Class AtomicReference<V>

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

Type Parameters:

V - The type of object referred to by this reference

All Implemented Interfaces:

Serializable

public class AtomicReference<V>
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.

Since:

1.5

Constructors

AtomicReference

public AtomicReference(V 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.

Methods

get

public final V get()

Gets the current value.

Returns:

the current value

set

public final void set(V newValue)

Sets to the given value.

Parameters:

newValue - the new value

lazySet

public final void lazySet(V newValue)

Eventually sets to the given value.

Parameters:

newValue - the new value

Since:

1.6

compareAndSet

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.

weakCompareAndSet

public final boolean weakCompareAndSet(V expect,
                                       V update)

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful

getAndSet

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

getAndUpdate

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

Since:

1.8

updateAndGet

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

Since:

1.8

getAndAccumulate

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

Since:

1.8

accumulateAndGet

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

Since:

1.8

toString

public String toString()

Returns the String representation of the current value.

Overrides:

toString in class Object

Returns:

the String representation of the current value