While rust can guarantee no data races in safe code, it can't avoid deadlocks. As systems grow large and multiple locks are involved, these become more likely, as expressed in the dining philosophers problem.
I'm somewhat surprised that I haven't seen any discussion of addressing this issue in rust. The way I'm most familiar with solving this is through a lock ordering policy. After poking around a bit, I think it's possible to enforce much of this at compile time with the typestate pattern. Here's a small proof-of-concept*.
Does this seems like a reasonable approach? How do others address this issue?
* There's a small hole in that dropping
ABGuard may drop
b, but I think that could be addressed by making the fields
Options and implementing
ABGuard manually; it just makes things uglier in a way that didn't seem necessary for the proof of concept.