com.scaleoutsoftware.soss.client.util

Class ResourcePool<R extends ResourceAllocationValidator>

java.lang.Object

com.scaleoutsoftware.soss.client.util.ResourcePool<R>

public class ResourcePool<R extends ResourceAllocationValidator>
extends java.lang.Object

A simple resource pool where resources are created as needed up to a fixed maximum number of resources. Once the maximum has been reached, resource acquirers will wait until a resource is freed before returning from a getResource() operation.

Constructor Summary

Constructors

Constructor and Description
ResourcePool(ResourceFactory<R> resourceFactory, int maxResourcesToUse, int maxResourceWaitTimeoutMillis)

Method Summary

Modifier and Type	Method and Description
void	destroyResource(R resource) A resource should be removed from the pool either because it is no longer usable or because it isn't needed anymore.
R	getResource() Return an available resource from the pool, lazily creating a new one if none are available and we haven't exceeded the maximum pool size.
void	releaseResource(R resource) Release a resource back to the pool.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourcePool

public ResourcePool(ResourceFactory<R> resourceFactory,
                    int maxResourcesToUse,
                    int maxResourceWaitTimeoutMillis)

Method Detail

getResource

public R getResource()
              throws java.util.concurrent.ExecutionException

Return an available resource from the pool, lazily creating a new one if none are available and we haven't exceeded the maximum pool size.

Returns:

an available resource

Throws:

java.util.concurrent.ExecutionException - as a wrapper around any Exceptions thrown by the resource factory.

releaseResource

public void releaseResource(R resource)

Release a resource back to the pool.

Parameters:

resource - the resource to return to the pool

destroyResource

public void destroyResource(R resource)

A resource should be removed from the pool either because it is no longer usable or because it isn't needed anymore. If the resource is still in the pool, remove the resource from the pool, update our accounting and release the first waiter (if any) to go create a replacement. If not in the pool, check its use count, update our accounting and release the first waiter.

Parameters:

resource - the resource we expect to find in the pool.