File	Doc	Category	Size	Date	Package
AtomicStampedReference.java	API Doc	Java SE 6 API	6463	Tue Jun 10 00:25:58 BST 2008	java.util.concurrent.atomic

AtomicStampedReference

• java.lang.Object

Fields Summary
private final AtomicReference	atomicRef

Constructors Summary
public AtomicStampedReference(V initialRef, int initialStamp) Creates a new {@code AtomicStampedReference} with the given initial values. param initialRef the initial reference param initialStamp the initial stamp atomicRef = new AtomicReference<ReferenceIntegerPair<V>> (new ReferenceIntegerPair<V>(initialRef, initialStamp));

Methods 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 {@code ==} to the expected reference. Any given invocation of this operation may fail (return {@code 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. param expectedReference the expected value of the reference param newStamp the new value for the stamp return true if successful ReferenceIntegerPair<V> current = atomicRef.get(); return expectedReference == current.reference && (newStamp == current.integer || atomicRef.compareAndSet(current, new ReferenceIntegerPair<V>(expectedReference, newStamp)));
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 {@code ==} to the expected reference and the current stamp is equal to the expected stamp. param expectedReference the expected value of the reference param newReference the new value for the reference param expectedStamp the expected value of the stamp param newStamp the new value for the stamp return true if successful ReferenceIntegerPair<V> current = atomicRef.get(); return expectedReference == current.reference && expectedStamp == current.integer && ((newReference == current.reference && newStamp == current.integer) || atomicRef.compareAndSet(current, new ReferenceIntegerPair<V>(newReference, newStamp)));
public V	get(int[] stampHolder) Returns the current values of both the reference and the stamp. Typical usage is {@code int[1] holder; ref = v.get(holder); }. param stampHolder an array of size of at least one. On return, {@code stampholder[0]} will hold the value of the stamp. return the current value of the reference ReferenceIntegerPair<V> p = atomicRef.get(); stampHolder[0] = p.integer; return p.reference;
public V	getReference() Returns the current value of the reference. return the current value of the reference return atomicRef.get().reference;
public int	getStamp() Returns the current value of the stamp. return the current value of the stamp return atomicRef.get().integer;
public void	set(V newReference, int newStamp) Unconditionally sets the value of both the reference and stamp. param newReference the new value for the reference param newStamp the new value for the stamp ReferenceIntegerPair<V> current = atomicRef.get(); if (newReference != current.reference || newStamp != current.integer) atomicRef.set(new ReferenceIntegerPair<V>(newReference, newStamp));
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 {@code ==} 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 {@code compareAndSet}. param expectedReference the expected value of the reference param newReference the new value for the reference param expectedStamp the expected value of the stamp param newStamp the new value for the stamp return true if successful ReferenceIntegerPair<V> current = atomicRef.get(); return expectedReference == current.reference && expectedStamp == current.integer && ((newReference == current.reference && newStamp == current.integer) || atomicRef.weakCompareAndSet(current, new ReferenceIntegerPair<V>(newReference, newStamp)));