Book Image

Oracle JRockit: The Definitive Guide

Book Image

Oracle JRockit: The Definitive Guide

Overview of this book

Oracle JRockit is one of the industry’s highest performing Java Virtual Machines. Java developers are always on the lookout for better ways to analyze application behavior and gain performance. As we all know, this is not as easy as it looks. Welcome to JRockit: The Definitive Guide.This book helps you gain in-depth knowledge of Java from the JVM’s point of view. We will explain how to write code that works well with the JVM to gain performance and scalability. Starting with the inner workings of the JRockit JVM and finishing with a thorough walkthrough of the tools in the JRockit Mission Control suite, this book is for anyone who wants to know more about how the JVM executes your Java application and how to profile for better performance.
Table of Contents (23 chapters)
Oracle JRockit
Credits
Foreword
About the Authors
Acknowledgement
About the Reviewers
Preface
12
Using the JRockit Management APIs
Bibliography
Glossary
AST
CAS
HIR
IR
JFR
JMX
JRA
JSR
LIR
MD5
MIR
PDE
RCP
SWT
TLA
Index

Implementing threads and synchronization in Java


Once again, it's time to look inside the JVM. This section covers some of the issues implementing threads and synchronization in a Java runtime. The aim is to provide enough insight and technical background so that the reader will be better equipped to handle parallel constructs and understand how to use synchronization without too much performance loss.

The Java Memory Model

On modern CPU architectures, data caches exist, which is a necessary mechanism for speeding up data access for loads and stores and for reducing contention on the processor bus. As with any cache mechanism, invalidation issues are a problem, especially on multiprocessor systems where we often get the situation that two processors want to access the same memory at the same time.

A memory model defines the circumstances under which different CPUs will and won't see the same data. Memory models can be strong (x86 is fairly strong), where multiple CPUs almost automatically...