bbqueue VS cortex-m

I particularly like lock-free (wait-free?) SPSC queues because they're (relatively) easy to get right, and are extremely useful for buffering in embedded systems. I end up with something like this on almost every project:

One side of the queue is a peripheral like a serial port that needs to be fed/drained like clockwork to avoid losing data or glitching (e.g. via interrupts or DMA), and the other side is usually software running on the main thread, that wants to be able to work at its own pace and also go to sleep sometimes.

An SPSC queue fits this use-case nicely. James Munns has a fancy one written in Rust [1], and I have a ~100 line C template [2].

[1] https://github.com/jamesmunns/bbqueue

[2] https://gist.github.com/ohazi/40746a16c7fea4593bd0b664638d70...

I would be interested in what you think of something like BBQueue:

https://github.com/jamesmunns/bbqueue

I do not have as strong of feelings as your parent, but:

1. A lot of the APIs make use of the typestate pattern, which is nice, but also very verbose, and might turn many people off.

2. The generated API documentation for the lower level crates relies on you knowing the feel for how it generates the various APIs. It can take some time to get used to, especially if you're used to the better documentation of the broader ecosystem.

3. A bunch of the ecosystem crates assume the "I am running one program in ring0" kind of thing, and not "I have an RTOS" sort of case. See the discussion in https://github.com/rust-embedded/cortex-m/issues/233 for example.

For cortex-m support, check out the cortex-m crate

See https://github.com/rust-embedded/cortex-m/tree/master/panic-semihosting

I don't think so. Once a function is compiled, it basically becomes a black box with a type signature so unless sleeping in a function affects its signature, that information is erased. If you pass in some kind of a sleep token that has to be used to sleep, then yeah I think you could enforce it by only being able to get that token in a non-atomic context and making it leak proof.

The Cortex-M crate does something similar, but for proving that you are in an atomic context. Another function that expects a CriticalSection type is then assured that it's running without interrupts enabled.

https://github.com/rust-embedded/cortex-m/blob/master/src/in...