source: branches/Async/HeuristicLab.Optimization/3.3/Algorithms/BasicAlgorithm.cs @ 13349

Last change on this file since 13349 was 13349, checked in by jkarder, 4 years ago

#2258: added StartAsync to IExecutable

File size: 4.6 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Threading;
24using System.Threading.Tasks;
25using HeuristicLab.Common;
26using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
27
28namespace HeuristicLab.Optimization {
29  [StorableClass]
30  public abstract class BasicAlgorithm : Algorithm, IStorableContent {
31    public string Filename { get; set; }
32
33    [Storable]
34    private ResultCollection results;
35    public override ResultCollection Results {
36      get { return results; }
37    }
38
39    private CancellationTokenSource cancellationTokenSource;
40    protected CancellationTokenSource CancellationTokenSource {
41      get { return cancellationTokenSource; }
42      private set { cancellationTokenSource = value; }
43    }
44
45    [StorableConstructor]
46    protected BasicAlgorithm(bool deserializing) : base(deserializing) { }
47    protected BasicAlgorithm(BasicAlgorithm original, Cloner cloner)
48      : base(original, cloner) {
49      results = cloner.Clone(original.Results);
50    }
51    protected BasicAlgorithm()
52      : base() {
53      results = new ResultCollection();
54    }
55
56    public override void Prepare() {
57      if (Problem == null) return;
58      base.Prepare();
59      results.Clear();
60      OnPrepared();
61    }
62
63    public override async Task StartAsync(CancellationToken cancellationToken) {
64      await base.StartAsync(cancellationToken);
65      CancellationTokenSource = new CancellationTokenSource();
66
67      OnStarted();
68      using (var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationTokenSource.Token, cancellationToken)) {
69        Task task = Task.Factory.StartNew(Run, cts.Token, cts.Token);
70        await task.ContinueWith(t => {
71          try {
72            t.Wait();
73          }
74          catch (AggregateException ex) {
75            try {
76              ex.Flatten().Handle(x => x is OperationCanceledException);
77            }
78            catch (AggregateException remaining) {
79              if (remaining.InnerExceptions.Count == 1) OnExceptionOccurred(remaining.InnerExceptions[0]);
80              else OnExceptionOccurred(remaining);
81            }
82          }
83          CancellationTokenSource.Dispose();
84          CancellationTokenSource = null;
85          OnStopped();
86        });
87      }
88    }
89
90    public override void Pause() {
91      throw new NotSupportedException("Pause is not supported in basic algorithms.");
92    }
93
94    public override void Stop() {
95      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise stop does nothing
96      // alternatively check the IsCancellationRequested property of the cancellation token
97      base.Stop();
98      CancellationTokenSource.Cancel();
99    }
100
101
102    private DateTime lastUpdateTime;
103    private void Run(object state) {
104      CancellationToken cancellationToken = (CancellationToken)state;
105      lastUpdateTime = DateTime.UtcNow;
106      System.Timers.Timer timer = new System.Timers.Timer(250);
107      timer.AutoReset = true;
108      timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
109      timer.Start();
110      try {
111        Run(cancellationToken);
112      }
113      finally {
114        timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
115        timer.Stop();
116        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
117      }
118    }
119
120    protected abstract void Run(CancellationToken cancellationToken);
121
122    #region Events
123    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
124      System.Timers.Timer timer = (System.Timers.Timer)sender;
125      timer.Enabled = false;
126      DateTime now = DateTime.UtcNow;
127      ExecutionTime += now - lastUpdateTime;
128      lastUpdateTime = now;
129      timer.Enabled = true;
130    }
131    #endregion
132
133  }
134}
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