AtomicMarkableReference (Java Platform SE 6) (original) (raw)
java.util.concurrent.atomic
Class AtomicMarkableReference
java.lang.Object
java.util.concurrent.atomic.AtomicMarkableReference
Type Parameters:
V - The type of object referred to by this reference
public class AtomicMarkableReference
extends Object
An AtomicMarkableReference maintains an object reference along with a mark bit, that can be updated atomically.
Implementation note. This implementation maintains markable references by creating internal objects representing "boxed" [reference, boolean] pairs.
Since:
1.5
| Constructor Summary |
|---|
| [AtomicMarkableReference](../../../../java/util/concurrent/atomic/AtomicMarkableReference.html#AtomicMarkableReference%28V, boolean%29)(V initialRef, boolean initialMark) Creates a new AtomicMarkableReference with the given initial values. |
| Method Summary | |
|---|---|
| boolean | [attemptMark](../../../../java/util/concurrent/atomic/AtomicMarkableReference.html#attemptMark%28V, boolean%29)(V expectedReference, boolean newMark) Atomically sets the value of the mark to the given update value if the current reference is == to the expected reference. |
| boolean | [compareAndSet](../../../../java/util/concurrent/atomic/AtomicMarkableReference.html#compareAndSet%28V, V, boolean, boolean%29)(V expectedReference,V newReference, boolean expectedMark, boolean newMark) Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark. |
| V | get(boolean[] markHolder) Returns the current values of both the reference and the mark. |
| V | getReference() Returns the current value of the reference. |
| boolean | isMarked() Returns the current value of the mark. |
| void | [set](../../../../java/util/concurrent/atomic/AtomicMarkableReference.html#set%28V, boolean%29)(V newReference, boolean newMark) Unconditionally sets the value of both the reference and mark. |
| boolean | [weakCompareAndSet](../../../../java/util/concurrent/atomic/AtomicMarkableReference.html#weakCompareAndSet%28V, V, boolean, boolean%29)(V expectedReference,V newReference, boolean expectedMark, boolean newMark) Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark. |
| Methods inherited from class java.lang.Object |
|---|
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../../../java/lang/Object.html#wait%28long, int%29) |
| Constructor Detail |
|---|
AtomicMarkableReference
public AtomicMarkableReference(V initialRef, boolean initialMark)
Creates a new AtomicMarkableReference with the given initial values.
Parameters:
initialRef - the initial reference
initialMark - the initial mark
| Method Detail |
|---|
getReference
public V getReference()
Returns the current value of the reference.
Returns:
the current value of the reference
isMarked
public boolean isMarked()
Returns the current value of the mark.
Returns:
the current value of the mark
get
public V get(boolean[] markHolder)
Returns the current values of both the reference and the mark. Typical usage is boolean[1] holder; ref = v.get(holder); .
Parameters:
markHolder - an array of size of at least one. On return,markholder[0] will hold the value of the mark.
Returns:
the current value of the reference
weakCompareAndSet
public boolean weakCompareAndSet(V expectedReference, V newReference, boolean expectedMark, boolean newMark)
Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.
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
expectedMark - the expected value of the mark
newMark - the new value for the mark
Returns:
true if successful
compareAndSet
public boolean compareAndSet(V expectedReference, V newReference, boolean expectedMark, boolean newMark)
Atomically sets the value of both the reference and mark to the given update values if the current reference is == to the expected reference and the current mark is equal to the expected mark.
Parameters:
expectedReference - the expected value of the reference
newReference - the new value for the reference
expectedMark - the expected value of the mark
newMark - the new value for the mark
Returns:
true if successful
set
public void set(V newReference, boolean newMark)
Unconditionally sets the value of both the reference and mark.
Parameters:
newReference - the new value for the reference
newMark - the new value for the mark
attemptMark
public boolean attemptMark(V expectedReference, boolean newMark)
Atomically sets the value of the mark 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
newMark - the new value for the mark
Returns:
true if successful
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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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