Thanks! To be fair, there are certain advanced scenarios which Rust's mutex model can't handle either -- sometimes you want to protect writes via a mutex, but allow reads without them (maybe you're okay with torn state on reads). This is a rare, expert use case with architecture-specific considerations that must be handled with care.

I do think Rust's mutexes handle almost every use case that can be thrown at them, though, and in a way where it's next to impossible to get it wrong. I think if you're writing a browser engine in the 21st century you should bake in parallelism and concurrency from the start, and Rust is the most suitable language to do that in.