edu.emory.mathcs.backport.java.util.concurrent.atomic

Class AtomicReference

public class AtomicReference extends Object implements Serializable

An object reference that may be updated atomically. See the edu.emory.mathcs.backport.java.util.concurrent.atomic package specification for description of the properties of atomic variables.

Since: 1.5

Author: Doug Lea

Constructor Summary
AtomicReference(Object initialValue)
Creates a new AtomicReference with the given initial value.
AtomicReference()
Creates a new AtomicReference with null initial value.
Method Summary
booleancompareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.
Objectget()
Gets the current value.
ObjectgetAndSet(Object newValue)
Atomically sets to the given value and returns the old value.
voidlazySet(Object newValue)
Eventually sets to the given value.
voidset(Object newValue)
Sets to the given value.
StringtoString()
Returns the String representation of the current value.
booleanweakCompareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.

Constructor Detail

AtomicReference

public AtomicReference(Object initialValue)
Creates a new AtomicReference with the given initial value.

Parameters: initialValue the initial value

AtomicReference

public AtomicReference()
Creates a new AtomicReference with null initial value.

Method Detail

compareAndSet

public final boolean compareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.

Parameters: expect the expected value update the new value

Returns: true if successful. False return indicates that the actual value was not equal to the expected value.

get

public final Object get()
Gets the current value.

Returns: the current value

getAndSet

public final Object getAndSet(Object newValue)
Atomically sets to the given value and returns the old value.

Parameters: newValue the new value

Returns: the previous value

lazySet

public final void lazySet(Object newValue)
Eventually sets to the given value.

Parameters: newValue the new value

Since: 1.6

set

public final void set(Object newValue)
Sets to the given value.

Parameters: newValue the new value

toString

public String toString()
Returns the String representation of the current value.

Returns: the String representation of the current value.

weakCompareAndSet

public final boolean weakCompareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.

May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to {@code compareAndSet}.

Parameters: expect the expected value update the new value

Returns: true if successful.