Skimming this I did not really understand the programming model difference from glommio or tokio-uring. Aside from striving to be cross-platform, how is this significantly different?
It’s frequently used to describe the problem of calling an async function from a sync one or vice versa. There’s other applications of the term though (pure vs impure functions).
I think it just happens to be that we like assigning colors to differentiate things in the mathematical side of CS.
The associated video has quite a cool intro [0], however after that it’s fairly slow and lack details, apart from perf and cross platform characteristics (which are cool).
I've always wondered why completion i/o systems require you to hand them a buffer rather than a buffer pool. Handing them a buffer means that you are keeping a huge amount of memory allocated when you have a huge number of connections.
For TCP, you'd generally want to have a buffer pool and issue one repeating request that takes buffers out from that pool. This is what io_uring allows you to do.
The difficulty comes from APIs ability to expose that buffer pool nicely. I am on the lookout to model this better, but no clear solution that does not make assumptions about the backend at play.
For now, however, with careful design you can skip the allocated buffers and supply a stack reference. So long as you have assurances the stack wont move (Rust's pinning guarantee), you should be able to pass that reference to the io system without problems. Not saying this results in zero copies being made - the backend usually has strict alignment requirements and alike, but hey, we at least get rid of one allocation!
bjfish|2 years ago
anacrolix|2 years ago
lokeg|2 years ago
atlas_hugged|2 years ago
From a quick google it’s about the “color” of a function being red or blue as defined here (I think): https://journal.stuffwithstuff.com/2015/02/01/what-color-is-...
Isn’t this weird and unnecessary? I dunno. It’s probably just me.
kritr|2 years ago
I think it just happens to be that we like assigning colors to differentiate things in the mathematical side of CS.
KolmogorovComp|2 years ago
[0]: https://www.youtube.com/watch?v=EBAC1KcjR28
threeseed|2 years ago
spullara|2 years ago
h33p|2 years ago
The difficulty comes from APIs ability to expose that buffer pool nicely. I am on the lookout to model this better, but no clear solution that does not make assumptions about the backend at play.
For now, however, with careful design you can skip the allocated buffers and supply a stack reference. So long as you have assurances the stack wont move (Rust's pinning guarantee), you should be able to pass that reference to the io system without problems. Not saying this results in zero copies being made - the backend usually has strict alignment requirements and alike, but hey, we at least get rid of one allocation!
wtallis|2 years ago