java.util.concurrent.atomic
Class AtomicReference<V>

java.lang.Object
  java.util.concurrent.atomic.AtomicReference

All Implemented Interfaces:

java.io.Serializable

public class AtomicReference<V>

extends java.lang.Object

implements java.io.Serializable

An AtomicReference maintains an object reference that is updated atomically. See the package specification for description of the properties of atomic variables.

Since:

1.5

Author:

Doug Lea

See Also:

Serialized Form

Constructor Summary

AtomicReference()
Create a new AtomicReference with null initial value.

AtomicReference(V initialValue)
Create a new AtomicReference with the given initial value.

Method Summary

boolean	compareAndSet(V expect, V update) Atomically set the value to the given updated value if the current value == the expected value.
V	get() Get the current value.
V	getAndSet(V newValue) Set to the given value and return the old value.
void	set(V newValue) Set to the given value.
boolean	weakCompareAndSet(V expect, V update) Atomically set the value 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, toString, wait, wait, wait

Constructor Detail

AtomicReference

public AtomicReference(V initialValue)

Create a new AtomicReference with the given initial value.

Parameters:

initialValue - the initial value

AtomicReference

public AtomicReference()

Create a new AtomicReference with null initial value.

Method Detail

get

public final V get()

Get the current value.

Returns:

the current value

set

public final void set(V newValue)

Set to the given value.

Parameters:

newValue - the new value

compareAndSet

public final boolean compareAndSet(V expect,
                                   V update)

Atomically set the value to the given updated value if the current value == the expected value.

Parameters:

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(V expect,
                                       V update)

Atomically set the value to the given updated value if the current value == the expected value. May fail spuriously.

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful.

getAndSet

public final V getAndSet(V newValue)

Set to the given value and return the old value.

Parameters:

newValue - the new value

Returns:

the previous value