Special Topics in Software Engineering:

Internals of the Java HotSpot VM

Overview

This course will give an overview of Oracle's Java HotSpot VM, which is among the best-performing Java virtual machines. Topics include its internal data structures, the interpreter, the garbage collectors and the two just-in-time compilers. The course will also show how to use the available visualization tools c1visualizer and IdealGraphVisualizer to comprehend its compilation mechanisms. There will be no exam, the participants will have to build the VM on their own computer and implement a small modification.

Contents

• Architecture Overview
  • Project Structure
  • Object Layout
  • C++ / Java Interface
  • Class Loading
  • Interpreter
  • Garbage Collector
• Client Compiler
  • Graph Builder
  • Block Builder
  • High-level Intermediate Representation
  • Canonicalizer
  • Global Value Numbering
  • Low-level Intermediate Representation
  • Linear Scan Register Allocator
  • Assembler and Machine Code Generator
• Server Compiler
  • Program Dependence Graph
  • Loop Unrolling
  • Graph Coloring Register Allocator
  • Machine Code Rewriting Rules

Dates

Online Resources

• The OpenJDK project
• List of scientific publications of our institute in this area
• HotSpot Internals Wiki
• Client compiler visualization: c1visualizer
• Server compiler visualization: IdealGraphVisualizer