public class DoubleAdder extends Number implements Serializable
double
sum. When updates (method add(double)
) are
contended across threads, the set of variables may grow dynamically
to reduce contention. Method sum()
(or, equivalently doubleValue()
) returns the current total combined across the
variables maintaining the sum.
This class extends Number
, but does not define
methods such as equals
, hashCode
and compareTo
because instances are expected to be mutated, and so are
not useful as collection keys.
jsr166e note: This class is targeted to be placed in java.util.concurrent.atomic.
Constructor and Description |
---|
DoubleAdder()
Creates a new adder with initial sum of zero.
|
Modifier and Type | Method and Description |
---|---|
void |
add(double x)
Adds the given value.
|
double |
doubleValue()
Equivalent to
sum() . |
float |
floatValue()
Returns the
sum() as a float
after a narrowing primitive conversion. |
int |
intValue()
Returns the
sum() as an int after a
narrowing primitive conversion. |
long |
longValue()
Returns the
sum() as a long after a
narrowing primitive conversion. |
void |
reset()
Resets variables maintaining the sum to zero.
|
double |
sum()
Returns the current sum.
|
double |
sumThenReset()
|
String |
toString()
Returns the String representation of the
sum() . |
byteValue, shortValue
public void add(double x)
x
- the value to addpublic double sum()
public void reset()
public double sumThenReset()
sum()
followed by reset()
. This method may apply for example during quiescent
points between multithreaded computations. If there are
updates concurrent with this method, the returned value is
not guaranteed to be the final value occurring before
the reset.public double doubleValue()
sum()
.doubleValue
in class Number
public long longValue()
sum()
as a long
after a
narrowing primitive conversion.public int intValue()
sum()
as an int
after a
narrowing primitive conversion.public float floatValue()
sum()
as a float
after a narrowing primitive conversion.floatValue
in class Number
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