Recent update for ACO solver.

- smaller default population and iteration size
- obey to timeout

jastadd-mquat-solver-aco/src/main/java/ir/ac/ui/eng/ACOSolver.java

@@ -22,8 +22,8 @@ import java.util.concurrent.TimeUnit;
  */
 public class ACOSolver implements BenchmarkableSolver {
 
-  int population_size = 100000;
-  int iteration_size = 20;
+  int population_size = 5;
+  int iteration_size = 1;
 
   private static final Logger logger = LogManager.getLogger(ACOSolver.class);
 
@@ -120,6 +120,11 @@ public class ACOSolver implements BenchmarkableSolver {
 
     for (int pop = 0; pop < population_size; pop++) {
 
+      if (stopWatch.time(TimeUnit.MILLISECONDS) > maxSolvingTime) {
+        timedOut = true;
+        break;
+      }
+
       logger.trace("pop: {}", pop);
       Solution currentSolution = new Solution();
       currentSolution.setModel(model);
@@ -197,6 +202,11 @@ public class ACOSolver implements BenchmarkableSolver {
     }
 
     for (int iteration = 0; iteration < iteration_size; iteration++) {
+      if (stopWatch.time(TimeUnit.MILLISECONDS) > maxSolvingTime) {
+        timedOut = true;
+        break;
+      }
+
       List<Ant> population = new ArrayList<>();
       for (int i = 0; i < currentSolutions.size(); i++) {
         Ant ant = new Ant(i, currentSolutions.get(i), currentPossibleResources.get(i), currentEta.get(i), currentSort.get(i), numAssignments);
@@ -227,11 +237,8 @@ public class ACOSolver implements BenchmarkableSolver {
                   antSolution.computeObjective());
             }
           }
-          ant = null;
         }
       });
-      population = null;
-      System.gc();
     }
 
     logger.info("Number of total software solutions: {}", numTotalSoftwareSolutions);