org.apache.jcs.engine.memory.shrinking
Class ShrinkerThread

java.lang.Object
  org.apache.jcs.engine.memory.shrinking.ShrinkerThread

All Implemented Interfaces:

java.lang.Runnable

public class ShrinkerThread

extends java.lang.Object

implements java.lang.Runnable

A background memory shrinker. Memory problems and concurrent modification exception caused by acting directly on an iterator of the underlying memory cache should have been solved.

Version:

$Id: ShrinkerThread.java 376828 2006-02-10 20:10:24Z asmuts $

Constructor Summary

ShrinkerThread(MemoryCache cache)
Constructor for the ShrinkerThread object.

Method Summary

void	run() Main processing method for the ShrinkerThread object
protected void	shrink() This method is called when the thread wakes up.

Methods inherited from class java.lang.Object

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

Constructor Detail

ShrinkerThread

public ShrinkerThread(MemoryCache cache)

Constructor for the ShrinkerThread object.

Parameters:

cache - The MemoryCache which the new shrinker should watch.

Method Detail

run

public void run()

Main processing method for the ShrinkerThread object

Specified by:

run in interface java.lang.Runnable

shrink

protected void shrink()

This method is called when the thread wakes up. Frist the method obtains an array of keys for the cache region. It iterates through the keys and tries to get the item from the cache without affecting the last access or position of the item. The item is checked for expiration, the expiration check has 3 parts:

1. Has the cacheattributes.MaxMemoryIdleTimeSeconds defined for the region been exceeded? If so, the item should be move to disk.
2. Has the item exceeded MaxLifeSeconds defined in the element attributes? If so, remove it.
3. Has the item exceeded IdleTime defined in the element atributes? If so, remove it. If there are event listeners registered for the cache element, they will be called.