@GwtIncompatible public class AtomicDouble extends Number implements Serializable
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(double, double)
by comparing their bitwise representation using Double.doubleToRawLongBits(double)
, which differs from both the primitive double ==
operator and
from Double.equals(java.lang.Object)
, 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 and DoubleMaxUpdater.
Constructor and Description |
---|
AtomicDouble()
Creates a new
AtomicDouble with initial value 0.0 . |
AtomicDouble(double initialValue)
Creates a new
AtomicDouble with the given initial value. |
Modifier and Type | Method and Description |
---|---|
double |
addAndGet(double delta)
Atomically adds the given value to the current value.
|
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.
|
double |
doubleValue()
Returns the value of this
AtomicDouble as a double . |
float |
floatValue()
Returns the value of this
AtomicDouble as a float after a narrowing primitive
conversion. |
double |
get()
Gets the current value.
|
double |
getAndAdd(double delta)
Atomically adds the given value to the current value.
|
double |
getAndSet(double newValue)
Atomically sets to the given value and returns the old value.
|
int |
intValue()
Returns the value of this
AtomicDouble as an int after a narrowing primitive
conversion. |
void |
lazySet(double newValue)
Eventually sets to the given value.
|
long |
longValue()
Returns the value of this
AtomicDouble as a long after a narrowing primitive
conversion. |
void |
set(double newValue)
Sets to the given value.
|
String |
toString()
Returns the String representation of the current value.
|
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.
|
byteValue, shortValue
public AtomicDouble(double initialValue)
AtomicDouble
with the given initial value.initialValue
- the initial valuepublic AtomicDouble()
AtomicDouble
with initial value 0.0
.public final double get()
public final void set(double newValue)
newValue
- the new valuepublic final void lazySet(double newValue)
newValue
- the new valuepublic final double getAndSet(double newValue)
newValue
- the new valuepublic final boolean compareAndSet(double expect, double update)
expect
- the expected valueupdate
- the new valuetrue
if successful. False return indicates that the actual value was not
bitwise equal to the expected value.public final boolean weakCompareAndSet(double expect, double update)
May
fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate
alternative to compareAndSet
.
expect
- the expected valueupdate
- the new valuetrue
if successful@CanIgnoreReturnValue public final double getAndAdd(double delta)
delta
- the value to add@CanIgnoreReturnValue public final double addAndGet(double delta)
delta
- the value to addpublic int intValue()
AtomicDouble
as an int
after a narrowing primitive
conversion.public long longValue()
AtomicDouble
as a long
after a narrowing primitive
conversion.public float floatValue()
AtomicDouble
as a float
after a narrowing primitive
conversion.floatValue
in class Number
float
.public double doubleValue()
AtomicDouble
as a double
.doubleValue
in class Number
double
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