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

Class AtomicReferenceArray

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.
Author:
Doug Lea
Since:
1.5
See Also:
Serialized Form

Constructor Summary

AtomicReferenceArray(Object[] 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 given length.

Method Summary

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

Constructor Details

AtomicReferenceArray

public AtomicReferenceArray(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

AtomicReferenceArray

public AtomicReferenceArray(int length)
Creates a new AtomicReferenceArray of given length.
Parameters:
length - the length of the array

Method Details

compareAndSet

public final boolean compareAndSet(int i,
                                   Object expect,
                                   Object 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.

get

public final Object get(int i)
Gets the current value at position i.
Parameters:
i - the index
Returns:
the current value

getAndSet

public final Object getAndSet(int i,
                              Object 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

lazySet

public final void lazySet(int i,
                          Object newValue)
Eventually sets the element at position i to the given value.
Parameters:
i - the index
newValue - the new value
Since:
1.6

length

public final int length()
Returns the length of the array.
Returns:
the length of the array

set

public final void set(int i,
                      Object newValue)
Sets the element at position i to the given value.
Parameters:
i - the index
newValue - the new value

toString

public String toString()
Returns the String representation of the current values of array.
Returns:
the String representation of the current values of array.

weakCompareAndSet

public final boolean weakCompareAndSet(int i,
                                       Object expect,
                                       Object update)
Atomically sets the element at position i to the given updated value if the current value == the expected value. May fail spuriously.
Parameters:
i - the index
expect - the expected value
update - the new value
Returns:
true if successful.