T
- The type of the object holding the updatable fieldpublic abstract class AtomicIntegerFieldUpdater<T> extends Object
volatile int
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 only with respect to other invocations of compareAndSet
and set
on the same updater.
Object arguments for parameters of type T
that are not instances of the class passed to newUpdater(java.lang.Class<U>, java.lang.String)
will result in a ClassCastException
being thrown.
Modifier | Constructor | Description |
---|---|---|
protected |
Protected do-nothing constructor for use by subclasses. |
Modifier and Type | Method | Description |
---|---|---|
final int |
accumulateAndGet |
Atomically updates (with memory effects as specified by VarHandle.compareAndSet(java.lang.Object...) ) the field of the given object managed by this updater with the results of applying the given function to the current and given values, returning the updated value. |
int |
addAndGet |
Atomically adds the given value to the current value of the field of the given object managed by this updater. |
abstract boolean |
compareAndSet |
Atomically sets the field of the given object managed by this updater to the given updated value if the current value == the expected value. |
int |
decrementAndGet |
Atomically decrements by one the current value of the field of the given object managed by this updater. |
abstract int |
get |
Returns the current value held in the field of the given object managed by this updater. |
final int |
getAndAccumulate |
Atomically updates (with memory effects as specified by VarHandle.compareAndSet(java.lang.Object...) ) the field of the given object managed by this updater with the results of applying the given function to the current and given values, returning the previous value. |
int |
getAndAdd |
Atomically adds the given value to the current value of the field of the given object managed by this updater. |
int |
getAndDecrement |
Atomically decrements by one the current value of the field of the given object managed by this updater. |
int |
getAndIncrement |
Atomically increments by one the current value of the field of the given object managed by this updater. |
int |
getAndSet |
Atomically sets the field of the given object managed by this updater to the given value and returns the old value. |
final int |
getAndUpdate |
Atomically updates (with memory effects as specified by VarHandle.compareAndSet(java.lang.Object...) ) the field of the given object managed by this updater with the results of applying the given function, returning the previous value. |
int |
incrementAndGet |
Atomically increments by one the current value of the field of the given object managed by this updater. |
abstract void |
lazySet |
Eventually sets the field of the given object managed by this updater to the given updated value. |
static <U> AtomicIntegerFieldUpdater |
newUpdater |
Creates and returns an updater for objects with the given field. |
abstract void |
set |
Sets the field of the given object managed by this updater to the given updated value. |
final int |
updateAndGet |
Atomically updates (with memory effects as specified by VarHandle.compareAndSet(java.lang.Object...) ) the field of the given object managed by this updater with the results of applying the given function, returning the updated value. |
abstract boolean |
weakCompareAndSet |
Atomically sets the field of the given object managed by this updater to the given updated value if the current value == the expected value. |
protected AtomicIntegerFieldUpdater()
public static <U> AtomicIntegerFieldUpdater<U> newUpdater(Class<U> tclass, String fieldName)
U
- the type of instances of tclasstclass
- the class of the objects holding the fieldfieldName
- the name of the field to be updatedIllegalArgumentException
- if the field is not a volatile integer typeRuntimeException
- with a nested reflection-based exception if the class does not hold field or is the wrong type, or the field is inaccessible to the caller according to Java language access controlpublic abstract boolean compareAndSet(T obj, int expect, int update)
==
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.obj
- An object whose field to conditionally setexpect
- the expected valueupdate
- the new valuetrue
if successfulpublic abstract boolean weakCompareAndSet(T obj, int expect, int update)
==
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. This operation may fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet
.
obj
- An object whose field to conditionally setexpect
- the expected valueupdate
- the new valuetrue
if successfulpublic abstract void set(T obj, int newValue)
compareAndSet
.obj
- An object whose field to setnewValue
- the new valuepublic abstract void lazySet(T obj, int newValue)
obj
- An object whose field to setnewValue
- the new valuepublic abstract int get(T obj)
obj
- An object whose field to getpublic int getAndSet(T obj, int newValue)
obj
- An object whose field to get and setnewValue
- the new valuepublic int getAndIncrement(T obj)
obj
- An object whose field to get and setpublic int getAndDecrement(T obj)
obj
- An object whose field to get and setpublic int getAndAdd(T obj, int delta)
obj
- An object whose field to get and setdelta
- the value to addpublic int incrementAndGet(T obj)
obj
- An object whose field to get and setpublic int decrementAndGet(T obj)
obj
- An object whose field to get and setpublic int addAndGet(T obj, int delta)
obj
- An object whose field to get and setdelta
- the value to addpublic final int getAndUpdate(T obj, IntUnaryOperator updateFunction)
VarHandle.compareAndSet(java.lang.Object...)
) the field of the given object managed by this updater with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.obj
- An object whose field to get and setupdateFunction
- a side-effect-free functionpublic final int updateAndGet(T obj, IntUnaryOperator updateFunction)
VarHandle.compareAndSet(java.lang.Object...)
) the field of the given object managed by this updater with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.obj
- An object whose field to get and setupdateFunction
- a side-effect-free functionpublic final int getAndAccumulate(T obj, int x, IntBinaryOperator accumulatorFunction)
VarHandle.compareAndSet(java.lang.Object...)
) the field of the given object managed by this updater with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.obj
- An object whose field to get and setx
- the update valueaccumulatorFunction
- a side-effect-free function of two argumentspublic final int accumulateAndGet(T obj, int x, IntBinaryOperator accumulatorFunction)
VarHandle.compareAndSet(java.lang.Object...)
) the field of the given object managed by this updater with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.obj
- An object whose field to get and setx
- the update valueaccumulatorFunction
- a side-effect-free function of two arguments
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Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/concurrent/atomic/AtomicIntegerFieldUpdater.html