vJUG24 Session: An introduction to JVM performance by Rafael Winterhalter

Session Abstract:

Writing software for a virtual machine allows developers to forget about machine code assembly, interrupts and processor caches. This makes Java a convenient language, but all too many developers see the JVM as a black box and are often unsure of how to optimize their code for performance. This unfortunately adds credence to the myth that Java is always outperformed by native languages. In this talk we’ll take a peek at the inner workings of the HotSpot Virtual Machine, its Just-In-Time Compiler and the interplay with a computer’s hardware. From this, we will understand the more common optimizations that a virtual machine applies to be better equipped to improve and to reason about a Java program’s performance, and how to correctly measure runtime!

Speaker: Rafael Winterhalter

Rafael works as a software consultant in Oslo, Norway. He is a proponent of static typing and a JVM enthusiast with particular interest in code instrumentation, concurrency and functional programming. Rafael blogs about software development, regularly presents at conferences and was pronounced a JavaOne Rock Star. When coding outside of his work place, he contributes to a wide range of open source projects and often works on Byte Buddy, a library for simple runtime code generation for the Java virtual machine. For his work, Rafael received a Duke’s Choice award and was elected a Java Champion.