Changeset 12856

Timestamp:

08/13/15 14:19:29 (9 years ago)

Author:

abeham

Message:

#2431: Added AlgorithmIterator instead of IRRestarter

• AlgorithmIterator implements IAlgorithm whereas IRRestarter implemented only IOptimizer
• Deriving from Algorithm leads to better design

Location:

branches/PerformanceComparison/HeuristicLab.Analysis/3.3

Files:

• HeuristicLab.Analysis-3.3.csproj (modified) (1 diff)
• Optimizers/AlgorithmIterator.cs (copied) (copied from branches/PerformanceComparison/HeuristicLab.Analysis/3.3/Optimizers/IRRestarter.cs) (6 diffs)

branches/PerformanceComparison/HeuristicLab.Analysis/3.3/HeuristicLab.Analysis-3.3.csproj

@@ -199 +199 @@
     <Compile Include="MultiObjective\RankBasedParetoFrontAnalyzer.cs" />
     <Compile Include="MultiObjective\ParetoFrontAnalyzer.cs" />
+    <Compile Include="Optimizers\AlgorithmIterator.cs" />
     <Compile Include="Optimizers\IRRestarter.cs" />
     <Compile Include="Plugin.cs" />

branches/PerformanceComparison/HeuristicLab.Analysis/3.3/Optimizers/AlgorithmIterator.cs

@@ -21 +21 @@
 
 using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Drawing;
 using System.Linq;
+using System.Threading;
 using HeuristicLab.Common;
-using HeuristicLab.Common.Resources;
 using HeuristicLab.Core;
 using HeuristicLab.Data;
 using HeuristicLab.Optimization;
+using HeuristicLab.Parameters;
 using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
+using System.Threading.Tasks;
 
 namespace HeuristicLab.Analysis {
-  public enum TerminationCriterium { OnlyByTime, OnlyByEvaluations, OnlyByTarget, ByTargetAndTime, ByTargetAndEvaluations, ByTimeAndEvaluations, WhicheverHitsFirst, WhicheverHitsLast }
   /// <summary>
   /// A run in which an algorithm is executed for a certain maximum time only.
   /// </summary>
-  [Item("Independent Random Restarter", "An optimizer that repeats an algorithm until either a certain target value is reached or a maximum budget is exceeded.")]
-  [Creatable(CreatableAttribute.Categories.TestingAndAnalysis, Priority = 117)]
+  [Item("Algorithm Iterator", "An algorithm that repeats an algorithm until either a certain target value is reached or a maximum budget is exceeded.")]
+  [Creatable(CreatableAttribute.Categories.TestingAndAnalysis, Priority = 116)]
   [StorableClass]
-  public sealed class IndepdentRandomRestarter : NamedItem, IOptimizer, IStorableContent, INotifyPropertyChanged {
+  public sealed class AlgorithmIterator : Algorithm, IStorableContent {
     private const string ExecutionTimeResultName = "Execution Time";
     private const string BestQualityResultName = "BestQuality";
@@ -48 +46 @@
     private const string QualityPerClockResultName = "QualityPerClock";
     private const string QualityPerEvaluationsResultName = "QualityPerEvaluations";
+    private const string EvaluationsResultName = "Evaluations";
 
     public string Filename { get; set; }
 
-    #region ItemImage
-    public static new Image StaticItemImage {
-      get { return VSImageLibrary.Event; }
-    }
-    public override Image ItemImage {
-      get { return (Algorithm != null) ? Algorithm.ItemImage : VSImageLibrary.ExecutableStopped; }
-    }
-    #endregion
+    public override Type ProblemType { get { return typeof(ISingleObjectiveHeuristicOptimizationProblem); } }
+    public new ISingleObjectiveHeuristicOptimizationProblem Problem {
+      get { return (ISingleObjectiveHeuristicOptimizationProblem)base.Problem; }
+      set {
+        base.Problem = value;
+        if (Algorithm != null) Algorithm.Problem = Problem;
+        if (Problem != null) UpdateTargetValueFromBestKnownQuality();
+      }
+    }
+
+    public IValueParameter<TimeSpanValue> MaximumExecutionTimeParameter {
+      get { return (IValueParameter<TimeSpanValue>)Parameters["MaximumExecutionTime"]; }
+    }
+
+    public IValueParameter<IntValue> MaximumEvaluationsParameter {
+      get { return (IValueParameter<IntValue>)Parameters["MaximumEvaluations"]; }
+    }
+
+    public IValueParameter<DoubleValue> TargetValueParameter {
+      get { return (IValueParameter<DoubleValue>)Parameters["TargetValue"]; }
+    }
+
+    private IFixedValueParameter<DoubleValue> MoveCostPerSolutionParameter {
+      get { return (IFixedValueParameter<DoubleValue>)Parameters["MoveCostPerSolution"]; }
+    }
+
+    private IFixedValueParameter<BoolValue> StoreSolutionInRunParameter {
+      get { return (IFixedValueParameter<BoolValue>)Parameters["StoreSolutionInRun"]; }
+    }
+
+    private IValueParameter<IAlgorithm> AlgorithmParameter {
+      get { return (IValueParameter<IAlgorithm>)Parameters["Algorithm"]; }
+    }
 
     [Storable]
-    private TerminationCriterium terminationCriterium;
-    public TerminationCriterium TerminationCriterium {
-      get { return terminationCriterium; }
-      set {
-        if (terminationCriterium == value) return;
-        terminationCriterium = value;
-        OnPropertyChanged("TerminationCriterium");
-      }
-    }
-
-    [Storable]
-    private TimeSpan maximumExecutionTime;
-    public TimeSpan MaximumExecutionTime {
-      get { return maximumExecutionTime; }
-      set {
-        if (maximumExecutionTime == value) return;
-        maximumExecutionTime = value;
-        OnPropertyChanged("MaximumExecutionTime");
-      }
-    }
-
-    [Storable]
-    private int maximumEvaluations;
-    public int MaximumEvaluations {
-      get { return maximumEvaluations; }
-      set {
-        if (maximumEvaluations == value) return;
-        maximumEvaluations = value;
-        OnPropertyChanged("MaximumEvaluations");
-      }
-    }
-
-    [Storable]
-    private double targetValue;
-    public double TargetValue {
-      get { return targetValue; }
-      set {
-        if (targetValue == value) return;
-        targetValue = value;
-        OnPropertyChanged("TargetValue");
-      }
-    }
-
-    [Storable]
-    private bool maximization;
-    public bool Maximization {
-      get { return maximization; }
-      set {
-        if (maximization == value) return;
-        maximization = value;
-        OnPropertyChanged("Maximization");
-      }
-    }
-
-    [Storable]
-    private double moveCostPerSolution;
-    public double MoveCostPerSolution {
-      get { return moveCostPerSolution; }
-      set {
-        if (moveCostPerSolution == value) return;
-        moveCostPerSolution = value;
-        perEvaluationsAnalyzer.MoveCostPerSolutionParameter.Value = new DoubleValue(moveCostPerSolution);
-        OnPropertyChanged("MoveCostPerSolution");
-      }
-    }
-
-    [Storable]
-    private bool storeSolutionInRun;
-    public bool StoreSolutionInRun {
-      get { return storeSolutionInRun; }
-      set {
-        if (storeSolutionInRun == value) return;
-        storeSolutionInRun = value;
-        OnPropertyChanged("StoreSolutionInRun");
-      }
+    private ResultCollection results;
+    public override ResultCollection Results {
+      get { return results; }
     }
 
@@ -143 +95 @@
     private QualityPerEvaluationsAnalyzer perEvaluationsAnalyzer;
 
-    [Storable]
-    private ExecutionState executionState;
-    public ExecutionState ExecutionState {
-      get { return executionState; }
-      private set {
-        if (executionState != value) {
-          executionState = value;
-          OnExecutionStateChanged();
-          OnItemImageChanged();
-        }
-      }
-    }
-
-    private TimeSpan lastAlgorithmExecutionTime;
-    [Storable]
-    private TimeSpan executionTime;
-    public TimeSpan ExecutionTime {
-      get { return executionTime; }
-      set {
-        if (executionTime == value) return;
-        executionTime = value;
-        OnPropertyChanged("ExecutionTime");
-        OnExecutionTimeChanged();
-      }
-    }
-
-    [Storable]
-    private double evaluations;
-    public double Evaluations {
-      get { return evaluations; }
-      set {
-        if (evaluations == value) return;
-        evaluations = value;
-        OnPropertyChanged("Evaluations");
-      }
-    }
-
-    [Storable]
-    private double bestSoFar;
-    public double BestSoFar {
-      get { return bestSoFar; }
-      set {
-        if (bestSoFar == value) return;
-        bestSoFar = value;
-        OnPropertyChanged("BestSoFar");
-      }
-    }
-
-    [Storable]
-    private IRun currentRun;
-    public IRun CurrentRun {
-      get { return currentRun; }
-      private set {
-        if (currentRun == value) return;
-        currentRun = value;
-        OnPropertyChanged("CurrentRun");
-      }
+    public double MoveCostPerSolution {
+      get { return MoveCostPerSolutionParameter.Value.Value; }
+      set { MoveCostPerSolutionParameter.Value.Value = value; }
+    }
+
+    public bool StoreSolutionInRun {
+      get { return StoreSolutionInRunParameter.Value.Value; }
+      set { StoreSolutionInRunParameter.Value.Value = value; }
     }
 
@@ -214 +117 @@
         algorithm = value;
         if (algorithm != null) {
+          if (algorithm.ExecutionState != ExecutionState.Prepared)
+            algorithm.Prepare(true);
+          algorithm.Problem = Problem;
           RegisterAlgorithmEvents();
           AddAlgorithmAnalyzers();
         }
-        OnPropertyChanged("Algorithm");
+        if (AlgorithmParameter.Value != algorithm)
+          AlgorithmParameter.Value = algorithm;
         Prepare();
       }
     }
 
-    [Storable]
-    private RunCollection runs;
-    public RunCollection Runs {
-      get { return runs; }
-      private set {
-        if (value == null) throw new ArgumentNullException();
-        if (runs == value) return;
-        runs = value;
-        OnPropertyChanged("Runs");
-      }
-    }
-
-    public IEnumerable<IOptimizer> NestedOptimizers {
-      get {
-        if (Algorithm == null) yield break;
-        yield return Algorithm;
-        foreach (var opt in Algorithm.NestedOptimizers)
-          yield return opt;
-      }
+    private bool Maximization {
+      get { return Problem != null && ((IValueParameter<BoolValue>)Problem.MaximizationParameter).Value.Value; }
     }
 
     private bool IsFinished {
       get {
-        var timeHit = ExecutionTime >= MaximumExecutionTime;
-        var evalHit = Evaluations >= MaximumEvaluations;
-        var targetHit = (Maximization && BestSoFar >= TargetValue || !Maximization && BestSoFar <= TargetValue);
-
-        return timeHit && evalHit && targetHit
-          || timeHit && (TerminationCriterium == TerminationCriterium.OnlyByTime
-                      || TerminationCriterium == TerminationCriterium.WhicheverHitsFirst
-                      || TerminationCriterium == TerminationCriterium.ByTargetAndTime
-                      || TerminationCriterium == TerminationCriterium.ByTimeAndEvaluations)
-          || evalHit && (TerminationCriterium == TerminationCriterium.OnlyByEvaluations
-                      || TerminationCriterium == TerminationCriterium.WhicheverHitsFirst
-                      || TerminationCriterium == TerminationCriterium.ByTargetAndEvaluations
-                      || TerminationCriterium == TerminationCriterium.ByTimeAndEvaluations)
-          || targetHit && (TerminationCriterium == TerminationCriterium.OnlyByTarget
-                        || TerminationCriterium == TerminationCriterium.WhicheverHitsFirst
-                        || TerminationCriterium == TerminationCriterium.ByTargetAndTime
-                        || TerminationCriterium == TerminationCriterium.ByTargetAndEvaluations);
-      }
-    }
-
-    private ISingleObjectiveHeuristicOptimizationProblem problem;
+        var executionTime = Results.ContainsKey(ExecutionTimeResultName) ? ((TimeSpanValue)Results[ExecutionTimeResultName].Value).Value : TimeSpan.Zero;
+        var evaluations = Results.ContainsKey(EvaluationsResultName) ? ((DoubleValue)Results[EvaluationsResultName].Value).Value : 0;
+        var bestQuality = Results.ContainsKey(BestQualityResultName) ? ((DoubleValue)Results[BestQualityResultName].Value).Value
+                                                                     : (Maximization ? double.MinValue : double.MaxValue);
+        var targetValue = TargetValueParameter.Value != null ? TargetValueParameter.Value.Value
+                                                             : Maximization ? double.MaxValue : double.MinValue;
+
+        var timeHit = MaximumExecutionTimeParameter.Value != null && executionTime >= MaximumExecutionTimeParameter.Value.Value;
+        var evalHit = MaximumEvaluationsParameter.Value != null && evaluations >= MaximumEvaluationsParameter.Value.Value;
+        var targetHit = Maximization && bestQuality >= targetValue || !Maximization && bestQuality <= targetValue;
+
+        return timeHit || evalHit || targetHit;
+      }
+    }
 
     [StorableConstructor]
-    private IndepdentRandomRestarter(bool deserializing) : base(deserializing) { }
-    private IndepdentRandomRestarter(IndepdentRandomRestarter original, Cloner cloner)
+    private AlgorithmIterator(bool deserializing) : base(deserializing) { }
+    private AlgorithmIterator(AlgorithmIterator original, Cloner cloner)
       : base(original, cloner) {
-      terminationCriterium = original.terminationCriterium;
-      maximumExecutionTime = original.maximumExecutionTime;
-      maximumEvaluations = original.maximumEvaluations;
-      moveCostPerSolution = original.moveCostPerSolution;
-      storeSolutionInRun = original.storeSolutionInRun;
-      targetValue = original.targetValue;
-      maximization = original.maximization;
-      executionTime = original.executionTime;
-      evaluations = original.evaluations;
-      bestSoFar = original.bestSoFar;
-      lastAlgorithmExecutionTime = original.lastAlgorithmExecutionTime;
-
+      results = cloner.Clone(original.Results);
       perClockAnalyzer = cloner.Clone(original.perClockAnalyzer);
       perEvaluationsAnalyzer = cloner.Clone(original.perEvaluationsAnalyzer);
 
-      algorithm = cloner.Clone(original.algorithm);
-      runs = cloner.Clone(original.runs);
-
-      ExecutionState = original.ExecutionState;
-
-      Initialize();
-    }
-    public IndepdentRandomRestarter()
+      RegisterEventHandlers();
+    }
+    public AlgorithmIterator()
       : base() {
-      name = ItemName;
-      description = ItemDescription;
-      terminationCriterium = TerminationCriterium.ByTargetAndEvaluations;
-      maximumExecutionTime = TimeSpan.FromMinutes(1);
-      maximumEvaluations = 10000000; // 10 mio
-      moveCostPerSolution = 1;
-      storeSolutionInRun = false;
-      targetValue = 0;
-      maximization = false;
-      executionTime = TimeSpan.Zero;
-      evaluations = 0;
-      bestSoFar = double.NaN;
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
+      results = new ResultCollection();
+      Parameters.Add(new OptionalValueParameter<TimeSpanValue>("MaximumExecutionTime", "The maximum wall-clock time that the algorithm should run."));
+      Parameters.Add(new OptionalValueParameter<IntValue>("MaximumEvaluations", "The maximum number of function evaluations that the algorithm should run.", new IntValue(100000000)));
+      Parameters.Add(new OptionalValueParameter<DoubleValue>("TargetValue", "The target value that the algorithm should run for."));
+      Parameters.Add(new FixedValueParameter<DoubleValue>("MoveCostPerSolution", "The amount of solution evaluation equivalents of a single move. Use 1 for a black-box scenario.", new DoubleValue(1)));
+      Parameters.Add(new FixedValueParameter<BoolValue>("StoreSolutionInRun", "Whether the solution data types should be kept in the run."));
+      Parameters.Add(new ValueParameter<IAlgorithm>("Algorithm", "The algorithm to iterate.") { GetsCollected = false }); // due to storage efficiency, by default we don't want to store the algorithm instance in the run
 
       perClockAnalyzer = new QualityPerClockAnalyzer();
       perEvaluationsAnalyzer = new QualityPerEvaluationsAnalyzer();
 
-      Runs = new RunCollection { OptimizerName = Name };
-      Initialize();
-    }
-    public IndepdentRandomRestarter(string name)
-      : base(name) {
-      description = ItemDescription;
-      terminationCriterium = TerminationCriterium.ByTargetAndEvaluations;
-      maximumExecutionTime = TimeSpan.FromMinutes(1);
-      maximumEvaluations = 10000000; // 10 mio
-      moveCostPerSolution = 1;
-      storeSolutionInRun = false;
-      targetValue = 0;
-      maximization = false;
-      executionTime = TimeSpan.Zero;
-      evaluations = 0;
-      bestSoFar = double.NaN;
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
-
-      perClockAnalyzer = new QualityPerClockAnalyzer();
-      perEvaluationsAnalyzer = new QualityPerEvaluationsAnalyzer();
-
-      Runs = new RunCollection { OptimizerName = Name };
-      Initialize();
-    }
-    public IndepdentRandomRestarter(string name, string description)
-      : base(name, description) {
-      terminationCriterium = TerminationCriterium.ByTargetAndEvaluations;
-      maximumExecutionTime = TimeSpan.FromMinutes(1);
-      maximumEvaluations = 10000000; // 10 mio
-      moveCostPerSolution = 1;
-      storeSolutionInRun = false;
-      targetValue = 0;
-      maximization = false;
-      executionTime = TimeSpan.Zero;
-      evaluations = 0;
-      bestSoFar = double.NaN;
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
-
-      perClockAnalyzer = new QualityPerClockAnalyzer();
-      perEvaluationsAnalyzer = new QualityPerEvaluationsAnalyzer();
-
-      Runs = new RunCollection { OptimizerName = Name };
-      Initialize();
+      RegisterEventHandlers();
     }
 
     public override IDeepCloneable Clone(Cloner cloner) {
       if (ExecutionState == ExecutionState.Started) throw new InvalidOperationException(string.Format("Clone not allowed in execution state \"{0}\".", ExecutionState));
-      return new IndepdentRandomRestarter(this, cloner);
+      return new AlgorithmIterator(this, cloner);
     }
 
     [StorableHook(HookType.AfterDeserialization)]
     private void AfterDeserialization() {
-      Initialize();
-    }
-
-    private void Initialize() {
-      if (algorithm != null) RegisterAlgorithmEvents();
-    }
-
-    private void Reset() {
-      ExecutionTime = TimeSpan.Zero;
-      Evaluations = 0;
-      BestSoFar = double.NaN;
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
-
-      CurrentRun = null;
-    }
-
-    public void Prepare() {
-      Prepare(false);
-    }
-    public void Prepare(bool clearRuns) {
-      if ((ExecutionState != ExecutionState.Prepared) && (ExecutionState != ExecutionState.Paused) && (ExecutionState != ExecutionState.Stopped))
-        throw new InvalidOperationException(string.Format("Prepare not allowed in execution state \"{0}\".", ExecutionState));
-      Reset();
-
-      if (Algorithm != null) {
-        Algorithm.Prepare(clearRuns);
-        ExecutionState = ExecutionState.Prepared;
-        OnPrepared();
-      }
-    }
-    public void Start() {
-      if ((ExecutionState != ExecutionState.Prepared) && (ExecutionState != ExecutionState.Paused))
-        throw new InvalidOperationException(string.Format("Start not allowed in execution state \"{0}\".", ExecutionState));
-
-      if (ExecutionState == ExecutionState.Prepared) {
-        CurrentRun = new Run(Algorithm) {
-          Name = Algorithm.Name + " IRRRun" + Runs.Count
-        };
-        if (!CurrentRun.Results.ContainsKey(ExecutionTimeResultName))
-          CurrentRun.Results.Add(ExecutionTimeResultName, new TimeSpanValue(TimeSpan.Zero));
-        // use double instead of int, otherwise one might run into int.MaxValue (at least with moves)
-        CurrentRun.Results.Add(EvaluatedSolutionsResultName, new DoubleValue(0));
-        CurrentRun.Results.Add(EvaluatedMovesResultName, new DoubleValue(0));
-        CurrentRun.Results.Add(BestQualityResultName, new DoubleValue(Maximization ? double.MinValue : double.MaxValue));
-        CurrentRun.Results.Add(RandomRestartsResultName, new IntValue(0));
-      }
-      if (Algorithm.ExecutionState == ExecutionState.Stopped)
+      RegisterEventHandlers();
+    }
+
+    #region Register Event Handlers
+    protected override void RegisterProblemEvents() {
+      var bkParam = Problem.BestKnownQualityParameter as IValueParameter<DoubleValue>;
+      if (bkParam != null) {
+        bkParam.ValueChanged += Problem_BestKnownQualityParameter_ValueChanged;
+      }
+      base.RegisterProblemEvents();
+    }
+    protected override void DeregisterProblemEvents() {
+      base.DeregisterProblemEvents();
+      var bkParam = Problem.BestKnownQualityParameter as IValueParameter<DoubleValue>;
+      if (bkParam != null) {
+        bkParam.ValueChanged -= Problem_BestKnownQualityParameter_ValueChanged;
+      }
+    }
+    private void RegisterAlgorithmEvents() {
+      Algorithm.ExceptionOccurred += Algorithm_ExceptionOccurred;
+      Algorithm.Paused += Algorithm_Paused;
+      Algorithm.Stopped += Algorithm_Stopped;
+      Algorithm.ProblemChanged += Algorithm_ProblemChanged;
+    }
+    private void DeregisterAlgorithmEvents() {
+      Algorithm.ExceptionOccurred -= Algorithm_ExceptionOccurred;
+      Algorithm.Paused -= Algorithm_Paused;
+      Algorithm.Stopped -= Algorithm_Stopped;
+      Algorithm.ProblemChanged -= Algorithm_ProblemChanged;
+    }
+    #endregion
+
+    private void RegisterEventHandlers() {
+      if (Algorithm != null) RegisterAlgorithmEvents();
+      if (Problem != null) RegisterProblemEvents();
+      AlgorithmParameter.ValueChanged += AlgorithmParameterOnValueChanged;
+    }
+
+    private void AlgorithmParameterOnValueChanged(object sender, EventArgs eventArgs) {
+      Algorithm = AlgorithmParameter.Value;
+    }
+
+    #region Prepare, Start, Pause, Stop
+    public override void Prepare() {
+      if (Problem == null || Algorithm == null) return;
+
+      Algorithm.Prepare(true);
+
+      results.Clear();
+      OnPrepared();
+    }
+
+    public override void Start() {
+      base.Start();
+      OnStarted();
+      var task = Task.Factory.StartNew(Run, null);
+      task.ContinueWith(t => {
+        try {
+          t.Wait();
+        } catch (AggregateException ex) {
+          try {
+            ex.Flatten().Handle(x => x is OperationCanceledException);
+          } catch (AggregateException remaining) {
+            if (remaining.InnerExceptions.Count == 1) OnExceptionOccurred(remaining.InnerExceptions[0]);
+            else OnExceptionOccurred(remaining);
+          }
+        }
+        if (Algorithm.ExecutionState == ExecutionState.Paused) OnPaused();
+        else OnStopped();
+      });
+    }
+
+    public override void Pause() {
+      base.Pause();
+      Algorithm.Pause();
+    }
+
+    public override void Stop() {
+      base.Stop();
+      Algorithm.Stop();
+    }
+    #endregion
+
+    private DateTime lastUpdateTime;
+    private void Run(object state) {
+      lastUpdateTime = DateTime.UtcNow;
+      System.Timers.Timer timer = new System.Timers.Timer(250);
+      timer.AutoReset = true;
+      timer.Elapsed += timer_Elapsed;
+      timer.Start();
+      try {
+        Run();
+      } finally {
+        timer.Elapsed -= timer_Elapsed;
+        timer.Stop();
+        ExecutionTime += DateTime.UtcNow - lastUpdateTime;
+      }
+    }
+
+    private readonly AutoResetEvent algorithmWaitHandle = new AutoResetEvent(false);
+    private void Run() {
+      if (!Results.ContainsKey(ExecutionTimeResultName)) Results.Add(new Result(ExecutionTimeResultName, new TimeSpanValue(TimeSpan.Zero)));
+      if (!Results.ContainsKey(EvaluatedSolutionsResultName)) Results.Add(new Result(EvaluatedSolutionsResultName, new DoubleValue(0)));
+      if (!Results.ContainsKey(EvaluatedMovesResultName)) Results.Add(new Result(EvaluatedMovesResultName, new DoubleValue(0)));
+      if (!Results.ContainsKey(EvaluationsResultName)) Results.Add(new Result(EvaluationsResultName, new DoubleValue(0)));
+      if (!Results.ContainsKey(BestQualityResultName)) Results.Add(new Result(BestQualityResultName, new DoubleValue(double.NaN)));
+
+      do {
+        if (!Results.ContainsKey(RandomRestartsResultName)) Results.Add(new Result(RandomRestartsResultName, new IntValue(0)));
+        else if (Algorithm.ExecutionState == ExecutionState.Prepared) ((IntValue)Results[RandomRestartsResultName].Value).Value++;
+
+        Algorithm.Start();
+        algorithmWaitHandle.WaitOne();
+
+        if (Algorithm.ExecutionState == ExecutionState.Paused) return;
+
+        var execTime = ((TimeSpanValue)Results[ExecutionTimeResultName].Value);
+        var solEvals = ((DoubleValue)Results[EvaluatedSolutionsResultName].Value);
+        var movEvals = ((DoubleValue)Results[EvaluatedMovesResultName].Value);
+        var restarts = ((IntValue)Results[RandomRestartsResultName].Value);
+        var evaluations = ((DoubleValue)Results[EvaluationsResultName].Value);
+        var bestQuality = ((DoubleValue)Results[BestQualityResultName].Value);
+        var improvement = false;
+
+        IResult result;
+        if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.EvaluatedSolutionsParameter.ActualName, out result)) {
+          var evals = ((IntValue)result.Value).Value;
+          evaluations.Value += evals;
+          solEvals.Value += evals;
+        }
+        if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.EvaluatedMovesParameter.ActualName, out result)) {
+          var evals = ((IntValue)result.Value).Value;
+          evaluations.Value += MoveCostPerSolution * evals;
+          movEvals.Value += evals;
+        }
+        if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.BestQualityParameter.ActualName, out result)) {
+          var newBestQuality = ((DoubleValue)result.Value).Value;
+          if (double.IsNaN(bestQuality.Value)
+              || Maximization && newBestQuality > bestQuality.Value
+              || !Maximization && newBestQuality < bestQuality.Value) {
+            bestQuality.Value = newBestQuality;
+            improvement = true;
+          }
+        }
+        if (Algorithm.Results.TryGetValue(perClockAnalyzer.QualityPerClockParameter.ResultName, out result)) {
+          UpdateQualityPerClockResult((IndexedDataTable<double>)result.Value, restarts.Value);
+        }
+        if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.QualityPerEvaluationsParameter.ResultName, out result)) {
+          UpdateQualityPerEvaluationsResult((IndexedDataTable<double>)result.Value, restarts.Value);
+        }
+        if (StoreSolutionInRun) {
+          foreach (var r in Algorithm.Results) {
+            if (r.Name.ToLower().EndsWith("solution") && improvement) {
+              if (!Results.TryGetValue(r.Name, out result))
+                Results.Add(new Result(r.Name, (IItem)r.Value.Clone()));
+              else result.Value = (IItem)r.Value.Clone();
+            }
+          }
+        }
+
+        execTime.Value = ExecutionTime;
+
         Algorithm.Prepare(true);
-      Algorithm.Start();
-      ExecutionState = ExecutionState.Started;
-      OnStarted();
-    }
-    public void Pause() {
-      if (ExecutionState != ExecutionState.Started)
-        throw new InvalidOperationException(string.Format("Pause not allowed in execution state \"{0}\".", ExecutionState));
-      Algorithm.Pause();
-      ExecutionState = ExecutionState.Paused;
-      OnPaused();
-    }
-
-    private bool forceStop = false;
-    public void Stop() {
-      if ((ExecutionState != ExecutionState.Started) && (ExecutionState != ExecutionState.Paused))
-        throw new InvalidOperationException(string.Format("Stop not allowed in execution state \"{0}\".", ExecutionState));
-      forceStop = true;
-      try {
-        Algorithm.Stop();
-      } catch (InvalidOperationException) {
-        // sometimes we hit the algorithm in an invalid state
-      }
-    }
-
-    private void AddAlgorithmAnalyzers() {
-      if (!Algorithm.Parameters.ContainsKey("Analyzer")) return;
-      var analyzerParam = Algorithm.Parameters["Analyzer"] as IValueParameter<MultiAnalyzer>;
-      if (analyzerParam == null) return;
-      if (!analyzerParam.Value.Operators.Contains(perClockAnalyzer))
-        analyzerParam.Value.Operators.Add(perClockAnalyzer);
-      if (!analyzerParam.Value.Operators.Contains(perEvaluationsAnalyzer))
-        analyzerParam.Value.Operators.Add(perEvaluationsAnalyzer);
-    }
-
-    private void RemoveAlgorithmAnalyzers() {
-      if (!Algorithm.Parameters.ContainsKey("Analyzer")) return;
-      var analyzerParam = Algorithm.Parameters["Analyzer"] as IValueParameter<MultiAnalyzer>;
-      if (analyzerParam == null) return;
-      analyzerParam.Value.Operators.Remove(perClockAnalyzer);
-      analyzerParam.Value.Operators.Remove(perEvaluationsAnalyzer);
-    }
-
-    #region Events
-    protected override void OnNameChanged() {
-      base.OnNameChanged();
-      runs.OptimizerName = Name;
-    }
-
-    public event PropertyChangedEventHandler PropertyChanged;
-    private void OnPropertyChanged(string property) {
-      var handler = PropertyChanged;
-      if (handler != null) handler(this, new PropertyChangedEventArgs(property));
-    }
-
-    #region IExecutable Events
-    public event EventHandler ExecutionStateChanged;
-    private void OnExecutionStateChanged() {
-      var handler = ExecutionStateChanged;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler ExecutionTimeChanged;
-    private void OnExecutionTimeChanged() {
-      var handler = ExecutionTimeChanged;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler Prepared;
-    private void OnPrepared() {
-      var handler = Prepared;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler Started;
-    private void OnStarted() {
-      var handler = Started;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler Paused;
-    private void OnPaused() {
-      var handler = Paused;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler Stopped;
-    private void OnStopped() {
-      var handler = Stopped;
-      if (handler != null) handler(this, EventArgs.Empty);
-    }
-    public event EventHandler<EventArgs<Exception>> ExceptionOccurred;
-    private void OnExceptionOccurred(Exception exception) {
-      var handler = ExceptionOccurred;
-      if (handler != null) handler(this, new EventArgs<Exception>(exception));
-    }
-    #endregion
-
-    #region Algorithm Events
-    private void RegisterAlgorithmEvents() {
-      algorithm.ExceptionOccurred += Algorithm_ExceptionOccurred;
-      algorithm.ExecutionTimeChanged += Algorithm_ExecutionTimeChanged;
-      algorithm.Paused += Algorithm_Paused;
-      algorithm.Prepared += Algorithm_Prepared;
-      algorithm.Stopped += Algorithm_Stopped;
-      algorithm.ProblemChanged += Algorithm_ProblemChanged;
-      Algorithm_ProblemChanged(algorithm, EventArgs.Empty);
-    }
-    private void DeregisterAlgorithmEvents() {
-      algorithm.ExceptionOccurred -= Algorithm_ExceptionOccurred;
-      algorithm.ExecutionTimeChanged -= Algorithm_ExecutionTimeChanged;
-      algorithm.Paused -= Algorithm_Paused;
-      algorithm.Prepared -= Algorithm_Prepared;
-      algorithm.Stopped -= Algorithm_Stopped;
-      algorithm.ProblemChanged -= Algorithm_ProblemChanged;
-    }
-    private void Algorithm_ExceptionOccurred(object sender, EventArgs<Exception> e) {
-      OnExceptionOccurred(e.Value);
-    }
-    private void Algorithm_ExecutionTimeChanged(object sender, EventArgs e) {
-      ExecutionTime += Algorithm.ExecutionTime - lastAlgorithmExecutionTime;
-      lastAlgorithmExecutionTime = Algorithm.ExecutionTime;
-    }
-    private void Algorithm_Paused(object sender, EventArgs e) {
-      ExecutionTime += Algorithm.ExecutionTime - lastAlgorithmExecutionTime;
-      lastAlgorithmExecutionTime = Algorithm.ExecutionTime;
-      OnPaused();
-    }
-    private void Algorithm_Prepared(object sender, EventArgs e) {
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
-    }
-    private void Algorithm_Stopped(object sender, EventArgs e) {
-      ExecutionTime += Algorithm.ExecutionTime - lastAlgorithmExecutionTime;
-      lastAlgorithmExecutionTime = Algorithm.ExecutionTime;
-
-      var execTime = ((TimeSpanValue)CurrentRun.Results[ExecutionTimeResultName]).Value;
-      var solEvals = ((DoubleValue)CurrentRun.Results[EvaluatedSolutionsResultName]).Value;
-      var movEvals = ((DoubleValue)CurrentRun.Results[EvaluatedMovesResultName]).Value;
-      var restarts = ((IntValue)CurrentRun.Results[RandomRestartsResultName]).Value;
-      var improvement = false;
-
-      IResult result;
-      if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.EvaluatedSolutionsParameter.ActualName, out result)) {
-        var evals = ((IntValue)result.Value).Value;
-        Evaluations += evals;
-        CurrentRun.Results[EvaluatedSolutionsResultName] = new DoubleValue(solEvals + evals);
-      }
-      if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.EvaluatedMovesParameter.ActualName, out result)) {
-        var evals = ((IntValue)result.Value).Value;
-        Evaluations += moveCostPerSolution * evals;
-        CurrentRun.Results[EvaluatedMovesResultName] = new DoubleValue(movEvals + evals);
-      }
-      if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.BestQualityParameter.ActualName, out result)) {
-        var bestQuality = ((DoubleValue)result.Value).Value;
-        if (double.IsNaN(BestSoFar)
-            || Maximization && bestQuality > BestSoFar
-            || !Maximization && bestQuality < BestSoFar) {
-          BestSoFar = bestQuality;
-          CurrentRun.Results[BestQualityResultName] = new DoubleValue(bestQuality);
-          improvement = true;
-        }
-      }
-      if (Algorithm.Results.TryGetValue(perClockAnalyzer.QualityPerClockParameter.ResultName, out result)) {
-        UpdateQualityPerClockResult((IndexedDataTable<double>)result.Value, execTime, restarts);
-      }
-      if (Algorithm.Results.TryGetValue(perEvaluationsAnalyzer.QualityPerEvaluationsParameter.ResultName, out result)) {
-        UpdateQualityPerEvaluationsResult((IndexedDataTable<double>)result.Value, solEvals, movEvals, restarts);
-      }
-      if (StoreSolutionInRun) {
-        foreach (var r in Algorithm.Results) {
-          if (r.Name.ToLower().EndsWith("solution") && improvement) {
-            CurrentRun.Results[r.Name] = (IItem)r.Value.Clone();
-          }
-        }
-      }
-
-      CurrentRun.Results[ExecutionTimeResultName] = new TimeSpanValue(execTime + Algorithm.ExecutionTime);
-
-      // Algorithm sets ExecutionTime to zero before firing Prepared
-      // We will thus see ExecutionTimeChanged before Prepared
-      lastAlgorithmExecutionTime = TimeSpan.Zero;
-
-      if (!forceStop && !IsFinished) {
-        CurrentRun.Results[RandomRestartsResultName] = new IntValue(restarts + 1);
-        Algorithm.Prepare(true);
-        Algorithm.Start();
-      } else {
-        forceStop = false;
-        Runs.Add(CurrentRun);
-        Algorithm.Prepare(true);
-        ExecutionState = ExecutionState.Stopped;
-        OnStopped();
-      }
-    }
-
-    private void UpdateQualityPerClockResult(IndexedDataTable<double> perClock, TimeSpan execTime, int restarts) {
+      } while (!IsFinished);
+    }
+
+    private void UpdateQualityPerClockResult(IndexedDataTable<double> perClock, int restarts) {
       IndexedDataTable<double> dt;
-      if (!CurrentRun.Results.ContainsKey(QualityPerClockResultName)) {
+      if (!Results.ContainsKey(QualityPerClockResultName)) {
         dt = (IndexedDataTable<double>)perClock.Clone();
         if (!dt.Rows.ContainsKey("Restarts"))
@@ -614 +362 @@
         foreach (var v in dt.Rows.First().Values)
           dt.Rows["Restarts"].Values.Add(Tuple.Create(v.Item1, 0.0));
-        CurrentRun.Results.Add(QualityPerClockResultName, dt);
+        Results.Add(new Result(QualityPerClockResultName, dt));
       } else {
-        dt = (IndexedDataTable<double>)CurrentRun.Results[QualityPerClockResultName];
-        var best = dt.Rows.First().Values.Last().Item2;
+        dt = (IndexedDataTable<double>)Results[QualityPerClockResultName].Value;
+        var qualityValues = dt.Rows.First().Values;
+        var restartValues = dt.Rows["Restarts"].Values;
+        var best = qualityValues.Last().Item2;
+        var execTime = qualityValues.Last().Item1;
+        var improvement = false;
         foreach (var tupl in perClock.Rows.First().Values) {
           if (Maximization && tupl.Item2 > best || !Maximization && tupl.Item2 < best) {
-            dt.Rows.First().Values.Add(Tuple.Create(execTime.TotalSeconds + tupl.Item1, tupl.Item2));
-            dt.Rows["Restarts"].Values.Add(Tuple.Create(execTime.TotalSeconds + tupl.Item1, (double)restarts));
+            if (!improvement) {
+              // the last entry always holds the same value, but with highest execution time
+              qualityValues.RemoveAt(qualityValues.Count - 1);
+              restartValues.RemoveAt(restartValues.Count - 1);
+              improvement = true;
+            }
+            qualityValues.Add(Tuple.Create(execTime + tupl.Item1, tupl.Item2));
+            restartValues.Add(Tuple.Create(execTime + tupl.Item1, (double)restarts));
             best = tupl.Item2;
           }
         }
-      }
-      if (IsFinished) {
-        dt.Rows.First().Values.Add(Tuple.Create(ExecutionTime.TotalSeconds, BestSoFar));
-        dt.Rows["Restarts"].Values.Add(Tuple.Create(ExecutionTime.TotalSeconds, (double)restarts));
-      }
-    }
-
-    private void UpdateQualityPerEvaluationsResult(IndexedDataTable<double> perEvaluations, double solEvals, double movEvals, int restarts) {
+        if (improvement) {
+          var totalExecTime = execTime + perClock.Rows.First().Values.Last().Item1;
+          qualityValues.Add(Tuple.Create(totalExecTime, best));
+          restartValues.Add(Tuple.Create(totalExecTime, (double)restarts));
+        }
+      }
+    }
+
+    private void UpdateQualityPerEvaluationsResult(IndexedDataTable<double> perEvaluations, int restarts) {
       IndexedDataTable<double> dt;
-      if (!CurrentRun.Results.ContainsKey(QualityPerEvaluationsResultName)) {
+      if (!Results.ContainsKey(QualityPerEvaluationsResultName)) {
         dt = (IndexedDataTable<double>)perEvaluations.Clone();
         if (!dt.Rows.ContainsKey("Restarts"))
@@ -645 +404 @@
         foreach (var v in dt.Rows.First().Values)
           dt.Rows["Restarts"].Values.Add(Tuple.Create(v.Item1, 0.0));
-        CurrentRun.Results.Add(QualityPerEvaluationsResultName, dt);
+        Results.Add(new Result(QualityPerEvaluationsResultName, dt));
       } else {
-        dt = (IndexedDataTable<double>)CurrentRun.Results[QualityPerEvaluationsResultName];
-        var best = dt.Rows.First().Values.Last().Item2;
+        dt = (IndexedDataTable<double>)Results[QualityPerEvaluationsResultName].Value;
+        var qualityValues = dt.Rows.First().Values;
+        var restartValues = dt.Rows["Restarts"].Values;
+        var best = qualityValues.Last().Item2;
+        var evaluations = qualityValues.Last().Item1;
+        var improvement = false;
         foreach (var tupl in perEvaluations.Rows.First().Values) {
           if (Maximization && tupl.Item2 > best || !Maximization && tupl.Item2 < best) {
-            dt.Rows.First().Values.Add(Tuple.Create(solEvals + moveCostPerSolution * movEvals + tupl.Item1, tupl.Item2));
-            dt.Rows["Restarts"].Values.Add(Tuple.Create(solEvals + moveCostPerSolution * movEvals + tupl.Item1, (double)restarts));
+            if (!improvement) {
+              // the last entry always holds the same value, but with highest evaluations
+              qualityValues.RemoveAt(qualityValues.Count - 1);
+              restartValues.RemoveAt(restartValues.Count - 1);
+              improvement = true;
+            }
+            qualityValues.Add(Tuple.Create(evaluations + tupl.Item1, tupl.Item2));
+            restartValues.Add(Tuple.Create(evaluations + tupl.Item1, (double)restarts));
             best = tupl.Item2;
           }
         }
-      }
-      if (IsFinished) {
-        dt.Rows.First().Values.Add(Tuple.Create(Evaluations, BestSoFar));
-        dt.Rows["Restarts"].Values.Add(Tuple.Create(Evaluations, (double)restarts));
-      }
+        if (improvement) { // add the best quality again as value with highest evaluations
+          var totalEvaluations = evaluations + perEvaluations.Rows.First().Values.Last().Item1;
+          qualityValues.Add(Tuple.Create(totalEvaluations, best));
+          restartValues.Add(Tuple.Create(totalEvaluations, (double)restarts));
+        }
+      }
+    }
+
+    private void UpdateTargetValueFromBestKnownQuality() {
+      var bkParam = Problem.BestKnownQualityParameter as IValueParameter<DoubleValue>;
+      if (bkParam != null && bkParam.Value != null)
+        TargetValueParameter.Value = new DoubleValue(bkParam.Value.Value);
+      else if (bkParam != null && bkParam.Value == null)
+        TargetValueParameter.Value = null;
+    }
+
+    private void AddAlgorithmAnalyzers() {
+      if (Algorithm == null) return;
+      if (!Algorithm.Parameters.ContainsKey("Analyzer")) return;
+      var analyzerParam = Algorithm.Parameters["Analyzer"] as IValueParameter<MultiAnalyzer>;
+      if (analyzerParam != null) {
+        foreach (var analyzer in analyzerParam.Value.Operators.OfType<QualityPerClockAnalyzer>().ToList())
+          analyzerParam.Value.Operators.Remove(analyzer);
+        analyzerParam.Value.Operators.Add(perClockAnalyzer);
+        foreach (var analyzer in analyzerParam.Value.Operators.OfType<QualityPerEvaluationsAnalyzer>().ToList())
+          analyzerParam.Value.Operators.Remove(analyzer);
+        analyzerParam.Value.Operators.Add(perEvaluationsAnalyzer);
+      } else {
+        var analyzerParam2 = Algorithm.Parameters["Analyzer"] as IValueParameter<IMultiAnalyzer>;
+        if (analyzerParam2 == null) return;
+        foreach (var analyzer in analyzerParam2.Value.Operators.OfType<QualityPerClockAnalyzer>().ToList())
+          analyzerParam2.Value.Operators.Remove(analyzer);
+        analyzerParam2.Value.Operators.Add(perClockAnalyzer);
+        foreach (var analyzer in analyzerParam2.Value.Operators.OfType<QualityPerEvaluationsAnalyzer>().ToList())
+          analyzerParam2.Value.Operators.Remove(analyzer);
+        analyzerParam2.Value.Operators.Add(perEvaluationsAnalyzer);
+      }
+    }
+
+    private void RemoveAlgorithmAnalyzers() {
+      if (Algorithm == null) return;
+      if (!Algorithm.Parameters.ContainsKey("Analyzer")) return;
+      var analyzerParam = Algorithm.Parameters["Analyzer"] as IValueParameter<MultiAnalyzer>;
+      if (analyzerParam != null) {
+        analyzerParam.Value.Operators.Remove(perClockAnalyzer);
+        analyzerParam.Value.Operators.Remove(perEvaluationsAnalyzer);
+      } else {
+        var analyzerParam2 = Algorithm.Parameters["Analyzer"] as IValueParameter<IMultiAnalyzer>;
+        if (analyzerParam2 != null) {
+          analyzerParam2.Value.Operators.Remove(perClockAnalyzer);
+          analyzerParam2.Value.Operators.Remove(perEvaluationsAnalyzer);
+        }
+      }
+    }
+
+    #region Event Handlers
+    private void Algorithm_ExceptionOccurred(object sender, EventArgs<Exception> e) {
+      OnExceptionOccurred(e.Value);
+    }
+    private void Algorithm_Paused(object sender, EventArgs e) {
+      algorithmWaitHandle.Set();
+    }
+    private void Algorithm_Stopped(object sender, EventArgs e) {
+      algorithmWaitHandle.Set();
     }
 
     private void Algorithm_ProblemChanged(object sender, EventArgs e) {
-      if (problem != null) DeregisterProblemEvents();
-
-      problem = Algorithm.Problem as ISingleObjectiveHeuristicOptimizationProblem;
-      if (problem == null) return;
-      RegisterProblemEvents();
-
+      if (Algorithm.Problem != Problem) Problem = (ISingleObjectiveHeuristicOptimizationProblem)Algorithm.Problem;
       AddAlgorithmAnalyzers();
-
-      var maxParam = problem.MaximizationParameter as IValueParameter<BoolValue>;
-      if (maxParam != null)
-        Maximization = maxParam.Value.Value;
-      var bkParam = problem.BestKnownQualityParameter as IValueParameter<DoubleValue>;
-      if (bkParam != null && bkParam.Value != null)
-        TargetValue = bkParam.Value.Value;
-
-      Reset();
-    }
-
-    private void RegisterProblemEvents() {
-      problem.Reset += ProblemOnReset;
-      problem.OperatorsChanged += ProblemOnOperatorsChanged;
-    }
-
-    private void DeregisterProblemEvents() {
-      problem.Reset -= ProblemOnReset;
-      problem.OperatorsChanged -= ProblemOnOperatorsChanged;
-    }
-
-    private void ProblemOnReset(object sender, EventArgs eventArgs) {
-      AddAlgorithmAnalyzers();
-    }
-
-    private void ProblemOnOperatorsChanged(object sender, EventArgs eventArgs) {
-      AddAlgorithmAnalyzers();
-    }
-    #endregion
+    }
+
+    private void Problem_BestKnownQualityParameter_ValueChanged(object sender, EventArgs e) {
+      var param = sender as IValueParameter<DoubleValue>;
+      if (param != null) {
+        if (param.Value != null) param.Value.ValueChanged += Problem_BestKnownQualityParameter_Value_ValueChanged;
+        UpdateTargetValueFromBestKnownQuality();
+      }
+    }
+
+    private void Problem_BestKnownQualityParameter_Value_ValueChanged(object sender, EventArgs e) {
+      UpdateTargetValueFromBestKnownQuality();
+    }
+
+    protected override void Problem_Reset(object sender, EventArgs eventArgs) {
+      if (Algorithm != null) AddAlgorithmAnalyzers();
+    }
+
+    protected override void Problem_OperatorsChanged(object sender, EventArgs eventArgs) {
+      if (Algorithm != null) AddAlgorithmAnalyzers();
+    }
+
+    private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {
+      System.Timers.Timer timer = (System.Timers.Timer)sender;
+      timer.Enabled = false;
+      DateTime now = DateTime.UtcNow;
+      ExecutionTime += now - lastUpdateTime;
+      lastUpdateTime = now;
+      timer.Enabled = true;
+    }
     #endregion
   }