/**
* Removes one token from the marked output places (subsets) of the tasks in <i>tasks</i> that
* contain <i>element</i>.
*
* @param element element to fire
* @param tasks whose output places point to element
*/
private void removeTokensOutputPlaces(int element, HNSubSet tasks) {
HNSubSet subset = null;
HNSet subsets = null;
Integer tokens = null;
int taskToFire;
int task;
// Checking if element is a start element
if (hNet.getInputSet(element).size() == 0) {
if (startPlace > 0) {
startPlace--;
numberTokens--;
}
} else {
taskToFire = element;
for (int iTasks = 0; iTasks < tasks.size(); iTasks++) {
task = tasks.get(iTasks);
subsets = auxMapping.getRelatedSubsets(taskToFire, task);
if (subsets != null) {
for (int iSubsets = 0; iSubsets < subsets.size(); iSubsets++) {
subset = subsets.get(iSubsets);
tokens = getNumberTokens(task, subset);
if (tokens.intValue() > 0) {
decreaseNumberTokens(task, subset);
numberTokens--;
}
}
}
}
}
}
/*
* Checks if a element is enabled at the current marking. <p> <b>Note:</b>
* The element MUST be in the Element.
*
* @param element element/transition to check
*
* @return true if the element is enabled at the current marking. false
* otherwise.
*/
public boolean isEnabled(int element) {
if (hNet.getInputSet(element) == null) {
return false;
}
if (hNet.getInputSet(element).size() == 0) {
if (startPlace < 1) {
return false;
}
} else {
bestCombination = findBestSetTasks(element);
if (bestCombination.getNumberMissingTokens() > 0) {
return false;
}
}
return true;
}
/**
* Build an initial marking for a given heuristics net.
*
* @param net an enhanced heuristics net to which the initial marking must be built.
* @throws java.lang.NullPointerException whenever the net has disconnected elements. An element
* is disconnected when its INPUT or OUTPUT set is null.
*/
public MarkingHeuristicsNet(HeuristicsNet net, Random generator) throws NullPointerException {
this.generator = generator;
size = net.size();
hNet = net;
// checking if all input and output sets are DIFFERENT from null...
for (int i = 0; i < size; i++) {
if (hNet.getInputSet(i) == null || hNet.getOutputSet(i) == null) {
throw new NullPointerException("Net has disconnected elements!!");
}
}
createMarking();
}
private CombinationTasksToFire findBestSetTasks(int element) {
CombinationTasksToFire bCombination = null;
CombinationTasksToFire combination = null;
HNSubSet noTokensFromTasks = null;
HNSubSet treatedTasks = null;
HNSet inputSet = null;
HNSet temp_inputSet = null;
HNSubSet subset = null;
int numberMissingTokens = 0;
int rootTask = ROOT_TASK_ID;
bCombination = new CombinationTasksToFire();
inputSet = hNet.getInputSet(element);
if (inputSet.size() == 0) {
if (startPlace <= 0) {
numberMissingTokens++; // one token is missing
}
} else {
// inputSubset is not empty. Search for tasks that "have tokens" to
// element
noTokensFromTasks = getTasksWithEmptyOutputPlaces(element);
// >>>>>>>>>>>>>>>>>> Hint!!! I think that's why I don't run into
// problems...
// /// Idea -> shrink the subsets without using a temp variable, get
// / the size before shrinking, shrink them, reorder the set and
// /remove the empty set (do this via a method in the class
// /HNSet, get the new size. This is the number of missing tokens.
// make a copy to avoid destroying the original net
inputSet = inputSet.deepCopy();
temp_inputSet = new HNSet();
// removing the tasks whose output subsets that contain element are
// empty
for (int iInputSubsets = 0; iInputSubsets < inputSet.size(); iInputSubsets++) {
subset = inputSet.get(iInputSubsets);
subset.removeAll(noTokensFromTasks);
if (subset.size() == 0) {
numberMissingTokens += 1;
} else {
temp_inputSet.add(subset);
}
}
inputSet = temp_inputSet;
// retrieving the best combination of tasks that can fire to enable
// element
if (inputSet.size() > 0) {
combination = new CombinationTasksToFire();
treatedTasks = new HNSubSet();
bCombination =
findBestCombination(bCombination, inputSet, rootTask, combination, treatedTasks);
}
}
bCombination.setElementToFire(element);
bCombination.setTokens(bCombination.getNumberMissingTokens() + numberMissingTokens);
return bCombination;
}