Package org.apache.commons.jcs3.engine

Class PooledCacheEventQueue<K,V>

java.lang.Object

org.apache.commons.jcs3.engine.AbstractCacheEventQueue<K,V>

org.apache.commons.jcs3.engine.PooledCacheEventQueue<K,V>

All Implemented Interfaces:

ICacheEventQueue<K,V>

Direct Known Subclasses:

CacheEventQueue

public class PooledCacheEventQueue<K,V>
extends AbstractCacheEventQueue<K,V>

An event queue is used to propagate ordered cache events to one and only one target listener.

This is a modified version of the experimental version. It uses a PooledExecutor and a BoundedBuffer to queue up events and execute them as threads become available.

The PooledExecutor is static, because presumably these processes will be IO bound, so throwing more than a few threads at them will serve no purpose other than to saturate the IO interface. In light of this, having one thread per region seems unnecessary. This may prove to be false.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.jcs3.engine.AbstractCacheEventQueue

AbstractCacheEventQueue.AbstractCacheEvent, AbstractCacheEventQueue.DisposeEvent, AbstractCacheEventQueue.PutEvent, AbstractCacheEventQueue.RemoveAllEvent, AbstractCacheEventQueue.RemoveEvent

Nested classes/interfaces inherited from interface org.apache.commons.jcs3.engine.behavior.ICacheEventQueue

ICacheEventQueue.QueueType

Field Summary

Fields

Modifier and Type	Field	Description
protected ExecutorService	pool	The Thread Pool to execute events with.
protected BlockingQueue<Runnable>	queue	The Thread Pool queue

Fields inherited from class org.apache.commons.jcs3.engine.AbstractCacheEventQueue

DEFAULT_WAIT_TO_DIE_MILLIS

Constructor Summary

Constructors

Constructor	Description
PooledCacheEventQueue(ICacheListener<K,V> listener, long listenerId, String cacheName, int maxFailure, int waitBeforeRetry, String threadPoolName)	Constructor for the CacheEventQueue object

Method Summary

Modifier and Type	Method	Description
protected ExecutorService	createPool(String threadPoolName)	Create the thread pool.
void	destroy()	Destroy the queue.
ICacheEventQueue.QueueType	getQueueType()	Return the type of event queue we are using, either single or pooled.
IStats	getStatistics()	Returns the historical and statistical data for an event queue cache.
protected void	initialize(ICacheListener<K,V> listener, long listenerId, String cacheName, int maxFailure, int waitBeforeRetry, String threadPoolName)	Initializes the queue.
boolean	isEmpty()	If the Queue is using a bounded channel we can determine the size.
protected void	put(AbstractCacheEventQueue<K,V>.AbstractCacheEvent event)	Adds an event to the queue.
int	size()	Returns the number of elements in the queue.

Methods inherited from class org.apache.commons.jcs3.engine.AbstractCacheEventQueue

addDisposeEvent, addPutEvent, addRemoveAllEvent, addRemoveEvent, getCacheName, getListenerId, getWaitToDieMillis, initialize, isWorking, setWaitToDieMillis, setWorking, toString

Methods inherited from class java.lang.Object

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

Field Details

pool

protected ExecutorService pool

The Thread Pool to execute events with.

queue

protected BlockingQueue<Runnable> queue

The Thread Pool queue

Constructor Details

PooledCacheEventQueue

public PooledCacheEventQueue(ICacheListener<K,V> listener,
 long listenerId,
 String cacheName,
 int maxFailure,
 int waitBeforeRetry,
 String threadPoolName)

Constructor for the CacheEventQueue object

Parameters:

listener -

listenerId -

cacheName -

maxFailure -

waitBeforeRetry -

threadPoolName -

Method Details

initialize

protected void initialize(ICacheListener<K,V> listener,
 long listenerId,
 String cacheName,
 int maxFailure,
 int waitBeforeRetry,
 String threadPoolName)

Initializes the queue.

Parameters:

listener -

listenerId -

cacheName -

maxFailure -

waitBeforeRetry -

threadPoolName -

createPool

protected ExecutorService createPool(String threadPoolName)

Create the thread pool.

Parameters:

threadPoolName -

Since:

3.1

getQueueType

public ICacheEventQueue.QueueType getQueueType()

Description copied from interface: ICacheEventQueue

Return the type of event queue we are using, either single or pooled.

Returns:

the queue type

destroy

public void destroy()

Destroy the queue. Interrupt all threads.

put

protected void put(AbstractCacheEventQueue<K,V>.AbstractCacheEvent event)

Adds an event to the queue.

Specified by:

put in class AbstractCacheEventQueue<K,V>

Parameters:

event -

getStatistics

public IStats getStatistics()

Description copied from interface: ICacheEventQueue

Returns the historical and statistical data for an event queue cache.

Returns:

IStats

isEmpty

public boolean isEmpty()

If the Queue is using a bounded channel we can determine the size. If it is zero or we can't determine the size, we return true.

Returns:

whether or not there are items in the queue

size

public int size()

Returns the number of elements in the queue. If the queue cannot determine the size accurately it will return 0.

Returns:

number of items in the queue.