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source: stable/HeuristicLab.Optimization/3.3/Algorithms/BasicAlgorithm.cs @ 17331

Last change on this file since 17331 was 17181, checked in by swagner, 5 years ago

#2875: Merged r17180 from trunk to stable

File size: 5.3 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 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 HeuristicLab.Common;
25using HeuristicLab.Core;
26using HEAL.Attic;
27
28namespace HeuristicLab.Optimization {
29  [StorableType("EFBEE5EB-B15B-4FBB-A210-C4E36898B89D")]
30  public abstract class BasicAlgorithm : Algorithm, IStorableContent {
31
32    private bool pausePending;
33    private DateTime lastUpdateTime;
34
35    public string Filename { get; set; }
36
37    public abstract bool SupportsPause { get; }
38    public virtual bool SupportsStop {
39      get { return true; }
40    }
41
42    [Storable]
43    private bool initialized;
44    [Storable]
45    private readonly ResultCollection results;
46    public override ResultCollection Results {
47      get { return results; }
48    }
49
50    private CancellationTokenSource cancellationTokenSource;
51    protected CancellationTokenSource CancellationTokenSource {
52      get { return cancellationTokenSource; }
53      private set { cancellationTokenSource = value; }
54    }
55
56    [StorableConstructor]
57    protected BasicAlgorithm(StorableConstructorFlag _) : base(_) { }
58    protected BasicAlgorithm(BasicAlgorithm original, Cloner cloner)
59      : base(original, cloner) {
60      results = cloner.Clone(original.Results);
61      initialized = original.initialized;
62    }
63    protected BasicAlgorithm()
64      : base() {
65      results = new ResultCollection();
66    }
67
68    public override void Prepare() {
69      if (Problem == null) return;
70      base.Prepare();
71      results.Clear();
72      initialized = false;
73      OnPrepared();
74    }
75
76    public override void Start(CancellationToken cancellationToken) {
77      base.Start(cancellationToken);
78      CancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
79      pausePending = false;
80      OnStarted();
81
82      try {
83        Run((object)cancellationTokenSource.Token);
84      } catch (OperationCanceledException) {
85      } catch (AggregateException ae) {
86        ae.FlattenAndHandle(new[] { typeof(OperationCanceledException) }, e => OnExceptionOccurred(e));
87      } catch (Exception e) {
88        OnExceptionOccurred(e);
89      }
90
91      CancellationTokenSource.Dispose();
92      CancellationTokenSource = null;
93      if (pausePending) OnPaused();
94      else OnStopped();
95    }
96
97    public override void Pause() {
98      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise pause does nothing
99      // alternatively check the IsCancellationRequested property of the cancellation token
100      if (!SupportsPause)
101        throw new NotSupportedException("Pause is not supported by this algorithm.");
102
103      base.Pause();
104      pausePending = true;
105      if (CancellationTokenSource != null) CancellationTokenSource.Cancel();
106    }
107
108    public override void Stop() {
109      // CancellationToken.ThrowIfCancellationRequested() must be called from within the Run method, otherwise stop does nothing
110      // alternatively check the IsCancellationRequested property of the cancellation token
111      if (!SupportsStop)
112        throw new NotSupportedException("Stop is not supported by this algorithm.");
113
114      base.Stop();
115      if (ExecutionState == ExecutionState.Paused) OnStopped();
116      else if (CancellationTokenSource != null) 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      } finally {
132        timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
133        timer.Stop();
134        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
135      }
136    }
137
138    protected virtual void Initialize(CancellationToken cancellationToken) { }
139    protected abstract void Run(CancellationToken cancellationToken);
140
141    #region Events
142    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
143      System.Timers.Timer timer = (System.Timers.Timer)sender;
144      timer.Enabled = false;
145      DateTime now = DateTime.UtcNow;
146      ExecutionTime += now - lastUpdateTime;
147      lastUpdateTime = now;
148      timer.Enabled = true;
149    }
150    #endregion
151
152  }
153}
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