org.multiverse.transactional
Class TransactionalAbaReference<E>

java.lang.Object
  org.multiverse.transactional.TransactionalAbaReference<E>

All Implemented Interfaces:

TransactionalReference<E>

public final class TransactionalAbaReference<E>
extends Object
implements TransactionalReference<E>

A TransactionalReference that doesn't suffer from the ABA problem. See the DefaultTransactionalReference for more information.

Author:

Peter Veentjer

Constructor Summary

TransactionalAbaReference()
Creates a new TransactionalAbaReference with a null reference.

TransactionalAbaReference(E reference)
Creates a new TransactionalAbaReference with the provided reference.

Method Summary

E	clear() Clears the ref and returns the old value of the ref (could be null).
E	get() Gets the current stored ref, or null if no ref is stored.
E	getOrAwait() Gets the current stored ref, or waits until a non null reference becomes available.
E	getOrAwaitInterruptibly() Gets the current stored reference, or waits until a non null references becomes available or until it is is Interrupted.
boolean	isNull() Checks if the ref is null.
E	set(E newRef) Sets the current ref.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionalAbaReference

public TransactionalAbaReference()

Creates a new TransactionalAbaReference with a null reference.

TransactionalAbaReference

public TransactionalAbaReference(E reference)

Creates a new TransactionalAbaReference with the provided reference. This reference is allowed to be null.

Parameters:

reference - the reference to store.

Method Detail

getOrAwait

public E getOrAwait()

Description copied from interface: TransactionalReference

Gets the current stored ref, or waits until a non null reference becomes available. So you will always get a non null ref.

This call is not interruptible, unless the enclosing transaction is configured as interruptible.

Specified by:

getOrAwait in interface TransactionalReference<E>

Returns:

the current stored reference.

getOrAwaitInterruptibly

public E getOrAwaitInterruptibly()
                          throws InterruptedException

Description copied from interface: TransactionalReference

Gets the current stored reference, or waits until a non null references becomes available or until it is is Interrupted.

This call is interruptible, unless the enclosing transaction isn't configured as interruptible.

Specified by:

getOrAwaitInterruptibly in interface TransactionalReference<E>

Returns:

the current stored reference.

Throws:

InterruptedException - if the thread is interrupted while waiting on a reference to come available.

get

public E get()

Description copied from interface: TransactionalReference

Gets the current stored ref, or null if no ref is stored.

Specified by:

get in interface TransactionalReference<E>

Returns:

the current stored ref, or null if no ref is stored.

isNull

public boolean isNull()

Description copied from interface: TransactionalReference

Checks if the ref is null.

Specified by:

isNull in interface TransactionalReference<E>

Returns:

true if the ref is null, false otherwise.

set

public E set(E newRef)

Description copied from interface: TransactionalReference

Sets the current ref. The ref is allowed to be null.

Specified by:

set in interface TransactionalReference<E>

Parameters:

newRef - the ref to set.

Returns:

the previous ref, which could be null.

clear

public E clear()

Description copied from interface: TransactionalReference

Clears the ref and returns the old value of the ref (could be null).

Specified by:

clear in interface TransactionalReference<E>

Returns:

the old value.

toString

public String toString()

Overrides:

toString in class Object