WASI support

[mankinskin]

In an effort to make tokio compatible with wasm32-wasi (tokio-rs/tokio#1597), it might make sense to make this crate WASI compatible aswell.

[Thomasdezeeuw]

I have an old tree: https://github.com/Thomasdezeeuw/mio/tree/wasm32-wasi, but its not functional and I don't have time to work on this.

[Thomasdezeeuw]

@mankinskin #1395.

[mankinskin]

@Thomasdezeeuw I have no experience in this codebase whatsoever so unfortunately I can't really help with this on the spot..

[Thomasdezeeuw]

Closing this due to lack of interest.

[ranile]

Can you clarify what you mean by lack of interest? As far as I can tell, this issue is blocked by missing WASI API (implementation: WebAssembly/WASI#312)

Mio can't implement socket connections until it is supported by the platform. I don't know of anything else that Mio can implement which is supported by WASI today

[Thomasdezeeuw]

Can you clarify what you mean by lack of interest? As far as I can tell, this issue is blocked by missing WASI API (implementation: WebAssembly/WASI#312)

Mio can't implement socket connections until it is supported by the platform. I don't know of anything else that Mio can implement which is supported by WASI today

It's true that Mio couldn't support socket creation, but as far as I can tell it is possible to pass a socket "from the outside" to wasm and use it from there. For example sock_recv has been part of the WASI API for a while. Mio can also already (sort of) implement Poll using poll_oneof. So an experimental implementation of parts of Mio is possible.

Re: lack of interest. This issue has seen very little activity and I know of no development effort to port Mio (except of my own, linked previously).

[xpepermint]

Is this permanently closed?

[Thomasdezeeuw]

@xpepermint no this issue just hasn't seen any real activity so that's why I closed it. We're still open to supporting WASM/WASI.

[dicej]

FWIW, rust-lang/rust#129638 adds support for wasm32-wasip2 sockets, which includes a much broader range of features than WASIp1 did, including the ability to make outgoing connections, bind, accept, etc.

While testing early, pre-release versions of WASIp2, I created https://github.com/dicej/wasi-sockets-tests, based on experimental forks of Rust, mio, tokio, and tokio-postgres. Once Rust has full wasm32-wasip2 socket support, it would be great to follow up with mio and tokio support. I'd be happy to update my mio fork, clean it up, and open a PR if appropriate.

Should we reopen this issue? Or else open a new one specifically about WASIp2?

[Thomasdezeeuw]

Prs would be welcome. We do have to ensure that we don't break support for preview 1 though.

[dicej]

#1836