Class 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
See Also:
Serialized Form

Constructors

Constructor and Description
AtomicReference()

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

Creates a new AtomicReference with the given initial value.

Methods

Modifier and Type Method and Description
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.
boolean compareAndSet(V expect, V update)

Atomically sets the value to the given updated value if the current value == the expected value.
V get()

Gets the current value.
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.
V getAndSet(V newValue)

Atomically sets to the given value and returns the old value.
V getAndUpdate(UnaryOperator<V> updateFunction)

Atomically updates the current value with the results of applying the given function, returning the previous value.
void lazySet(V newValue)

Eventually sets to the given value.
void set(V newValue)

Sets to the given value.
String toString()

Returns the String representation of the current value.
V updateAndGet(UnaryOperator<V> updateFunction)

Atomically updates the current value with the results of applying the given function, returning the updated value.
boolean weakCompareAndSet(V expect, V update)

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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)

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

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

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https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicReference.html