[flagged]
Io_uring, kTLS and Rust for zero syscall HTTPS server
11–20 of 173 posts
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#12This was a good read and great work. Can't wait to see the performance tests. Your write up connected some early knowledge from when I was 11 where I was trying to set up a database/backend and was finding lots of cgi-bin online. I realize now those were spinning up new processes with each request https://en.wikipedia.org/wiki/Common_Gateway_Interface I remember when sendfile became available for my large gaming foru…
It wasn't just CGI, every HTTP session was commonly a forked copy of the entire server in the CERN and Apache lineage! Apache gradually had better answers, but their API with common addons made it a bit difficult to transition so webservers like nginx took off which are built closer to the architecture in the article with event driven I/O from the beginning.
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#13[flagged]
FWIW Rust advice is maybe 15% of the bottom of the article, most of the decisions apply equally to C and the article is a fairly sensible survey of APIs.
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#14> For example when submitting a write operation, the memory location of those bytes must not be deallocated or overwritten. > The io-uring crate doesn’t help much with this. The API doesn’t allow the borrow checker to protect you at compile time, and I don’t see it doing any runtime checks either. I've seen comments like this before[1], and I get the impression that building a a safe async Rust library around io_urin…
There is, I think, an ownership model that Rust's borrow checker very poorly supports, and for lack of a better name, I've called it hot potato ownership. The basic idea is that you have a buffer which you can give out as ownership in the expectation that the person you gave it to will (eventually) give it back to you. It's a sort of non-lexical borrowing problem, and I very quickly discovered when trying to implement it myself in purely safe Rust that the "giving the buffer back" is just really gnarly to write.
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#15> For example when submitting a write operation, the memory location of those bytes must not be deallocated or overwritten. > The io-uring crate doesn’t help much with this. The API doesn’t allow the borrow checker to protect you at compile time, and I don’t see it doing any runtime checks either. I've seen comments like this before[1], and I get the impression that building a a safe async Rust library around io_urin…
I think the right way to build a safe interface around io_uring would be to use ring-owned buffers, ask the ring for a buffer when you want one, and give the buffer back to the ring when initiating a write.
This is something that Amos Wenger (fasterthanlime) has worked on: https://github.com/bearcove/loona/blob/main/crates/buffet/RE...
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#16> For example when submitting a write operation, the memory location of those bytes must not be deallocated or overwritten. > The io-uring crate doesn’t help much with this. The API doesn’t allow the borrow checker to protect you at compile time, and I don’t see it doing any runtime checks either. I've seen comments like this before[1], and I get the impression that building a a safe async Rust library around io_urin…
There is, I think, an ownership model that Rust's borrow checker very poorly supports, and for lack of a better name, I've called it hot potato ownership. The basic idea is that you have a buffer which you can give out as ownership in the expectation that the person you gave it to will (eventually) give it back to you. It's a sort of non-lexical borrowing problem, and I very quickly discovered when trying to implemen…
Maybe I’m misunderstanding, but why is that not possible with a
Fn(_: T) -> TRe: Io_uring, kTLS and Rust for zero syscall HTTPS server
#17Earlier quoted context omitted.
There is, I think, an ownership model that Rust's borrow checker very poorly supports, and for lack of a better name, I've called it hot potato ownership. The basic idea is that you have a buffer which you can give out as ownership in the expectation that the person you gave it to will (eventually) give it back to you. It's a sort of non-lexical borrowing problem, and I very quickly discovered when trying to implemen…
Maybe I’m misunderstanding, but why is that not possible with a Fn(_: T) -> T
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#18> For example when submitting a write operation, the memory location of those bytes must not be deallocated or overwritten. > The io-uring crate doesn’t help much with this. The API doesn’t allow the borrow checker to protect you at compile time, and I don’t see it doing any runtime checks either. I've seen comments like this before[1], and I get the impression that building a a safe async Rust library around io_urin…
There is, I think, an ownership model that Rust's borrow checker very poorly supports, and for lack of a better name, I've called it hot potato ownership. The basic idea is that you have a buffer which you can give out as ownership in the expectation that the person you gave it to will (eventually) give it back to you. It's a sort of non-lexical borrowing problem, and I very quickly discovered when trying to implemen…
Refcel didn't work? Or rc?
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#19Excellent read. I'd like to see DPDK style full kernel bypass next
Not sure if you are aware of this, but LUNA does this already.
Re: Io_uring, kTLS and Rust for zero syscall HTTPS server
#20Earlier quoted context omitted.
There is, I think, an ownership model that Rust's borrow checker very poorly supports, and for lack of a better name, I've called it hot potato ownership. The basic idea is that you have a buffer which you can give out as ownership in the expectation that the person you gave it to will (eventually) give it back to you. It's a sort of non-lexical borrowing problem, and I very quickly discovered when trying to implemen…
Maybe I’m misunderstanding, but why is that not possible with a Fn(_: T) -> T
As sibling notes, it is. It's very rarely seen though.
One place you might see something like it is if an API takes ownership, but returns it on error; you see the error side carry the resource you gave it, so you could try again.