[Repast-developer] Scheduler trip-up

[Beyeler, W. E <we...@sa...>]

My application makes heavy use of the Schedule.removeAction method.  I
am regularly getting an array index out of bounds exception due to an
attempt to get at a missing array element:

Exception in thread "Thread-2" java.lang.IndexOutOfBoundsException:
Index: 1, Size: 1
	at java.util.ArrayList.RangeCheck(ArrayList.java:546)
	at java.util.ArrayList.get(ArrayList.java:321)
	at uchicago.src.sim.engine.ScheduleGroup.execute(Unknown Source)
	at uchicago.src.sim.engine.RandomScheduleGroup.execute(Unknown
Source)
	at uchicago.src.sim.engine.Schedule.execute(Unknown Source)
	at uchicago.src.sim.engine.BaseController$1.run(Unknown Source)
	at java.lang.Thread.run(Thread.java:595)


Looking at the code for ScheduleGroup.execute

  public void execute() {
    for (int i =3D 0, n =3D actions.size(); i < n; i++) {
      ((BasicAction)actions.get(i)).execute();
    }
  }

it seems that if the executed action happens to modify "actions" by
deletion then the variable "n" will still reflect the original size and
so allow a bad address.  It looks like this iteration construct, rather
than one using the Iterator class, helps get around the concurrent
modification exception that would otherwise occur when I try to change
the schedule.  If you mean to allow schedule changes within
BasicAction.execute() shouldn't the size be re-set within the loop, or
some other precaution taken?

Thanks

 -- Walt