AtomicIntegerFieldUpdater (Java Platform SE 7 b138)

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

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.

Since:

1.5

Constructor Summary

Constructors
Modifier Constructor and Description

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

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

Method Summary

Methods
Modifier and Type	Method and Description
`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.
`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.
`int`	`decrementAndGet(T obj)` Atomically decrements by one the current value of the field of the given object managed by this updater.
`abstract int`	`get(T obj)` Gets the current value held in the field of the given object managed by this updater.
`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.
`int`	`getAndDecrement(T obj)` Atomically decrements by one the current value of the field of the given object managed by this updater.
`int`	`getAndIncrement(T obj)` Atomically increments by one the current value of the field of the given object managed by this updater.
`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.
`int`	`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, int newValue)` Eventually sets the field of the given object managed by this updater to the given updated value.
`static <U> AtomicIntegerFieldUpdater<U>`	`newUpdater(Class<U> tclass, String fieldName)` Creates and returns an updater for objects with the given field.
`abstract void`	`set(T obj, int newValue)` Sets the field of the given object managed by this updater to the given updated value.
`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.

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

- Constructor Detail
  - AtomicIntegerFieldUpdater
```
protected AtomicIntegerFieldUpdater()
```
    Protected do-nothing constructor for use by subclasses.
- Method Detail
  - 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.
    
    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
  - 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
    
    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,
                        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.
    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,
       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
  - 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
  - get
```
public abstract int 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 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
  - 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
  - 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
  - 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
  - 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
  - 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
  - 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

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DRAFT ea-b138

Class AtomicIntegerFieldUpdater<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

AtomicIntegerFieldUpdater

Method Detail

newUpdater

compareAndSet

weakCompareAndSet

set

lazySet

get

getAndSet

getAndIncrement

getAndDecrement

getAndAdd

incrementAndGet

decrementAndGet

addAndGet