Build for wasm32-unknown-unknown ?

[andrewzah]

Version

tokio-executor v0.1.6 (dependency of reqwest v0.9.9)

Platform

Darwin mbp.local 18.2.0 Darwin Kernel Version 18.2.0: Mon Nov 12 20:24:46 PST 2018; root:xnu-4903.231.4~2/RELEASE_X86_64 x86_64

but compiling for wasm32-unknown-unknown

Subcrates

tokio-executor

Description

Compiling this fails when targeting wasm32-unknown-unknown. Are there any plans to address this (if possible)?

   Compiling tokio-executor v0.1.6
error[E0432]: unresolved import `sys`
  --> /Users/andrewzah/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/tcp.rs:18:5
   |
18 | use sys::c;
   |     ^^^ maybe a missing `extern crate sys;`?

error[E0432]: unresolved import `sys`
  --> /Users/andrewzah/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/udp.rs:18:5
   |
18 | use sys::c;
   |     ^^^ maybe a missing `extern crate sys;`?

error[E0432]: unresolved import `sys`
  --> /Users/andrewzah/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/socket.rs:22:5
   |
22 | use sys;
   |     ^^^ no `sys` in the root

error[E0432]: unresolved import `sys`
  --> /Users/andrewzah/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/socket.rs:23:5
   |
23 | use sys::c;
   |     ^^^ maybe a missing `extern crate sys;`?

Note that tokio-rs/tokio-core#327 by saschagrunert existed but was archived.

[davidbarsky]

Are there any plans to address this?

I can't speak for Carl or anybody else, but getting Tokio to compile to wasm32-unknown-unknown would be a big lift, and I don't know if it make sense to get Tokio compiling for that target. Being able to move away from libc would be a win in view, a lot of things Tokio depends on aren't defined in WASM at the moment. However, the wasm_bindgen_futures crate might be a reasonable thing to use in the meantime, especially if you're targeting Node.js/browsers.

I'll close this issue in the meantime. Feel free to open a new one if you encounter any issues.

[r-ocket]

@davidbarsky has the state of things changed from when this was closed? would it be more feasible now to get tokio to compile for wasm32-unknown-unknown? I think some browsers now support wasm threads (even tho it's still only at proposal stage)

[Darksonn]

Not much has happened for a while. We don't have threading support. You can find up-to-date information in the documentation: https://docs.rs/tokio/latest/tokio/#wasm-support