Changeset 15375

Timestamp:

09/20/17 15:12:10 (7 years ago)

Author:

pfleck

Message:

#2822

• Correctly triggers optimizer task exception within continuation.
• Using lazy evaluation to re-include "externally started but then paused" optimizers.

File:

• branches/ParallelExperiment/HeuristicLab.Optimization/3.3/MetaOptimizers/Experiment.cs (modified) (1 diff)

branches/ParallelExperiment/HeuristicLab.Optimization/3.3/MetaOptimizers/Experiment.cs

@@ -204 +204 @@
       if ((ExecutionState != ExecutionState.Prepared) && (ExecutionState != ExecutionState.Paused))
         throw new InvalidOperationException(string.Format("Start not allowed in execution state \"{0}\".", ExecutionState));
-      if (!Optimizers.Any(x => x.ExecutionState == ExecutionState.Prepared || x.ExecutionState == ExecutionState.Paused)) return;
+
+      // Multiple enumerations of runnableOptimizers is done on purpose to get the latest list of runnnable optimizers lazily
+      var runnableOptimizers = Optimizers.Where(x => x.ExecutionState == ExecutionState.Prepared || x.ExecutionState == ExecutionState.Paused);
+      if (!runnableOptimizers.Any()) return;
 
       experimentStarted = true;
       experimentStopped = false;
 
-      var startedTasks = new List<Task>();
+      var startedOptimizers = new Dictionary<IOptimizer, Task>(); // track already started optimizers (.StartAsync does not set the executionstate immediately)
       using (var availableWorkers = new SemaphoreSlim(NumberOfWorkers, NumberOfWorkers)) {
-        var runnableOptimizers = Optimizers.Where(o => o.ExecutionState == ExecutionState.Prepared || o.ExecutionState == ExecutionState.Paused).ToList();
-        if (!runnableOptimizers.Any()) return;
-
-        while (runnableOptimizers.Any()) {
+        while (runnableOptimizers.Any(o => !startedOptimizers.ContainsKey(o))) {
           try {
             availableWorkers.Wait(cancellationToken);
             if (experimentStopped || !experimentStarted) break;
-            // some optimizers might be started manually somewhere else
-            runnableOptimizers.RemoveAll(o => !(o.ExecutionState == ExecutionState.Prepared || o.ExecutionState == ExecutionState.Paused));
-            if (runnableOptimizers.Any()) {
-              var optimizer = runnableOptimizers.First();
-              runnableOptimizers.Remove(optimizer);
-              var startedTask = optimizer.StartAsync(cancellationToken).ContinueWith(x => {
-                availableWorkers.Release(); // is not disposed yet because Task.WaitAll at the end of the using is blocking
+            var optimizer = runnableOptimizers.FirstOrDefault(o => !startedOptimizers.ContainsKey(o));
+            if (optimizer != null) {
+              var startedTask = optimizer.StartAsync(cancellationToken).ContinueWith(async t => {
+                availableWorkers.Release(); // is guaranteed to be not disposed yet because Task.WaitAll blocks before the end of the using
+                await t; // trigger a potential exception on the optimizerTask
               });
-              startedTasks.Add(startedTask);
+              startedOptimizers.Add(optimizer, startedTask.Unwrap()); // unwrap task because lambda of .ContinueWith is async
             }
           } catch (InvalidOperationException) { } catch (OperationCanceledException) { }
         }
 
+        Task.WaitAll(startedOptimizers.Values.ToArray()); // retreive exeptions of the asyncrounously started optimizer
         allOptimizerFinished.Wait();
-        Task.WaitAll(startedTasks.ToArray()); // retreive exeptions of the asyncrounously started optimizer
       }
     }