Class AtomicLong

• java.lang.Object
• • java.lang.Number
  • • java.util.concurrent.atomic.AtomicLong

All Implemented Interfaces:

Serializable

public class AtomicLong
extends Number
implements Serializable

A long value that may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables. An AtomicLong is used in applications such as atomically incremented sequence numbers, and cannot be used as a replacement for a Long. However, this class does extend Number to allow uniform access by tools and utilities that deal with numerically-based classes.

Since:

1.5

Constructors

AtomicLong

public AtomicLong(long initialValue)

Creates a new AtomicLong with the given initial value.

Parameters:

initialValue - the initial value

AtomicLong

public AtomicLong()

Creates a new AtomicLong with initial value 0.

Methods

get

public final long get()

Gets the current value.

Returns:

the current value

set

public final void set(long newValue)

Sets to the given value.

Parameters:

newValue - the new value

lazySet

public final void lazySet(long newValue)

Eventually sets to the given value.

Parameters:

newValue - the new value

Since:

1.6

getAndSet

public final long getAndSet(long 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(long expect,
                                   long 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(long expect,
                                       long update)

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful

getAndIncrement

public final long getAndIncrement()

Atomically increments by one the current value.

Returns:

the previous value

getAndDecrement

public final long getAndDecrement()

Atomically decrements by one the current value.

Returns:

the previous value

getAndAdd

public final long getAndAdd(long delta)

Atomically adds the given value to the current value.

Parameters:

delta - the value to add

Returns:

the previous value

incrementAndGet

public final long incrementAndGet()

Atomically increments by one the current value.

Returns:

the updated value

decrementAndGet

public final long decrementAndGet()

Atomically decrements by one the current value.

Returns:

the updated value

addAndGet

public final long addAndGet(long delta)

Atomically adds the given value to the current value.

Parameters:

delta - the value to add

Returns:

the updated value

getAndUpdate

public final long getAndUpdate(LongUnaryOperator 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 long updateAndGet(LongUnaryOperator 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 long getAndAccumulate(long x,
                                   LongBinaryOperator 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 long accumulateAndGet(long x,
                                   LongBinaryOperator 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 AtomicLong as an int after a narrowing primitive conversion.

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 AtomicLong as a long.

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 AtomicLong 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 AtomicLong 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.