org.jboss.ejb.plugins
Class AbstractInstanceCache

java.lang.Object
  |
  +--org.jboss.ejb.plugins.AbstractInstanceCache

All Implemented Interfaces:

ContainerPlugin, InstanceCache, MetricsConstants, Monitorable, Service, XmlLoadable

Direct Known Subclasses:

EntityInstanceCache, StatefulSessionInstanceCache

public abstract class AbstractInstanceCache

extends java.lang.Object

implements InstanceCache, XmlLoadable, Monitorable, MetricsConstants

Base class for caches of entity and stateful beans.

It manages the cache entries through a CachePolicy object; the implementation of the cache policy object must respect the following requirements:

• Have a public constructor that takes a single argument of type AbstractInstanceCache.class or a subclass

Version:

$Revision: 1.10.2.6 $

Revisions:

20010703 marcf:

• Synchronization is on the context and not on the mutex any longer

20010704 marcf:

• Commented the getLock removeLock, temporarely, might need to come back when we go beyond locking at the context level and lock by ID

2001/07/26: billb

1. Locking is now separate from EntityEnterpriseContext objects and is now encapsulated in BeanLock and BeanLockManager. Did this because the lifetime of an EntityLock is sometimes longer than the lifetime of the ctx.

2001/08/07: billb

1. releaseLockRef should be enclosed in peek in remove()

2001/12/03: billb

1. Make sure ctx.getID() is non-null when received from unschedulePassivation.

Author:

Simone Bordet, Bill Burke, Marc Fleury, Scott Stark

Inner Class Summary

protected class

AbstractInstanceCache.PassivationHelper Helper class that schedules, unschedules, and executes the passivation jobs.

Field Summary

protected Logger

log The log for this cache instance

Fields inherited from interface org.jboss.monitor.MetricsConstants

ACTIVITY, APPLICATION, BEAN, BEANCACHE_METRICS, CHECKPOINT, INVOCATION_METRICS, MEMORY_MONITOR, METHOD, PRIMARY_KEY, SYSTEM_METRICS, THREAD_MONITOR, TIME, TYPE

Constructor Summary

AbstractInstanceCache()

Method Summary

protected abstract EnterpriseContext	acquireContext() Acquires an EnterpriseContext from the pool
protected abstract void	activate(EnterpriseContext ctx) Activates the given EnterpriseContext
protected abstract boolean	canPassivate(EnterpriseContext ctx) Returns whether the given context can be passivated or not
javax.jms.Message	createMessage(java.lang.Object id)
void	destroy()
protected abstract void	freeContext(EnterpriseContext ctx) Frees the given EnterpriseContext to the pool
EnterpriseContext	get(java.lang.Object id) Gets a bean instance from this cache given the identity.
protected CachePolicy	getCache() Returns the cache policy used for this cache.
java.lang.Object	getCacheLock() Returns the mutex used to sync access to the cache policy object
protected abstract Container	getContainer() Returns the container for this cache.
protected abstract java.lang.Object	getKey(EnterpriseContext ctx) Returns the key used by the cache to map the given context
void	importXml(org.w3c.dom.Element element)
void	init()
void	insert(EnterpriseContext ctx) Inserts an active bean instance after creation or activation.
boolean	isActive(java.lang.Object id) Checks whether an instance corresponding to a particular id is active
boolean	isJMSMonitoringEnabled()
protected void	logActivation(java.lang.Object id)
protected void	logPassivation(java.lang.Object id)
protected void	logPassivationPostponed(java.lang.Object id)
protected void	logPassivationScheduled(java.lang.Object id)
protected abstract void	passivate(EnterpriseContext ctx) Passivates the given EnterpriseContext
void	release(EnterpriseContext ctx) Releases the given bean instance from this cache.
void	remove(java.lang.Object id) Removes a bean instance from this cache given the identity.
void	resetStatistic()
java.util.Map	retrieveStatistic()
void	sample(java.lang.Object s) Samples the status of the implementor object and register the status into the snapshot argument.
protected void	schedulePassivation(EnterpriseContext ctx) Schedules the given EnterpriseContext for passivation
void	sendMessage(javax.jms.Message message)
void	setJMSMonitoringEnabled(boolean enable)
protected abstract void	setKey(java.lang.Object id, EnterpriseContext ctx) Sets the given id as key for the given context
void	start()
void	stop()
protected EnterpriseContext	unschedulePassivation(java.lang.Object id) Tries to unschedule the given EnterpriseContext for passivation; returns the unscheduled context if it wasn't passivated yet, null if the passivation already happened.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.ejb.ContainerPlugin

setContainer

Field Detail

log

protected Logger log

The log for this cache instance

Constructor Detail

AbstractInstanceCache

public AbstractInstanceCache()

Method Detail

sample

public void sample(java.lang.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

retrieveStatistic

public java.util.Map retrieveStatistic()

resetStatistic

public void resetStatistic()

setJMSMonitoringEnabled

public void setJMSMonitoringEnabled(boolean enable)

isJMSMonitoringEnabled

public boolean isJMSMonitoringEnabled()

sendMessage

public void sendMessage(javax.jms.Message message)

createMessage

public javax.jms.Message createMessage(java.lang.Object id)

get

public EnterpriseContext get(java.lang.Object id)
                      throws java.rmi.RemoteException,
                             java.rmi.NoSuchObjectException

Description copied from interface: InstanceCache

Gets a bean instance from this cache given the identity. This method may involve activation if the instance is not in the cache. Implementation should have O(1) complexity. This method is never called for stateless session beans.

Specified by:

get in interface InstanceCache

Following copied from interface: org.jboss.ejb.InstanceCache

Parameters:

id - the primary key of the bean

Returns:

the EnterpriseContext related to the given id

Throws:

java.rmi.RemoteException - in case of illegal calls (concurrent / reentrant), NoSuchObjectException if the bean cannot be found.

See Also:

InstanceCache.release(org.jboss.ejb.EnterpriseContext)

insert

public void insert(EnterpriseContext ctx)

Description copied from interface: InstanceCache

Inserts an active bean instance after creation or activation. Implementation should guarantee proper locking and O(1) complexity.

Specified by:

insert in interface InstanceCache

Following copied from interface: org.jboss.ejb.InstanceCache

Parameters:

ctx - the EnterpriseContext to insert in the cache

See Also:

InstanceCache.remove(java.lang.Object)

release

public void release(EnterpriseContext ctx)

Description copied from interface: InstanceCache

Releases the given bean instance from this cache. This method may passivate the bean to get it out of the cache. Implementation should return almost immediately leaving the passivation to be executed by another thread.

Specified by:

release in interface InstanceCache

Following copied from interface: org.jboss.ejb.InstanceCache

Parameters:

ctx - the EnterpriseContext to release

See Also:

InstanceCache.get(java.lang.Object)

remove

public void remove(java.lang.Object id)

Description copied from interface: InstanceCache

Removes a bean instance from this cache given the identity. Implementation should have O(1) complexity and guarantee proper locking.

Specified by:

remove in interface InstanceCache

Following copied from interface: org.jboss.ejb.InstanceCache

Parameters:

id - the pimary key of the bean

See Also:

InstanceCache.insert(org.jboss.ejb.EnterpriseContext)

isActive

public boolean isActive(java.lang.Object id)

Description copied from interface: InstanceCache

Checks whether an instance corresponding to a particular id is active

Specified by:

isActive in interface InstanceCache

Following copied from interface: org.jboss.ejb.InstanceCache

Parameters:

id - the pimary key of the bean

See Also:

InstanceCache.insert(org.jboss.ejb.EnterpriseContext)

importXml

public void importXml(org.w3c.dom.Element element)
               throws DeploymentException

Specified by:

importXml in interface XmlLoadable

init

public void init()
          throws java.lang.Exception

Specified by:

init in interface Service

start

public void start()
           throws java.lang.Exception

Specified by:

start in interface Service

stop

public void stop()

Specified by:

stop in interface Service

destroy

public void destroy()

Specified by:

destroy in interface Service

schedulePassivation

protected void schedulePassivation(EnterpriseContext ctx)

Schedules the given EnterpriseContext for passivation

See Also:

AbstractInstanceCache.PassivationHelper.schedule(org.jboss.ejb.EnterpriseContext)

unschedulePassivation

protected EnterpriseContext unschedulePassivation(java.lang.Object id)

Tries to unschedule the given EnterpriseContext for passivation; returns the unscheduled context if it wasn't passivated yet, null if the passivation already happened.

See Also:

AbstractInstanceCache.PassivationHelper.unschedule(java.lang.Object)

logActivation

protected void logActivation(java.lang.Object id)

logPassivationScheduled

protected void logPassivationScheduled(java.lang.Object id)

logPassivation

protected void logPassivation(java.lang.Object id)

logPassivationPostponed

protected void logPassivationPostponed(java.lang.Object id)

getContainer

protected abstract Container getContainer()

Returns the container for this cache.

getCache

protected CachePolicy getCache()

Returns the cache policy used for this cache.

getCacheLock

public java.lang.Object getCacheLock()

Returns the mutex used to sync access to the cache policy object

passivate

protected abstract void passivate(EnterpriseContext ctx)
                           throws java.rmi.RemoteException

Passivates the given EnterpriseContext

activate

protected abstract void activate(EnterpriseContext ctx)
                          throws java.rmi.RemoteException

Activates the given EnterpriseContext

acquireContext

protected abstract EnterpriseContext acquireContext()
                                             throws java.lang.Exception

Acquires an EnterpriseContext from the pool

freeContext

protected abstract void freeContext(EnterpriseContext ctx)

Frees the given EnterpriseContext to the pool

getKey

protected abstract java.lang.Object getKey(EnterpriseContext ctx)

Returns the key used by the cache to map the given context

setKey

protected abstract void setKey(java.lang.Object id,
                               EnterpriseContext ctx)

Sets the given id as key for the given context

canPassivate

protected abstract boolean canPassivate(EnterpriseContext ctx)

Returns whether the given context can be passivated or not