I feel like I’m pretty good at writing multithreaded code. I’ve done it a lot. As long as you use primitives like Rust Mutex that enforce correctness for data access (ie no accessing data without the lock) it’s pretty simple. Define a clean boundary API and you’re off to the races.
async code is so so so much more complex. It’s so hard to read and rationalize. I could not follow this post. I tried. But it’s just a full extra order of complexity.
Which is a shame because async code is supposed to make code simpler! But I’m increasingly unconfident that’s true.
Async code isn't supposed to be simpler than sync code, it's supposed to be simpler than doing thing like continuation passing.
Async code is simpler because you're implicitly holding a lock on the CPU. That's also why you should stay away from it: it increases latency. Especially since Rust is about speed and responsiveness. In general, async programming in Rust makes little sense.
I love Rust. But I’m 100% convinced Rust chose the wrong tradeoffs with their async model. Just give me green threads and use malloc to grow the stack. It’s fine. That would have been better imho.
Hell, even force threads to be allocated from a bucket of N threads defined at compile time. Surely that'd work for embedded / GPU space?
You can't have a low-level language and green threads at the same time.
Why not?
Why not?