A file descriptor is just a number, so safe Rust code could hand any number to an API that trusts it. I/O safety closes that gap with OwnedFd and BorrowedFd. In October 2026 tokio deprecated four safe AsyncFd constructors for breaking it.
One blocking call in a Tokio task can stall every other task on that thread. How to recognise blocking work, when spawn_blocking is the answer, and when a dedicated thread is the better one.
A standard mutex works well for short updates in async Rust. Learn when holding its guard across an await can deadlock, and when Tokio’s async mutex is worth its cost.
Rust runs `Drop` when values are destroyed, but `Drop` cannot await a future. Give asynchronous resources an explicit shutdown path while `AsyncDrop` remains experimental.
Cloudflare previews experimental wasm-bindgen support for Rust's Emscripten target on Workers. The integration maps files, sockets, timers, and Tokio onto a JavaScript host.