- java.lang.Object
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- java.util.concurrent.atomic.AtomicStampedReference<V>
 
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- Type Parameters:
- V- The type of object referred to by this reference
 
 public class AtomicStampedReference<V> extends Object AnAtomicStampedReferencemaintains 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
 
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Constructor SummaryConstructors Constructor Description AtomicStampedReference(V initialRef, int initialStamp)Creates a newAtomicStampedReferencewith the given initial values.
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Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanattemptStamp(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.booleancompareAndSet(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.Vget(int[] stampHolder)Returns the current values of both the reference and the stamp.VgetReference()Returns the current value of the reference.intgetStamp()Returns the current value of the stamp.voidset(V newReference, int newStamp)Unconditionally sets the value of both the reference and stamp.booleanweakCompareAndSet(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.
 
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Constructor Detail- 
AtomicStampedReferencepublic AtomicStampedReference(V initialRef, int initialStamp) Creates a newAtomicStampedReferencewith the given initial values.- Parameters:
- initialRef- the initial reference
- initialStamp- the initial stamp
 
 
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Method Detail- 
getReferencepublic V getReference() Returns the current value of the reference.- Returns:
- the current value of the reference
 
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getStamppublic int getStamp() Returns the current value of the stamp.- Returns:
- the current value of the stamp
 
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getpublic V get(int[] stampHolder) Returns the current values of both the reference and the stamp. Typical usage isint[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
 
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weakCompareAndSetpublic 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:
- trueif successful
 
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compareAndSetpublic 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:
- trueif successful
 
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setpublic 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
 
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attemptStamppublic 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 (returnfalse) 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:
- trueif successful
 
 
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