Class LightArrayRevolverScheduler

  • All Implemented Interfaces:
    Scheduler,, java.lang.AutoCloseable

    public class LightArrayRevolverScheduler
    extends java.lang.Object
    implements Scheduler,
    This scheduler implementation is based on a revolving wheel of buckets, like Netty’s HashedWheelTimer, which it advances at a fixed tick rate and dispatches tasks it finds in the current bucket to their respective ExecutionContexts. The tasks are held in TaskHolders, which upon cancellation null out their reference to the actual task, leaving only this shell to be cleaned up when the wheel reaches that bucket next time. This enables the use of a simple linked list to chain the TaskHolders off the wheel.

    Also noteworthy is that this scheduler does not obtain a current time stamp when scheduling single-shot tasks, instead it always rounds up the task delay to a full multiple of the TickDuration. This means that tasks are scheduled possibly one tick later than they could be (if checking that “now() + delay <= nextTick” were done).

    • Constructor Detail

      • LightArrayRevolverScheduler

        public LightArrayRevolverScheduler​(com.typesafe.config.Config config,
                                           LoggingAdapter log,
                                           java.util.concurrent.ThreadFactory threadFactory)
    • Method Detail

      • WheelSize

        public int WheelSize()
      • TickDuration

        public scala.concurrent.duration.FiniteDuration TickDuration()
      • ShutdownTimeout

        public scala.concurrent.duration.FiniteDuration ShutdownTimeout()
      • clock

        protected long clock()
        Clock implementation is replaceable (for testing); the implementation must return a monotonically increasing series of Long nanoseconds.
      • startTick

        protected int startTick()
        Replaceable for testing.
      • getShutdownTimeout

        protected scala.concurrent.duration.FiniteDuration getShutdownTimeout()
        Overridable for tests
      • waitNanos

        protected void waitNanos​(long nanos)
        Overridable for tests
      • scheduleWithFixedDelay

        public Cancellable scheduleWithFixedDelay​(scala.concurrent.duration.FiniteDuration initialDelay,
                                                  scala.concurrent.duration.FiniteDuration delay,
                                                  java.lang.Runnable runnable,
                                                  scala.concurrent.ExecutionContext executor)
        Description copied from interface: Scheduler
        Scala API: Schedules a Runnable to be run repeatedly with an initial delay and a fixed delay between subsequent executions. E.g. if you would like the function to be run after 2 seconds and thereafter every 100ms you would set delay=Duration(2, TimeUnit.SECONDS) and interval=Duration(100, TimeUnit.MILLISECONDS).

        It will not compensate the delay between tasks if the execution takes a long time or if scheduling is delayed longer than specified for some reason. The delay between subsequent execution will always be (at least) the given delay. In the long run, the frequency of execution will generally be slightly lower than the reciprocal of the specified delay.

        If the Runnable throws an exception the repeated scheduling is aborted, i.e. the function will not be invoked any more.

        Specified by:
        scheduleWithFixedDelay in interface Scheduler
      • scheduleOnce

        public Cancellable scheduleOnce​(scala.concurrent.duration.FiniteDuration delay,
                                        java.lang.Runnable runnable,
                                        scala.concurrent.ExecutionContext executor)
        Description copied from interface: Scheduler
        Scala API: Schedules a Runnable to be run once with a delay, i.e. a time period that has to pass before the runnable is executed.

        Specified by:
        scheduleOnce in interface Scheduler
      • close

        public void close()
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface
      • maxFrequency

        public double maxFrequency()
        Description copied from interface: Scheduler
        The maximum supported task frequency of this scheduler, i.e. the inverse of the minimum time interval between executions of a recurring task, in Hz.
        Specified by:
        maxFrequency in interface Scheduler