Comment by dboreham
7 hours ago
Never, ever, ever, write your own userland threading library.
(rule broken by almost every language in common use, unfortunately)
7 hours ago
Never, ever, ever, write your own userland threading library.
(rule broken by almost every language in common use, unfortunately)
That’s an absurd statement. Optimizing every language around what a runc-like program would need is absurd.
Where does this advice come from? Most web servers would use a lot more resources if they didn't use userland threading, wouldn't they?
I think you're confusing userland threading (also known as green threads) with a regular thread pool implementation (that uses regular OS threads).
Because most web servers use OS threads. Nginx, Apache, litespeed, they all spin up `core count` threads but they can all work single threaded just fine as well.
No, I mean that Tokio, Go, etc., were built with general-purpose web servers in mind, and they decided that lightweight threads were necessary for that purpose because OS threads had too much overhead to be used per-request.
NGINX uses a state machine per task, which as far as I know is kind of what Rust's async functions end up desugaring to.