Rust

Who Runs Your Rust Future? Hands-On Intro to Async Rust

I wrote a hands-on intro to async Rust where you build a future and the runner that drives it. It assumes you've written async/await in JS and know Rust basics (structs, enums, closures). No prior async Rust needed.

What the first chapter covers:

• Who actually runs your async code in Rust
• What calling an async function actually does, compared to a JS Promise
• What 'running' a future actually means, step by step
• The waker: how a future says when it's worth polling again, so you can sleep instead of spinning the CPU
• Building a Oneshot channel by hand
• Writing block_on, a runner that drives a future to completion

Everything is built from std only, no dependencies. Also, this chapter is a part of a bigger series that goes deep into async Rust.