org.multiverse.transactional.refs
Interface Ref<E>

All Known Implementing Classes:

AbaRef, BasicRef

public interface Ref<E>

The Ref is responsible for storing a value while providing transactional guarantees (failure atomicity, isolation)

Timed versions of the getOrAwait methods will be added in the near future.

Author:

Peter Veentjer

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.

Method Detail

get

E get()

Gets the current value stored in this reference.

Returns:

the current value.

getOrAwait

E getOrAwait()

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.

Returns:

the current stored reference.

getOrAwaitInterruptibly

E getOrAwaitInterruptibly()
                          throws java.lang.InterruptedException

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.

Returns:

the current stored reference.

Throws:

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

set

E set(E newValue)

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

Parameters:

newValue - the new value

Returns:

the previous value, which could be null.

clear

E clear()

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

Returns:

the old value.

isNull

boolean isNull()

Checks if the value is null.

Returns:

true if the value is null, false otherwise.