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

Chapter 5: Threads, Memory, and Concurrency

Until now, we have studied the performance of a single CPU executing one program, one instruction sequence. In the introduction of Chapter 1, Introduction to Performance and Concurrency, we mentioned that this is not the world we live in anymore, and we never touched the subject again. Instead, we studied every aspect of the performance of a single-threaded program running on one CPU. We have now learned all we need to know about the performance of one thread and are ready to study the performance of concurrent programs.

In this chapter, we're going to cover the following main topics:

  • Overview of threads
  • Multi-threaded and multi-core memory accesses
  • Data races and memory access synchronization
  • Locks and atomic operations
  • Memory model
  • Memory order and memory barriers