added in API level 1

AtomicReference

public class AtomicReference
extends Object implements Serializable

java.lang.Object
   ↳ java.util.concurrent.atomic.AtomicReference<V>


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

Summary

Public constructors

AtomicReference(V initialValue)

Creates a new AtomicReference with the given initial value.

AtomicReference()

Creates a new AtomicReference with null initial value.

Public methods

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 methods

Public constructors

AtomicReference

added in API level 1
public AtomicReference (V initialValue)

Creates a new AtomicReference with the given initial value.

Parameters
initialValue V: the initial value

AtomicReference

added in API level 1
public AtomicReference ()

Creates a new AtomicReference with null initial value.

Public methods

accumulateAndGet

added in API level 24
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 V: the update value

accumulatorFunction BinaryOperator: a side-effect-free function of two arguments

Returns
V the updated value

compareAndSet

added in API level 1
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 V: the expected value

update V: the new value

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

get

added in API level 1
public final V get ()

Gets the current value.

Returns
V the current value

getAndAccumulate

added in API level 24
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 V: the update value

accumulatorFunction BinaryOperator: a side-effect-free function of two arguments

Returns
V the previous value

getAndSet

added in API level 1
public final V getAndSet (V newValue)

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

Parameters
newValue V: the new value

Returns
V the previous value

getAndUpdate

added in API level 24
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 UnaryOperator: a side-effect-free function

Returns
V the previous value

lazySet

added in API level 9
public final void lazySet (V newValue)

Eventually sets to the given value.

Parameters
newValue V: the new value

set

added in API level 1
public final void set (V newValue)

Sets to the given value.

Parameters
newValue V: the new value

toString

added in API level 1
public String toString ()

Returns the String representation of the current value.

Returns
String the String representation of the current value

updateAndGet

added in API level 24
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 UnaryOperator: a side-effect-free function

Returns
V the updated value

weakCompareAndSet

added in API level 1
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 V: the expected value

update V: the new value

Returns
boolean true if successful