Guava: Google Core Libraries for Java 32.1.2-jre · com.google.common.util.concurrent.AtomicDouble

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

This class compares primitive double values in methods such as compareAndSet by comparing their bitwise representation using Double#doubleToRawLongBits, which differs from both the primitive double == operator and from Double#equals, as if implemented by:

static boolean bitEquals(double x, double y) {
  long xBits = Double.doubleToRawLongBits(x);
  long yBits = Double.doubleToRawLongBits(y);
  return xBits == yBits;
}

It is possible to write a more scalable updater, at the cost of giving up strict atomicity. See for example DoubleAdder.

Field Summary

Modifier and Type	Field and Description
private static final long	serialVersionUID Hides java.lang.Number.serialVersionUID.
private static final AtomicLongFieldUpdater<AtomicDouble>	updater
private transient volatile long	value

Constructor Summary

Access	Constructor and Description
public	AtomicDouble(double the initial value initialValue) Creates a new `AtomicDouble` with the given initial value.
public	AtomicDouble() Creates a new `AtomicDouble` with initial value `0.0`.

Method Summary

Modifier and Type	Method and Description
public final double	Returns: the updated value accumulateAndGet(double the update value x, DoubleBinaryOperator the accumulator function accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values.
public final double	Returns: the updated value addAndGet(double the value to add delta) Atomically adds the given value to the current value.
public final boolean	Returns: `true` if successful. False return indicates that the actual value was not bitwise equal to the expected value. compareAndSet(double the expected value expect, double the new value update) Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value.
public double	doubleValue() Implements abstract java.lang.Number.doubleValue. Returns the value of this `AtomicDouble` as a `double`.
public float	floatValue() Implements abstract java.lang.Number.floatValue. Returns the value of this `AtomicDouble` as a `float` after a narrowing primitive conversion.
public final double	Returns: the current value get() Gets the current value.
public final double	Returns: the previous value getAndAccumulate(double the update value x, DoubleBinaryOperator the accumulator function accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values.
public final double	Returns: the previous value getAndAdd(double the value to add delta) Atomically adds the given value to the current value.
public final double	Returns: the previous value getAndSet(double the new value newValue) Atomically sets to the given value and returns the old value.
public final double	Returns: the previous value getAndUpdate(DoubleUnaryOperator the update function updateFunction) Atomically updates the current value with the results of applying the given function.
public int	intValue() Implements abstract java.lang.Number.intValue. Returns the value of this `AtomicDouble` as an `int` after a narrowing primitive conversion.
public final void	lazySet(double the new value newValue) Eventually sets to the given value.
public long	longValue() Implements abstract java.lang.Number.longValue. Returns the value of this `AtomicDouble` as a `long` after a narrowing primitive conversion.
private void	readObject(ObjectInputStream s) Reconstitutes the instance from a stream (that is, deserializes it).
public final void	set(double the new value newValue) Sets to the given value.
public String	Returns: the String representation of the current value toString() Overrides java.lang.Object.toString. Returns the String representation of the current value.
public final double	Returns: the updated value updateAndGet(DoubleUnaryOperator the update function updateFunction) Atomically updates the current value with the results of applying the given function.
public final boolean	Returns: `true` if successful weakCompareAndSet(double the expected value expect, double the new value update) Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value.
private void	writeObject(ObjectOutputStream s) Saves the state to a stream (that is, serializes it).

Inherited from java.lang.Number:: byteValue shortValue

Field Detail

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.lang.Number.serialVersionUID.

updater	back to summary
private static final AtomicLongFieldUpdater<AtomicDouble> updater

value	back to summary
private transient volatile long value

Constructor Detail

AtomicDouble back to summary

AtomicDouble	back to summary
public AtomicDouble(double initialValue) Creates a new `AtomicDouble` with the given initial value. Parameters initialValue:double the initial value

public AtomicDouble(double initialValue)

Creates a new AtomicDouble with the given initial value.

Parameters

initialValue:double: the initial value

AtomicDouble	back to summary
public AtomicDouble() Creates a new `AtomicDouble` with initial value `0.0`.

Method Detail

accumulateAndGet	back to summary
public final double accumulateAndGet(double x, DoubleBinaryOperator accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values. Parameters x:double the update value accumulatorFunction:DoubleBinaryOperator the accumulator function Returns:double the updated value Annotations @CanIgnoreReturnValue Since 31.1

accumulateAndGet

back to summary

public final double accumulateAndGet(double x, DoubleBinaryOperator accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values.

Parameters

x:double: the update value
accumulatorFunction:DoubleBinaryOperator: the accumulator function

Returns:double

the updated value

Annotations

@CanIgnoreReturnValue

Since

31.1

addAndGet	back to summary
public final double addAndGet(double delta) Atomically adds the given value to the current value. Parameters delta:double the value to add Returns:double the updated value Annotations @CanIgnoreReturnValue

addAndGet

back to summary

public final double addAndGet(double delta)

Atomically adds the given value to the current value.

Parameters

delta:double: the value to add

Returns:double

the updated value

Annotations

@CanIgnoreReturnValue

compareAndSet back to summary

compareAndSet	back to summary
public final boolean compareAndSet(double expect, double update) Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value. Parameters expect:double the expected value update:double the new value Returns:boolean `true` if successful. False return indicates that the actual value was not bitwise equal to the expected value.

public final boolean compareAndSet(double expect, double update)

Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value.

Parameters

expect:double: the expected value
update:double: the new value

Returns:boolean

true if successful. False return indicates that the actual value was not bitwise equal to the expected value.

doubleValue back to summary

doubleValue	back to summary
public double doubleValue() Implements abstract java.lang.Number.doubleValue. Returns the value of this `AtomicDouble` as a `double`. Returns:double Doc from java.lang.Number.doubleValue. the numeric value represented by this object after conversion to type `double`. Annotations @Override

public double doubleValue()

Implements abstract java.lang.Number.doubleValue.

Returns the value of this AtomicDouble as a double.

Returns:double

Doc from java.lang.Number.doubleValue.

the numeric value represented by this object after conversion to type double.

Annotations

@Override

floatValue back to summary

floatValue	back to summary
public float floatValue() Implements abstract java.lang.Number.floatValue. Returns the value of this `AtomicDouble` as a `float` after a narrowing primitive conversion. Returns:float Doc from java.lang.Number.floatValue. the numeric value represented by this object after conversion to type `float`. Annotations @Override

public float floatValue()

Implements abstract java.lang.Number.floatValue.

Returns the value of this AtomicDouble as a float after a narrowing primitive conversion.

Returns:float

Doc from java.lang.Number.floatValue.

the numeric value represented by this object after conversion to type float.

Annotations

@Override

get	back to summary
public final double get() Gets the current value. Returns:double the current value

get

back to summary

public final double get()

Gets the current value.

Returns:double: the current value

getAndAccumulate	back to summary
public final double getAndAccumulate(double x, DoubleBinaryOperator accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values. Parameters x:double the update value accumulatorFunction:DoubleBinaryOperator the accumulator function Returns:double the previous value Annotations @CanIgnoreReturnValue Since 31.1

getAndAccumulate

back to summary

public final double getAndAccumulate(double x, DoubleBinaryOperator accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values.

Parameters

x:double: the update value
accumulatorFunction:DoubleBinaryOperator: the accumulator function

Returns:double

the previous value

Annotations

@CanIgnoreReturnValue

Since

31.1

getAndAdd	back to summary
public final double getAndAdd(double delta) Atomically adds the given value to the current value. Parameters delta:double the value to add Returns:double the previous value Annotations @CanIgnoreReturnValue

getAndAdd

back to summary

public final double getAndAdd(double delta)

Atomically adds the given value to the current value.

Parameters

delta:double: the value to add

Returns:double

the previous value

Annotations

@CanIgnoreReturnValue

getAndSet	back to summary
public final double getAndSet(double newValue) Atomically sets to the given value and returns the old value. Parameters newValue:double the new value Returns:double the previous value

getAndSet

back to summary

public final double getAndSet(double newValue)

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

Parameters

newValue:double: the new value

Returns:double

the previous value

getAndUpdate	back to summary
public final double getAndUpdate(DoubleUnaryOperator updateFunction) Atomically updates the current value with the results of applying the given function. Parameters updateFunction:DoubleUnaryOperator the update function Returns:double the previous value Annotations @CanIgnoreReturnValue Since 31.1

getAndUpdate

back to summary

public final double getAndUpdate(DoubleUnaryOperator updateFunction)

Atomically updates the current value with the results of applying the given function.

Parameters

updateFunction:DoubleUnaryOperator: the update function

Returns:double

the previous value

Annotations

@CanIgnoreReturnValue

Since

31.1

intValue back to summary

intValue	back to summary
public int intValue() Implements abstract java.lang.Number.intValue. Returns the value of this `AtomicDouble` as an `int` after a narrowing primitive conversion. Returns:int Doc from java.lang.Number.intValue. the numeric value represented by this object after conversion to type `int`. Annotations @Override

public int intValue()

Implements abstract java.lang.Number.intValue.

Returns the value of this AtomicDouble as an int after a narrowing primitive conversion.

Returns:int

Doc from java.lang.Number.intValue.

the numeric value represented by this object after conversion to type int.

Annotations

@Override

lazySet	back to summary
public final void lazySet(double newValue) Eventually sets to the given value. Parameters newValue:double the new value

lazySet

back to summary

public final void lazySet(double newValue)

Eventually sets to the given value.

Parameters

newValue:double: the new value

longValue back to summary

longValue	back to summary
public long longValue() Implements abstract java.lang.Number.longValue. Returns the value of this `AtomicDouble` as a `long` after a narrowing primitive conversion. Returns:long Doc from java.lang.Number.longValue. the numeric value represented by this object after conversion to type `long`. Annotations @Override

public long longValue()

Implements abstract java.lang.Number.longValue.

Returns the value of this AtomicDouble as a long after a narrowing primitive conversion.

Returns:long

Doc from java.lang.Number.longValue.

the numeric value represented by this object after conversion to type long.

Annotations

@Override

readObject	back to summary
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException Reconstitutes the instance from a stream (that is, deserializes it).

set	back to summary
public final void set(double newValue) Sets to the given value. Parameters newValue:double the new value

set

back to summary

public final void set(double newValue)

Sets to the given value.

Parameters

newValue:double: the new value

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns the String representation of the current value. Returns:String the String representation of the current value Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Returns the String representation of the current value.

Returns:String

the String representation of the current value

Annotations

@Override

updateAndGet	back to summary
public final double updateAndGet(DoubleUnaryOperator updateFunction) Atomically updates the current value with the results of applying the given function. Parameters updateFunction:DoubleUnaryOperator the update function Returns:double the updated value Annotations @CanIgnoreReturnValue Since 31.1

updateAndGet

back to summary

public final double updateAndGet(DoubleUnaryOperator updateFunction)

Atomically updates the current value with the results of applying the given function.

Parameters

updateFunction:DoubleUnaryOperator: the update function

Returns:double

the updated value

Annotations

@CanIgnoreReturnValue

Since

31.1

weakCompareAndSet back to summary

weakCompareAndSet	back to summary
public final boolean weakCompareAndSet(double expect, double update) Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value. May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to `compareAndSet`. Parameters expect:double the expected value update:double the new value Returns:boolean `true` if successful

public final boolean weakCompareAndSet(double expect, double update)

Atomically sets the value to the given updated value if the current value is bitwise equal to the expected value.

May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

Parameters

expect:double: the expected value
update:double: the new value

Returns:boolean

true if successful

writeObject back to summary

writeObject	back to summary
private void writeObject(ObjectOutputStream s) throws IOException Saves the state to a stream (that is, serializes it). Serial data The current value is emitted (a `double`).

private void writeObject(ObjectOutputStream s) throws IOException

Saves the state to a stream (that is, serializes it).

Serial data: The current value is emitted (a double).

public Class AtomicDouble

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