AtomicInteger
public
class
AtomicInteger
extends Number
implements
Serializable
| java.lang.Object | ||
| ↳ | java.lang.Number | |
| ↳ | java.util.concurrent.atomic.AtomicInteger | |
An int value that may be updated atomically. See the
java.util.concurrent.atomic package specification for
description of the properties of atomic variables. An
AtomicInteger is used in applications such as atomically
incremented counters, and cannot be used as a replacement for an
Integer. However, this class does extend
Number to allow uniform access by tools and utilities that
deal with numerically-based classes.
Summary
Public constructors | |
|---|---|
AtomicInteger(int initialValue)
Creates a new AtomicInteger with the given initial value. |
|
AtomicInteger()
Creates a new AtomicInteger with initial value |
|
Public methods | |
|---|---|
final
int
|
accumulateAndGet(int x, IntBinaryOperator accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value. |
final
int
|
addAndGet(int delta)
Atomically adds the given value to the current value. |
final
boolean
|
compareAndSet(int expect, int update)
Atomically sets the value to the given updated value
if the current value |
final
int
|
decrementAndGet()
Atomically decrements by one the current value. |
double
|
doubleValue()
Returns the value of this |
float
|
floatValue()
Returns the value of this |
final
int
|
get()
Gets the current value. |
final
int
|
getAndAccumulate(int x, IntBinaryOperator accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value. |
final
int
|
getAndAdd(int delta)
Atomically adds the given value to the current value. |
final
int
|
getAndDecrement()
Atomically decrements by one the current value. |
final
int
|
getAndIncrement()
Atomically increments by one the current value. |
final
int
|
getAndSet(int newValue)
Atomically sets to the given value and returns the old value. |
final
int
|
getAndUpdate(IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the previous value. |
final
int
|
incrementAndGet()
Atomically increments by one the current value. |
int
|
intValue()
Returns the value of this |
final
void
|
lazySet(int newValue)
Eventually sets to the given value. |
long
|
longValue()
Returns the value of this |
final
void
|
set(int newValue)
Sets to the given value. |
String
|
toString()
Returns the String representation of the current value. |
final
int
|
updateAndGet(IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the updated value. |
final
boolean
|
weakCompareAndSet(int expect, int update)
Atomically sets the value to the given updated value
if the current value |
Inherited methods | |
|---|---|
Public constructors
AtomicInteger
public AtomicInteger (int initialValue)
Creates a new AtomicInteger with the given initial value.
| Parameters | |
|---|---|
initialValue |
int: the initial value |
AtomicInteger
public AtomicInteger ()
Creates a new AtomicInteger with initial value 0.
Public methods
accumulateAndGet
public final int accumulateAndGet (int x,
IntBinaryOperator accumulatorFunction)
Atomically updates the current value 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 | |
|---|---|
x |
int: the update value |
accumulatorFunction |
IntBinaryOperator: a side-effect-free function of two arguments |
| Returns | |
|---|---|
int |
the updated value |
addAndGet
public final int addAndGet (int delta)
Atomically adds the given value to the current value.
| Parameters | |
|---|---|
delta |
int: the value to add |
| Returns | |
|---|---|
int |
the updated value |
compareAndSet
public final boolean compareAndSet (int expect,
int update)
Atomically sets the value to the given updated value
if the current value == the expected value.
| Parameters | |
|---|---|
expect |
int: the expected value |
update |
int: the new value |
| Returns | |
|---|---|
boolean |
true if successful. False return indicates that
the actual value was not equal to the expected value. |
decrementAndGet
public final int decrementAndGet ()
Atomically decrements by one the current value.
| Returns | |
|---|---|
int |
the updated value |
doubleValue
public double doubleValue ()
Returns the value of this AtomicInteger as a double
after a widening primitive conversion.
| Returns | |
|---|---|
double |
the numeric value represented by this object after conversion
to type double. |
floatValue
public float floatValue ()
Returns the value of this AtomicInteger as a float
after a widening primitive conversion.
| Returns | |
|---|---|
float |
the numeric value represented by this object after conversion
to type float. |
get
public final int get ()
Gets the current value.
| Returns | |
|---|---|
int |
the current value |
getAndAccumulate
public final int getAndAccumulate (int x,
IntBinaryOperator accumulatorFunction)
Atomically updates the current value 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 | |
|---|---|
x |
int: the update value |
accumulatorFunction |
IntBinaryOperator: a side-effect-free function of two arguments |
| Returns | |
|---|---|
int |
the previous value |
getAndAdd
public final int getAndAdd (int delta)
Atomically adds the given value to the current value.
| Parameters | |
|---|---|
delta |
int: the value to add |
| Returns | |
|---|---|
int |
the previous value |
getAndDecrement
public final int getAndDecrement ()
Atomically decrements by one the current value.
| Returns | |
|---|---|
int |
the previous value |
getAndIncrement
public final int getAndIncrement ()
Atomically increments by one the current value.
| Returns | |
|---|---|
int |
the previous value |
getAndSet
public final int getAndSet (int newValue)
Atomically sets to the given value and returns the old value.
| Parameters | |
|---|---|
newValue |
int: the new value |
| Returns | |
|---|---|
int |
the previous value |
getAndUpdate
public final int getAndUpdate (IntUnaryOperator updateFunction)
Atomically updates the current value 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 | |
|---|---|
updateFunction |
IntUnaryOperator: a side-effect-free function |
| Returns | |
|---|---|
int |
the previous value |
incrementAndGet
public final int incrementAndGet ()
Atomically increments by one the current value.
| Returns | |
|---|---|
int |
the updated value |
intValue
public int intValue ()
Returns the value of this AtomicInteger as an int.
Equivalent to get().
| Returns | |
|---|---|
int |
the numeric value represented by this object after conversion
to type int. |
lazySet
public final void lazySet (int newValue)
Eventually sets to the given value.
| Parameters | |
|---|---|
newValue |
int: the new value |
longValue
public long longValue ()
Returns the value of this AtomicInteger as a long
after a widening primitive conversion.
| Returns | |
|---|---|
long |
the numeric value represented by this object after conversion
to type long. |
set
public final void set (int newValue)
Sets to the given value.
| Parameters | |
|---|---|
newValue |
int: the new value |
toString
public String toString ()
Returns the String representation of the current value.
| Returns | |
|---|---|
String |
the String representation of the current value |
updateAndGet
public final int updateAndGet (IntUnaryOperator updateFunction)
Atomically updates the current value 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 | |
|---|---|
updateFunction |
IntUnaryOperator: a side-effect-free function |
| Returns | |
|---|---|
int |
the updated value |
weakCompareAndSet
public final boolean weakCompareAndSet (int expect,
int update)
Atomically sets the value to the given updated value
if the current value == the expected value.
May fail
spuriously and does not provide ordering guarantees, so is
only rarely an appropriate alternative to compareAndSet.
| Parameters | |
|---|---|
expect |
int: the expected value |
update |
int: the new value |
| Returns | |
|---|---|
boolean |
true if successful |