Module java.base

Class DoubleAdder

java.lang.Object
java.lang.Number
java.util.concurrent.atomic.DoubleAdder
All Implemented Interfaces:
Serializable

public class DoubleAdder extends Number implements Serializable
One or more variables that together maintain an initially zero 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. The order of accumulation within or across threads is not guaranteed. Thus, this class may not be applicable if numerical stability is required, especially when combining values of substantially different orders of magnitude.

This class is usually preferable to alternatives when multiple threads update a common value that is used for purposes such as summary statistics that are frequently updated but less frequently read.

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.

Since:
1.8
See Also: