source: branches/symbreg-factors-2650/HeuristicLab.Optimization/3.3/Algorithms/BasicAlgorithm.cs @ 14542

Last change on this file since 14542 was 14542, checked in by gkronber, 3 years ago

#2650: merged r14504:14533 from trunk to branch

File size: 5.2 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2016 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.Core;
27using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
28
29namespace HeuristicLab.Optimization {
30  [StorableClass]
31  public abstract class BasicAlgorithm : Algorithm, IStorableContent {
32
33    private bool pausePending;
34    private DateTime lastUpdateTime;
35
36    public string Filename { get; set; }
37
38    public abstract bool SupportsPause { get; }
39
40    [Storable]
41    private bool initialized;
42    [Storable]
43    private readonly ResultCollection results;
44    public override ResultCollection Results {
45      get { return results; }
46    }
47
48    private CancellationTokenSource cancellationTokenSource;
49    protected CancellationTokenSource CancellationTokenSource {
50      get { return cancellationTokenSource; }
51      private set { cancellationTokenSource = value; }
52    }
53
54    [StorableConstructor]
55    protected BasicAlgorithm(bool deserializing) : base(deserializing) { }
56    protected BasicAlgorithm(BasicAlgorithm original, Cloner cloner)
57      : base(original, cloner) {
58      results = cloner.Clone(original.Results);
59    }
60    protected BasicAlgorithm()
61      : base() {
62      results = new ResultCollection();
63    }
64
65    public override void Prepare() {
66      if (Problem == null) return;
67      base.Prepare();
68      results.Clear();
69      initialized = false;
70      OnPrepared();
71    }
72
73    public override void Start() {
74      base.Start();
75      CancellationTokenSource = new CancellationTokenSource();
76      pausePending = false;
77      OnStarted();
78
79      Task task = Task.Factory.StartNew(Run, CancellationTokenSource.Token, CancellationTokenSource.Token);
80      task.ContinueWith(t => {
81        try {
82          t.Wait();
83        }
84        catch (AggregateException ex) {
85          try {
86            ex.Flatten().Handle(x => x is OperationCanceledException);
87          }
88          catch (AggregateException remaining) {
89            if (remaining.InnerExceptions.Count == 1) OnExceptionOccurred(remaining.InnerExceptions[0]);
90            else OnExceptionOccurred(remaining);
91          }
92        }
93        CancellationTokenSource.Dispose();
94        CancellationTokenSource = null;
95        if (pausePending) OnPaused();
96        else OnStopped();
97      });
98    }
99
100    public override void Pause() {
101      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise pause does nothing
102      // alternatively check the IsCancellationRequested property of the cancellation token
103      if (!SupportsPause)
104        throw new NotSupportedException("Pause is not supported by this algorithm.");
105
106      base.Pause();
107      pausePending = true;
108      CancellationTokenSource.Cancel();
109    }
110
111    public override void Stop() {
112      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise stop does nothing
113      // alternatively check the IsCancellationRequested property of the cancellation token
114      base.Stop();
115      if (ExecutionState == ExecutionState.Paused) OnStopped();
116      else CancellationTokenSource.Cancel();
117    }
118
119    private void Run(object state) {
120      CancellationToken cancellationToken = (CancellationToken)state;
121      lastUpdateTime = DateTime.UtcNow;
122      System.Timers.Timer timer = new System.Timers.Timer(250);
123      timer.AutoReset = true;
124      timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
125      timer.Start();
126      try {
127        if (!initialized)
128          Initialize(cancellationToken);
129        initialized = true;
130        Run(cancellationToken);
131      }
132      finally {
133        timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
134        timer.Stop();
135        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
136      }
137    }
138
139    protected virtual void Initialize(CancellationToken cancellationToken) { }
140    protected abstract void Run(CancellationToken cancellationToken);
141
142    #region Events
143    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
144      System.Timers.Timer timer = (System.Timers.Timer)sender;
145      timer.Enabled = false;
146      DateTime now = DateTime.UtcNow;
147      ExecutionTime += now - lastUpdateTime;
148      lastUpdateTime = now;
149      timer.Enabled = true;
150    }
151    #endregion
152
153  }
154}
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