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

Concurrency support in C++11

Before C++11, the C++ standard made no mention of concurrency. Of course, in practice, programmers wrote multi-threaded and distributed programs in C++ long before 2011. What made that possible was the fact that the compiler writers have voluntarily adopted additional restrictions and guarantees, usually by way of complying with both the C++ standard (for the language) and another standard, such as POSIX, for concurrency support.

C++11 has changed that by introducing the C++ memory model. The memory model describes how threads interact through memory. For the first time, the C++ language was on a solid foundation about concurrency. The immediate practical impact, however, was rather muted since the new C++ memory model was quite similar to the memory models already supported by most compiler writers. There were some subtle differences between those models, and the new standard finally guaranteed the portable behavior of the programs that encounter these...