Book Image

The Art of Writing Efficient Programs

By : Fedor G. Pikus
3 (2)
Book Image

The Art of Writing Efficient Programs

3 (2)
By: Fedor G. Pikus

Overview of this book

The great free lunch of "performance taking care of itself" is over. Until recently, programs got faster by themselves as CPUs were upgraded, but that doesn't happen anymore. The clock frequency of new processors has almost peaked, and while new architectures provide small improvements to existing programs, this only helps slightly. To write efficient software, you now have to know how to program by making good use of the available computing resources, and this book will teach you how to do that. The Art of Efficient Programming covers all the major aspects of writing efficient programs, such as using CPU resources and memory efficiently, avoiding unnecessary computations, measuring performance, and how to put concurrency and multithreading to good use. You'll also learn about compiler optimizations and how to use the programming language (C++) more efficiently. Finally, you'll understand how design decisions impact performance. By the end of this book, you'll not only have enough knowledge of processors and compilers to write efficient programs, but you'll also be able to understand which techniques to use and what to measure while improving performance. At its core, this book is about learning how to learn.
Table of Contents (18 chapters)
1
Section 1 – Performance Fundamentals
7
Section 2 – Advanced Concurrency
11
Section 3 – Designing and Coding High-Performance Programs

Summary

In this chapter, we have learned about the performance of the basic building blocks of any concurrent program. All accesses to the shared data must be protected or synchronized, but there is a wide range of options when it comes to implementing such synchronization. While mutex is the most commonly used and the simplest alternative, we have learned several other, better-performing options: spinlocks and their variants, as well as lock-free synchronization.

The key to an efficient concurrent program is to make as much data as possible local to one thread and minimize the operations on the shared data. The requirements specific to each problem usually dictate that such operations cannot be eliminated completely, so this chapter is all about making the concurrent data accesses more efficient.

We studied how to count or accumulate results across multiple threads, again with and without locks. Understanding the data dependency issues led us to the discovery of the publishing...