> Poisoning: Panic Safety in Mutexes
This is one of the biggest design flaws in Rust's std, in my opinion.
Poisoning mutexes can have its use, but it's very rare in practice. Usually it's a huge misfeature that only introduces problems. More often than not panicking in a critical section is fine[1], but on the other hand poisoning a Mutex is a very convenient avenue for a denial-of-service attack, since a poisoned Mutex will just completely brick a given critical section.
I'm not saying such a project doesn't exist, but I don't think I've ever seen a project which does anything sensible with Mutex's `Poisoned` error besides ignoring it. It's always either an `unwrap` (and we know how well that can go [2]), or do the sensible thing and do this ridiculous song-and-dance:
let guard = match mutex {
Ok(guard) => guard,
Err(poisoned) => poisoned.into_inner()
};
Suffice to say, it's a pain.
So in a lot of projects when I need a mutex I just add `parking_lot`, because its performance is stellar, and it doesn't have the poisoning insanity to deal with.
[1] -- obviously it depends on a case-by-case basis, but if you're using such a low level primitive you should know what you're doing
[2] -- https://blog.cloudflare.com/18-november-2025-outage/#memory-...
This is one of the biggest design flaws in Rust's std, in my opinion.
Poisoning mutexes can have its use, but it's very rare in practice. Usually it's a huge misfeature that only introduces problems. More often than not panicking in a critical section is fine[1], but on the other hand poisoning a Mutex is a very convenient avenue for a denial-of-service attack, since a poisoned Mutex will just completely brick a given critical section.
I'm not saying such a project doesn't exist, but I don't think I've ever seen a project which does anything sensible with Mutex's `Poisoned` error besides ignoring it. It's always either an `unwrap` (and we know how well that can go [2]), or do the sensible thing and do this ridiculous song-and-dance:
Suffice to say, it's a pain.So in a lot of projects when I need a mutex I just add `parking_lot`, because its performance is stellar, and it doesn't have the poisoning insanity to deal with.
[1] -- obviously it depends on a case-by-case basis, but if you're using such a low level primitive you should know what you're doing
[2] -- https://blog.cloudflare.com/18-november-2025-outage/#memory-...