org.multiverse.transactional.refs
Class AbaRef<E>

java.lang.Object
  org.multiverse.transactional.refs.AbaRef<E>

All Implemented Interfaces:

Ref<E>

public class AbaRef<E>
extends Object
implements Ref<E>

A Ref that doesn't suffer from the ABA problem. See the BasicRef for more information.

Author:

Peter Veentjer

Constructor Summary

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

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

Method Summary

E	clear() Clears the value and returns the old value (could be null).
E	get() Gets the current value stored in this reference.
E	getOrAwait() Gets the current non null value, or waits until a non null value comes available.
E	getOrAwaitInterruptibly() Gets the current non null value, or waits until a non null value becomes available or until it is is Interrupted.
boolean	isNull() Checks if the value is null.
E	set(E newValue) Sets the new value value.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

AbaRef

public AbaRef()

Creates a new TransactionalAbaReference with a null reference.

AbaRef

public AbaRef(E value)

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

Parameters:

value - the reference to store.

Method Detail

getOrAwait

public final E getOrAwait()

Description copied from interface: Ref

Gets the current non null value, or waits until a non null value comes 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 Ref<E>

Returns:

the current stored reference.

getOrAwaitInterruptibly

public final E getOrAwaitInterruptibly()
                                throws InterruptedException

Description copied from interface: Ref

Gets the current non null value, or waits until a non null value 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 Ref<E>

Returns:

the current stored reference.

Throws:

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

get

public final E get()

Description copied from interface: Ref

Gets the current value stored in this reference.

Specified by:

get in interface Ref<E>

Returns:

the current value.

isNull

public final boolean isNull()

Description copied from interface: Ref

Checks if the value is null.

Specified by:

isNull in interface Ref<E>

Returns:

true if the value is null, false otherwise.

set

public final E set(E newValue)

Description copied from interface: Ref

Sets the new value value. The value is allowed to be null.

Specified by:

set in interface Ref<E>

Parameters:

newValue - the new value

Returns:

the previous value, which could be null.

clear

public final E clear()

Description copied from interface: Ref

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

Specified by:

clear in interface Ref<E>

Returns:

the old value.

toString

public final String toString()

Overrides:

toString in class Object