Book Image

Clojure High Performance Programming

By : Shantanu Kumar
Book Image

Clojure High Performance Programming

By: Shantanu Kumar

Overview of this book

<p>Clojure is a young, dynamic, functional programming language that runs on the Java Virtual Machine. It is built with performance, pragmatism, and simplicity in mind. Like most general purpose languages, Clojure’s features have different performance characteristics that one should know in order to write high performance code.<br /><br />Clojure High Performance Programming is a practical, to-the-point guide that shows you how to evaluate the performance implications of different Clojure abstractions, learn about their underpinnings, and apply the right approach for optimum performance in real-world programs.<br /><br />This book discusses the Clojure language in the light of performance factors that you can exploit in your own code.</p> <p>You will also learn about hardware and JVM internals that also impact Clojure’s performance. Key features include performance vocabulary, performance analysis, optimization techniques, and how to apply these to your programs. You will also find detailed information on Clojure's concurrency, state-management, and parallelization primitives.</p> <p>This book is your key to writing high performance Clojure code using the right abstraction, in the right place, using the right technique.</p>
Table of Contents (15 chapters)
Clojure High Performance Programming
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Chapter 4. Host Performance

In the previous chapters, we noted how Clojure interoperates with Java. In this chapter we will go a bit deeper to understand the internals better. We will touch upon several layers of the entire stack, but our major focus will be the Java Virtual Machine (JVM), in particular the Oracle HotSpot JVM, though there are several JVM vendors to choose from (http://en.wikipedia.org/wiki/List_of_Java_virtual_machines). At the time of writing, Oracle JDK 1.7 is the latest stable release, and early OpenJDK 1.8 milestones are available. In this chapter we will discuss:

  • How the hardware subsystems function from a performance viewpoint

  • Organization of the JVM internals and how that is related to performance

  • How to measure the amount of space occupied by various objects in the heap

  • How to profile Clojure code for latency using Criterium