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

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 and Description
protected boolean	addedIdleBeanWork
protected boolean	addedResizeTask
protected boolean	inResizing

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, poolProbeNotifier, poolReturned, poolSuccess, resizeQuantity, steadyPoolSize, waitCount

Constructor Summary

Constructors

Modifier	Constructor and 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 and Description
void	close() Close the pool
void	destroyObject(Object object) Destroys an Object.
protected void	doResize()
String	getAllAttrValues()
Object	getObject(boolean canWait, Object param) Get an object.
Object	getObject(long maxWaitTime, Object param)
Object	getObject(Object param) Get an object from the pool within the specified time.
protected void	initializePool(ObjectFactory factory, int steadyPoolSize, int resizeQuantity, int maxPoolSize, int idleTimeoutInSeconds, ClassLoader loader)
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.
void	setContainerClassLoader(ClassLoader loader)

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

appendStats, getAllMonitoredAttrbuteValues, getCreatedCount, getDestroyedCount, getIdleTimeoutInSeconds, getJmsMaxMessagesLoad, getMaxPoolSize, getMaxWaitTimeInMillis, getNumBeansInPool, getNumThreadsWaiting, getPoolSuccess, getResizeQuantity, getSize, getSteadyPoolSize, getTotalBeansCreated, getTotalBeansDestroyed, getWaitCount, initializePool, setConfigData, 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

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

initializePool

protected void initializePool(ObjectFactory factory,
                              int steadyPoolSize,
                              int resizeQuantity,
                              int maxPoolSize,
                              int idleTimeoutInSeconds,
                              ClassLoader loader)

setContainerClassLoader

public void setContainerClassLoader(ClassLoader loader)

Overrides:

setContainerClassLoader in class AbstractPool

getObject

public Object getObject(boolean canWait,
                        Object param)
                 throws PoolException

Get an object. Application can use pool.getObject() to get an object instead of using new XXX().

Specified by:

getObject in interface Pool

Overrides:

getObject in class AbstractPool

Parameters:

canWait - Must be true if the calling thread is willing to wait for infinite time to get an object, false if the calling thread does not want to wait at all.

Throws:

PoolException

getObject

public Object getObject(long maxWaitTime,
                        Object param)
                 throws PoolException

Specified by:

getObject in interface Pool

Overrides:

getObject in class AbstractPool

Throws:

PoolException

getObject

public Object getObject(Object param)

Description copied from interface: Pool

Get an object from the pool within the specified time.

Specified by:

getObject in interface Pool

Overrides:

getObject in class AbstractPool

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).

Specified by:

returnObject in interface Pool

Overrides:

returnObject in class AbstractPool

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.

Specified by:

destroyObject in interface Pool

Overrides:

destroyObject in class AbstractPool

preload

protected void preload(int count)

Preload the pool with objects.

Overrides:

preload in class AbstractPool

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

Overrides:

close in class AbstractPool

remove

protected void remove(int count)

Overrides:

remove in class AbstractPool

removeIdleObjects

protected void removeIdleObjects()

Specified by:

removeIdleObjects in class AbstractPool

doResize

protected void doResize()

getAllAttrValues

public String getAllAttrValues()

Overrides:

getAllAttrValues in class AbstractPool