AtomicMarkableReference< V > Class Reference

List of all members.

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Detailed Description

An AtomicMarkableReference maintains an object reference along with a mark bit, that can be updated atomically.

Implementation note. This implementation maintains markable references by creating internal objects representing "boxed" [reference, boolean] pairs.

Since:

1.5

Author:

Doug Lea

Parameters:

<V>

The type of object referred to by this reference

Public Member Functions
	AtomicMarkableReference (V initialRef, boolean initialMark)
	Creates a new AtomicMarkableReference with the given initial values.
V	getReference ()
	Returns the current value of the reference.
boolean	isMarked ()
	Returns the current value of the mark.
V	get (boolean[] markHolder)
	Returns the current values of both the reference and the mark.
boolean	weakCompareAndSet (V expectedReference, V newReference, boolean expectedMark, boolean newMark)
	Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.
boolean	compareAndSet (V expectedReference, V newReference, boolean expectedMark, boolean newMark)
	Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.
void	set (V newReference, boolean newMark)
	Unconditionally sets the value of both the reference and mark.
boolean	attemptMark (V expectedReference, boolean newMark)
	Atomically sets the value of the mark to the given update value if the current reference is == to the expected reference.
Private Attributes
final AtomicReference < ReferenceBooleanPair< V > >	atomicRef
Classes
class	ReferenceBooleanPair< T >

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Constructor & Destructor Documentation

AtomicMarkableReference	(	V	initialRef,
		boolean	initialMark
	)

Creates a new AtomicMarkableReference with the given initial values.

Parameters:

	initialRef	the initial reference
	initialMark	the initial mark

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Member Function Documentation

V getReference

(

)

Returns the current value of the reference.

Returns:

the current value of the reference

boolean isMarked

(

)

Returns the current value of the mark.

Returns:

the current value of the mark

V get

(

boolean[]

markHolder

)

Returns the current values of both the reference and the mark.

Typical usage is boolean[1] holder; ref = v.get(holder); .

Parameters:

markHolder

an array of size of at least one. On return, markholder[0] will hold the value of the mark.

Returns:

the current value of the reference

boolean weakCompareAndSet	(	V	expectedReference,
		V	newReference,
		boolean	expectedMark,
		boolean	newMark
	)

Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.

Any given invocation of this operation may fail (return false) spuriously, but repeated invocation when the current value holds the expected value and no other thread is also attempting to set the value will eventually succeed.

Parameters:

	expectedReference	the expected value of the reference
	newReference	the new value for the reference
	expectedMark	the expected value of the mark
	newMark	the new value for the mark

Returns:

true if successful

boolean compareAndSet	(	V	expectedReference,
		V	newReference,
		boolean	expectedMark,
		boolean	newMark
	)

Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.

Parameters:

	expectedReference	the expected value of the reference
	newReference	the new value for the reference
	expectedMark	the expected value of the mark
	newMark	the new value for the mark

Returns:

true if successful

void set	(	V	newReference,
		boolean	newMark
	)

Unconditionally sets the value of both the reference and mark.

Parameters:

	newReference	the new value for the reference
	newMark	the new value for the mark

boolean attemptMark	(	V	expectedReference,
		boolean	newMark
	)

Atomically sets the value of the mark to the given update value if the current reference is == to the expected reference.

Any given invocation of this operation may fail (return false) spuriously, but repeated invocation when the current value holds the expected value and no other thread is also attempting to set the value will eventually succeed.

Parameters:

	expectedReference	the expected value of the reference
	newMark	the new value for the mark

Returns:

true if successful

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Member Data Documentation

final AtomicReference<ReferenceBooleanPair<V> > atomicRef [private]