AtomicReferenceArray

public class AtomicReferenceArray extends Object
implements Serializable

An array of object references in which elements may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables.

Public Constructor Summary

	AtomicReferenceArray(int length) Creates a new AtomicReferenceArray of the given length, with all elements initially null.
	AtomicReferenceArray(E[] array) Creates a new AtomicReferenceArray with the same length as, and all elements copied from, the given array.

Public Method Summary

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

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public AtomicReferenceArray (int length)

Creates a new AtomicReferenceArray of the given length, with all elements initially null.

Parameters

length	the length of the array

public AtomicReferenceArray (E[] array)

Creates a new AtomicReferenceArray with the same length as, and all elements copied from, the given array.

Parameters

array	the array to copy elements from

Throws

NullPointerException	if array is null

Public Methods

public final E accumulateAndGet (int i, E x, BinaryOperator<E> accumulatorFunction)

Atomically updates the element at index i 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 at index i as its first argument, and the given update as the second argument.

Parameters

i	the index
x	the update value
accumulatorFunction	a side-effect-free function of two arguments

Returns

• the updated value

public final boolean compareAndSet (int i, E expect, E update)

Atomically sets the element at position i to the given updated value if the current value == the expected value.

Parameters

i	the index
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 E get (int i)

Gets the current value at position i.

Parameters

i	the index

Returns

• the current value

public final E getAndAccumulate (int i, E x, BinaryOperator<E> accumulatorFunction)

Atomically updates the element at index i 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 at index i as its first argument, and the given update as the second argument.

Parameters

i	the index
x	the update value
accumulatorFunction	a side-effect-free function of two arguments

Returns

• the previous value

public final E getAndSet (int i, E newValue)

Atomically sets the element at position i to the given value and returns the old value.

Parameters

i	the index
newValue	the new value

Returns

• the previous value

public final E getAndUpdate (int i, UnaryOperator<E> updateFunction)

Atomically updates the element at index i 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

i	the index
updateFunction	a side-effect-free function

Returns

• the previous value

public final void lazySet (int i, E newValue)

Eventually sets the element at position i to the given value.

Parameters

i	the index
newValue	the new value

public final int length ()

Returns the length of the array.

Returns

• the length of the array

public final void set (int i, E newValue)

Sets the element at position i to the given value.

Parameters

i	the index
newValue	the new value

public String toString ()

Returns the String representation of the current values of array.

Returns

• the String representation of the current values of array

public final E updateAndGet (int i, UnaryOperator<E> updateFunction)

Atomically updates the element at index i 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

i	the index
updateFunction	a side-effect-free function

Returns

• the updated value

public final boolean weakCompareAndSet (int i, E expect, E update)

Atomically sets the element at position i 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

i	the index
expect	the expected value
update	the new value

Returns

• true if successful