SSF.OS
Class ObjectPool

java.lang.Object
  |
  +--SSF.OS.ObjectPool

public abstract class ObjectPool

extends java.lang.Object

Generic base class for pools of objects. By using an object pool, an alert modeler may be able to avoid calling new() to create new objects. This can save significant amounts of time, especially in parallel code, since new() has the potential to create lock contention for the heap.

To create a pool of objects of class Foo, one might use an anonymous inner class:

         ObjectPool fooPool = new ObjectPool() {
            public Object makeObject() { return new Foo(); };
         };
 

Then you would replace calls to

new Foo()

by calls to

fooPool.obtain()

. If the pool is empty,

obtain

simply calls

new()

, so little time is wasted.

To get the benefits of using a pool, you must also try to return instances of Foo to the pool after their last use, by calling

fooPool.recycle(deadFoo)

. Remember to 'clean up' each object before you recycle it, by removing all references to it from elsewhere in your data.

If you forget to recycle an object, it's okay: the Java garbage collector will eventually do so for you.

If you specify a pool that's too large, and don't make use of the objects awaiting recycling, you may increase memory consumption by preventing the Java garbage collector from doing its job. Try to choose a max pool size that reflects the typical imbalance at any point between recyclers and consumers of Objects.

Field Summary

static int	DEFAULT_MAX_POOL_SIZE
static int	DEFAULT_MIN_POOL_SIZE

Constructor Summary

ObjectPool()

ObjectPool(int min, int max)

Method Summary

abstract java.lang.Object	makeObject()
java.lang.Object	obtain()
void	recycle(java.lang.Object obj)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MIN_POOL_SIZE

public static final int DEFAULT_MIN_POOL_SIZE

See Also:

Constant Field Values

DEFAULT_MAX_POOL_SIZE

public static final int DEFAULT_MAX_POOL_SIZE

See Also:

Constant Field Values

Constructor Detail

ObjectPool

public ObjectPool()

ObjectPool

public ObjectPool(int min,
                  int max)

Method Detail

makeObject

public abstract java.lang.Object makeObject()

obtain

public java.lang.Object obtain()

recycle

public void recycle(java.lang.Object obj)