public void execute(ExecutionImpl execution) {
Activity activity = execution.getActivity();
// evaluate the conditions and select the forking transitions
List<Transition> forkingTransitions = new ArrayList<Transition>();
for (Transition transition : activity.getOutgoingTransitions()) {
Condition condition = ((TransitionImpl) transition).getCondition();
if (condition == null || condition.evaluate(execution)) {
forkingTransitions.add(transition);
}
}
switch (forkingTransitions.size()) {
case 0:
// if no outgoing transitions should be forked, end this execution
execution.end();
break;
case 1:
// if there is exactly one transition to be taken, just use the incoming execution
execution.take(forkingTransitions.get(0));
break;
default:
// if there are more transitions, perform full fork
ExecutionImpl concurrentRoot;
if (Execution.STATE_ACTIVE_ROOT.equals(execution.getState())) {
concurrentRoot = execution;
execution.setState(Execution.STATE_INACTIVE_CONCURRENT_ROOT);
execution.setActivity(null);
} else if (Execution.STATE_ACTIVE_CONCURRENT.equals(execution.getState())) {
concurrentRoot = execution.getParent();
execution.end();
} else {
throw new AssertionError(execution.getState());
}
Map<Transition, ExecutionImpl> concurrentExecutions =
new HashMap<Transition, ExecutionImpl>();
for (Transition transition : forkingTransitions) {
ExecutionImpl concurrentExecution = concurrentRoot.createExecution(transition.getName());
concurrentExecution.setActivity(activity);
concurrentExecution.setState(Execution.STATE_ACTIVE_CONCURRENT);
concurrentExecutions.put(transition, concurrentExecution);
}
for (Entry<Transition, ExecutionImpl> entry : concurrentExecutions.entrySet()) {
entry.getValue().take(entry.getKey());
if (concurrentRoot.isEnded()) break;
}
}
}
