public void execute(ActivityExecution execution) throws Exception {
// If there is only one incoming sequence flow, we can directly execute the fork behavior
int nbrOfExecutionsToJoin = execution.getIncomingTransitions().size();
if (nbrOfExecutionsToJoin == 1) {
if (log.isLoggable(Level.FINE)) {
log.fine(
"Only one incoming sequence flow found for parallel gateway "
+ execution.getActivity().getId());
}
fork(execution);
} else {
Activity joinActivity = execution.getActivity();
List<ActivityExecution> joinedExecutions = new ArrayList<ActivityExecution>();
List<? extends ActivityExecution> concurrentExecutions =
execution.getExecutionController().getExecutions();
for (ActivityExecution concurrentExecution : concurrentExecutions) {
if (concurrentExecution.getActivity().equals(joinActivity)) {
joinedExecutions.add(concurrentExecution);
}
}
int nbrOfExecutionsJoined = joinedExecutions.size();
if (log.isLoggable(Level.FINE)) {
log.fine(
nbrOfExecutionsJoined
+ " of "
+ nbrOfExecutionsToJoin
+ " joined in "
+ execution.getActivity().getId());
}
if (nbrOfExecutionsJoined == nbrOfExecutionsToJoin) {
ActivityExecution outgoingExecution = join(execution, joinedExecutions);
// After all incoming executions are joined, potentially there can be multiple
// outgoing sequence flow, requiring fork behavior.
fork(outgoingExecution);
} else {
if (log.isLoggable(Level.FINE)) {
log.fine(
"Not all executions arrived in parallel gateway '"
+ execution.getActivity().getId()
+ "'");
}
}
}
}
protected ActivityExecution join(
ActivityExecution execution, List<ActivityExecution> joinedExecutions) {
// Child executions must be ended before selecting the ougoing sequence flowm
// since the children endings have an influence on the reusal of the parent execution
for (ActivityExecution joinedExecution : joinedExecutions) {
joinedExecution.getExecutionController().end();
}
// HACKHACKHACKHACKHACKHACKHACK
CommandContext.getCurrent().getPersistenceSession().flush();
// HACKHACKHACKHACKHACKHACKHACK
ActivityExecution outgoingExecution = execution.getExecutionController().createExecution();
outgoingExecution.getExecutionController().setActivity(execution.getActivity());
return outgoingExecution;
}