Mutable

[lacasaprivata2]

tokio/tokio/src/sync/mpsc/unbounded.rs

Line 126 in d1a4009

pub async fn recv(&mut self) -> Option<T> {

Why does this need to be mutable when it's known to be accessed from 1 thread / send() is not mutable?

[Darksonn]

The mpsc channel is a multi-producer single-consumer channel, and having the recv methods take &self would allow several threads to receive in parallel, in contradiction with it being a single-consumer channel.

The send method can take &self because having multiple threads send in parallel is fine.

[lacasaprivata2]

Hm - thought this would be up to the programmer to verify

how would you recommend going about storing receivers in a global, static vector for a single worker thread to poll?

[Darksonn]

If you wrap the receiver (or the vector with receivers) in a mutex, you can do it. Otherwise you can also use an mpmc channel, which is available in e.g. the async-channel crate.