edu.emory.mathcs.backport.java.util.concurrent.atomic
Class AtomicReferenceArray

java.lang.Object
  edu.emory.mathcs.backport.java.util.concurrent.atomic.AtomicReferenceArray

All Implemented Interfaces:

java.io.Serializable

public class AtomicReferenceArray

extends java.lang.Object

implements java.io.Serializable

An array of object references in which elements may be updated atomically. See the edu.emory.mathcs.backport.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

AtomicReferenceArray(int length)
Creates a new AtomicReferenceArray of given length.

AtomicReferenceArray(java.lang.Object[] array)
Creates a new AtomicReferenceArray with the same length as, and all elements copied from, the given array.

Method Summary

boolean	compareAndSet(int i, java.lang.Object expect, java.lang.Object update) Atomically sets the element at position to the given updated value if the current value the expected value.
java.lang.Object	get(int i) Gets the current value at position .
java.lang.Object	getAndSet(int i, java.lang.Object newValue) Atomically sets the element at position to the given value and returns the old value.
void	lazySet(int i, java.lang.Object newValue) Eventually sets the element at position to the given value.
int	length() Returns the length of the array.
void	set(int i, java.lang.Object newValue) Sets the element at position to the given value.
java.lang.String	toString() Returns the String representation of the current values of array.
boolean	weakCompareAndSet(int i, java.lang.Object expect, java.lang.Object update) Atomically sets the element at position 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 given length.

Parameters:

length - the length of the array

AtomicReferenceArray

public AtomicReferenceArray(java.lang.Object[] 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:

java.lang.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 java.lang.Object get(int i)

Gets the current value at position .

Parameters:

i - the index

Returns:

the current value

set

public final void set(int i,
                      java.lang.Object newValue)

Sets the element at position to the given value.

Parameters:

i - the index

newValue - the new value

lazySet

public final void lazySet(int i,
                          java.lang.Object newValue)

Eventually sets the element at position to the given value.

Parameters:

i - the index

newValue - the new value

Since:

1.6

getAndSet

public final java.lang.Object getAndSet(int i,
                                        java.lang.Object newValue)

Atomically sets the element at position 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,
                                   java.lang.Object expect,
                                   java.lang.Object update)

Atomically sets the element at position 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,
                                       java.lang.Object expect,
                                       java.lang.Object update)

Atomically sets the element at position 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 .

Parameters:

i - the index

expect - the expected value

update - the new value

Returns:

true if successful.

toString

public java.lang.String toString()

Returns the String representation of the current values of array.

Returns:

the String representation of the current values of array.