
 137                 {
 138                         if (cleaned)
 139                                 throw GetDisposed ();
 140                         SignalAndWait ((c) => { c.Wait (token); return true; });
 141                 }
 142
 143                 public bool SignalAndWait (int millisecondTimeout)
 144                 {
 145                         if (cleaned)
 146                                 throw GetDisposed ();
 147                         return SignalAndWait ((c) => c.Wait (millisecondTimeout));
 148                 }
 149
 150                 public bool SignalAndWait (TimeSpan ts)
 151                 {
 152                         if (cleaned)
 153                                 throw GetDisposed ();
 154                         return SignalAndWait ((c) => c.Wait (ts));
 155                 }
 156
 157                 public bool SignalAndWait (int millisecondTimeout, CancellationToken token)
 158                 {
 159                         if (cleaned)
 160                                 throw GetDisposed ();
 161                         return SignalAndWait ((c) => c.Wait (millisecondTimeout, token));
 162                 }
 163
 164                 public bool SignalAndWait (TimeSpan ts, CancellationToken token)
 165                 {
 166                         if (cleaned)
 167                                 throw GetDisposed ();
 168                         return SignalAndWait ((c) => c.Wait (ts, token));
 169                 }
 170
 171                 bool SignalAndWait (Func<CountdownEvent, bool> associate)
 172                 {
 173                         bool result;
 174                         CountdownEvent temp = cntd;
 175                         ManualResetEventSlim evt = postPhaseEvt;
 176
 177                         if (!temp.Signal ()) {
 178                                 result = Wait (associate, temp, evt);
 179                         } else {
 180                                 result = true;
 181                                 PostPhaseAction (evt);
 182                         }
 183
 184                         return result;
 185                 }
 186
 187                 bool Wait (Func<CountdownEvent, bool> associate, CountdownEvent temp, ManualResetEventSlim evt)
 188                 {
 189                         if (!associate (temp))
 190                                 return false;
 191
 192                         evt.Wait ();
 193
 194                         return true;
 195                 }
 196
 197                 void PostPhaseAction (ManualResetEventSlim evt)
 198                 {
 199                         if (postPhaseAction != null) {
 200                                 try {
 201                                         postPhaseAction (this);
 202                                 } catch (Exception e) {
 203                                         throw new BarrierPostPhaseException (e);
 204                                 }
 205                         }
 206
 207                         InitCountdownEvent ();
 208                         phase++;
 209
 210                         evt.Set ();
 211                 }
 212
 213                 public long CurrentPhaseNumber {
 214                         get {
 215                                 return phase;
 216                         }
 217                 }
 218
 219                 public int ParticipantCount  {
 220                         get {
 221                                 return participants;
 222                         }
 223                 }
 224         }
 225 }
 226 #endif