com.shimari.framework
Class Cron

java.lang.Object
  com.shimari.framework.Cron

All Implemented Interfaces:

Component, java.lang.Runnable

public class Cron

extends java.lang.Object

implements java.lang.Runnable, Component

Execute periodic events. We have a pool of worker thread which execute tasks on a periodic schedule. The tasks themselves are responsible for scheduling decisions. The model followed is to wait until the next task's execution time, _remove_ that task from the queue and execute it. Once the task has completed we put it back into the queue, querying it to see how long until its next run (if the answer is '0' we drop the task). The minimum wait time is 100 milliseconds (1/10th of a second).

We remove the task from the queue when we execute it for a few reasons: one, so that the same task won't be executed by concurrent threads if it takes longer than its interval time to execute; two, so that if it hangs it just blocks one thread and since it's not back on the queue won't block anyone else. We will hang completely only if N different tasks all hang, where N is the number of threads we have available.

Constructor Summary

Cron(Config config)

Method Summary

void	addTask(CronTask task) Add a new task to the queue.
void	init(Registry registry)
void	run()

Methods inherited from class java.lang.Object

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

Constructor Detail

Cron

public Cron(Config config)
     throws ConfigException

Method Detail

init

public void init(Registry registry)

Specified by:

init in interface Component

See Also:

Component.init(com.shimari.framework.Registry)

addTask

public void addTask(CronTask task)

Add a new task to the queue.

run

public void run()

Specified by:

run in interface java.lang.Runnable