AtomicIntegerArray

public class AtomicIntegerArray extends Object
implements Serializable

An int array 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

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

Public Method Summary

final int	accumulateAndGet(int i, int x, IntBinaryOperator 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 int	addAndGet(int i, int delta) Atomically adds the given value to the element at index i.
final boolean	compareAndSet(int i, int expect, int update) Atomically sets the element at position i to the given updated value if the current value == the expected value.
final int	decrementAndGet(int i) Atomically decrements by one the element at index i.
final int	get(int i) Gets the current value at position i.
final int	getAndAccumulate(int i, int x, IntBinaryOperator 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 int	getAndAdd(int i, int delta) Atomically adds the given value to the element at index i.
final int	getAndDecrement(int i) Atomically decrements by one the element at index i.
final int	getAndIncrement(int i) Atomically increments by one the element at index i.
final int	getAndSet(int i, int newValue) Atomically sets the element at position i to the given value and returns the old value.
final int	getAndUpdate(int i, IntUnaryOperator updateFunction) Atomically updates the element at index i with the results of applying the given function, returning the previous value.
final int	incrementAndGet(int i) Atomically increments by one the element at index i.
final void	lazySet(int i, int 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, int newValue) Sets the element at position i to the given value.
String	toString() Returns the String representation of the current values of array.
final int	updateAndGet(int i, IntUnaryOperator 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, int expect, int 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 AtomicIntegerArray (int length)

Creates a new AtomicIntegerArray of the given length, with all elements initially zero.

Parameters

length	the length of the array

public AtomicIntegerArray (int[] array)

Creates a new AtomicIntegerArray 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 int accumulateAndGet (int i, int x, IntBinaryOperator 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 int addAndGet (int i, int delta)

Atomically adds the given value to the element at index i.

Parameters

i	the index
delta	the value to add

Returns

• the updated value

public final boolean compareAndSet (int i, int expect, int 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 int decrementAndGet (int i)

Atomically decrements by one the element at index i.

Parameters

i	the index

Returns

• the updated value

public final int get (int i)

Gets the current value at position i.

Parameters

i	the index

Returns

• the current value

public final int getAndAccumulate (int i, int x, IntBinaryOperator 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 int getAndAdd (int i, int delta)

Atomically adds the given value to the element at index i.

Parameters

i	the index
delta	the value to add

Returns

• the previous value

public final int getAndDecrement (int i)

Atomically decrements by one the element at index i.

Parameters

i	the index

Returns

• the previous value

public final int getAndIncrement (int i)

Atomically increments by one the element at index i.

Parameters

i	the index

Returns

• the previous value

public final int getAndSet (int i, int 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 int getAndUpdate (int i, IntUnaryOperator 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 int incrementAndGet (int i)

Atomically increments by one the element at index i.

Parameters

i	the index

Returns

• the updated value

public final void lazySet (int i, int 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, int 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 int updateAndGet (int i, IntUnaryOperator 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, int expect, int 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