java.util.concurrent.atomic

Class AtomicReference<V>

Implemented Interfaces:
Serializable

public class AtomicReference<V>
extends Object
implements Serializable

An object reference that may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables.
Since:
1.5
See Also:
Serialized Form

Constructor Summary

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

Method Summary

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

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

AtomicReference

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

AtomicReference

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

Method Details

compareAndSet

public final boolean compareAndSet(V expect,
                                   V 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 V get()
Gets the current value.
Returns:
the current value

getAndSet

public final V getAndSet(V 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(V newValue)
Eventually sets to the given value.
Parameters:
newValue - the new value
Since:
1.6

set

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

toString

public String toString()
Returns the String representation of the current value.
Overrides:
toString in interface Object
Returns:
the String representation of the current value.

weakCompareAndSet

public final boolean weakCompareAndSet(V expect,
                                       V update)
Atomically sets the value 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:
expect - the expected value
update - the new value
Returns:
true if successful.