added in API level 1

AtomicReferenceArray

public class AtomicReferenceArray
extends Object implements Serializable

java.lang.Object
   ↳ java.util.concurrent.atomic.AtomicReferenceArray<E>


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.

Summary

Public constructors

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 methods

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 methods

Public constructors

AtomicReferenceArray

added in API level 1
public AtomicReferenceArray (int length)

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

Parameters
length int: the length of the array

AtomicReferenceArray

added in API level 1
public AtomicReferenceArray (E[] array)

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

Parameters
array E: the array to copy elements from

Throws
NullPointerException if array is null

Public methods

accumulateAndGet

added in API level 24
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 int: the index

x E: the update value

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

Returns
E the updated value

compareAndSet

added in API level 1
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 int: the index

expect E: the expected value

update E: 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 E get (int i)

Gets the current value at position i.

Parameters
i int: the index

Returns
E the current value

getAndAccumulate

added in API level 24
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 int: the index

x E: the update value

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

Returns
E the previous value

getAndSet

added in API level 1
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 int: the index

newValue E: the new value

Returns
E the previous value

getAndUpdate

added in API level 24
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 int: the index

updateFunction UnaryOperator: a side-effect-free function

Returns
E the previous value

lazySet

added in API level 9
public final void lazySet (int i, 
                E newValue)

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

Parameters
i int: the index

newValue E: the new value

length

added in API level 1
public final int length ()

Returns the length of the array.

Returns
int the length of the array

set

added in API level 1
public final void set (int i, 
                E newValue)

Sets the element at position i to the given value.

Parameters
i int: the index

newValue E: the new value

toString

added in API level 1
public String toString ()

Returns the String representation of the current values of array.

Returns
String the String representation of the current values of array

updateAndGet

added in API level 24
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 int: the index

updateFunction UnaryOperator: a side-effect-free function

Returns
E the updated value

weakCompareAndSet

added in API level 1
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 int: the index

expect E: the expected value

update E: the new value

Returns
boolean true if successful