java.util.concurrent.atomic
Class AtomicIntegerFieldUpdater<T>

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by 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 sample code for java.lang.Object definition code for java.lang.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 and volatile semantics only with respect to other invocations of compareAndSet and set.

Since:
1.5

Constructor Summary
protected AtomicIntegerFieldUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.AtomicIntegerFieldUpdater() definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.AtomicIntegerFieldUpdater() ()
          Protected do-nothing constructor for use by subclasses.
 
Method Summary
 int addAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.addAndGet(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.addAndGet(T, int) (T obj, int delta)
          Atomically add the given value to current value.
abstract  boolean compareAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.compareAndSet(T, int, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.compareAndSet(T, int, int) (T obj, int expect, int 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.
 int decrementAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.decrementAndGet(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.decrementAndGet(T) (T obj)
          Atomically decrement by one the current value.
abstract  int get sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.get(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.get(T) (T obj)
          Get the current value held in the field by the given object.
 int getAndAdd sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndAdd(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndAdd(T, int) (T obj, int delta)
          Atomically add the given value to current value.
 int getAndDecrement sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndDecrement(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndDecrement(T) (T obj)
          Atomically decrement by one the current value.
 int getAndIncrement sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndIncrement(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndIncrement(T) (T obj)
          Atomically increment by one the current value.
 int getAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndSet(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndSet(T, int) (T obj, int newValue)
          Set to the given value and return the old value.
 int incrementAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.incrementAndGet(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.incrementAndGet(T) (T obj)
          Atomically increment by one the current value.
static
<U> AtomicIntegerFieldUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater <U>
newUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.newUpdater(java.lang.Class, java.lang.String) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.newUpdater(java.lang.Class, java.lang.String) (Class sample code for java.lang.Class definition code for java.lang.Class <U> tclass, String sample code for java.lang.String definition code for java.lang.String  fieldName)
          Creates an updater for objects with the given field.
abstract  void set sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.set(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.set(T, int) (T obj, int newValue)
          Set the field of the given object managed by this updater.
abstract  boolean weakCompareAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.weakCompareAndSet(T, int, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.weakCompareAndSet(T, int, int) (T obj, int expect, int 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.
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , toString sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Constructor Detail

AtomicIntegerFieldUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater() definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater()

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

Method Detail

newUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.<U>newUpdater(java.lang.Class<U>, java.lang.String) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.<U>newUpdater(java.lang.Class<U>, java.lang.String)

public static <U> AtomicIntegerFieldUpdater sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater <U> newUpdater(Class sample code for java.lang.Class definition code for java.lang.Class <U> tclass,
                                                          String sample code for java.lang.String definition code for java.lang.String  fieldName)
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.
Returns:
the updater
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if the field is not a volatile integer type.
RuntimeException sample code for java.lang.RuntimeException definition code for java.lang.RuntimeException - with a nested reflection-based exception if the class does not hold field or is the wrong type.

compareAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.compareAndSet(T, int, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.compareAndSet(T, int, int)

public abstract boolean compareAndSet(T obj,
                                      int expect,
                                      int 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
Returns:
true if successful.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if obj is not an instance of the class possessing the field established in the constructor.

weakCompareAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.weakCompareAndSet(T, int, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.weakCompareAndSet(T, int, int)

public abstract boolean weakCompareAndSet(T obj,
                                          int expect,
                                          int 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
Returns:
true if successful.
Throws:
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException - if obj is not an instance of the class possessing the field established in the constructor.

set sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.set(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.set(T, int)

public abstract void set(T obj,
                         int 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

get sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.get(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.get(T)

public abstract int get(T obj)
Get the current value held in the field by the given object.

Parameters:
obj - An object whose field to get
Returns:
the current value

getAndSet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndSet(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndSet(T, int)

public int getAndSet(T obj,
                     int 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
Returns:
the previous value

getAndIncrement sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndIncrement(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndIncrement(T)

public int getAndIncrement(T obj)
Atomically increment by one the current value.

Parameters:
obj - An object whose field to get and set
Returns:
the previous value;

getAndDecrement sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndDecrement(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndDecrement(T)

public int getAndDecrement(T obj)
Atomically decrement by one the current value.

Parameters:
obj - An object whose field to get and set
Returns:
the previous value;

getAndAdd sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndAdd(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.getAndAdd(T, int)

public int getAndAdd(T obj,
                     int delta)
Atomically add the given value to current value.

Parameters:
obj - An object whose field to get and set
delta - the value to add
Returns:
the previous value;

incrementAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.incrementAndGet(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.incrementAndGet(T)

public int incrementAndGet(T obj)
Atomically increment by one the current value.

Parameters:
obj - An object whose field to get and set
Returns:
the updated value;

decrementAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.decrementAndGet(T) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.decrementAndGet(T)

public int decrementAndGet(T obj)
Atomically decrement by one the current value.

Parameters:
obj - An object whose field to get and set
Returns:
the updated value;

addAndGet sample code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.addAndGet(T, int) definition code for java.util.concurrent.atomic.AtomicIntegerFieldUpdater.addAndGet(T, int)

public int addAndGet(T obj,
                     int delta)
Atomically add the given value to current value.

Parameters:
obj - An object whose field to get and set
delta - the value to add
Returns:
the updated value;