Package org.apache.pekko.actor

Class LightArrayRevolverScheduler

java.lang.Object
org.apache.pekko.actor.LightArrayRevolverScheduler
All Implemented Interfaces:
Closeable, AutoCloseable, Scheduler
public class LightArrayRevolverScheduler extends Object implements Scheduler, Closeable
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 Details

    • LightArrayRevolverScheduler

      public LightArrayRevolverScheduler(com.typesafe.config.Config config, LoggingAdapter log, ThreadFactory threadFactory)

  • Method Details

    • 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, 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

    • schedule

      protected Cancellable schedule(scala.concurrent.duration.FiniteDuration initialDelay, scala.concurrent.duration.FiniteDuration delay, Runnable runnable, scala.concurrent.ExecutionContext executor)
      Specified by:
      schedule in interface Scheduler

    • scheduleOnce

      public Cancellable scheduleOnce(scala.concurrent.duration.FiniteDuration delay, 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 AutoCloseable
      Specified by:
      close in interface Closeable

    • 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