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

Read many, write exclusive locks – RwLock

Consider a situation where you have a resource that must be manipulated only a single thread at a time, but is safe to be queried by many—that is, you have many readers and only one writer. While we could protect this resource with a Mutex, the trouble is that the mutex makes no distinction between its lockers; every thread will be forced to wait, no matter what their intentions. RwLock<T> is an alternative to the mutex concept, allowing for two kinds of locks—read and write. Analogously to Rust's references, there can only be one write lock taken at a time but multiple reader locks, exclusive of a write lock. Let's look at an example:

use std::thread;
use std::sync::{Arc, RwLock};

fn main() {
    let resource: Arc<RwLock<u16>> = Arc::new(RwLock::new(0));

    let total_readers = 5;

    let mut reader_jhs = Vec::with_capacity(total_readers);
    for _ in 0..total_readers {
        let resource = Arc::clone(&resource);