/** * Registers a single shot timer for the current actor. The timer is automatically disposed on deactivation. * The timer calls will keep the actor active. Timer calls are serialized according to the actor policy. * Each stateless actor activation has it's on set of timers. * * @param futureCallable a callable that returns a Task * @param dueTime Time to the first timer call * @param period Interval between calls, if period <= 0 then the timer will be single shot. * @param timeUnit Time unit for dueTime and period * @return A registration object that allows the actor to cancel the timer. */ protected Registration registerTimer(Callable<Task<?>> futureCallable, long dueTime, TimeUnit timeUnit) { return registerTimer(futureCallable, dueTime, 0L, timeUnit); }