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
  28
  29 using System;
  30 using System.Diagnostics;
  31
  32 namespace System.Threading
  33 {
  34         [DebuggerDisplay ("Participant Count={ParticipantCount},Participants Remaining={ParticipantsRemaining}")]
  35         public class Barrier : IDisposable
  36         {
  37                 const int MaxParticipants = 32767;
  38                 Action<Barrier> postPhaseAction;
  39
  40                 int participants;
  41                 bool cleaned;
  42                 CountdownEvent cntd;
  43                 ManualResetEventSlim postPhaseEvt = new ManualResetEventSlim ();
  44                 long phase;
  45
  46                 public Barrier (int participantCount)
  47                         : this (participantCount, null)
  48                 {
  49                 }
  50
  51                 public Barrier (int participantCount, Action<Barrier> postPhaseAction)
  52                 {
  53                         if (participantCount < 0 || participantCount > MaxParticipants)
  54                                 throw new ArgumentOutOfRangeException ("participantCount");
  55
  56                         this.participants = participantCount;
  57                         this.postPhaseAction = postPhaseAction;
  58
  59                         InitCountdownEvent ();
  60                 }
  61
  62                 public void Dispose ()
  63                 {
  64                         Dispose (true);
  65                 }
  66
  67                 protected virtual void Dispose (bool disposing)
  68                 {
  69                         if (disposing){
  70                                 if (cntd != null){
  71                                         cntd.Dispose ();
  72                                         cntd = null;
  73                                 }
  74                                 postPhaseAction = null;
  75                                 cleaned = true;
  76                         }
  77                 }
  78
  79                 void InitCountdownEvent ()
  80                 {
  81                         postPhaseEvt = new ManualResetEventSlim (false);
  82                         cntd = new CountdownEvent (participants);
  83                 }
  84
  85                 public long AddParticipant ()
  86                 {
  87                         return AddParticipants (1);
  88                 }
  89
  90                 static Exception GetDisposed ()
  91                 {
  92                         return new ObjectDisposedException ("Barrier");
  93                 }
  94
  95                 public long AddParticipants (int participantCount)
  96                 {
  97                         if (cleaned)
  98                                 throw GetDisposed ();
  99
 100                         if (participantCount < 0)
 101                                 throw new InvalidOperationException ();
 102
 103                         // Basically, we try to add ourselves and return
 104                         // the phase. If the call return false, we repeatdly try
 105                         // to add ourselves for the next phase
 106                         do {
 107                                 if (cntd.TryAddCount (participantCount)) {
 108                                         Interlocked.Add (ref participants, participantCount);
 109                                         return phase;
 110                                 }
 111                         } while (true);
 112                 }
 113
 114                 public void RemoveParticipant ()
 115                 {
 116                         RemoveParticipants (1);
 117                 }
 118
 119                 public void RemoveParticipants (int participantCount)
 120                 {
 121                         if (cleaned)
 122                                 throw GetDisposed ();
 123                         if (participantCount < 0)
 124                                 throw new ArgumentOutOfRangeException ("participantCount");
 125
 126                         if (cntd.Signal (participantCount))
 127                                 PostPhaseAction (postPhaseEvt);
 128
 129                         Interlocked.Add (ref participants, -participantCount);
 130                 }
 131
 132                 public void SignalAndWait ()
 133                 {
 134                         if (cleaned)
 135                                 throw GetDisposed ();
 136                         SignalAndWait ((c) => { c.Wait (); return true; });
 137                 }
 138
 139                 public void SignalAndWait (CancellationToken cancellationToken)
 140                 {
 141                         if (cleaned)
 142                                 throw GetDisposed ();
 143                         SignalAndWait ((c) => { c.Wait (cancellationToken); return true; });
 144                 }
 145
 146                 public bool SignalAndWait (int millisecondsTimeout)
 147                 {
 148                         if (cleaned)
 149                                 throw GetDisposed ();
 150                         return SignalAndWait ((c) => c.Wait (millisecondsTimeout));
 151                 }
 152
 153                 public bool SignalAndWait (TimeSpan timeout)
 154                 {
 155                         if (cleaned)
 156                                 throw GetDisposed ();
 157                         return SignalAndWait ((c) => c.Wait (timeout));
 158                 }
 159
 160                 public bool SignalAndWait (int millisecondsTimeout, CancellationToken cancellationToken)
 161                 {
 162                         if (cleaned)
 163                                 throw GetDisposed ();
 164                         return SignalAndWait ((c) => c.Wait (millisecondsTimeout, cancellationToken));
 165                 }
 166
 167                 public bool SignalAndWait (TimeSpan timeout, CancellationToken cancellationToken)
 168                 {
 169                         if (cleaned)
 170                                 throw GetDisposed ();
 171                         return SignalAndWait ((c) => c.Wait (timeout, cancellationToken));
 172                 }
 173
 174                 bool SignalAndWait (Func<CountdownEvent, bool> associate)
 175                 {
 176                         bool result;
 177                         CountdownEvent temp = cntd;
 178                         ManualResetEventSlim evt = postPhaseEvt;
 179
 180                         if (!temp.Signal ()) {
 181                                 result = Wait (associate, temp, evt);
 182                         } else {
 183                                 result = true;
 184                                 PostPhaseAction (evt);
 185                         }
 186
 187                         return result;
 188                 }
 189
 190                 bool Wait (Func<CountdownEvent, bool> associate, CountdownEvent temp, ManualResetEventSlim evt)
 191                 {
 192                         if (!associate (temp))
 193                                 return false;
 194
 195                         evt.Wait ();
 196
 197                         return true;
 198                 }
 199
 200                 void PostPhaseAction (ManualResetEventSlim evt)
 201                 {
 202                         if (postPhaseAction != null) {
 203                                 try {
 204                                         postPhaseAction (this);
 205                                 } catch (Exception e) {
 206                                         throw new BarrierPostPhaseException (e);
 207                                 }
 208                         }
 209
 210                         InitCountdownEvent ();
 211                         phase++;
 212
 213                         evt.Set ();
 214                 }
 215
 216                 public long CurrentPhaseNumber {
 217                         get {
 218                                 return phase;
 219                         }
 220                 }
 221
 222                 public int ParticipantCount  {
 223                         get {
 224                                 return participants;
 225                         }
 226                 }
 227
 228                 [MonoTODO]
 229                 public int ParticipantsRemaining {
 230                         get {
 231                                 return -1;
 232                         }
 233                 }
 234         }
 235 }
 236 #endif