AtomicReference

public class AtomicReference extends Object
implements Serializable

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

Public Constructor Summary

AtomicReference(V initialValue)
Creates a new AtomicReference with the given initial value.
AtomicReference()
Creates a new AtomicReference with null initial value.

Public Method Summary

final V
accumulateAndGet(V x, BinaryOperator<V> accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value.
final boolean
compareAndSet(V expect, V update)
Atomically sets the value to the given updated value if the current value == the expected value.
final V
get()
Gets the current value.
final V
getAndAccumulate(V x, BinaryOperator<V> accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value.
final V
getAndSet(V newValue)
Atomically sets to the given value and returns the old value.
final V
getAndUpdate(UnaryOperator<V> updateFunction)
Atomically updates the current value with the results of applying the given function, returning the previous value.
final void
lazySet(V newValue)
Eventually sets to the given value.
final void
set(V newValue)
Sets to the given value.
String
toString()
Returns the String representation of the current value.
final V
updateAndGet(UnaryOperator<V> updateFunction)
Atomically updates the current value with the results of applying the given function, returning the updated value.
final boolean
weakCompareAndSet(V expect, V update)
Atomically sets the value to the given updated value if the current value == the expected value.

Inherited Method Summary

Public Constructors

public AtomicReference (V initialValue)

Creates a new AtomicReference with the given initial value.

Parameters
initialValue the initial value

public AtomicReference ()

Creates a new AtomicReference with null initial value.

Public Methods

public final V accumulateAndGet (V x, BinaryOperator<V> accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters
x the update value
accumulatorFunction a side-effect-free function of two arguments
Returns
  • the updated value

public final boolean compareAndSet (V expect, V update)

Atomically sets the value to the given updated value if the current value == 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.

public final V get ()

Gets the current value.

Returns
  • the current value

public final V getAndAccumulate (V x, BinaryOperator<V> accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters
x the update value
accumulatorFunction a side-effect-free function of two arguments
Returns
  • the previous value

public final V getAndSet (V newValue)

Atomically sets to the given value and returns the old value.

Parameters
newValue the new value
Returns
  • the previous value

public final V getAndUpdate (UnaryOperator<V> updateFunction)

Atomically updates the current value with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters
updateFunction a side-effect-free function
Returns
  • the previous value

public final void lazySet (V newValue)

Eventually sets to the given value.

Parameters
newValue the new value

public final void set (V newValue)

Sets to the given value.

Parameters
newValue the new value

public String toString ()

Returns the String representation of the current value.

Returns
  • the String representation of the current value

public final V updateAndGet (UnaryOperator<V> updateFunction)

Atomically updates the current value with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters
updateFunction a side-effect-free function
Returns
  • the updated value

public final boolean weakCompareAndSet (V expect, V update)

Atomically sets the value to the given updated value if the current value == the expected value.

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

Parameters
expect the expected value
update the new value
Returns
  • true if successful