Package com.yahoo.jdisc

Class AbstractResource

java.lang.Object

com.yahoo.jdisc.AbstractResource

All Implemented Interfaces:

SharedResource

Direct Known Subclasses:

AbstractRequestHandler, AbstractServerProvider, ActiveContainer, Request, ResourcePool

public abstract class AbstractResource
extends java.lang.Object
implements SharedResource

This class provides a thread-safe implementation of the SharedResource interface, and should be used for all subclasses of RequestHandler, ClientProvider and ServerProvider. Once the reference count of this resource reaches zero, the destroy() method is called.

Author:

Simon Thoresen Hult

Nested Class Summary

Nested classes/interfaces inherited from interface com.yahoo.jdisc.SharedResource

SharedResource.Debug

Field Summary

Fields inherited from interface com.yahoo.jdisc.SharedResource

DEBUG, SYSTEM_PROPERTY_NAME_DEBUG

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractResource()

Method Summary

Modifier and Type	Method	Description
java.lang.String	currentState()	Returns a string describing the current state of references in human-friendly terms.
protected void	destroy()	This method signals that this AbstractResource can dispose of any internal resources, and commence with shut down of any internal threads.
ResourceReference	refer()	Creates a reference to this resource.
ResourceReference	refer(java.lang.Object context)	Creates a reference to this resource.
void	release()	Releases the "main" reference to this resource (the implicit reference due to creation of the object).
int	retainCount()	Returns the reference count of this resource.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractResource

protected AbstractResource()

Method Detail

refer

public final ResourceReference refer()

Description copied from interface: SharedResource

Creates a reference to this resource. You call this method to prevent an object from being destroyed until you have finished using it.

You MUST keep the returned ResourceReference object and release the reference by calling ResourceReference.close() on it. A reference created by this method can NOT be released by calling SharedResource.release().

Specified by:

refer in interface SharedResource

See Also:

ResourceReference.close()

refer

public final ResourceReference refer(java.lang.Object context)

Description copied from interface: SharedResource

Creates a reference to this resource. You call this method to prevent an object from being destroyed until you have finished using it. You can attach a context that will live as long as the reference.

Specified by:

refer in interface SharedResource

Parameters:

context - A context to be associated with the reference. It should give some clue as to who referenced it.

You MUST keep the returned ResourceReference object and release the reference by calling ResourceReference.close() on it. A reference created by this method can NOT be released by calling SharedResource.release().

See Also:

ResourceReference.close()

release

public final void release()

Description copied from interface: SharedResource

Releases the "main" reference to this resource (the implicit reference due to creation of the object).

References obtained by calling SharedResource.refer() must be released by calling ResourceReference.close() on the ResourceReference returned from SharedResource.refer(), NOT by calling this method. You call this method once you are done using an object that you have previously caused instantiation of.

Specified by:

release in interface SharedResource

See Also:

ResourceReference

retainCount

public final int retainCount()

Returns the reference count of this resource. This typically has no value for other than single-threaded unit- tests, as it is merely a snapshot of the counter.

Returns:

The current value of the reference counter.

destroy

protected void destroy()

This method signals that this AbstractResource can dispose of any internal resources, and commence with shut down of any internal threads. This will be called once the reference count of this resource reaches zero.

currentState

public java.lang.String currentState()

Returns a string describing the current state of references in human-friendly terms. May be used for debugging.