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 7:

  1. Any data structure designed for thread safety must have a transactional interface: every operation must either not change the state of the data structure or transform it from one well-defined state to another well-defined state.
  2. This comes to the general observation of the performance of concurrent code: the more shared variables there are, the slower the code is. A complex data structure usually needs more data shared between threads that access it concurrently. In addition, there are simple algorithms (some are wait-free) that allow limited thread-safe operations on the data structures.
  3. With an efficient lock, a lock-guarded data structure is not necessarily slower. Often, it is faster. Again, it comes to how many variables are shared: a lock-free scheme that requires multiple atomic variables may be slower than a single lock. We also have to consider the locality of the access: if the data structure is accessed in one or two places (like a queue), the lock...