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

The Java Virtual Machine


The Java Virtual Machine is a bytecode-oriented, garbage-collected virtual machine that specifies its own instruction set. The instructions have equivalent bytecodes that are interpreted and compiled to the underlying OS and hardware by the Java Runtime Environment (JRE). Objects are referred to using symbolic references. The data types in the JVM are fully standardized as a single spec across all JVM implementations on all platforms and architectures. The JVM also follows the network byte order, which means communication between Java programs on different architectures can happen using the big-endian byte order. Jvmtop (https://code.google.com/p/jvmtop/) is a handy JVM monitoring tool like the top command in Unix-like systems.

The just-in-time (JIT) compiler

The JIT compiler is part of the JVM. When the JVM starts up, the JIT compiler knows hardly anything about the running code, so it simply interprets the JVM bytecodes. As the program keeps running, the JIT compiler...