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 hardware


There are various hardware components that may impact the performance of software in different ways. The processors, caches, memory subsystem, I/O subsystems, and so on, all have varying degrees of performance impact depending upon the use cases. In the following sections we will look into each of those aspects.

Processors

Since about the late 1980s, microprocessors have been employing pipelining and instruction-level parallelism to speed up their performance. Processing an instruction at the CPU level consists of typically four cycles: fetch, decode, execute, and writeback. Modern processors optimize the cycles by running them in parallel—while one instruction is executed, the next instruction is being decoded and the one after that is being fetched, and so on. This style is called instruction pipelining.

In practice, in order to speed up execution even further, the stages are subdivided into many shorter stages, thus leading to deeper super-pipeline architecture. The length...