public class

AtomicMarkableReference

extends Object
java.lang.Object
   ↳ java.util.concurrent.atomic.AtomicMarkableReference<V>

Class Overview

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.

Summary

Public Constructors
AtomicMarkableReference(V initialRef, boolean initialMark)
Creates a new AtomicMarkableReference with the given initial values.
Public Methods
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.
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.
V get(boolean[] markHolder)
Returns the current values of both the reference and the mark.
V getReference()
Returns the current value of the reference.
boolean isMarked()
Returns the current value of the mark.
void set(V newReference, boolean newMark)
Unconditionally sets the value of both the reference and 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.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public AtomicMarkableReference (V initialRef, boolean initialMark)

Since: API Level 1

Creates a new AtomicMarkableReference with the given initial values.

Parameters
initialRef the initial reference
initialMark the initial mark

Public Methods

public boolean attemptMark (V expectedReference, boolean newMark)

Since: API Level 1

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

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

Since: API Level 1

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

public V get (boolean[] markHolder)

Since: API Level 1

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

public V getReference ()

Since: API Level 1

Returns the current value of the reference.

Returns
  • the current value of the reference

public boolean isMarked ()

Since: API Level 1

Returns the current value of the mark.

Returns
  • the current value of the mark

public void set (V newReference, boolean newMark)

Since: API Level 1

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

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

Since: API Level 1

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.

May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

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