java.util.concurrent.atomic

Class AtomicIntegerArray

java.lang.Object

java.util.concurrent.atomic.AtomicIntegerArray

All Implemented Interfaces:

Serializable

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.

Since:

1.5

Author:

Doug Lea

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
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.

Method Summary

Modifier and Type	Method and Description
int	addAndGet(int i, int delta) Atomically adds the given value to the element at index i.
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.
int	decrementAndGet(int i) Atomically decrements by one the element at index i.
int	get(int i) Gets the current value at position i.
int	getAndAdd(int i, int delta) Atomically adds the given value to the element at index i.
int	getAndDecrement(int i) Atomically decrements by one the element at index i.
int	getAndIncrement(int i) Atomically increments by one the element at index i.
int	getAndSet(int i, int newValue) Atomically sets the element at position i to the given value and returns the old value.
int	incrementAndGet(int i) Atomically increments by one the element at index i.
void	lazySet(int i, int newValue) Eventually sets the element at position i to the given value.
int	length() Returns the length of the array.
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.
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.

Methods inherited from class java.lang.Object

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

Constructor Detail

AtomicIntegerArray

public AtomicIntegerArray(int length)

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

Parameters:

length - the length of the array

AtomicIntegerArray

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

Method Detail

length

public final int length()

Returns the length of the array.

Returns:

the length of the array

get

public final int get(int i)

Gets the current value at position i.

Parameters:

i - the index

Returns:

the current value

set

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

lazySet

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

Since:

1.6

getAndSet

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

compareAndSet

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.

weakCompareAndSet

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.

getAndIncrement

public final int getAndIncrement(int i)

Atomically increments by one the element at index i.

Parameters:

i - the index

Returns:

the previous value

getAndDecrement

public final int getAndDecrement(int i)

Atomically decrements by one the element at index i.

Parameters:

i - the index

Returns:

the previous value

getAndAdd

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

incrementAndGet

public final int incrementAndGet(int i)

Atomically increments by one the element at index i.

Parameters:

i - the index

Returns:

the updated value

decrementAndGet

public final int decrementAndGet(int i)

Atomically decrements by one the element at index i.

Parameters:

i - the index

Returns:

the updated value

addAndGet

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

toString

public String toString()

Returns the String representation of the current values of array.

Overrides:

toString in class Object

Returns:

the String representation of the current values of array