LongAdder Class

Definition

[Android.Runtime.Register("java/util/concurrent/atomic/LongAdder", ApiSince=24, DoNotGenerateAcw=true)]
public class LongAdder : Java.Lang.Number, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("java/util/concurrent/atomic/LongAdder", ApiSince=24, DoNotGenerateAcw=true)>]
type LongAdder = class
    inherit Number
    interface ISerializable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance

Object

Object

Number

LongAdder

Attributes

RegisterAttribute

Implements

IJavaObject IJavaPeerable ISerializable IDisposable

Remarks

One or more variables that together maintain an initially zero long sum. When updates (method #add) are contended across threads, the set of variables may grow dynamically to reduce contention. Method #sum (or, equivalently, #longValue) returns the current total combined across the variables maintaining the sum.

This class is usually preferable to AtomicLong when multiple threads update a common sum that is used for purposes such as collecting statistics, not for fine-grained synchronization control. Under low update contention, the two classes have similar characteristics. But under high contention, expected throughput of this class is significantly higher, at the expense of higher space consumption.

LongAdders can be used with a java.util.concurrent.ConcurrentHashMap to maintain a scalable frequency map (a form of histogram or multiset). For example, to add a count to a ConcurrentHashMap<String,LongAdder> freqs, initializing if not already present, you can use freqs.computeIfAbsent(key, k -> new LongAdder()).increment();

This class extends Number, but does <em>not</em> define methods such as equals, hashCode and compareTo because instances are expected to be mutated, and so are not useful as collection keys.

Added in 1.8.

Java documentation for java.util.concurrent.atomic.LongAdder.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Properties

Methods

Explicit Interface Implementations

Extension Methods

Applies to