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

Class AtomicReference

Implemented Interfaces:
java.io.Serializable

public class AtomicReference
extends java.lang.Object
implements java.io.Serializable

An object reference that 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

AtomicReference()
Creates a new AtomicReference with null initial value.
AtomicReference(Object initialValue)
Creates a new AtomicReference with the given initial value.

Method Summary

boolean
compareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value == the expected value.
Object
get()
Gets the current value.
Object
getAndSet(Object newValue)
Atomically sets to the given value and returns the old value.
void
lazySet(Object newValue)
Eventually sets to the given value.
void
set(Object newValue)
Sets to the given value.
String
toString()
Returns the String representation of the current value.
boolean
weakCompareAndSet(Object expect, Object update)
Atomically sets the value to the given updated value if the current value == the expected value.

Constructor Details

AtomicReference

public AtomicReference()
Creates a new AtomicReference with null initial value.

AtomicReference

public AtomicReference(Object initialValue)
Creates a new AtomicReference with the given initial value.
Parameters:
initialValue - the initial value

Method Details

compareAndSet

public final boolean compareAndSet(Object expect,
                                   Object update)
Atomically sets 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.

get

public final Object get()
Gets the current value.
Returns:
the current value

getAndSet

public final Object getAndSet(Object newValue)
Atomically sets to the given value and returns the old value.
Parameters:
newValue - the new value
Returns:
the previous value

lazySet

public final void lazySet(Object newValue)
Eventually sets to the given value.
Parameters:
newValue - the new value
Since:
1.6

set

public final void set(Object newValue)
Sets to the given value.
Parameters:
newValue - the new value

toString

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

weakCompareAndSet

public final boolean weakCompareAndSet(Object expect,
                                       Object update)
Atomically sets 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.