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

Diminishing returns

The hard truth is that there's a diminishing return when applying more and more concurrent computational resources to a problem. Performing parallel computations implies some coordination overhead—spawning new threads, chunking data, and memory bus issues in the presence of barriers or fences, depending on your CPU. Parallel computing is not free. Consider this Hello, world! program:

fn main() {
    println!("GREETINGS, HUMANS");

Straightforward enough, yeah? Compile and run it 100 times:

hello_worlds > rustc -C opt-level=3
hello_worlds > time for i in {1..100}; do ./sequential_hello_world > /dev/null; done

real    0m0.091s
user    0m0.004s
sys     0m0.012s

Now, consider basically the same program but involving the overhead of spawning a thread:

use std::thread;

fn main() {
    thread::spawn(|| println!("GREETINGS, HUMANS"))

Compile and run it 100 times:

hello_worlds > rustc -C opt-level=3 parallel_hello_world...