@Override
public BDD visitIfThenElse(
BooleanFormula pCondition, BooleanFormula pThenFormula, BooleanFormula pElseFormula) {
BDD condition = convert(pCondition);
BDD thenBDD = convert(pThenFormula);
BDD elseBDD = convert(pElseFormula);
BDD result = condition.ite(thenBDD, elseBDD);
condition.free();
thenBDD.free();
elseBDD.free();
return result;
}
@Override
public BDD visitNot(BooleanFormula pOperand) {
BDD operand = convert(pOperand);
BDD result = operand.not();
operand.free();
return result;
}
@Override
public void close() {
for (BDD bdd : cache.values()) {
bdd.free();
}
cache.clear();
}
@Override
public void close() {
checkState(currentCube == null);
for (BDD bdd : cubes) {
bdd.free();
}
cubes.clear();
}
@Override
public boolean entails(Region pF1, Region pF2) {
cleanupReferences();
// check entailment using BDDs: create the BDD representing
// the implication, and check that it is the TRUE formula
BDD imp = unwrap(pF1).imp(unwrap(pF2));
boolean result = imp.isOne();
imp.free();
return result;
}
/**
* Cleanup all references to BDDs that are no longer needed. We call this method from all public
* methods, so that this gets done as soon as possible. Usually we would do this in a daemon
* thread in the background, but the BDD library is not multi-threaded.
*/
private void cleanupReferences() {
cleanupTimer.start();
try {
int count = 0;
Reference<? extends JavaBDDRegion> ref;
while ((ref = referenceQueue.poll()) != null) {
count++;
BDD bdd = referenceMap.remove(ref);
assert bdd != null;
bdd.free();
}
cleanupQueueSize.setNextValue(count);
} finally {
cleanupTimer.stop();
}
}
@Override
public Region makeExists(Region pF1, Region... pF2) {
cleanupReferences();
if (pF2.length == 0) {
return pF1;
}
// we use id() to get copies of the BDDs, otherwise we would delete them
BDD f = unwrap(pF2[0]).id();
for (int i = 1; i < pF2.length; i++) {
f.andWith(unwrap(pF2[i]).id());
}
Region result = wrap(unwrap(pF1).exist(f));
f.free();
return result;
}
