Oh man this finishes too early, I would want to read more!
There's this line:
> Wouldn’t it be cool if we could just use standard OS threads, blocking APIs, avoid new shinies like io_uring, but still get to cancel any work reliably?
Wish more was said about this: why would that be cool? I get that having robust cancellation in standard threads is cool, but why do we want to avoid io_uring?
io_uring has been one of the greatest sources of exploits for the Linux kernel in years. io_uring has resulted in so many practical privilege escalation attacks that many containers completely block it, and companies like Google keep it entirely disabled. RHEL also ships a kernel without it by default.
This is an example why Go is such a successful language, in my view. It hides the async complexity and allows you to pretend you have a simple continuous thread of execution. It's just cheaper than system threads. Imagine if operating system threads and the blocking syscalls were this efficient.
I've spent the last year building a similar runtime for Zig. Purely because I want my applications to forget they are using things like io_uring in the background.