java.util.concurrent.atomic.AtomicLongFieldUpdater<T>
A reflection-based utility that enables atomic updates to
designated volatile long fields of designated classes.
This class is designed for use in atomic data structures in which
several fields of the same node are independently subject to atomic
updates.
Note that the guarantees of the compareAndSet method
in this class are weaker than in other atomic classes. Because this
class cannot ensure that all uses of the field are appropriate for
purposes of atomic access, it can guarantee atomicity and volatile
semantics only with respect to other invocations of
compareAndSet and set.
Summary
Protected Constructors
Public Methods
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
Protected Constructors
protected
AtomicLongFieldUpdater()
Protected do-nothing constructor for use by subclasses.
Public Methods
public
long
addAndGet(T obj, long delta)
Atomically add the given value to current value.
Parameters
obj
| An object whose field to get and set |
delta
| the value to add |
public
abstract
boolean
compareAndSet(T obj, long expect, long update)
Atomically set the value of the field of the given object managed
by this Updater to the given updated value if the current value
== the expected value. This method is guaranteed to be
atomic with respect to other calls to
compareAndSet and
set, but not necessarily with respect to other
changes in the field.
Parameters
obj
| An object whose field to conditionally set |
expect
| the expected value |
update
| the new value |
Throws
ClassCastException
| if obj is not an instance
of the class possessing the field established in the constructor.
|
public
long
decrementAndGet(T obj)
Atomically decrement by one the current value.
Parameters
obj
| An object whose field to get and set |
public
abstract
long
get(T obj)
Get the current value held in the field by the given object.
Parameters
obj
| An object whose field to get |
public
long
getAndAdd(T obj, long delta)
Atomically add the given value to current value.
Parameters
obj
| An object whose field to get and set |
delta
| the value to add |
public
long
getAndDecrement(T obj)
Atomically decrement by one the current value.
Parameters
obj
| An object whose field to get and set |
public
long
getAndIncrement(T obj)
Atomically increment by one the current value.
Parameters
obj
| An object whose field to get and set |
public
long
getAndSet(T obj, long newValue)
Set to the given value and return the old value.
Parameters
obj
| An object whose field to get and set |
newValue
| the new value |
public
long
incrementAndGet(T obj)
Atomically increment by one the current value.
Parameters
obj
| An object whose field to get and set |
Creates an updater for objects with the given field. The Class
argument is needed to check that reflective types and generic
types match.
Parameters
tclass
| the class of the objects holding the field |
fieldName
| the name of the field to be updated. |
public
abstract
void
set(T obj, long newValue)
Set the field of the given object managed by this updater. This
operation is guaranteed to act as a volatile store with respect
to subsequent invocations of
compareAndSet.
Parameters
obj
| An object whose field to set |
newValue
| the new value
|
public
abstract
boolean
weakCompareAndSet(T obj, long expect, long update)
Atomically set the value of the field of the given object managed
by this Updater to the given updated value if the current value
== the expected value. This method is guaranteed to be
atomic with respect to other calls to
compareAndSet and
set, but not necessarily with respect to other
changes in the field, and may fail spuriously.
Parameters
obj
| An object whose field to conditionally set |
expect
| the expected value |
update
| the new value |
Throws
ClassCastException
| if obj is not an instance
of the class possessing the field established in the constructor.
|