Package Summary  Overview Summary

class:AtomicIntegerFieldUpdater [NONE]
Type Parameters:
T - The type of the object holding the updatable field
public abstract class AtomicIntegerFieldUpdater<T>extends Object
A reflection-based utility that enables atomic updates to designated 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.

Since:
1.5

constructor:AtomicIntegerFieldUpdater() [NONE]

  • AtomicIntegerFieldUpdater

    protected AtomicIntegerFieldUpdater()
    Protected do-nothing constructor for use by subclasses.

method:newUpdater(java.lang.Class,java.lang.String) [NONE]

  • newUpdater

    public static  <U> AtomicIntegerFieldUpdater<U> newUpdater (Class<U> tclass, String fieldName)
    Creates and returns an updater for objects with the given field. The Class argument is needed to check that reflective types and generic types match.
    Type Parameters:
    U - the type of instances of tclass
    Parameters:
    tclass - the class of the objects holding the field
    fieldName - the name of the field to be updated
    Returns:
    the updater
    Throws:
    IllegalArgumentException - if the field is not a volatile integer type
    RuntimeException - 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 control

    • method:compareAndSet(T,int,int) [NONE]

    compareAndSet

    public abstract  boolean compareAndSet (T obj, int expect, int update)
    Atomically sets 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
    Returns:
    true if successful

    method:weakCompareAndSet(T,int,int) [NONE]

    weakCompareAndSet

    public abstract  boolean weakCompareAndSet (T obj, int expect, int update)
    Atomically sets 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.

    This operation may fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

    Parameters:
    obj - An object whose field to conditionally set
    expect - the expected value
    update - the new value
    Returns:
    true if successful

    method:set(T,int) [NONE]

    set

    public abstract  void set (T obj, int newValue)
    Sets the field of the given object managed by this updater to the given updated value. 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

    method:lazySet(T,int) [NONE]

    lazySet

    public abstract  void lazySet (T obj, int newValue)
    Eventually sets the field of the given object managed by this updater to the given updated value.
    Parameters:
    obj - An object whose field to set
    newValue - the new value
    Since:
    1.6

    method:get(T) [NONE]

    get

    public abstract  int get (T obj)
    Returns the current value held in the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get
    Returns:
    the current value

    method:getAndSet(T,int) [NONE]

    getAndSet

    public int getAndSet (T obj, int newValue)
    Atomically sets the field of the given object managed by this updater to the given value and returns the old value.
    Parameters:
    obj - An object whose field to get and set
    newValue - the new value
    Returns:
    the previous value

    method:getAndIncrement(T) [NONE]

    getAndIncrement

    public int getAndIncrement (T obj)
    Atomically increments by one the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    Returns:
    the previous value

    method:getAndDecrement(T) [NONE]

    getAndDecrement

    public int getAndDecrement (T obj)
    Atomically decrements by one the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    Returns:
    the previous value

    method:getAndAdd(T,int) [NONE]

    getAndAdd

    public int getAndAdd (T obj, int delta)
    Atomically adds the given value to the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    delta - the value to add
    Returns:
    the previous value

    method:incrementAndGet(T) [NONE]

    incrementAndGet

    public int incrementAndGet (T obj)
    Atomically increments by one the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    Returns:
    the updated value

    method:decrementAndGet(T) [NONE]

    decrementAndGet

    public int decrementAndGet (T obj)
    Atomically decrements by one the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    Returns:
    the updated value

    method:addAndGet(T,int) [NONE]

    addAndGet

    public int addAndGet (T obj, int delta)
    Atomically adds the given value to the current value of the field of the given object managed by this updater.
    Parameters:
    obj - An object whose field to get and set
    delta - the value to add
    Returns:
    the updated value

    method:getAndUpdate(T,java.util.function.IntUnaryOperator) [NONE]

    getAndUpdate

    public final  int getAndUpdate (T obj, IntUnaryOperator updateFunction)
    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. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.
    Parameters:
    obj - An object whose field to get and set
    updateFunction - a side-effect-free function
    Returns:
    the previous value
    Since:
    1.8

    method:updateAndGet(T,java.util.function.IntUnaryOperator) [NONE]

    updateAndGet

    public final  int updateAndGet (T obj, IntUnaryOperator updateFunction)
    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. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.
    Parameters:
    obj - An object whose field to get and set
    updateFunction - a side-effect-free function
    Returns:
    the updated value
    Since:
    1.8

    method:getAndAccumulate(T,int,java.util.function.IntBinaryOperator) [NONE]

    getAndAccumulate

    public final  int getAndAccumulate (T obj, int x, IntBinaryOperator accumulatorFunction)
    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. 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.
    Parameters:
    obj - An object whose field to get and set
    x - the update value
    accumulatorFunction - a side-effect-free function of two arguments
    Returns:
    the previous value
    Since:
    1.8

    method:accumulateAndGet(T,int,java.util.function.IntBinaryOperator) [NONE]

    accumulateAndGet

    public final  int accumulateAndGet (T obj, int x, IntBinaryOperator accumulatorFunction)
    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. 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.
    Parameters:
    obj - An object whose field to get and set
    x - the update value
    accumulatorFunction - a side-effect-free function of two arguments
    Returns:
    the updated value
    Since:
    1.8

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