Book Image

Hands-On Concurrency with Rust

By : Brian L. Troutwine
Book Image

Hands-On Concurrency with Rust

By: Brian L. Troutwine

Overview of this book

Most programming languages can really complicate things, especially with regard to unsafe memory access. The burden on you, the programmer, lies across two domains: understanding the modern machine and your language's pain-points. This book will teach you to how to manage program performance on modern machines and build fast, memory-safe, and concurrent software in Rust. It starts with the fundamentals of Rust and discusses machine architecture concepts. You will be taken through ways to measure and improve the performance of Rust code systematically and how to write collections with confidence. You will learn about the Sync and Send traits applied to threads, and coordinate thread execution with locks, atomic primitives, data-parallelism, and more. The book will show you how to efficiently embed Rust in C++ code and explore the functionalities of various crates for multithreaded applications. It explores implementations in depth. You will know how a mutex works and build several yourself. You will master radically different approaches that exist in the ecosystem for structuring and managing high-scale systems. By the end of the book, you will feel comfortable with designing safe, consistent, parallel, and high-performance applications in Rust.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Packt Upsell

Memory layout

Rust has a handful of mechanisms to lay out compound types in memory. They are as follows:

  • Arrays
  • Enums
  • Structs
  • Tuples

Exactly how these are laid out in memory depends on the representation chosen. By default, everything in Rust is repr(Rust). All repr(Rust) types are aligned on byte boundaries to the power of two. Every type is at least one byte in memory, then two, then four, and so forth. Primitives—u8, usize, bool, and &T—are aligned to their size. In Rust, representation structures have alignment according to the largest field. Consider the following struct:

struct AGC {
  elapsed_time2: u16,
  elapsed_time1: u16,
  wait_list_upper: u32,
  wait_list_lower: u16,
  digital_autopilot: u16,
  fine_scale: u16

AGC is aligned to u32 with padding inserted as appropriate to match that 32-bit alignment. Rust will re-order fields to achieve maximal packing. Enums are different, being subject to a host of optimizations, most notably null pointer optimization. See the following enumeration...