com.carrotsearch.hppcrt

Class ObjectPool<E>

java.lang.Object

com.carrotsearch.hppcrt.ObjectPool<E>

Type Parameters:

E -

Direct Known Subclasses:

IteratorPool

public class ObjectPool<E>
extends java.lang.Object

An Object pool of configurable and extensible size, from which pre-allocated objects can be borrowed, and released after use by returning them to the pool.

Field Summary

Fields

Modifier and Type	Field and Description
protected E[]	arrayPool The low-level array holding the object instances.
protected int	capacity Capacity of the pool, i.e max number of Objects managed by this pool.
protected int	currentSize Current number of available (free) objects currently in the pool.
protected ObjectFactory<E>	factory The ObjectFactory used for creating or re-initializing objects of the pool.
protected ArraySizingStrategy	growthPolicy Controls the way more objects are produced when the pool is empty.

Constructor Summary

Constructors

Constructor and Description
ObjectPool(ObjectFactory<E> objFactory, int initialSize, ArraySizingStrategy growthPolicy) Create a new pool of Objects E, constructed with objFactory, of size initialSize at startup, with growthStrategy as a policy when new objects need to be allocated.

Method Summary

Modifier and Type	Method and Description
E	borrow() Borrow an Object from the pool.
int	capacity() get the capacity of the pool, i.e max number of Objects managed by this pool.
void	release(E releasedObject) Release this object E by putting it back to the pool.
int	size() get the current number of available (free) objects in the pool.

Methods inherited from class java.lang.Object

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

Field Detail

factory

protected ObjectFactory<E> factory

The ObjectFactory used for creating or re-initializing objects of the pool.

currentSize

protected int currentSize

Current number of available (free) objects currently in the pool.

capacity

protected int capacity

Capacity of the pool, i.e max number of Objects managed by this pool.

growthPolicy

protected ArraySizingStrategy growthPolicy

Controls the way more objects are produced when the pool is empty. The meaning of ArraySizingStrategy.grow() differs a bit in the ObjectPool context:

a) if grow() >= 0, follow the original contract,

b) if -capacity() < grow() < 0 (grow() == -nbNewElements), it means that the pool is to generate nbNewElements Objects, but the capacity is unchanged, which means that (nbNewElements) Objects allocated previously are virtually discarded, for GC to collect. This particular policy prevent the pool to grow indefinitely if some reference Objects get "lost" over time when a proper release() was impossible to do on them.

See Also:

release(E)

arrayPool

protected E[] arrayPool

The low-level array holding the object instances.

Constructor Detail

ObjectPool

public ObjectPool(ObjectFactory<E> objFactory,
                  int initialSize,
                  ArraySizingStrategy growthPolicy)

Create a new pool of Objects E, constructed with objFactory, of size initialSize at startup, with growthStrategy as a policy when new objects need to be allocated.

Parameters:

objFactory -

initialSize -

growthPolicy -

Method Detail

borrow

public E borrow()

Borrow an Object from the pool. If there is no more Objects, more of them are allocated using the growthPolicy policy. The returned object is assured to be initialized with factory.initialize().

release

public void release(E releasedObject)

Release this object E by putting it back to the pool. Of course, using releasedObject after it has been released is a logical error, since such object is supposed to be "freed".

Parameters:

releasedObject -

size

public int size()

get the current number of available (free) objects in the pool.

capacity

public int capacity()

get the capacity of the pool, i.e max number of Objects managed by this pool.