AtomicMarkableReference
public
class
AtomicMarkableReference
extends Object
java.lang.Object  
↳  java.util.concurrent.atomic.AtomicMarkableReference<V> 
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 
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 
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 
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 
Inherited methods  

Public constructors
AtomicMarkableReference
public AtomicMarkableReference (V initialRef, boolean initialMark)
Creates a new AtomicMarkableReference
with the given
initial values.
Parameters  

initialRef 
V : the initial reference 
initialMark 
boolean : the initial mark

Public methods
attemptMark
public 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 
V : the expected value of the reference 
newMark 
boolean : the new value for the mark 
Returns  

boolean 
true if successful

compareAndSet
public 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 
V : the expected value of the reference 
newReference 
V : the new value for the reference 
expectedMark 
boolean : the expected value of the mark 
newMark 
boolean : the new value for the mark 
Returns  

boolean 
true if successful

get
public 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 
boolean : an array of size of at least one. On return,
markHolder[0] will hold the value of the mark. 
Returns  

V 
the current value of the reference 
getReference
public V getReference ()
Returns the current value of the reference.
Returns  

V 
the current value of the reference 
isMarked
public boolean isMarked ()
Returns the current value of the mark.
Returns  

boolean 
the current value of the mark 
set
public void set (V newReference, boolean newMark)
Unconditionally sets the value of both the reference and mark.
Parameters  

newReference 
V : the new value for the reference 
newMark 
boolean : the new value for the mark

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

expectedReference 
V : the expected value of the reference 
newReference 
V : the new value for the reference 
expectedMark 
boolean : the expected value of the mark 
newMark 
boolean : the new value for the mark 
Returns  

boolean 
true if successful
