Book Image

Asynchronous Programming in Rust

By : Carl Fredrik Samson
5 (2)
Book Image

Asynchronous Programming in Rust

5 (2)
By: Carl Fredrik Samson

Overview of this book

Step into the world of asynchronous programming with confidence by conquering the challenges of unclear concepts with this hands-on guide. Using functional examples, this book simplifies the trickiest concepts, exploring goroutines, fibers, futures, and callbacks to help you navigate the vast Rust async ecosystem with ease. You’ll start by building a solid foundation in asynchronous programming and explore diverse strategies for modeling program flow. The book then guides you through concepts like epoll, coroutines, green threads, and callbacks using practical examples. The final section focuses on Rust, examining futures, generators, and the reactor-executor pattern. You’ll apply your knowledge to create your own runtime, solidifying expertise in this dynamic domain. Throughout the book, you’ll not only gain proficiency in Rust's async features but also see how Rust models asynchronous program flow. By the end of the book, you'll possess the knowledge and practical skills needed to actively contribute to the Rust async ecosystem.
Table of Contents (16 chapters)
Free Chapter
1
Part 1:Asynchronous Programming Fundamentals
5
Part 2:Event Queues and Green Threads
8
Part 3:Futures and async/await in Rust

Readiness-based event queues

epoll and kqueue are known as readiness-based event queues, which means they let you know when an action is ready to be performed. An example of this is a socket that is ready to be read from.

To give an idea about how this works in practice, we can take a look at what happens when we read data from a socket using epoll/kqueue:

  1. We create an event queue by calling the syscall epoll_create or kqueue.
  2. We ask the OS for a file descriptor representing a network socket.
  3. Through another syscall, we register an interest in Read events on this socket. It’s important that we also inform the OS that we’ll be expecting to receive a notification when the event is ready in the event queue we created in step 1.
  4. Next, we call epoll_wait or kevent to wait for an event. This will block (suspend) the thread it’s called on.
  5. When the event is ready, our thread is unblocked (resumed) and we return from our wait call with data about...