AtomicLongFieldUpdater (Java Platform SE 8 )

java.lang.Object
- java.util.concurrent.atomic.AtomicLongFieldUpdater<T>

Type Parameters:

T - The type of the object holding the updatable field
```
public abstract class AtomicLongFieldUpdater<T>
extends Object
```
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 only with respect to other invocations of compareAndSet and set on the same updater.

Since:

1.5

Constructor Summary

Constructors
Modifier Constructor and Description

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

Constructors
Modifier	Constructor and Description
`protected`	`AtomicLongFieldUpdater()` Protected do-nothing constructor for use by subclasses.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`long`	`accumulateAndGet(T obj, long x, LongBinaryOperator accumulatorFunction)` Atomically updates 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.
`long`	`addAndGet(T obj, long delta)` Atomically adds the given value to the current value of the field of the given object managed by this updater.
`abstract boolean`	`compareAndSet(T obj, long expect, long 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.
`long`	`decrementAndGet(T obj)` Atomically decrements by one the current value of the field of the given object managed by this updater.
`abstract long`	`get(T obj)` Gets the current value held in the field of the given object managed by this updater.
`long`	`getAndAccumulate(T obj, long x, LongBinaryOperator accumulatorFunction)` Atomically updates 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.
`long`	`getAndAdd(T obj, long delta)` Atomically adds the given value to the current value of the field of the given object managed by this updater.
`long`	`getAndDecrement(T obj)` Atomically decrements by one the current value of the field of the given object managed by this updater.
`long`	`getAndIncrement(T obj)` Atomically increments by one the current value of the field of the given object managed by this updater.
`long`	`getAndSet(T obj, long newValue)` Atomically sets the field of the given object managed by this updater to the given value and returns the old value.
`long`	`getAndUpdate(T obj, LongUnaryOperator updateFunction)` Atomically updates the field of the given object managed by this updater with the results of applying the given function, returning the previous value.
`long`	`incrementAndGet(T obj)` Atomically increments by one the current value of the field of the given object managed by this updater.
`abstract void`	`lazySet(T obj, long newValue)` Eventually sets the field of the given object managed by this updater to the given updated value.
`static <U> AtomicLongFieldUpdater<U>`	`newUpdater(Class<U> tclass, String fieldName)` Creates and returns an updater for objects with the given field.
`abstract void`	`set(T obj, long newValue)` Sets the field of the given object managed by this updater to the given updated value.
`long`	`updateAndGet(T obj, LongUnaryOperator updateFunction)` Atomically updates 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(T obj, long expect, long 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.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - AtomicLongFieldUpdater
```
protected AtomicLongFieldUpdater()
```
    Protected do-nothing constructor for use by subclasses.
- Method Detail
  - newUpdater
```
public static <U> AtomicLongFieldUpdater<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 long 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
  - compareAndSet
```
public abstract boolean compareAndSet(T obj,
                                      long expect,
                                      long 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
    
    Throws:
    
    ClassCastException - if obj is not an instance of the class possessing the field established in the constructor
  - weakCompareAndSet
```
public abstract boolean weakCompareAndSet(T obj,
                                          long expect,
                                          long 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.
    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
    
    Throws:
    
    ClassCastException - if obj is not an instance of the class possessing the field established in the constructor
  - set
```
public abstract void set(T obj,
                         long 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
  - lazySet
```
public abstract void lazySet(T obj,
                             long 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
  - get
```
public abstract long get(T obj)
```
    Gets 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
  - getAndSet
```
public long getAndSet(T obj,
                      long 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
  - getAndIncrement
```
public long 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
  - getAndDecrement
```
public long 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
  - getAndAdd
```
public long getAndAdd(T obj,
                      long 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
  - incrementAndGet
```
public long 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
  - decrementAndGet
```
public long 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
  - addAndGet
```
public long addAndGet(T obj,
                      long 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
  - getAndUpdate
```
public final long getAndUpdate(T obj,
                               LongUnaryOperator updateFunction)
```
    Atomically updates 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
  - updateAndGet
```
public final long updateAndGet(T obj,
                               LongUnaryOperator updateFunction)
```
    Atomically updates 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
  - getAndAccumulate
```
public final long getAndAccumulate(T obj,
                                   long x,
                                   LongBinaryOperator accumulatorFunction)
```
    Atomically updates 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
  - accumulateAndGet
```
public final long accumulateAndGet(T obj,
                                   long x,
                                   LongBinaryOperator accumulatorFunction)
```
    Atomically updates 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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Class AtomicLongFieldUpdater<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

AtomicLongFieldUpdater

Method Detail

newUpdater

compareAndSet

weakCompareAndSet

set

lazySet

get

getAndSet

getAndIncrement

getAndDecrement

getAndAdd

incrementAndGet

decrementAndGet

addAndGet

getAndUpdate

updateAndGet

getAndAccumulate

accumulateAndGet