JVM Tutorials - Herong's Tutorial Examples

∟OpenJ9 by Eclipse Foundation

This chapter provides tutorial notes and example codes on OpenJ9 JVM. Topics include downloading and installing OpenJ9; running Java programs on OpenJ9 JVM; memory footprint of OpenJ9 JVM; comparison of startup time and footprint between OpenJ9 and HotSpot.

What Is Eclipse OpenJ9

Install OpenJ9 JVM with OpenJDK on CentOS Systems

Footprint Comparison - OpenJ9 vs. HotSpot

Startup Time Comparison - OpenJ9 vs. HotSpot

Takeaways:

• OpenJ9 JVM is developed by Eclipse Foundation.
• OpenJDK/OpenJ9 JVM combination has a smaller footprint than OpenJDK/HotSpot JVM combination.
• OpenJDK/OpenJ9 JVM combination is slower than OpenJDK/HotSpot JVM combination when running the simple Hello.java program.

Table of Contents

 About This Book

 JVM (Java Virtual Machine) Specification

 Java HotSpot VM - JVM by Oracle/Sun

 java.lang.Runtime Class - The JVM Instance

 java.lang.System Class - The Operating System

 ClassLoader Class - Class Loaders

 Class Class - Class Reflections

 JVM Runtime Data Areas

 JVM Stack, Frame and Stack Overflow

 Thread Testing Program and Result

 CPU Impact of Multi-Thread Applications

 I/O Impact of Multi-Thread Applications

 CDS (Class Data Sharing)

 Micro Benchmark Runner and JVM Options

 Micro Benchmark Tests on "int" Operations

 Micro Benchmark Tests on "long" Operations

 Micro Benchmark Tests in JIT Compilation Mode

 Micro Benchmark Tests on "float" and "double" Operations

►OpenJ9 by Eclipse Foundation

 JRockit JVM 28.2.7 by Oracle Corporation

 Archived Tutorials

 References

 Full Version in PDF/EPUB

OpenJ9 by Eclipse Foundation - Updated in 2022, by Dr. Herong Yang