java.util.concurrent.atomic

Class AtomicReferenceArray<E>

java.lang.Object

java.util.concurrent.atomic.AtomicReferenceArray<E>

Type Parameters:

E - The base class of elements held in this array

All Implemented Interfaces:

Serializable

public class AtomicReferenceArray<E>
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.

Since:

1.5

Author:

Doug Lea

See Also:

Serialized Form

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
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.
E	get(int i) Gets the current value at position i.
E	getAndSet(int i, E newValue) Atomically sets the element at position i to the given value and returns the old value.
void	lazySet(int i, E newValue) Eventually sets the element at position i to the given value.
int	length() Returns the length of the array.
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.
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.

Methods inherited from class java.lang.Object

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

Constructor Detail

AtomicReferenceArray

public AtomicReferenceArray(int length)

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

Parameters:

length - the length of the array

AtomicReferenceArray

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

Method Detail

length

public final int length()

Returns the length of the array.

Returns:

the length of the array

get

public final E 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,
                      E 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,
                          E 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 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

compareAndSet

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.

weakCompareAndSet

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.

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