Dabaoshi

Aug 16, 2026 · Fundamentals

CAS and Java Atomic Classes Explained: Mechanics, Pitfalls, and LongAdder

This article demystifies Java's Compare‑And‑Swap (CAS) instruction, shows how atomic classes like AtomicInteger achieve lock‑free increments, discusses CAS's three main drawbacks, surveys the entire java.util.concurrent.atomic family, and explains how LongAdder improves high‑contention counting.