Package org.cache2k.core.timing

Class TimerWheels

java.lang.Object

org.cache2k.core.timing.TimerWheels

All Implemented Interfaces:

TimerStructure

public class TimerWheels
extends Object
implements TimerStructure

Hierarchical timer wheel implementation. The implementation is flexible and can work with variable delta time per time slot and variable slots per wheel level.

This implementation is rather simple and has opportunities to improve performance.

Author:

Jens Wilke

Constructor Summary

Constructors

Constructor	Description
TimerWheels(long startTime, long delta, int slots)

Method Summary

Modifier and Type	Method	Description
void	cancelAll()	Cancel all tasks
long	nextRun()	Time of next run, or MAX_VALUE if no more tasks are scheduled
TimerTask	removeNextToRun(long time)	Return a task that is supposed to execute at the given time or earlier.
long	schedule(TimerTask task, long time)	Insert task.

Methods inherited from class java.lang.Object

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

Constructor Detail

TimerWheels

public TimerWheels(long startTime,
                   long delta,
                   int slots)

Method Detail

schedule

public long schedule(TimerTask task,
                     long time)

Description copied from interface: TimerStructure

Insert task. Scheduling might be not possible if tasks for the requested time have already be run.

Specified by:

schedule in interface TimerStructure

Returns:

0, if time is already in the past. Or a positive value indicating the execution time of the timer slot

cancelAll

public void cancelAll()

Description copied from interface: TimerStructure

Cancel all tasks

Specified by:

cancelAll in interface TimerStructure

removeNextToRun

public TimerTask removeNextToRun(long time)

Description copied from interface: TimerStructure

Return a task that is supposed to execute at the given time or earlier. This also moves the clock hand of the timer structure.

It may rarely happen that a subsequent method call has an earlier time, in case the operating system schedule delays a thread until the next scheduler event happens.

Specified by:

removeNextToRun in interface TimerStructure

Returns:

a task or null, if no more tasks are scheduled for the given time

nextRun

public long nextRun()

Description copied from interface: TimerStructure

Time of next run, or MAX_VALUE if no more tasks are scheduled

Specified by:

nextRun in interface TimerStructure