- parallel solver: added ability to run in a single solution mode

src/ctt.properties

@@ -42,4 +42,7 @@ SimulatedAnnealing.ReheatLengthCoef=7
 Extensions.Classes=org.cpsolver.ifs.extension.ConflictStatistics
 
 #Other
-General.SaveBestUnassigned=0
+General.SaveBestUnassigned=0
+
+ParallelSolver.SingleSolution=false
+ParallelSolver.SingleSolutionNeighbourCheck=true

src/exam.properties

@@ -35,4 +35,7 @@ General.SaveBestUnassigned=0
 #Extensions
 Exam.AllowDirectConflict=false
 Exam.AllowBinaryViolations=false
-Extensions.Classes=org.cpsolver.ifs.extension.ConflictStatistics
+Extensions.Classes=org.cpsolver.ifs.extension.ConflictStatistics
+
+ParallelSolver.SingleSolution=false
+ParallelSolver.SingleSolutionNeighbourCheck=true

src/net/sf/cpsolver/itc/ItcModel.java

@@ -54,4 +54,9 @@ public boolean cvsPrint(Assignment<V, T> assignment) {
     public void makeFeasible(Assignment<V, T> assignment) {}
 
     public abstract Assignment<V, T> createAssignment(int index, Assignment<V, T> assignment);
+
+    @Override
+    public String toString(Assignment<V, T> a) {
+    	return "V:"+a.nrAssignedVariables()+"/"+variables().size()+", P:"+Math.round(getTotalValue(a))+" ("+csvLine(a)+")";
+    }
 }

src/net/sf/cpsolver/itc/ItcTest.java

@@ -4,6 +4,8 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.lang.management.ManagementFactory;
+import java.lang.management.OperatingSystemMXBean;
 import java.text.DecimalFormat;
 import java.util.Collection;
 import java.util.List;
@@ -250,24 +252,27 @@ protected Solution createParallelSolution(int index) {
                     solution.addSolutionListener(listener);
                 return solution;
             }
+        	@Override
+            public boolean hasSingleSolution() {
+        		return sConfig.getPropertyBoolean("ParallelSolver.SingleSolution", false);
+        	}
         };
 		Solution solution = new Solution(model, model.createAssignment(0, null));
         solver.setInitalSolution(solution);
+        solution.getModel().createAssignmentContexts(solution.getAssignment(), false);
 
         solver.currentSolution().addSolutionListener(new SolutionListener() {
-            public void solutionUpdated(Solution solution) {}
+            public void solutionUpdated(Solution solution) {
+            	//sLog.info("**CURRENT["+solution.getIteration()+"]** " + solution);
+            }
             public void getInfo(Solution solution, Map info) {}
             public void getInfo(Solution solution, Map info, Collection variables) {}
             public void bestCleared(Solution solution) {}
             public void bestSaved(Solution solution) {
-                ItcModel m = (ItcModel)solution.getModel();
-                Assignment a = solution.getAssignment();
-                sLog.info("**BEST["+solution.getIteration()+"]** V:"+a.nrAssignedVariables()+"/"+m.variables().size()+", P:"+Math.round(m.getTotalValue(a))+" ("+m.csvLine(a)+")");
+                sLog.info("**BEST["+solution.getIteration()+"]** " + solution);
             }
             public void bestRestored(Solution solution) {
-                ItcModel m = (ItcModel)solution.getModel();
-                Assignment a = solution.getAssignment();
-            	sLog.info("##RESTORED["+solution.getIteration()+"]## V:"+a.nrAssignedVariables()+"/"+m.variables().size()+", P:"+Math.round(m.getTotalValue(a))+" ("+m.csvLine(a)+")");
+            	sLog.info("##RESTORED["+solution.getIteration()+"]## " + solution);
             }
         });
 
@@ -287,7 +292,7 @@ public static Solution solve() {
             Solution solution = solver.currentSolution();
             solution.restoreBest();
             ((ItcModel)solution.getModel()).makeFeasible(solution.getAssignment());
-            solution.saveBest();
+            // solution.saveBest();
 
             return output(solver);
         } catch (Exception e) {
@@ -305,7 +310,7 @@ private static Solution output(Solver solver) throws Exception {
             sLog.error("No best solution found.");
             return null;
         }
-        solution.restoreBest();
+        // solution.restoreBest();
 
         sLog.info("Best solution:"+ToolBox.dict2string(solution.getExtendedInfo(),1));
 
@@ -325,14 +330,22 @@ private static Solution output(Solver solver) throws Exception {
             ItcModel m = (ItcModel)solution.getModel();
             Assignment a = solution.getAssignment();
             DecimalFormat df = new DecimalFormat("0.00");
+            double cpu = 0.0;
+            OperatingSystemMXBean bean = ManagementFactory.getOperatingSystemMXBean();
+            if (bean instanceof com.sun.management.OperatingSystemMXBean) {
+            	cpu = ((com.sun.management.OperatingSystemMXBean)bean).getProcessCpuTime() / 1e9;
+            }
             w.println(
                     sSeed+","+
                     sTimeOut+","+
                     df.format(solution.getBestTime())+","+
                     solution.getBestIteration()+","+
                     Math.round(m.getTotalValue(solution.getAssignment()) + 5000 * a.nrUnassignedVariables(m))+","+
                     model.csvLine(a) + "," +
-                    model.getProperties().getPropertyInt("Parallel.NrSolvers", 4));
+                    model.getProperties().getPropertyInt("Parallel.NrSolvers", 4) +
+                    (solver.hasSingleSolution() ? "s": "p") +
+                    (solver.hasSingleSolution() && model.getProperties().getPropertyBoolean("ParallelSolver.SingleSolutionQueue", true) ? "q" : "") + "," +
+                    df.format(solution.getIteration() / solution.getTime()) + "," + df.format(cpu));
             w.flush(); w.close();
         }
 
@@ -353,7 +366,7 @@ public void run() {
                 Solution solution = iSolver.currentSolution();
                 solution.restoreBest();
                 ((ItcModel)solution.getModel()).makeFeasible(solution.getAssignment());
-                solution.saveBest();
+                // solution.saveBest();
 
                 output(iSolver);
             } catch (Exception e) {

src/net/sf/cpsolver/itc/ctt/model/CttAssignment.java

@@ -7,6 +7,7 @@
 
 import org.cpsolver.ifs.assignment.Assignment;
 import org.cpsolver.ifs.assignment.AssignmentAbstract;
+import org.cpsolver.ifs.assignment.context.AssignmentContextHolder;
 import org.cpsolver.ifs.assignment.context.DefaultParallelAssignmentContextHolder;
 import org.cpsolver.ifs.model.Model;
 
@@ -34,17 +35,28 @@
  * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
  */
 public class CttAssignment extends AssignmentAbstract<CttLecture, CttPlacement> {
-	private CttModel iModel;
-	private int iIndex;
-	private int iNrAssigned = 0;
+	protected CttModel iModel;
+	protected int iIndex;
+	protected int iNrAssigned = 0;
+	protected CttPlacement[] iAssignment = null;
+	protected CttAssignment iParent = null;
 
 	public CttAssignment(CttModel model, int index, Assignment<CttLecture, CttPlacement> assignment) {
 		super(new DefaultParallelAssignmentContextHolder<CttLecture, CttPlacement>(index));
 		iIndex = index;
 		iModel = model;
-		if (assignment != null)
-            for (CttPlacement value: assignment.assignedValues())
-                setValueInternal(0, value.variable(), value);
+		iParent = (CttAssignment) assignment;
+		if (iParent == null) {
+			iAssignment = new CttPlacement[model.variables().size()];
+			iNrAssigned = 0;
+		} else {
+			iAssignment = Arrays.copyOf(((CttAssignment)iParent).toArray(), model.variables().size());
+			iNrAssigned = iParent.nrAssignedVariables();
+		}
+	}
+
+	protected CttAssignment(AssignmentContextHolder<CttLecture, CttPlacement> contextHolder) {
+		super(contextHolder);
 	}
 
 	@Override
@@ -97,35 +109,16 @@ public Collection<CttLecture> assignedVariables() {
 		return assigned;
 	}
 
-    protected CttPlacement[] getAssignments(CttLecture variable) {
-        synchronized (variable) {
-            CttPlacement[] assignments = (CttPlacement[])variable.getExtra();
-            if (assignments == null) {
-                assignments = (CttPlacement[])new CttPlacement[Math.max(10, 1 + iIndex)];
-                variable.setExtra(assignments);
-            } else if (assignments.length <= iIndex) {
-                assignments = Arrays.copyOf(assignments, 10 + iIndex);
-                variable.setExtra(assignments);
-            }
-            return assignments;
-        }
-    }
-
 	@Override
-    @SuppressWarnings("deprecation")
     protected CttPlacement getValueInternal(CttLecture variable) {
-    	if (iIndex == 1)
-    		return variable.getAssignment();
-        return getAssignments(variable)[iIndex];
+        // return (CttPlacement) variable.getAssignments()[iIndex];
+		return iAssignment[variable.getIndex()];
     }
 
 	@Override
-    @SuppressWarnings("deprecation")
     protected void setValueInternal(long iteration, CttLecture variable, CttPlacement value) {
-    	if (iIndex == 1)
-    		variable.setAssignment(value);
-    	else
-    		getAssignments(variable)[iIndex] = value;
+    	//variable.getAssignments()[iIndex] = value;
+    	iAssignment[variable.getIndex()] = value;
         if (value == null)
         	iNrAssigned --;
         else
@@ -141,4 +134,12 @@ public int getIndex() {
     public int nrAssignedVariables() {
         return iNrAssigned;
     }
+
+    public CttPlacement[] toArray() {
+    	return iAssignment;
+    }
+
+	public Assignment<CttLecture, CttPlacement> getParentAssignment() {
+		return iParent;
+	}
 }

src/net/sf/cpsolver/itc/ctt/model/CttCurricula.java

@@ -1,12 +1,14 @@
 package net.sf.cpsolver.itc.ctt.model;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 import org.cpsolver.ifs.assignment.Assignment;
 import org.cpsolver.ifs.assignment.context.AssignmentConstraintContext;
+import org.cpsolver.ifs.assignment.context.CanInheritContext;
 import org.cpsolver.ifs.assignment.context.ConstraintWithContext;
 import org.cpsolver.ifs.model.ConstraintListener;
 
@@ -148,7 +150,7 @@ public int getCompactPenalty(Assignment<CttLecture, CttPlacement> assignment, Ct
      * same curricula are placed at the same time.
      *
      */
-    public class CurriculaConstraint extends ConstraintWithContext<CttLecture, CttPlacement, CttCurricula.Table> {
+    public class CurriculaConstraint extends ConstraintWithContext<CttLecture, CttPlacement, CttCurricula.Table> implements CanInheritContext<CttLecture, CttPlacement, CttCurricula.Table> {
 
         /** Constructor */
         public CurriculaConstraint() {
@@ -212,9 +214,14 @@ public int hashCode() {
 		public Table createAssignmentContext(Assignment<CttLecture, CttPlacement> assignment) {
 			return new Table(assignment);
 		}
+
+		@Override
+		public Table inheritAssignmentContext(Assignment<CttLecture, CttPlacement> assignment, Table parentContext) {
+			return new Table(assignment, parentContext);
+		}
     }
 
-    private class Table implements AssignmentConstraintContext<CttLecture, CttPlacement> {
+    public class Table implements AssignmentConstraintContext<CttLecture, CttPlacement> {
         public CttPlacement[] iPlacement;
 
         public Table(Assignment<CttLecture, CttPlacement> assignment) {
@@ -226,6 +233,10 @@ public Table(Assignment<CttLecture, CttPlacement> assignment) {
 				if (p != null) assigned(assignment, p);
 			}
 		}
+
+        public Table(Assignment<CttLecture, CttPlacement> assignment, Table parent) {
+        	iPlacement = Arrays.copyOf(parent.iPlacement, parent.iPlacement.length);
+        }
 
 		@Override
 		public void assigned(Assignment<CttLecture, CttPlacement> assignment, CttPlacement p) {

src/net/sf/cpsolver/itc/ctt/model/CttInheritedAssignment.java

@@ -0,0 +1,56 @@
+package net.sf.cpsolver.itc.ctt.model;
+
+import java.util.Arrays;
+import java.util.concurrent.locks.Lock;
+
+import org.cpsolver.ifs.assignment.InheritedAssignment;
+import org.cpsolver.ifs.assignment.context.InheritedAssignmentContextHolder;
+import org.cpsolver.ifs.solution.Solution;
+
+/**
+ * Curriculum based Course Timetabling (CTT) inherited assignment model.
+ * 
+ * @version
+ * ITC2007 1.0<br>
+ * Copyright (C) 2014 Tomas Muller<br>
+ * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
+ * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
+ * <br>
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ * <br><br>
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * <br><br>
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not see
+ * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
+ */
+public class CttInheritedAssignment extends CttAssignment implements InheritedAssignment<CttLecture, CttPlacement> {
+	private long iVersion = -1;
+
+	public CttInheritedAssignment(Solution<CttLecture, CttPlacement> solution, int index) {
+		super(new InheritedAssignmentContextHolder<CttLecture, CttPlacement>(index, solution.getIteration()));
+		iIndex = index;
+		iVersion = solution.getIteration();
+		iModel = (CttModel) solution.getModel();
+		iParent = (CttAssignment) solution.getAssignment();
+		Lock lock = solution.getLock().readLock();
+		lock.lock();
+		try {
+			iNrAssigned = iParent.nrAssignedVariables();
+			iAssignment = Arrays.copyOf(((CttAssignment)iParent).toArray(), iModel.variables().size());
+		} finally {
+			lock.unlock();
+		}
+	}
+
+	@Override
+	public long getVersion() {
+		return iVersion;
+	}
+}

src/net/sf/cpsolver/itc/ctt/model/CttLecture.java

@@ -4,9 +4,10 @@
 import java.util.List;
 
 import org.cpsolver.ifs.assignment.Assignment;
+import org.cpsolver.ifs.model.LazySwap;
 import org.cpsolver.ifs.model.Neighbour;
 import org.cpsolver.ifs.model.Variable;
-import net.sf.cpsolver.itc.heuristics.neighbour.ItcLazySwap;
+
 import net.sf.cpsolver.itc.heuristics.neighbour.ItcSwap.Swapable;
 
 /**
@@ -37,6 +38,7 @@
 public class CttLecture extends Variable<CttLecture, CttPlacement> implements Swapable<CttLecture, CttPlacement> {
     private int iIdx;
     private CttCourse iCourse = null;
+    private int iHashCode;
 
     /** Constructor
      * @param course course to which this lecture belongs
@@ -54,6 +56,7 @@ public CttLecture(CttCourse course, int idx) {
             curricula.getConstraint().addVariable(this);
         setValues(computeValues());
         getModel().addVariable(this);
+        iHashCode = toString().hashCode();
     }
 
     /** Return course to which this lecture belong */
@@ -102,7 +105,7 @@ public boolean equals(Object o) {
 
     /** Hash code */
     public int hashCode() {
-        return toString().hashCode();
+        return iHashCode;
     }
 
     /** Compare two lectures, return the harder one. That is the one with more curriculas, or smaller domain/constraint ratio. */
@@ -142,7 +145,7 @@ public Neighbour<CttLecture, CttPlacement> findSwap(Assignment<CttLecture, CttPl
         }
         CttPlacement np1 = new CttPlacement(this, p2.getRoom(), p2.getDay(), p2.getSlot());
         CttPlacement np2 = new CttPlacement(lecture, p1.getRoom(), p1.getDay(), p1.getSlot());
-        return new ItcLazySwap<CttLecture, CttPlacement>(assignment, np1, np2);
+        return new LazySwap<CttLecture, CttPlacement>(np1, np2);
         /*
         double value = 0;
         //value += np1.extraPenalty() + np2.extraPenalty() - p1.extraPenalty() - p2.extraPenalty();