This article explains the purpose and usage of Java’s synchronized keyword, covering object locks, method locks, synchronized blocks, and class locks, along with detailed code examples that demonstrate how threads acquire and release locks to ensure data consistency in multithreaded environments.
The article explains how Java’s synchronized keyword works by describing instance, static and block locks, the monitor‑enter/exit bytecodes, the ART object header’s lock word states (thin, fat, hash, forwarding), lock inflation mechanisms, and the internal runtime functions that implement Object.wait(), notify() and related futex handling.
This article explains the difference between class locks (static synchronized) and object locks (instance synchronized) in Java, demonstrates their behavior with multithreaded examples, and shows how lock scope affects execution order and synchronization.
This article explains how Java's synchronized(this) keyword creates an object lock that allows only one thread to execute a synchronized block at a time, demonstrates various scenarios with code examples, and shows how non‑synchronized sections remain concurrent while all synchronized sections on the same object are blocked.
