Class AtomicInteger

java.lang.Object
- java.lang.Number
- - java.util.concurrent.atomic.AtomicInteger

All Implemented Interfaces:: Serializable

public class AtomicInteger
extends Number
implements Serializable

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.

Since:: 1.5
See Also:: Serialized Form

Constructors

Constructor and Description
`AtomicInteger()` Creates a new AtomicInteger with initial value `0`.
`AtomicInteger(int initialValue)` Creates a new AtomicInteger with the given initial value.

Methods

Modifier and Type	Method and Description
`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.
`int`	`addAndGet(int delta)` Atomically adds the given value to the current value.
`boolean`	`compareAndSet(int expect, int update)` Atomically sets the value to the given updated value if the current value `==` the expected value.
`int`	`decrementAndGet()` Atomically decrements by one the current value.
`double`	`doubleValue()` Returns the value of this `AtomicInteger` as a `double` after a widening primitive conversion.
`float`	`floatValue()` Returns the value of this `AtomicInteger` as a `float` after a widening primitive conversion.
`int`	`get()` Gets the current value.
`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.
`int`	`getAndAdd(int delta)` Atomically adds the given value to the current value.
`int`	`getAndDecrement()` Atomically decrements by one the current value.
`int`	`getAndIncrement()` Atomically increments by one the current value.
`int`	`getAndSet(int newValue)` Atomically sets to the given value and returns the old value.
`int`	`getAndUpdate(IntUnaryOperator updateFunction)` Atomically updates the current value with the results of applying the given function, returning the previous value.
`int`	`incrementAndGet()` Atomically increments by one the current value.
`int`	`intValue()` Returns the value of this `AtomicInteger` as an `int`.
`void`	`lazySet(int newValue)` Eventually sets to the given value.
`long`	`longValue()` Returns the value of this `AtomicInteger` as a `long` after a widening primitive conversion.
`void`	`set(int newValue)` Sets to the given value.
`String`	`toString()` Returns the String representation of the current value.
`int`	`updateAndGet(IntUnaryOperator updateFunction)` Atomically updates the current value with the results of applying the given function, returning the updated value.
`boolean`	`weakCompareAndSet(int expect, int update)` Atomically sets the value to the given updated value if the current value `==` the expected value.

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructors

AtomicInteger

public AtomicInteger(int initialValue)

Creates a new AtomicInteger with the given initial value.

Parameters:: initialValue - the initial value

AtomicInteger

public AtomicInteger()

Creates a new AtomicInteger with initial value 0.

Methods

get

public final int get()

Gets the current value.

Returns:: the current value

set

public final void set(int newValue)

Sets to the given value.

Parameters:: newValue - the new value

lazySet

public final void lazySet(int newValue)

Eventually sets to the given value.

Parameters:: newValue - the new value
Since:: 1.6

getAndSet

public final int getAndSet(int newValue)

Atomically sets to the given value and returns the old value.

Parameters:: newValue - the new value
Returns:: the previous 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 - the expected value; update - the new value
Returns:: true if successful. False return indicates that the actual value was not equal to the expected 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 - the expected value; update - the new value
Returns:: true if successful

getAndIncrement

public final int getAndIncrement()

Atomically increments by one the current value.

Returns:: the previous value

getAndDecrement

public final int getAndDecrement()

Atomically decrements by one the current value.

Returns:: the previous value

getAndAdd

public final int getAndAdd(int delta)

Atomically adds the given value to the current value.

Parameters:: delta - the value to add
Returns:: the previous value

incrementAndGet

public final int incrementAndGet()

Atomically increments by one the current value.

Returns:: the updated value

decrementAndGet

public final int decrementAndGet()

Atomically decrements by one the current value.

Returns:: the updated value

addAndGet

public final int addAndGet(int delta)

Atomically adds the given value to the current value.

Parameters:: delta - the value to add
Returns:: the updated 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 - a side-effect-free function
Returns:: the previous value
Since:: 1.8

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 - a side-effect-free function
Returns:: the updated value
Since:: 1.8

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 - the update value; accumulatorFunction - a side-effect-free function of two arguments
Returns:: the previous value
Since:: 1.8

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 - the update value; accumulatorFunction - a side-effect-free function of two arguments
Returns:: the updated value
Since:: 1.8

toString

public String toString()

Returns the String representation of the current value.

Overrides:: toString in class Object
Returns:: the String representation of the current value

intValue

public int intValue()

Returns the value of this AtomicInteger as an int.

Specified by:: intValue in class Number
Returns:: the numeric value represented by this object after conversion to type int.

longValue

public long longValue()

Returns the value of this AtomicInteger as a long after a widening primitive conversion.

Specified by:: longValue in class Number
Returns:: the numeric value represented by this object after conversion to type long.

floatValue

public float floatValue()

Returns the value of this AtomicInteger as a float after a widening primitive conversion.

Specified by:: floatValue in class Number
Returns:: the numeric value represented by this object after conversion to type float.

doubleValue

public double doubleValue()

Returns the value of this AtomicInteger as a double after a widening primitive conversion.

Specified by:: doubleValue in class Number
Returns:: the numeric value represented by this object after conversion to type double.

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https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicInteger.html