Tagged articles

heavyweight-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

Top Architect

Feb 7, 2023 · Fundamentals

Understanding Java Heavyweight Locks: ObjectMonitor vs AQS

This article explains the differences and similarities between Java's ObjectMonitor and the AbstractQueuedSynchronizer (AQS) implementations of heavyweight locks, covering their internal data structures, waiting queues, lock acquisition order, and how synchronized interacts with wait/notify mechanisms.

AQSConcurrencyJVM

0 likes · 11 min read

Understanding Java Heavyweight Locks: ObjectMonitor vs AQS

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