source: stable/HeuristicLab.Optimization/3.3/Algorithms/BasicAlgorithm.cs @ 15317

Last change on this file since 15317 was 15317, checked in by abeham, 2 years ago

#2816: merged to stable

File size: 5.1 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.Linq;
24using System.Threading;
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      initialized = original.initialized;
60    }
61    protected BasicAlgorithm()
62      : base() {
63      results = new ResultCollection();
64    }
65
66    public override void Prepare() {
67      if (Problem == null) return;
68      base.Prepare();
69      results.Clear();
70      initialized = false;
71      OnPrepared();
72    }
73
74    public override void Start(CancellationToken cancellationToken) {
75      base.Start(cancellationToken);
76      CancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
77      pausePending = false;
78      OnStarted();
79
80      try {
81        Run((object)cancellationTokenSource.Token);
82      }
83      catch (OperationCanceledException) {
84      }
85      catch (AggregateException ae) {
86        OnExceptionOccurred(ae.InnerExceptions.SingleOrDefault() ?? ae);
87      }
88      catch (Exception e) {
89        OnExceptionOccurred(e);
90      }
91
92      CancellationTokenSource.Dispose();
93      CancellationTokenSource = null;
94      if (pausePending) OnPaused();
95      else OnStopped();
96    }
97
98    public override void Pause() {
99      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise pause does nothing
100      // alternatively check the IsCancellationRequested property of the cancellation token
101      if (!SupportsPause)
102        throw new NotSupportedException("Pause is not supported by this algorithm.");
103
104      base.Pause();
105      pausePending = true;
106      CancellationTokenSource.Cancel();
107    }
108
109    public override void Stop() {
110      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise stop does nothing
111      // alternatively check the IsCancellationRequested property of the cancellation token
112      base.Stop();
113      if (ExecutionState == ExecutionState.Paused) OnStopped();
114      else CancellationTokenSource.Cancel();
115    }
116
117    private void Run(object state) {
118      CancellationToken cancellationToken = (CancellationToken)state;
119      lastUpdateTime = DateTime.UtcNow;
120      System.Timers.Timer timer = new System.Timers.Timer(250);
121      timer.AutoReset = true;
122      timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
123      timer.Start();
124      try {
125        if (!initialized)
126          Initialize(cancellationToken);
127        initialized = true;
128        Run(cancellationToken);
129      }
130      finally {
131        timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
132        timer.Stop();
133        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
134      }
135    }
136
137    protected virtual void Initialize(CancellationToken cancellationToken) { }
138    protected abstract void Run(CancellationToken cancellationToken);
139
140    #region Events
141    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
142      System.Timers.Timer timer = (System.Timers.Timer)sender;
143      timer.Enabled = false;
144      DateTime now = DateTime.UtcNow;
145      ExecutionTime += now - lastUpdateTime;
146      lastUpdateTime = now;
147      timer.Enabled = true;
148    }
149    #endregion
150
151  }
152}
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