| java.lang.Object
 java.util.concurrent.atomic.AtomicStampedReference
| AtomicStampedReference | | public class AtomicStampedReference (Code) | | 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.
since:
1.5
author:
Doug Lea<
Parameters:
V - > The type of object referred to by this reference |
| Constructor Summary | |
| public | AtomicStampedReference(V initialRef, int initialStamp)
Creates a new
AtomicStampedReference with the given
initial values. |
| Method Summary | |
| 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. | | 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. | | 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. | | public V | getReference()
Returns the current value of the reference. | | public int | getStamp()
Returns the current value of the stamp. | | public void | set(V newReference, int newStamp)
Unconditionally sets the value of both the reference and 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. |
| AtomicStampedReference | | public AtomicStampedReference(V initialRef, int initialStamp)(Code) | | Creates a new
AtomicStampedReference with the given
initial values.
Parameters:
initialRef - the initial reference
Parameters:
initialStamp - the initial stamp |
| attemptStamp | | public boolean attemptStamp(V expectedReference, int newStamp)(Code) | | 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
Parameters:
newStamp - the new value for the stamp true if successful |
| compareAndSet | | public boolean compareAndSet(V expectedReference, V newReference, int expectedStamp, int newStamp)(Code) | | 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
Parameters:
newReference - the new value for the reference
Parameters:
expectedStamp - the expected value of the stamp
Parameters:
newStamp - the new value for the stamp true if successful |
| get | | public V get(int[] stampHolder)(Code) | | 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. the current value of the reference |
| getReference | | public V getReference()(Code) | | Returns the current value of the reference.
the current value of the reference |
| getStamp | | public int getStamp()(Code) | | Returns the current value of the stamp.
the current value of the stamp |
| set | | public void set(V newReference, int newStamp)(Code) | | Unconditionally sets the value of both the reference and stamp.
Parameters:
newReference - the new value for the reference
Parameters:
newStamp - the new value for the stamp |
| weakCompareAndSet | | public boolean weakCompareAndSet(V expectedReference, V newReference, int expectedStamp, int newStamp)(Code) | | 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.
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
Parameters:
newReference - the new value for the reference
Parameters:
expectedStamp - the expected value of the stamp
Parameters:
newStamp - the new value for the stamp true if successful |
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