How to compat tokio and smol?

[lz1998]

I write my binary crate with tokio, and now I want to run my program on ESP32 (a small IoT chip), but it only supports smol.

I use tokio::spawn, tokio::sync::RwLock, tokio::sync::broadcast, tokio::io::{AsyncRead, AsyncWrite}, tokio_util::codec::LengthDelimitedCodec, tokio::select! in my program.

Is there some simple way to compat tokio and smol?

[Darksonn]

It sounds weird that it would only support smol? I don't see why a chip type would be tied to an async runtime.

But no, there isn't any way to compat them. You can run both runtimes at the same time though.

[memoryruins]

It sounds weird that it would only support smol?

It appears it's not that they only support smol, but rather mio requires epoll/kqueue while ESP-IDF's libc only has poll/select.

ivmarkov/rust-esp32-std-demo#9 (comment)

[lz1998]

It sounds weird that it would only support smol?

It appears it's not that they only support smol, but rather mio requires epoll/kqueue while ESP-IDF's libc only has poll/select.

ivmarkov/rust-esp32-std-demo#9 (comment)

Is it possible to patch tokio in the same way? I don't want to maintain two repository.

[memoryruins]

Based on tokio-rs/mio#1472 (comment) and tokio-rs/mio#1152 (comment), my impression is that it could be possible to add support for it in mio, but it would need someone willing to maintain the support.

Another option could be to request support from espressif for something like epoll in ESP-IDF, though I'm unsure where would be the best place for that (whether espressif's forum, ESP-IDF's issue tracker, or somewhere else). Perhaps the esp-rs matrix could give some advice.

[jasta]

It is now possible to use tokio directly with the esp32 family of devices: https://github.com/jasta/esp32-tokio-demo