source: stable/HeuristicLab.Optimization/3.3/Algorithms/BasicAlgorithm.cs @ 15292

Last change on this file since 15292 was 15292, checked in by jkarder, 2 years ago

#2258: merged r15287 into stable

File size: 5.0 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    }
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(CancellationToken cancellationToken) {
74      base.Start(cancellationToken);
75      CancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
76      pausePending = false;
77      OnStarted();
78
79      try {
80        Run((object)cancellationTokenSource.Token);
81      } catch (OperationCanceledException) {
82      } catch (AggregateException ae) {
83        OnExceptionOccurred(ae.InnerExceptions.SingleOrDefault() ?? ae);
84      } catch (Exception e) {
85        OnExceptionOccurred(e);
86      }
87
88      CancellationTokenSource.Dispose();
89      CancellationTokenSource = null;
90      if (pausePending) OnPaused();
91      else OnStopped();
92    }
93
94    public override void Pause() {
95      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise pause does nothing
96      // alternatively check the IsCancellationRequested property of the cancellation token
97      if (!SupportsPause)
98        throw new NotSupportedException("Pause is not supported by this algorithm.");
99
100      base.Pause();
101      pausePending = true;
102      CancellationTokenSource.Cancel();
103    }
104
105    public override void Stop() {
106      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise stop does nothing
107      // alternatively check the IsCancellationRequested property of the cancellation token
108      base.Stop();
109      if (ExecutionState == ExecutionState.Paused) OnStopped();
110      else CancellationTokenSource.Cancel();
111    }
112
113    private void Run(object state) {
114      CancellationToken cancellationToken = (CancellationToken)state;
115      lastUpdateTime = DateTime.UtcNow;
116      System.Timers.Timer timer = new System.Timers.Timer(250);
117      timer.AutoReset = true;
118      timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
119      timer.Start();
120      try {
121        if (!initialized)
122          Initialize(cancellationToken);
123        initialized = true;
124        Run(cancellationToken);
125      }
126      finally {
127        timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
128        timer.Stop();
129        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
130      }
131    }
132
133    protected virtual void Initialize(CancellationToken cancellationToken) { }
134    protected abstract void Run(CancellationToken cancellationToken);
135
136    #region Events
137    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
138      System.Timers.Timer timer = (System.Timers.Timer)sender;
139      timer.Enabled = false;
140      DateTime now = DateTime.UtcNow;
141      ExecutionTime += now - lastUpdateTime;
142      lastUpdateTime = now;
143      timer.Enabled = true;
144    }
145    #endregion
146
147  }
148}
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