org.objectweb.perseus.pool.api
Interface Pool

All Known Implementing Classes:

ArrayListPool, LArrayPool

public interface Pool

The interface Pool defines an object that pools resources of any kind. Resources must be requested (getResource) and released (releaseResource) on demand. A Pool object can be parameterized along different dimensions. All these dimensions are represented by PoolAttributes interface.

Method Summary

int	getFreeResourceNumber()
java.lang.Object	getResource(java.lang.Object hints) getResource is used to allocate a PoolResource from the Pool.
java.lang.Object	getResource(java.lang.Object hints, java.lang.Object user) getResource is used to allocate a PoolResource from the Pool.
int	getSize()
int	getUsedResourceNumber()
java.util.Collection	getUsers()
void	releaseResource(java.lang.Object resource) releaseResource releases a PoolResource in order to allow the Pool to recycle this PoolResource.

Method Detail

getResource

public java.lang.Object getResource(java.lang.Object hints)
                             throws PoolException

getResource is used to allocate a PoolResource from the Pool. Some hints are passed in order to specialise the matching or creation of PoolResource.

Parameters:

hints - Some properties to specialise the matching or the creation of PoolResource.

Returns:

The PoolResource allocated from the Pool.

Throws:

PoolException

getResource

public java.lang.Object getResource(java.lang.Object hints,
                                    java.lang.Object user)
                             throws PoolException,
                                    DeadLockException

getResource is used to allocate a PoolResource from the Pool. Some hints are passed in order to specialise the matching or creation of PoolResource. The user parameter avoids dead lock by the use of a dependency graph.

Parameters:

hints - Some properties to specialise the matching or the creation of PoolResource.

user - is an identifier of the context wanting a resource in the pool.

Returns:

The PoolResource allocated from the Pool.

Throws:

PoolException

DeadLockException

releaseResource

public void releaseResource(java.lang.Object resource)
                     throws PoolException

releaseResource releases a PoolResource in order to allow the Pool to recycle this PoolResource.

Parameters:

resource - The PoolResource to be released.

Throws:

PoolException

getSize

public int getSize()

Returns:

the number resource used and free

getFreeResourceNumber

public int getFreeResourceNumber()

Returns:

the number of unsused resource

getUsedResourceNumber

public int getUsedResourceNumber()

Returns:

the number of used resource

getUsers

public java.util.Collection getUsers()

Returns:

collection of user. The collection can be empty even if resource are used, in case of the user did not specify any reference on getResource.