AtomicStampedReference (Java Platform SE 7 b138)

java.lang.Object
- java.util.concurrent.atomic.AtomicStampedReference<V>

Type Parameters:
V - The type of object referred to by this reference
```
public class AtomicStampedReference<V>
extends Object
```
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

Constructor Summary

Constructors
Constructor and Description

AtomicStampedReference(V initialRef, int initialStamp)
Creates a new AtomicStampedReference with the given initial values.

Constructors
Constructor and Description
`AtomicStampedReference(V initialRef, int initialStamp)` Creates a new `AtomicStampedReference` with the given initial values.

Method Summary

Methods
Modifier and Type	Method and Description
`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.
`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.
`V`	`get(int[] stampHolder)` Returns the current values of both the reference and the stamp.
`V`	`getReference()` Returns the current value of the reference.
`int`	`getStamp()` Returns the current value of the stamp.
`void`	`set(V newReference, int newStamp)` Unconditionally sets the value of both the reference and stamp.
`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.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - AtomicStampedReference
```
public AtomicStampedReference(V initialRef,
                      int initialStamp)
```
    Creates a new AtomicStampedReference with the given initial values.
    
    Parameters:
    initialRef - the initial reference
    initialStamp - the initial stamp
- Method Detail
  - getReference
```
public V getReference()
```
    Returns the current value of the reference.
    
    Returns:
    the current value of the reference
  - getStamp
```
public int getStamp()
```
    Returns the current value of the stamp.
    
    Returns:
    the current value of the stamp
  - get
```
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
  - weakCompareAndSet
```
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.
    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
    expectedStamp - the expected value of the stamp
    newStamp - the new value for the stamp
    
    Returns:
    true if successful
  - compareAndSet
```
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
    
    Returns:
    true if successful
  - set
```
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
  - attemptStamp
```
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
    
    Returns:
    true if successful

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.
DRAFT ea-b138

Class AtomicStampedReference<V>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

AtomicStampedReference

Method Detail

getReference

getStamp

get

weakCompareAndSet

compareAndSet

set

attemptStamp