Package com.sun.ejb.containers.util.pool

Class NonBlockingPool

java.lang.Object

com.sun.ejb.containers.util.pool.AbstractPool

com.sun.ejb.containers.util.pool.NonBlockingPool

All Implemented Interfaces:

Pool

Direct Known Subclasses:

BlockingPool

public class NonBlockingPool
extends AbstractPool

NonBlockingPool pool provides the basic implementation of an object pool. The implementation uses a linked list to maintain a list of (available) objects. If the pool is empty it simply creates one using the ObjectFactory instance. Subclasses can change this behaviour by overriding getObject(...) and returnObject(....) methods. This class provides basic support for synchronization, event notification, pool shutdown and pool object recycling. It also does some very basic bookkeeping like the number of objects created, number of threads waiting for object.

Subclasses can make use of these book-keeping data to provide complex pooling mechanism like LRU / MRU / Random. Also, note that AbstractPool does not have a notion of pool limit. It is upto to the derived classes to implement these features.

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	addedIdleBeanWork
protected boolean	addedResizeTask
protected boolean	inResizing
protected boolean	singletonBeanPool	If glassfish-ejb-jar.xml singleton-bean-pool is true, steadyPoolSize is 1, and maxPoolSize is 1, then this field is set to true, and only 1 bean instance is created.

Fields inherited from class com.sun.ejb.containers.util.pool.AbstractPool

_logger, appName, beanId, configData, containerClassLoader, createdCount, destroyedCount, ejbName, factory, idleTimeoutInSeconds, list, maxPoolSize, maxWaitTimeInMillis, modName, poolName, poolProbeNotifier, poolReturned, poolSuccess, resizeQuantity, steadyPoolSize, waitCount

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NonBlockingPool()
	NonBlockingPool(long beanId, String poolName, ObjectFactory factory, int steadyPoolSize, int resizeQuantity, int maxPoolSize, int idleTimeoutInSeconds, ClassLoader loader)
	NonBlockingPool(long beanId, String poolName, ObjectFactory factory, int steadyPoolSize, int resizeQuantity, int maxPoolSize, int idleTimeoutInSeconds, ClassLoader loader, boolean singletonBeanPool)

Method Summary

Modifier and Type	Method	Description
void	close()	Close the pool
void	destroyObject(Object object)	Destroys an Object.
protected void	doResize()
String	getAllAttrValues()
Object	getObject(Object param)	Get an object from the pool within the specified time.
protected void	preload(int count)	Preload the pool with objects.
void	prepopulate(int count)	Prepopulate the pool with objects.
protected void	remove(int count)
protected void	removeIdleObjects()
void	returnObject(Object object)	Return an object back to the pool.

Methods inherited from class com.sun.ejb.containers.util.pool.AbstractPool

appendStats, getAllMonitoredAttrbuteValues, getCreatedCount, getDestroyedCount, getIdleTimeoutInSeconds, getJmsMaxMessagesLoad, getMaxPoolSize, getMaxWaitTimeInMillis, getNumBeansInPool, getNumThreadsWaiting, getObject, getObject, getPoolSuccess, getResizeQuantity, getSize, getSteadyPoolSize, getTotalBeansCreated, getTotalBeansDestroyed, getWaitCount, setConfigData, setContainerClassLoader, setInfo, unregisterProbeProvider

Methods inherited from class java.lang.Object

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

Field Detail

addedResizeTask

protected boolean addedResizeTask

addedIdleBeanWork

protected volatile boolean addedIdleBeanWork

inResizing

protected boolean inResizing

singletonBeanPool

protected boolean singletonBeanPool

If glassfish-ejb-jar.xml singleton-bean-pool is true, steadyPoolSize is 1, and maxPoolSize is 1, then this field is set to true, and only 1 bean instance is created. The pool size at any given time may be 0 or 1. Both PoolResizeTimerTask and ReSizeWork are skipped.

Constructor Detail

NonBlockingPool

protected NonBlockingPool()

NonBlockingPool

public NonBlockingPool(long beanId,
                       String poolName,
                       ObjectFactory factory,
                       int steadyPoolSize,
                       int resizeQuantity,
                       int maxPoolSize,
                       int idleTimeoutInSeconds,
                       ClassLoader loader)

NonBlockingPool

public NonBlockingPool(long beanId,
                       String poolName,
                       ObjectFactory factory,
                       int steadyPoolSize,
                       int resizeQuantity,
                       int maxPoolSize,
                       int idleTimeoutInSeconds,
                       ClassLoader loader,
                       boolean singletonBeanPool)

Method Detail

getObject

public Object getObject(Object param)

Description copied from interface: Pool

Get an object from the pool within the specified time. The amount of time the calling thread agrees to wait. Some value that might be used while creating the object

Returns:

an Object or null if an object could not be returned in 'waitForMillis' millisecond.

returnObject

public void returnObject(Object object)

Return an object back to the pool. An object that is obtained through getObject() must always be returned back to the pool using either returnObject(obj) or through destroyObject(obj).

Parameters:

object -

destroyObject

public void destroyObject(Object object)

Destroys an Object. Note that applications should not ignore the reference to the object that they got from getObject(). An object that is obtained through getObject() must always be returned back to the pool using either returnObject(obj) or through destroyObject(obj). This method tells that the object should be destroyed and cannot be reused.

Parameters:

object - Object to be destroyed.

preload

protected void preload(int count)

Preload the pool with objects.

Parameters:

count - the number of objects to be added.

prepopulate

public void prepopulate(int count)

Prepopulate the pool with objects.

Parameters:

count - the number of objects to be added.

close

public void close()

Close the pool

Specified by:

close in class AbstractPool

remove

protected void remove(int count)

removeIdleObjects

protected void removeIdleObjects()

Specified by:

removeIdleObjects in class AbstractPool

doResize

protected void doResize()

getAllAttrValues

public String getAllAttrValues()

Overrides:

getAllAttrValues in class AbstractPool