akka.actor

Class LightArrayRevolverScheduler

java.lang.Object

akka.actor.LightArrayRevolverScheduler

All Implemented Interfaces:

Scheduler, java.io.Closeable, java.lang.AutoCloseable

public class LightArrayRevolverScheduler
extends java.lang.Object
implements Scheduler, java.io.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).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	LightArrayRevolverScheduler.TaskHolder INTERNAL API
protected static interface	LightArrayRevolverScheduler.TimerTask INTERNAL API

Constructor Summary

Constructors

Constructor and Description
LightArrayRevolverScheduler(com.typesafe.config.Config config, LoggingAdapter log, java.util.concurrent.ThreadFactory threadFactory)

Method Summary

Modifier and Type	Method and Description
protected long	clock() Clock implementation is replaceable (for testing); the implementation must return a monotonically increasing series of Long nanoseconds.
void	close()
protected scala.concurrent.duration.FiniteDuration	getShutdownTimeout() Overridable for tests
double	maxFrequency() The maximum supported task frequency of this scheduler, i.e.
Cancellable	schedule(scala.concurrent.duration.FiniteDuration initialDelay, scala.concurrent.duration.FiniteDuration delay, java.lang.Runnable runnable, scala.concurrent.ExecutionContext executor) Schedules a function to be run repeatedly with an initial delay and a frequency.
Cancellable	scheduleOnce(scala.concurrent.duration.FiniteDuration delay, java.lang.Runnable runnable, scala.concurrent.ExecutionContext executor) Schedules a Runnable to be run once with a delay, i.e.
scala.concurrent.duration.FiniteDuration	ShutdownTimeout()
scala.concurrent.duration.FiniteDuration	TickDuration()
protected void	waitNanos(long nanos) Overridable for tests
int	WheelSize()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface akka.actor.Scheduler

schedule, schedule, scheduleOnce, scheduleOnce

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.

Returns:

(undocumented)

getShutdownTimeout

protected scala.concurrent.duration.FiniteDuration getShutdownTimeout()

Overridable for tests

Returns:

(undocumented)

waitNanos

protected void waitNanos(long nanos)

Overridable for tests

Parameters:

nanos - (undocumented)

schedule

public Cancellable schedule(scala.concurrent.duration.FiniteDuration initialDelay,
                            scala.concurrent.duration.FiniteDuration delay,
                            java.lang.Runnable runnable,
                            scala.concurrent.ExecutionContext executor)

Description copied from interface: Scheduler

Schedules a function to be run repeatedly with an initial delay and a frequency. 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). If the execution of the runnable takes longer than the interval, the subsequent execution will start immediately after the prior one completes (there will be no overlap of executions of the runnable). In such cases, the actual execution interval will differ from the interval passed to this method.

Java API

Specified by:

schedule in interface Scheduler

Parameters:

initialDelay - (undocumented)

delay - (undocumented)

runnable - (undocumented)

executor - (undocumented)

Returns:

(undocumented)

scheduleOnce

public Cancellable scheduleOnce(scala.concurrent.duration.FiniteDuration delay,
                                java.lang.Runnable runnable,
                                scala.concurrent.ExecutionContext executor)

Description copied from interface: Scheduler

Schedules a Runnable to be run once with a delay, i.e. a time period that has to pass before the runnable is executed.

Java & Scala API

Specified by:

scheduleOnce in interface Scheduler

Parameters:

delay - (undocumented)

runnable - (undocumented)

executor - (undocumented)

Returns:

(undocumented)

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

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

Returns:

(undocumented)