@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Marking other = (Marking) obj;
if (this.petriNet != other.petriNet
&& (this.petriNet == null || !this.petriNet.equals(other.petriNet))) {
return false;
}
if (this.map == other.map) {
return true;
}
Set<Place> places = new HashSet<Place>(); // because map is sparse
places.addAll(this.map.keySet());
places.addAll(other.map.keySet());
for (Place place : places) {
if (this.getTokens(place) != other.getTokens(place)) {
return false;
}
}
return true;
}
private Set<FiringSequence> getAllFiringSequencesRecursively(
Marking marking, Set<Marking> visitedMarkings) throws PetriNetException {
Set<FiringSequence> firingSequences = new HashSet<FiringSequence>();
Set<Transition> enabledTransitions = marking.getAllEnabledTransitions();
for (Transition transition : enabledTransitions) {
Marking newMarking = marking.getMarkingAfterFiring(transition);
if (visitedMarkings.contains(newMarking)) {
throw new PetriNetException("There is a loop.");
}
visitedMarkings.add(newMarking);
if (!newMarking.isEnabledByAnyTransition()) { // leaf marking
FiringSequence firingSequence = new FiringSequence();
firingSequence.add(transition);
firingSequences.add(firingSequence);
}
for (FiringSequence nextFiringSequence :
getAllFiringSequencesRecursively(newMarking, visitedMarkings)) {
FiringSequence firingSequence = new FiringSequence();
firingSequence.add(transition);
firingSequence.addAll(nextFiringSequence);
firingSequences.add(firingSequence);
}
visitedMarkings.remove(newMarking);
}
return firingSequences;
}
/**
* Returns a new marking after firing a transition. Original marking is not changed.
*
* @param transition transition to be fired
* @return new marking with fired transition
*/
public Marking getMarkingAfterFiring(Transition transition) {
if (!this.isEnabled(transition)) {
return null;
}
Marking newMarking = new Marking(this);
newMarking.fire(transition);
return newMarking;
}
/**
* Copy constructor.
*
* @param marking the marking to be copied.
*/
public Marking(Marking marking) {
marking.getLock().readLock().lock();
try {
this.map = new ConcurrentHashMap<Place, Integer>(marking.map);
} finally {
marking.getLock().readLock().unlock();
}
this.petriNet = marking.petriNet;
}
/**
* Returns a marking after firing a sequence of transitions. The original marking is not changed.
*
* @param firingSequence sequence of transitions to be fired one after the other
* @return a new marking after firing a sequence of transitions
*/
public Marking getMarkingAfterFiring(FiringSequence firingSequence) {
Marking newMarking = new Marking(this);
for (Transition transition : firingSequence) {
if (!newMarking.isEnabled(transition)) {
return null;
}
newMarking.fire(transition);
}
return newMarking;
}