fixed missing oderConstraints

src/main/java/de/dhbwstuttgart/typeinference/unify/ConstraintSetRepository.java

@@ -0,0 +1,21 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class ConstraintSetRepository {
+    private Set<Integer> sets = new HashSet<>();
+
+    public boolean containsSet(Set<Set<UnifyPair>> set){
+        Integer hash = Integer.valueOf(set.hashCode());
+
+        if(sets.contains(hash)){
+            return true;
+        }else{
+            sets.add(hash);
+            return false;
+        }
+    }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/IUnifyResultListener.java

@@ -0,0 +1,11 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+
+import java.util.Set;
+
+public interface IUnifyResultListener {
+
+	void onNewTypeResultFound(Set<Set<UnifyPair>> evt);
+
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnify.java

@@ -3,16 +3,12 @@ package de.dhbwstuttgart.typeinference.unify;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.Writer;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ForkJoinPool;
 
 import de.dhbwstuttgart.typeinference.constraints.Constraint;
-import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
-import de.dhbwstuttgart.typeinference.constraints.Pair;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
-import de.dhbwstuttgart.typeinference.unify.model.FiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
 
 public class TypeUnify {
@@ -28,9 +24,12 @@ public class TypeUnify {
 	 * @param cons
 	 * @return
 	 */
-	public Set<Set<UnifyPair>> unify(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
-		ForkJoinPool pool = new ForkJoinPool();
+	public Set<Set<UnifyPair>> unify(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModelParallel ret, UnifyTaskModelParallel usedTasks) {
+		ForkJoinPool pool = new ForkJoinPool(Runtime.getRuntime().availableProcessors(), ForkJoinPool.defaultForkJoinWorkerThreadFactory, null, true);
+		ConstraintSetRepository constraintSetRepository = new ConstraintSetRepository();
+		usedTasks.setPool(pool);
+		ret.setPool(pool);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, constraintSetRepository);
 		pool.invoke(unifyTask);
 		Set<Set<UnifyPair>> res =  unifyTask.join();
 		try {
@@ -54,9 +53,12 @@ public class TypeUnify {
 	 * @param ret
 	 * @return
 	 */
-	public UnifyResultModel unifyAsync(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
-		ForkJoinPool pool = new ForkJoinPool();
+	public UnifyResultModelParallel unifyAsync(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModelParallel ret, UnifyTaskModelParallel usedTasks) {
+		ForkJoinPool pool = new ForkJoinPool(Runtime.getRuntime().availableProcessors(), ForkJoinPool.defaultForkJoinWorkerThreadFactory, null, true);
+		ConstraintSetRepository constraintSetRepository = new ConstraintSetRepository();
+		usedTasks.setPool(pool);
+		ret.setPool(pool);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, constraintSetRepository);
 		pool.invoke(unifyTask);
 		return ret;
 	}
@@ -72,10 +74,12 @@ public class TypeUnify {
 	 * @param ret
 	 * @return
 	 */
-	public UnifyResultModel unifyParallel(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
-		TypeUnifyTask unifyTask = //new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks);
-				new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, usedTasks, statistics);
-		ForkJoinPool pool = new ForkJoinPool();
+	public UnifyResultModelParallel unifyParallel(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModelParallel ret, UnifyTaskModelParallel usedTasks) {
+		ForkJoinPool pool = new ForkJoinPool(Runtime.getRuntime().availableProcessors(), ForkJoinPool.defaultForkJoinWorkerThreadFactory, null, true);
+		ConstraintSetRepository constraintSetRepository = new ConstraintSetRepository();
+		usedTasks.setPool(pool);
+		ret.setPool(pool);
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, true, logFile, log, 0, ret, constraintSetRepository, statistics);
 		pool.invoke(unifyTask);
 		Set<Set<UnifyPair>> res =  unifyTask.join();
 		try {
@@ -108,8 +112,9 @@ public class TypeUnify {
 	 * @param cons
 	 * @return
 	 */
-	public Set<Set<UnifyPair>> unifyOderConstraints(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModel ret, UnifyTaskModel usedTasks) {
-		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, false, logFile, log, 0, ret, usedTasks);
+	public Set<Set<UnifyPair>> unifyOderConstraints(Set<UnifyPair> undConstrains, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, Writer logFile, Boolean log, UnifyResultModelParallel ret, UnifyTaskModelParallel usedTasks) {
+		ConstraintSetRepository constraintSetRepository = new ConstraintSetRepository();
+		TypeUnifyTask unifyTask = new TypeUnifyTask(undConstrains, oderConstraints, fc, false, logFile, log, 0, ret, constraintSetRepository);
 		unifyTask.statistics = statistics;
 		Set<Set<UnifyPair>> res = unifyTask.compute();
 		try {

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnify2Task.java

@@ -15,62 +15,58 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
 import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
 
 public class TypeUnify2Task extends TypeUnifyTask {
-       
-       Set<Set<UnifyPair>> setToFlatten;
-       Set<UnifyPair> methodSignatureConstraintUebergabe;
 
-       //statistics
-       TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq, 
-    		   List<Set<Constraint<UnifyPair>>> oderConstraints, 
-    		   Set<UnifyPair> nextSetElement, 
-    		   IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks, 
-    		   Set<UnifyPair> methodSignatureConstraintUebergabe, Writer statistics) {
-    	   this(setToFlatten, eq, oderConstraints, nextSetElement, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, methodSignatureConstraintUebergabe );
-    	   
-       }
-       
-       public TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, Set<UnifyPair> nextSetElement, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks, Set<UnifyPair> methodSignatureConstraintUebergabe) {
-               super(eq, oderConstraints, fc, parallel, logFile, log, rekTiefe, urm, usedTasks);
-               this.setToFlatten = setToFlatten;
-               this.nextSetElement = nextSetElement;
-               this.methodSignatureConstraintUebergabe = methodSignatureConstraintUebergabe;
-       }
-       
-       Set<UnifyPair> getNextSetElement() {
-    	   return nextSetElement;
-       }
-       
-       @Override
-       protected Set<Set<UnifyPair>> compute() {
-               if (one) {
-                       System.out.println("two");
-               }
-               one = true;
-               Set<Set<UnifyPair>> res = unify2(setToFlatten, eq, oderConstraintsField, fc, parallel, rekTiefeField, methodSignatureConstraintUebergabe);
+    Set<Set<UnifyPair>> setToFlatten;
+    Set<UnifyPair> methodSignatureConstraintUebergabe;
+
+    //statistics
+    TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq,
+                   List<Set<Constraint<UnifyPair>>> oderConstraints,
+                   Set<UnifyPair> nextSetElement,
+                   IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModelParallel urm,
+                   Set<UnifyPair> methodSignatureConstraintUebergabe, ConstraintSetRepository constraintSetRepository, Writer statistics) {
+        this(setToFlatten, eq, oderConstraints, nextSetElement, fc, parallel, logFile, log, rekTiefe, urm, methodSignatureConstraintUebergabe, constraintSetRepository);
+
+    }
+
+    public TypeUnify2Task(Set<Set<UnifyPair>> setToFlatten, Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, Set<UnifyPair> nextSetElement, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModelParallel urm, Set<UnifyPair> methodSignatureConstraintUebergabe, ConstraintSetRepository constraintSetRepository) {
+        super(eq, oderConstraints, fc, parallel, logFile, log, rekTiefe, urm, constraintSetRepository);
+        this.setToFlatten = setToFlatten;
+        this.nextSetElement = nextSetElement;
+        this.methodSignatureConstraintUebergabe = methodSignatureConstraintUebergabe;
+    }
+
+    Set<UnifyPair> getNextSetElement() {
+        return nextSetElement;
+    }
+
+    @Override
+    protected Set<Set<UnifyPair>> compute() {
+        if (one) {
+            System.out.println("two");
+        }
+        one = true;
+        Set<Set<UnifyPair>> res = new HashSet<>();
+
+        if (!constraintSetRepository.containsSet(setToFlatten)) {
+            res = unify2(setToFlatten, eq, oderConstraintsField, fc, parallel, rekTiefeField, methodSignatureConstraintUebergabe);
+        }
                /*if (isUndefinedPairSetSet(res)) { 
                        return new HashSet<>(); }
                else
-               */ 
-               //writeLog("xxx");
-               //noOfThread--;
-               synchronized (usedTasks) {
-            	   if (this.myIsCancelled()) {
-   						return new HashSet<>();
-   					}
-   					else {
-   						return res;
-   					}
-   				}
-       	}
-       
-       public void closeLogFile() {
+               */
+        //writeLog("xxx");
+        //noOfThread--;
+        return res;
+    }
 
-           try {
-				logFile.close();
-			}
-			catch (IOException ioE) {
-				System.err.println("no log-File" + thNo);
-			}
-           
-       }
+    public void closeLogFile() {
+
+        try {
+            logFile.close();
+        } catch (IOException ioE) {
+            System.err.println("no log-File" + thNo);
+        }
+
+    }
 }

src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java

@@ -73,12 +73,10 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 	/**
 	 * Fuer die Threads
 	 */
-	UnifyResultModel urm;
-	protected static int noOfThread = 0;
+	UnifyResultModelParallel urm;
 	private static int totalnoOfThread = 0;
 	int thNo;
 	protected boolean one = false;
-	Integer MaxNoOfThreads = 128;
 
 	public static final String rootDirectory = System.getProperty("user.dir")+"/test/logFiles/";
 	Writer logFile;
@@ -127,11 +125,8 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 	
 	static Integer  noShortendElements = 0;
 	
-	Boolean myIsCanceled = false;
-	
-	volatile UnifyTaskModel usedTasks;
-	
 	static Writer statistics;
+	protected ConstraintSetRepository constraintSetRepository;
 	
 	public TypeUnifyTask() { 
 		rules = new RuleSet();
@@ -152,11 +147,11 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 	*/
 	
 	//statistics
-	public TypeUnifyTask(Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks, Writer statistics) {
-		this(eq,oderConstraints,  fc,  parallel,  logFile,  log,  rekTiefe,  urm,  usedTasks);
+	public TypeUnifyTask(Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModelParallel urm, ConstraintSetRepository constraintSetRepository, Writer statistics) {
+		this(eq,oderConstraints,  fc,  parallel,  logFile,  log,  rekTiefe,  urm, constraintSetRepository);
 		this.statistics = statistics;
 	}
-	public TypeUnifyTask(Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks) {
+	public TypeUnifyTask(Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModelParallel urm, ConstraintSetRepository constraintSetRepository) {
 		synchronized (this) {
             if(statistics==null){
                 statistics = new NullWriter();
@@ -179,8 +174,7 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 			this.parallel = parallel;
 			this.logFile = logFile;
 			this.log = log;
-			
-			noOfThread++; 
+
 			totalnoOfThread++;
 			//writeLog("thNo1 " + thNo);
 			thNo = totalnoOfThread;
@@ -210,8 +204,7 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 			rules = new RuleSet(logFile);
 			this.rekTiefeField = rekTiefe;
 			this.urm = urm;
-			this.usedTasks = usedTasks;
-			this.usedTasks.add(this);
+			this.constraintSetRepository = constraintSetRepository;
 		}
 	}
 	
@@ -247,13 +240,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		}		
 }
 */
-	void myCancel(Boolean b) {
-		myIsCanceled = true;
-	}
-	
-	public boolean myIsCancelled() {
-		return myIsCanceled;
-	}
 	
 	protected Set<Set<UnifyPair>> compute() {
 		if (one) {
@@ -269,7 +255,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 				.filter(x -> x.size()>1)
 				.collect(Collectors.toCollection(ArrayList::new));
 		Set<Set<UnifyPair>> res = unify(neweq, remainingOderconstraints, fc, parallel, rekTiefeField, new HashSet<>());
-		noOfThread--;
 		try {
 			logFile.close();
 		}
@@ -283,14 +268,7 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 				throw new DebugException("Unresolved constraints: " + res.toString()); //return new HashSet<>();
 			}
 		else {
-			synchronized (usedTasks) {
-				if (this.myIsCancelled()) {
-					return new HashSet<>();
-				}
-				else {
-					return res;
-				}
-			}
+			return res;
 		}
 	}
 /*	
@@ -323,12 +301,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 
                 //.collect(Collectors.toCollection(HashSet::new)));
 		
-		synchronized (usedTasks) {
-			if (this.myIsCancelled()) {
-				return new HashSet<>();
-			}
-		}
-		
 		rekTiefe++;
 		nOfUnify++;
         writeLog(nOfUnify.toString() + " Unifikation: " + eq.toString());
@@ -510,12 +482,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		//		.collect(Collectors.toCollection(HashSet::new));
 		//Muss auskommentiert werden, wenn computeCartesianRecursive ENDE
 		
-		synchronized (usedTasks) {
-			if (this.myIsCancelled()) {
-				return new HashSet<>();
-			}
-		}
-		
 		Set<Set<UnifyPair>> eqPrimePrimeSet = new HashSet<>();
 		
 		Set<TypeUnifyTask> forks = new HashSet<>();
@@ -689,15 +655,8 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 			System.out.print("");
 		}
 		*/
-		Set<Set<UnifyPair>> result = new HashSet<>(); 
-		int variance = 0;
-		
-		/* Varianzbestimmung Anfang 
-		 * Oderconstraint, wenn entweder kein Basepair oder unterschiedliche Basepairs => oderConstraint = true;
-		 * Varianz = 1 => Argumentvariable
-		 * Varianz = -1 => Rückgabevariable
-		 * Varianz = 0 => unklar 
-		 * Varianz = 2 => Operatoren oderConstraints */
+		Set<Set<UnifyPair>> result = new HashSet<>();
+
 		ArrayList<UnifyPair> zeroNextElem = new ArrayList<>(nextSetasList.get(0)); 
 		UnifyPair fstBasePair = zeroNextElem.remove(0).getBasePair();
 		Boolean oderConstraint = false;
@@ -715,9 +674,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 						.filter(d -> d.isPresent())
 						.map(e -> e.get())
 						.findAny();
-				if (xi.isPresent()) {
-					variance = xi.get();
-				}
 			}
 			else {
 				oderConstraint = true;
@@ -726,29 +682,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		else {
 			oderConstraint = true;
 		}
-		
-		//Varianz-Bestimmung Oder-Constraints 
-		if (oderConstraint) {
-			if (printtag) System.out.println("nextSetasList " + nextSetasList);
-			Optional<Integer> optVariance = 
-					nextSetasList.iterator()
-				 			  	 .next()
-				 			  	 .stream()
-				 			  	 .filter(x -> x.getGroundBasePair().getLhsType() instanceof PlaceholderType && 
-				 			  			! (x.getRhsType() instanceof PlaceholderType) &&
-				 			  			 x.getPairOp() == PairOperator.EQUALSDOT)
-				 			  	 .map(x -> 
-				 			  	 ((PlaceholderType)x.getGroundBasePair().getLhsType()).getVariance())
-				 			  	 .reduce((n,m) ->  { if ((n == 0) && (m==0)) return 0;
-				 			  	 					 else if (n !=0) return n;  //es muss mindestens eine Variance != 0 sein
-				 			  	 					      else return m;
-				 			  	                   });
-			//Fuer Operatorenaufrufe wird variance auf 2 gesetzt.
-			//da kein Receiver existiert also kein x.getGroundBasePair().getLhsType() instanceof PlaceholderType
-			//Bei Varianz = 2 werden alle Elemente des Kartesischen Produkts abgearbeitet
-			variance = optVariance.isPresent() ? optVariance.get() : 2;
-		}
-		/* Varianzbestimmung Ende */
 
 		//writeLog("nextSetasList: " + nextSetasList.toString());
 		Set<UnifyPair> nextSetElem =  nextSetasList.get(0);
@@ -815,80 +748,7 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 			
 			writeLog("nextSet: " + nextSet.toString());
 			writeLog("nextSetasList: " + nextSetasList.toString());
-			
-			/* staistics Nextvar an Hand Varianzbestimmung auskommentieren Anfang 
-			if (variance == 1) {
-				a = oup.max(nextSetasList.iterator());
-				nextSetasList.remove(a);
-				if (oderConstraint) {
-					nextSetasListOderConstraints.add(((Constraint<UnifyPair>)a).getExtendConstraint());
-				}	
-				writeLog("nextSetasListOderConstraints 1: " + nextSetasListOderConstraints);
-				nextSetasListRest = new ArrayList<>(nextSetasList);
-				Iterator<Set<UnifyPair>> nextSetasListItRest = new ArrayList<Set<UnifyPair>>(nextSetasListRest).iterator();
-				while (nextSetasListItRest.hasNext()) {
-					Set<UnifyPair> a_next = nextSetasListItRest.next();
-					if (//a.equals(a_next) || 
-							(oup.compare(a, a_next) == 1)) {
-						nextSetasListRest.remove(a_next);
-					}
-				}
-				
-				//Alle maximale Elemente in  nextSetasListRest bestimmen
-				//nur für diese wird parallele Berechnung angestossen.
-				nextSetasListRest = oup.maxElements(nextSetasListRest);
-			}
-			else if (variance == -1) {
-				a = oup.min(nextSetasList.iterator());
-				writeLog("Min: a in " + variance + " "+ a);
-				if (oderConstraint) {
-					nextSetasListOderConstraints.add(((Constraint<UnifyPair>)a).getExtendConstraint());
-				}	
-				writeLog("nextSetasListOderConstraints -1: " + nextSetasListOderConstraints);
-				nextSetasList.remove(a);
-				nextSetasListRest = new ArrayList<>(nextSetasList);
-				Iterator<Set<UnifyPair>> nextSetasListItRest = new ArrayList<Set<UnifyPair>>(nextSetasListRest).iterator();
-				while (nextSetasListItRest.hasNext()) {
-					Set<UnifyPair> a_next = nextSetasListItRest.next();
-					if (//a.equals(a_next) || 
-							(oup.compare(a, a_next) == -1)) {
-						nextSetasListRest.remove(a_next);
-					}
-				}
-				//Alle minimalen Elemente in  nextSetasListRest bestimmen
-				//nur für diese wird parallele Berechnung angestossen.
-				nextSetasListRest = oup.minElements(nextSetasListRest);
-			}
-			else if (variance == 2) {
-				a = nextSetasList.remove(0);
-				
-				//Fuer alle Elemente wird parallele Berechnung angestossen.
-				nextSetasListRest = new ArrayList<>(nextSetasList);
-			} 
-			else if (variance == 0) {
-				//wenn a <. theta dann ist ein maximales Element sehr wahrscheinlich
-				//wenn theta <. a dann ist ein minimales Element sehr wahrscheinlich
-				if (!oderConstraint && optOrigPair != null && optOrigPair.isPresent()) {
-					if (optOrigPair.get().getBasePair().getLhsType() instanceof PlaceholderType) {
-						a = oup.max(nextSetasList.iterator());
-					}
-					else {
-						a = oup.min(nextSetasList.iterator());
-					}
-					nextSetasList.remove(a);
-				}
-				else {
-					if (oderConstraint) {
-						a = oup.max(nextSetasList.iterator());
-						nextSetasList.remove(a);
-						nextSetasListOderConstraints.add(((Constraint<UnifyPair>)a).getExtendConstraint());
-					}
-					else {
-						a = nextSetasList.remove(0);
-					}
-				}
-			}
-			Nextvar an Hand Varianzbestimmung auskommentieren Ende */
+
 			a = nextSetasList.remove(0); //statisticsList
 			
 			//writeStatistics(a.toString());
@@ -899,7 +759,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 
 			i++;
 			Set<Set<UnifyPair>> elems = new HashSet<Set<UnifyPair>>(oneElems);
-			writeLog("a1: " + rekTiefe + "  "+ "variance:  "+ variance + " " + a.toString()+ "\n");
 			
 			//Ergebnisvariable für den aktuelle Thread
 			Set<Set<UnifyPair>> res = new HashSet<>();
@@ -924,292 +783,50 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 			/* Wenn parallel gearbeitet wird, wird je nach Varianz ein neuer Thread
 			 * gestartet, der parallel weiterarbeitet.
 			 */
-			if(parallel && (variance == 1) && noOfThread <= MaxNoOfThreads) {
+			if(parallel){
 				Set<TypeUnify2Task> forks = new HashSet<>();
 				Set<UnifyPair> newEqOrig = new HashSet<>(eq);
 				Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
 				List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
 				newElemsOrig.add(a);
-				
-				/* FORK ANFANG */
-				TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, methodSignatureConstraint);
-				//forks.add(forkOrig);
-				synchronized(usedTasks) {
-					if (this.myIsCancelled()) {
-						return new HashSet<>();
-					}
-					forkOrig.fork();
-				}
-				/* FORK ENDE */
-				
-				synchronized (this) {
-					writeLog("a in " + variance + " "+ a);
-					writeLog("nextSetasListRest: " + nextSetasListRest.toString());
-				}
+				TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, parallel, logFile, log, rekTiefe, urm, methodSignatureConstraint, constraintSetRepository);
+				//Überprüfen, ob das Set bereits berechnet wurde
+				forkOrig.fork();
+
 				while (!nextSetasList.isEmpty()) {
-					Set<UnifyPair> nSaL = nextSetasList.remove(0);
-					synchronized (this) { //nextSetasList.remove(nSaL);
-						writeLog("1 RM" + nSaL.toString());
-					}
-					
-					if (!oderConstraint) {
-						
-						/* statistics sameEq wird nicht betrachtet ANGFANG
-						//ueberpruefung ob zu a =. ty \in nSaL in sameEqSet ein Widerspruch besteht
-						if (!sameEqSet.isEmpty() && !checkNoContradiction(nSaL, sameEqSet, result)) {
-							nSaL = null;
-							noShortendElements++;
-							continue;
-						}
-						statistics sameEq wird nicht betrachtet ENDE */
-					}
-					else {
-						nextSetasListOderConstraints.add(((Constraint<UnifyPair>)nSaL).getExtendConstraint());
+					Set<UnifyPair> nSaL = nextSetasList.removeFirst();
+
+					if (oderConstraint) {
+						nextSetasListOderConstraints.add(((Constraint<UnifyPair>) nSaL).getExtendConstraint());
 					}
+
 					Set<UnifyPair> newEq = new HashSet<>(eq);
 					Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
 					List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
 					newElems.add(nSaL);
-					TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, new HashSet<>(methodSignatureConstraint));
+					TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, parallel, logFile, log, rekTiefe, urm, new HashSet<>(methodSignatureConstraint), constraintSetRepository);
 					forks.add(fork);
-					synchronized(usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-						fork.fork();
-					}
+					fork.fork();
 				}
-				//res = unify2(newElemsOrig, newEqOrig, newOderConstraintsOrig, fc, parallel, rekTiefe);
-				
-				/* FORK ANFANG */
-				synchronized (this) {
-					writeLog("wait "+ forkOrig.thNo);
-					noOfThread--;
-					res = forkOrig.join();
-					synchronized (usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-					}
-					//noOfThread++;
-					forkOrig.writeLog("final Orig 1");
-					forkOrig.closeLogFile();
-					//Set<Set<UnifyPair>> fork_res = forkOrig.join();
-					writeLog("JoinOrig " + new Integer(forkOrig.thNo).toString());
-					//noOfThread--; an das Ende von compute verschoben 
-					//add_res.add(fork_res);
-				};
-				/* FORK ENDE */
-				
+
+				res = forkOrig.join();
+
 				forks.forEach(x -> writeLog("wait: " + x.thNo));
-				for(TypeUnify2Task fork : forks) {
-					synchronized (this) {
-						noOfThread--;
-						Set<Set<UnifyPair>> fork_res = fork.join();
-						synchronized (usedTasks) {
-							if (this.myIsCancelled()) {
-								return new HashSet<>();
-							}
-						}
-						//noOfThread++;
-						writeLog("Join " + new Integer(fork.thNo).toString());
-						//noOfThread--; an das Ende von compute verschoben
-						writeLog("fork_res: " + fork_res.toString());
-						writeLog(new Boolean((isUndefinedPairSetSet(fork_res))).toString());
-						add_res.add(fork_res);
-						if (!isUndefinedPairSetSet(fork_res)) {
-							aParDef.add(fork.getNextSetElement());
-						}
-						fork.writeLog("final 1");
-						fork.closeLogFile();
-					};
-				}
-				//noOfThread++;
-			} else {
-			if(parallel && (variance == -1) && noOfThread <= MaxNoOfThreads) {
-				Set<TypeUnify2Task> forks = new HashSet<>();
-				Set<UnifyPair> newEqOrig = new HashSet<>(eq);
-				Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
-				List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
-				newElemsOrig.add(a);
-				
-				/* FORK ANFANG */
-				TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, new HashSet<>(methodSignatureConstraint));
-				//forks.add(forkOrig);
-				synchronized(usedTasks) {
-					if (this.myIsCancelled()) {
-						return new HashSet<>();
-					}
-					forkOrig.fork();
-				}
-				/* FORK ENDE */
-				
-				synchronized (this) {
-					writeLog("a in " + variance + " "+ a);
-					writeLog("nextSetasListRest: " + nextSetasListRest.toString());
-				}
-				while (!nextSetasList.isEmpty()) {
-					Set<UnifyPair> nSaL = nextSetasList.remove(0);
-					synchronized (this) { //nextSetasList.remove(nSaL);
-						writeLog("-1 RM" + nSaL.toString());
-					}
-					
-					if (!oderConstraint) {
-						/* statistics sameEq wird nicht betrachtet ANGFANG
-						//ueberpruefung ob zu a =. ty \in nSaL in sameEqSet ein Widerspruch besteht
-						if (!sameEqSet.isEmpty() && !checkNoContradiction(nSaL, sameEqSet, result)) {
-							nSaL = null;
-							noShortendElements++;
-							continue;
-						}
-						statistics sameEq wird nicht betrachtet ENDE */
-					}
-					else {
-						nextSetasListOderConstraints.add(((Constraint<UnifyPair>)nSaL).getExtendConstraint());
-					}
-					Set<UnifyPair> newEq = new HashSet<>(eq);
-					Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
-					List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
-					newElems.add(nSaL);
-					TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, new HashSet<>(methodSignatureConstraint));
-					forks.add(fork);
-					synchronized(usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-						fork.fork();
+				for (TypeUnify2Task fork : forks) {
+					Set<Set<UnifyPair>> fork_res = new HashSet<>();
+					fork_res = fork.join();
+					add_res.add(fork_res);
+					if (!isUndefinedPairSetSet(fork_res)) {
+						aParDef.add(fork.getNextSetElement());
 					}
 				}
-				//res = unify2(newElemsOrig, newEqOrig, newOderConstraintsOrig, fc, parallel, rekTiefe);
-				
-				/* FORK ANFANG */
-				synchronized (this) {
-					writeLog("wait "+ forkOrig.thNo);
-					noOfThread--;
-					res = forkOrig.join();
-					synchronized (usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-					}
-					//noOfThread++;
-					forkOrig.writeLog("final Orig -1");
-					forkOrig.closeLogFile();
-					//Set<Set<UnifyPair>> fork_res = forkOrig.join();
-					writeLog("JoinOrig " + new Integer(forkOrig.thNo).toString());
-					//noOfThread--; an das Ende von compute verschoben 
-					//add_res.add(fork_res);
-				};
-				/* FORK ENDE */
-				
-				forks.forEach(x -> writeLog("wait: " + x.thNo));
-				for(TypeUnify2Task fork : forks) {
-					synchronized (this) {
-						noOfThread--;
-						Set<Set<UnifyPair>> fork_res = fork.join();
-						synchronized (usedTasks) {
-							if (this.myIsCancelled()) {
-								return new HashSet<>();
-							}
-						}
-						//noOfThread++;
-						writeLog("Join " + new Integer(fork.thNo).toString());
-						//noOfThread--; an das Ende von compute verschoben 
-						writeLog("fork_res: " + fork_res.toString());
-						writeLog(new Boolean((isUndefinedPairSetSet(fork_res))).toString());
-						add_res.add(fork_res);
-						if (!isUndefinedPairSetSet(fork_res)) {
-							aParDef.add(fork.getNextSetElement());
-						}
-						fork.writeLog("final -1");
-						fork.closeLogFile();
-					};
+			}else{
+				elems.add(a);
+				//Überprüfen ob das Set bereits berechnet wurde
+				if(!constraintSetRepository.containsSet(elems)){
+					res = unify2(elems, eq, oderConstraints, fc, parallel, rekTiefe, new HashSet<>(methodSignatureConstraint));
 				}
-				//noOfThread++;
-		    } else {
-		    if(parallel && (variance == 2) && noOfThread <= MaxNoOfThreads) {
-		    	writeLog("var2einstieg");
-		    	Set<TypeUnify2Task> forks = new HashSet<>();
-		    	Set<UnifyPair> newEqOrig = new HashSet<>(eq);
-		    	Set<Set<UnifyPair>> newElemsOrig = new HashSet<>(elems);
-		    	List<Set<Constraint<UnifyPair>>> newOderConstraintsOrig = new ArrayList<>(oderConstraints);
-		    	newElemsOrig.add(a);
-				
-				/* FORK ANFANG */
-		    	TypeUnify2Task forkOrig = new TypeUnify2Task(newElemsOrig, newEqOrig, newOderConstraintsOrig, a, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, new HashSet<>(methodSignatureConstraint));
-		    	//forks.add(forkOrig);
-		    	synchronized(usedTasks) {
-					if (this.myIsCancelled()) {
-						return new HashSet<>();
-					}
-					forkOrig.fork();
-		    	}
-		    	/* FORK ENDE */
-		    	
-		    	synchronized (this) {
-					writeLog("a in " + variance + " "+ a);
-					writeLog("nextSetasListRest: " + nextSetasListRest.toString());
-				}
-		    	while (!nextSetasList.isEmpty()) {
-		    		Set<UnifyPair> nSaL = nextSetasList.remove(0);
-		    		//nextSetasList.remove(nSaL); //PL einkommentiert 20-02-03
-		    		Set<UnifyPair> newEq = new HashSet<>(eq);
-		    		Set<Set<UnifyPair>> newElems = new HashSet<>(elems);
-		    		List<Set<Constraint<UnifyPair>>> newOderConstraints = new ArrayList<>(oderConstraints);
-		    		newElems.add(nSaL);
-		    		TypeUnify2Task fork = new TypeUnify2Task(newElems, newEq, newOderConstraints, nSaL, fc, parallel, logFile, log, rekTiefe, urm, usedTasks, methodSignatureConstraint);
-		    		forks.add(fork);
-		    		synchronized(usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-						fork.fork();
-		    		}
-		    	}
-		    	//res = unify2(newElemsOrig, newEqOrig, newOderConstraintsOrig, fc, parallel, rekTiefe);
-		    	
-		    	/* FORK ANFANG */
-		    	synchronized (this) {
-		    		writeLog("wait "+ forkOrig.thNo);
-		    		noOfThread--;
-					res = forkOrig.join();
-					synchronized (usedTasks) {
-						if (this.myIsCancelled()) {
-							return new HashSet<>();
-						}
-					}
-					//noOfThread++;
-					forkOrig.writeLog("final Orig 2");
-					forkOrig.closeLogFile();
-					//Set<Set<UnifyPair>> fork_res = forkOrig.join();
-					writeLog("JoinOrig " + new Integer(forkOrig.thNo).toString());
-					//noOfThread--; an das Ende von compute verschoben 
-					//add_res.add(fork_res); //vermutlich falsch
-				};
-				/* FORK ENDE */
-		    	forks.forEach(x -> writeLog("wait: " + x.thNo));
-		    	for(TypeUnify2Task fork : forks) {
-		    		synchronized (this) {
-		    			noOfThread--;
-						Set<Set<UnifyPair>> fork_res = fork.join();
-						synchronized (usedTasks) {
-							if (this.myIsCancelled()) {
-								return new HashSet<>();
-							}
-						}
-						//noOfThread++;
-						writeLog("Join " + new Integer(fork.thNo).toString());
-						//noOfThread--; an das Ende von compute verschoben 
-						add_res.add(fork_res);
-						fork.writeLog("final 2");
-						fork.closeLogFile();
-					};
-				} 
-		    	//noOfThread++;	
-		    } else {//parallel = false oder MaxNoOfThreads ist erreicht, sequentiell weiterarbeiten
-				elems.add(a); //PL 2019-01-16 muss das wirklich hin steht schon in Zeile 859 ja braucht man siehe Zeile 859
-				res = unify2(elems, eq, oderConstraints, fc, parallel, rekTiefe, new HashSet<>(methodSignatureConstraint));
-		    }}}
+			}
 			
 			//Ab hier alle parallele Berechnungen wieder zusammengeführt.
 			//if (hilf == 1)
@@ -2612,7 +2229,6 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		if (log && finalresult) {
 			try {
 				logFile.write("Thread no.:" + thNo + "\n");
-				logFile.write("noOfThread:" + noOfThread + "\n");
 				logFile.write("parallel:" + parallel + "\n");
 				logFile.write(str+"\n\n");
 				logFile.flush();

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyResultListener.java

@@ -1,7 +0,0 @@
-package de.dhbwstuttgart.typeinference.unify;
-
-public interface UnifyResultListener {
-
-	void onNewTypeResultFound(UnifyResultEvent evt);
-
-}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyResultListenerImpl.java

@@ -1,21 +0,0 @@
-package de.dhbwstuttgart.typeinference.unify;
-
-import java.sql.ResultSet;
-import java.util.ArrayList;
-import java.util.List;
-
-import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
-
-public class UnifyResultListenerImpl implements UnifyResultListener {
-
-	List<ResultSet> results = new ArrayList<>();
-	
-	public synchronized void onNewTypeResultFound(UnifyResultEvent evt) {
-		results.addAll(evt.getNewTypeResult());
-	}
-	
-	public List<ResultSet> getResults() {
-		return results;
-	}
-
-}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyResultModel.java

@@ -1,41 +0,0 @@
-package de.dhbwstuttgart.typeinference.unify;
-
-import java.sql.ResultSet;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
-import java.util.stream.Collectors;
-
-import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
-import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
-import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
-import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
-
-public class UnifyResultModel {
-	
-	ConstraintSet<de.dhbwstuttgart.typeinference.constraints.Pair> cons;
-	
-	IFiniteClosure fc;
-	
-	public UnifyResultModel(ConstraintSet<de.dhbwstuttgart.typeinference.constraints.Pair> cons,
-					 IFiniteClosure fc) {
-		this.cons = cons;
-		this.fc = fc;
-	}
-	
-	private List<UnifyResultListener> listeners = new ArrayList<>();
-	
-	public void addUnifyResultListener(UnifyResultListener listenerToAdd) {
-		listeners.add(listenerToAdd);
-	}
-
-	public void removeUnifyResultListener(UnifyResultListener listenerToRemove) {
-		listeners.remove(listenerToRemove);
-	}
-	
-	public void notify(Set<Set<UnifyPair>> eqPrimePrimeSet) {
-
-	}
-}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyResultModelParallel.java

@@ -0,0 +1,51 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+import de.dhbwstuttgart.typeinference.constraints.ConstraintSet;
+import de.dhbwstuttgart.typeinference.constraints.Pair;
+import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
+import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
+import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
+
+import java.util.*;
+import java.util.concurrent.ForkJoinPool;
+import java.util.stream.Collectors;
+
+public class UnifyResultModelParallel {
+    private ForkJoinPool pool;
+    private ConstraintSet<Pair> cons;
+    private IFiniteClosure fc;
+    private List<IUnifyResultListener> listeners = new ArrayList<>();
+
+    public UnifyResultModelParallel(ConstraintSet<Pair> cons, IFiniteClosure fc){
+        this.cons = cons;
+        this.fc = fc;
+    }
+
+    public void setPool(ForkJoinPool pool){
+        this.pool = pool;
+    }
+    public void addUnifyResultListener(IUnifyResultListener listenerToAdd) {
+        listeners.add(listenerToAdd);
+    }
+    public void removeUnifyResultListener(IUnifyResultListener listenerToRemove) {
+        listeners.remove(listenerToRemove);
+    }
+    public void notify(Set<Set<UnifyPair>> eqPrimePrimeSet){
+        pool.execute(()->{
+            Set<Set<UnifyPair>> eqPrimePrimeSetRet = eqPrimePrimeSet.stream().map(x -> {
+                Optional<Set<UnifyPair>> res = new RuleSet().subst(x.stream().map(y -> {
+                    if (y.getPairOp() == PairOperator.SMALLERDOTWC) y.setPairOp(PairOperator.EQUALSDOT);
+                    return y; //alle Paare a <.? b erden durch a =. b ersetzt
+                }).collect(Collectors.toCollection(HashSet::new)));
+                if (res.isPresent()) {//wenn subst ein Erg liefert wurde was veraendert
+                    return new TypeUnifyTask().applyTypeUnificationRules(res.get(), fc);
+                }
+                else return x; //wenn nichts veraendert wurde wird x zurueckgegeben
+            }).collect(Collectors.toCollection(HashSet::new));
+
+            for (IUnifyResultListener listener : listeners) {
+                listener.onNewTypeResultFound(eqPrimePrimeSetRet);
+            }
+        });
+    }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyTaskModel.java

@@ -1,18 +0,0 @@
-package de.dhbwstuttgart.typeinference.unify;
-
-import java.util.ArrayList;
-
-public class UnifyTaskModel {
-
-	ArrayList<TypeUnifyTask> usedTasks = new ArrayList<>();
-	
-	public synchronized void add(TypeUnifyTask t) {
-		usedTasks.add(t);
-	}
-    
-    public synchronized void cancel() {
-    	for(TypeUnifyTask t : usedTasks) {
-    		t.myCancel(true);
-    	}
-    }
-}

src/main/java/de/dhbwstuttgart/typeinference/unify/UnifyTaskModelParallel.java

@@ -0,0 +1,18 @@
+package de.dhbwstuttgart.typeinference.unify;
+
+
+import java.util.concurrent.ForkJoinPool;
+
+public class UnifyTaskModelParallel {
+    private ForkJoinPool pool;
+
+    public void setPool(ForkJoinPool pool){
+        this.pool = pool;
+    }
+
+    public void cancel(){
+        if(this.pool != null){
+            this.pool.shutdown();
+        }
+    }
+}

src/main/java/de/dhbwstuttgart/typeinference/unify/model/PlaceholderType.java

@@ -1,13 +1,10 @@
 package de.dhbwstuttgart.typeinference.unify.model;
 
-import java.io.File;
-import java.io.FileWriter;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Random;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 import de.dhbwstuttgart.typeinference.unify.distributeVariance;
 import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
@@ -23,7 +20,7 @@ public final class PlaceholderType extends UnifyType{
 	 * Static list containing the names of all existing placeholders.
 	 * Used for generating fresh placeholders.
 	 */
-	public static final ArrayList<String> EXISTING_PLACEHOLDERS = new ArrayList<String>();
+	public static final Set<String> EXISTING_PLACEHOLDERS = ConcurrentHashMap.newKeySet();
 	
 	/**
 	 * Prefix of auto-generated placeholder names.
@@ -96,7 +93,7 @@ public final class PlaceholderType extends UnifyType{
 	 * A user could later instantiate a type using the same name that is equivalent to this type.
 	 * @return A fresh placeholder type.
 	 */
-	public synchronized static PlaceholderType freshPlaceholder() {
+	public static PlaceholderType freshPlaceholder() {
 		String name = nextName + (char) (rnd.nextInt(22) + 97); // Returns random char between 'a' and 'z'
 		// Add random chars while the name is in use.
 		while(EXISTING_PLACEHOLDERS.contains(name)) {