java.util.concurrent.atomic.AtomicStampedReference<V>
An AtomicStampedReference maintains an object reference
along with an integer "stamp", that can be updated atomically.
Implementation note. This implementation maintains stamped
references by creating internal objects representing "boxed"
[reference, integer] pairs.
Summary
Public Constructors
Public Methods
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
Public Constructors
public
AtomicStampedReference(V initialRef, int initialStamp)
Creates a new
AtomicStampedReference with the given
initial values.
Parameters
initialRef
| the initial reference |
initialStamp
| the initial stamp
|
Public Methods
public
boolean
attemptStamp(V expectedReference, int newStamp)
Atomically sets the value of the stamp 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 |
newStamp
| the new value for the stamp |
public
boolean
compareAndSet(V expectedReference, V newReference, int expectedStamp, int newStamp)
Atomically sets the value of both the reference and stamp
to the given update values if the
current reference is
== to the expected reference
and the current stamp is equal to the expected stamp.
Parameters
expectedReference
| the expected value of the reference |
newReference
| the new value for the reference |
expectedStamp
| the expected value of the stamp |
newStamp
| the new value for the stamp |
public
V
get(int[] stampHolder)
Returns the current values of both the reference and the stamp.
Typical usage is
int[1] holder; ref = v.get(holder); .
Parameters
stampHolder
| an array of size of at least one. On return,
stampholder[0] will hold the value of the stamp. |
Returns
- the current value of the reference
public
V
getReference()
Returns the current value of the reference.
Returns
- the current value of the reference
public
int
getStamp()
Returns the current value of the stamp.
Returns
- the current value of the stamp
public
void
set(V newReference, int newStamp)
Unconditionally sets the value of both the reference and stamp.
Parameters
newReference
| the new value for the reference |
newStamp
| the new value for the stamp
|
public
boolean
weakCompareAndSet(V expectedReference, V newReference, int expectedStamp, int newStamp)
Atomically sets the value of both the reference and stamp
to the given update values if the
current reference is
== to the expected reference
and the current stamp is equal to the expected stamp. 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 |
expectedStamp
| the expected value of the stamp |
newStamp
| the new value for the stamp |