org.jboss.ejb.plugins
Class LRUEnterpriseContextCachePolicy

java.lang.Object
  org.jboss.util.LRUCachePolicy
      org.jboss.ejb.plugins.LRUEnterpriseContextCachePolicy

All Implemented Interfaces:

XmlLoadable, Monitorable, org.jboss.util.CachePolicy

Direct Known Subclasses:

LRUStatefulContextCachePolicy

public class LRUEnterpriseContextCachePolicy
extends org.jboss.util.LRUCachePolicy
implements XmlLoadable, Monitorable

Least Recently Used cache policy for EnterpriseContexts.

Version:

$Revision: 57209 $

Author:

Simone Bordet, Bill Burke

See Also:

AbstractInstanceCache

Nested Class Summary

protected class	LRUEnterpriseContextCachePolicy.ContextLRUList Subclass that logs list activity events.
protected class	LRUEnterpriseContextCachePolicy.OveragerTask This TimerTask passivates cached beans that have not been called for a while.
protected class	LRUEnterpriseContextCachePolicy.ResizerTask This TimerTask resizes the cache capacity using the cache miss frequency algorithm, that is the more cache misses we have, the more the cache size is enlarged, and viceversa.

Nested classes/interfaces inherited from class org.jboss.util.LRUCachePolicy

org.jboss.util.LRUCachePolicy.LRUCacheEntry, org.jboss.util.LRUCachePolicy.LRUList

Field Summary

protected static org.jboss.logging.Logger	log
protected static Timer	tasksTimer

Fields inherited from class org.jboss.util.LRUCachePolicy

m_list, m_map, m_maxCapacity, m_minCapacity

Constructor Summary

LRUEnterpriseContextCachePolicy(AbstractInstanceCache eic)
Creates a LRU cache policy object given the instance cache that use this policy object.

Method Summary

protected void	ageOut(org.jboss.util.LRUCachePolicy.LRUCacheEntry entry)
protected void	cacheMiss()
protected org.jboss.util.LRUCachePolicy.LRUList	createList()
void	destroy()
void	flush() Flush is overriden here because in this policy impl flush might not actually remove all the instances from the cache.
void	importXml(Element element) Reads from the configuration the parameters for this cache policy, that are all optionals.
void	sample(Object s) Samples the status of the implementor object and register the status into the snapshot argument.
void	start()
void	stop()

Methods inherited from class org.jboss.util.LRUCachePolicy

create, createCacheEntry, get, insert, peek, remove, size

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static org.jboss.logging.Logger log

tasksTimer

protected static Timer tasksTimer

Constructor Detail

LRUEnterpriseContextCachePolicy

public LRUEnterpriseContextCachePolicy(AbstractInstanceCache eic)

Creates a LRU cache policy object given the instance cache that use this policy object.

Method Detail

sample

public void sample(Object s)

Description copied from interface: Monitorable

Samples the status of the implementor object and register the status into the snapshot argument.

Specified by:

sample in interface Monitorable

start

public void start()

Specified by:

start in interface org.jboss.util.CachePolicy

Overrides:

start in class org.jboss.util.LRUCachePolicy

stop

public void stop()

Specified by:

stop in interface org.jboss.util.CachePolicy

Overrides:

stop in class org.jboss.util.LRUCachePolicy

destroy

public void destroy()

Specified by:

destroy in interface org.jboss.util.CachePolicy

Overrides:

destroy in class org.jboss.util.LRUCachePolicy

importXml

public void importXml(Element element)
               throws org.jboss.deployment.DeploymentException

Reads from the configuration the parameters for this cache policy, that are all optionals. FIXME 20010626 marcf: Simone seriously arent' all the options overkill? give it another 6 month . Remember you are exposing the guts of this to the end user, also provide defaults so that if an entry is not specified you can still work and it looks _much_ better in the configuration files.

Specified by:

importXml in interface XmlLoadable

Throws:

org.jboss.deployment.DeploymentException

flush

public void flush()

Flush is overriden here because in this policy impl flush might not actually remove all the instances from the cache. Those instances that are in use (associated with a transaction) should not be removed from the cache. So, the iteration is done not until the cache is empty but until we tried to age-out every instance in the cache.

Specified by:

flush in interface org.jboss.util.CachePolicy

Overrides:

flush in class org.jboss.util.LRUCachePolicy

createList

protected org.jboss.util.LRUCachePolicy.LRUList createList()

Overrides:

createList in class org.jboss.util.LRUCachePolicy

ageOut

protected void ageOut(org.jboss.util.LRUCachePolicy.LRUCacheEntry entry)

Overrides:

ageOut in class org.jboss.util.LRUCachePolicy

cacheMiss

protected void cacheMiss()

Overrides:

cacheMiss in class org.jboss.util.LRUCachePolicy