Tagged articles

biased-lock

3 articles · Page 1 of 1

Programmer1970

Aug 6, 2026 · Backend Development

Revisiting synchronized lock upgrade: JVM‑level details of biased, lightweight and heavyweight locks

This article explains how the JVM implements synchronized by using the object header's Mark Word to transition through biased, lightweight, and heavyweight lock states, covering the underlying data structures, lock acquisition and release processes, revocation, downgrade, tuning parameters, practical verification, performance pitfalls, and a comparison with ReentrantLock.

JVMJavaPerformance

0 likes · 16 min read

Revisiting synchronized lock upgrade: JVM‑level details of biased, lightweight and heavyweight locks

Xiaokun's Architecture Exploration Notes

Jan 15, 2020 · Fundamentals

Inside JVM: How synchronized Locks Work, From Biased to Heavyweight

This article explains the JVM's synchronized lock implementation, detailing where lock data is stored, the different lock states (no lock, biased, lightweight, heavyweight), the source code for lock acquisition and release, and the optimization strategies used to improve performance.

JVMJava concurrencybiased-lock

0 likes · 10 min read

Inside JVM: How synchronized Locks Work, From Biased to Heavyweight

Java Captain

Feb 28, 2019 · Fundamentals

Understanding the Implementation of Java synchronized: Biased, Lightweight, and Heavyweight Locks

This article provides a comprehensive analysis of the HotSpot JVM's synchronized implementation, covering the object header, the three lock states (biased, lightweight, heavyweight), their acquisition and release processes, bytecode details, and the conditions that trigger lock upgrades and optimizations.

ConcurrencyJVMJava

0 likes · 15 min read

Understanding the Implementation of Java synchronized: Biased, Lightweight, and Heavyweight Locks