org.jgroups.util
Class DefaultTimeScheduler

java.lang.Object
  java.util.concurrent.AbstractExecutorService
      java.util.concurrent.ThreadPoolExecutor
          java.util.concurrent.ScheduledThreadPoolExecutor
              org.jgroups.util.DefaultTimeScheduler

All Implemented Interfaces:

java.util.concurrent.Executor, java.util.concurrent.ExecutorService, java.util.concurrent.ScheduledExecutorService, TimeScheduler

public class DefaultTimeScheduler
extends java.util.concurrent.ScheduledThreadPoolExecutor
implements TimeScheduler

Implementation of TimeScheduler by extending ScheduledThreadPoolExecutor to keep tasks sorted. Tasks will get executed in order of execution time (by using a DelayQueue internally.

Author:

Bela Ban

Nested Class Summary

protected static class	DefaultTimeScheduler.RobustRunnable Class which catches exceptions in run() - https://jira.jboss.org/jira/browse/JGRP-1062
protected class	DefaultTimeScheduler.TaskWrapper<V>

Nested classes/interfaces inherited from class java.util.concurrent.ThreadPoolExecutor

java.util.concurrent.ThreadPoolExecutor.AbortPolicy, java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardPolicy

Nested classes/interfaces inherited from interface org.jgroups.util.TimeScheduler

TimeScheduler.Task

Field Summary

protected static Log

log

Constructor Summary

DefaultTimeScheduler()
Create a scheduler that executes tasks in dynamically adjustable intervals

DefaultTimeScheduler(int corePoolSize)

DefaultTimeScheduler(ThreadFactory factory)

DefaultTimeScheduler(ThreadFactory factory, int max_threads)

Method Summary

java.lang.String	dumpTimerTasks() Returns a list of tasks currently waiting for execution.
int	getCurrentThreads() Returns the current threads in the pool, or -1 if not applicable
long	getKeepAliveTime() Returns the keep alive time (in ms) of the thread pool, or -1 if not applicable
int	getMaxThreads() Returns the configured max threads, or -1 if not applicable
int	getMinThreads() Returns the configured core threads, or -1 if not applicable
java.util.concurrent.Future<?>	scheduleWithDynamicInterval(TimeScheduler.Task task) Schedule a task for execution at varying intervals.
java.util.concurrent.ScheduledFuture<?>	scheduleWithFixedDelay(java.lang.Runnable command, long initialDelay, long delay, java.util.concurrent.TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given delay between the termination of one execution and the commencement of the next.
void	setKeepAliveTime(long time) Sets the keep alive time (in ms) of the thread pool.
void	setMaxThreads(int size) Sets the max pool size.
void	setMinThreads(int size) Sets the core pool size.
void	setThreadFactory(ThreadFactory factory)
int	size() Answers the number of tasks currently in the queue.
void	stop() Stop the scheduler if it's running.
java.lang.String	toString()

Methods inherited from class java.util.concurrent.ScheduledThreadPoolExecutor

decorateTask, decorateTask, execute, getContinueExistingPeriodicTasksAfterShutdownPolicy, getExecuteExistingDelayedTasksAfterShutdownPolicy, getQueue, remove, schedule, schedule, scheduleAtFixedRate, setContinueExistingPeriodicTasksAfterShutdownPolicy, setExecuteExistingDelayedTasksAfterShutdownPolicy, shutdown, shutdownNow, submit, submit, submit

Methods inherited from class java.util.concurrent.ThreadPoolExecutor

afterExecute, allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, beforeExecute, finalize, getActiveCount, getCompletedTaskCount, getCorePoolSize, getKeepAliveTime, getLargestPoolSize, getMaximumPoolSize, getPoolSize, getRejectedExecutionHandler, getTaskCount, getThreadFactory, isShutdown, isTerminated, isTerminating, prestartAllCoreThreads, prestartCoreThread, purge, setCorePoolSize, setKeepAliveTime, setMaximumPoolSize, setRejectedExecutionHandler, setThreadFactory, terminated

Methods inherited from class java.util.concurrent.AbstractExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, newTaskFor, newTaskFor

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jgroups.util.TimeScheduler

execute, isShutdown, schedule, scheduleAtFixedRate

Methods inherited from interface java.util.concurrent.ExecutorService

awaitTermination, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isTerminated

Field Detail

log

protected static final Log log

Constructor Detail

DefaultTimeScheduler

public DefaultTimeScheduler()

Create a scheduler that executes tasks in dynamically adjustable intervals

DefaultTimeScheduler

public DefaultTimeScheduler(ThreadFactory factory)

DefaultTimeScheduler

public DefaultTimeScheduler(ThreadFactory factory,
                            int max_threads)

DefaultTimeScheduler

public DefaultTimeScheduler(int corePoolSize)

Method Detail

setThreadFactory

public void setThreadFactory(ThreadFactory factory)

Specified by:

setThreadFactory in interface TimeScheduler

dumpTimerTasks

public java.lang.String dumpTimerTasks()

Description copied from interface: TimeScheduler

Returns a list of tasks currently waiting for execution. If there are a lot of tasks, the returned string should probably only return the number of tasks rather than a full dump.

Specified by:

dumpTimerTasks in interface TimeScheduler

Returns:

getCurrentThreads

public int getCurrentThreads()

Description copied from interface: TimeScheduler

Returns the current threads in the pool, or -1 if not applicable

Specified by:

getCurrentThreads in interface TimeScheduler

Returns:

getMinThreads

public int getMinThreads()

Description copied from interface: TimeScheduler

Returns the configured core threads, or -1 if not applicable

Specified by:

getMinThreads in interface TimeScheduler

Returns:

setMinThreads

public void setMinThreads(int size)

Description copied from interface: TimeScheduler

Sets the core pool size. Can be ignored if not applicable

Specified by:

setMinThreads in interface TimeScheduler

getMaxThreads

public int getMaxThreads()

Description copied from interface: TimeScheduler

Returns the configured max threads, or -1 if not applicable

Specified by:

getMaxThreads in interface TimeScheduler

Returns:

setMaxThreads

public void setMaxThreads(int size)

Description copied from interface: TimeScheduler

Sets the max pool size. Can be ignored if not applicable

Specified by:

setMaxThreads in interface TimeScheduler

getKeepAliveTime

public long getKeepAliveTime()

Description copied from interface: TimeScheduler

Returns the keep alive time (in ms) of the thread pool, or -1 if not applicable

Specified by:

getKeepAliveTime in interface TimeScheduler

setKeepAliveTime

public void setKeepAliveTime(long time)

Description copied from interface: TimeScheduler

Sets the keep alive time (in ms) of the thread pool. Can be ignored if not applicable

Specified by:

setKeepAliveTime in interface TimeScheduler

scheduleWithDynamicInterval

public java.util.concurrent.Future<?> scheduleWithDynamicInterval(TimeScheduler.Task task)

Schedule a task for execution at varying intervals. After execution, the task will get rescheduled after org.jgroups.util.DefaultTimeScheduler.Task#nextInterval() milliseconds. The task is neve done until nextInterval() return a value <= 0 or the task is cancelled.

Specified by:

scheduleWithDynamicInterval in interface TimeScheduler

Parameters:

task - the task to execute

relative - scheduling scheme: true:
Task is rescheduled relative to the last time it actually started execution

false:
Task is scheduled relative to its last execution schedule. This has the effect that the time between two consecutive executions of the task remains the same.

Note that relative is always true; we always schedule the next execution relative to the last *actual* (not scheduled) execution

scheduleWithFixedDelay

public java.util.concurrent.ScheduledFuture<?> scheduleWithFixedDelay(java.lang.Runnable command,
                                                                      long initialDelay,
                                                                      long delay,
                                                                      java.util.concurrent.TimeUnit unit)

Description copied from interface: TimeScheduler

Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given delay between the termination of one execution and the commencement of the next. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.

Specified by:

scheduleWithFixedDelay in interface java.util.concurrent.ScheduledExecutorService

Specified by:

scheduleWithFixedDelay in interface TimeScheduler

Overrides:

scheduleWithFixedDelay in class java.util.concurrent.ScheduledThreadPoolExecutor

Parameters:

command - the task to execute

initialDelay - the time to delay first execution

delay - the delay between the termination of one execution and the commencement of the next

unit - the time unit of the initialDelay and delay parameters

Returns:

a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

size

public int size()

Answers the number of tasks currently in the queue.

Specified by:

size in interface TimeScheduler

Returns:

The number of tasks currently in the queue.

stop

public void stop()

Stop the scheduler if it's running. Switch to stopped, if it's suspended. Clear the task queue, cancelling all un-executed tasks

Specified by:

stop in interface TimeScheduler

Throws:

java.lang.InterruptedException - if interrupted while waiting for thread to return

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object