JD Tech

Nov 19, 2021 · Fundamentals

Understanding the Java Memory Model (JMM) and JSR‑133: Concepts, Guarantees, and Memory Barriers

This article explains the Java Memory Model (JMM) defined by JSR‑133, covering its core theory, the role of keywords like volatile, synchronized, and final, the underlying hardware memory models, cache‑coherence protocols, happens‑before rules, memory barriers, and how they ensure atomicity, visibility, and ordering in multithreaded Java programs.