Re: [PATCH v4] rust: lock: Export Guard::do_unlocked()

[Paolo Bonzini]

On 10/31/25 10:31, Alice Ryhl wrote:
> I do agree that this behavior has a lot of potential to surprise
> users, but I don't think it's incorrect per se. It was done
> intentionally for Condvar, and it's not unsound. Just surprising.

Yes, I agree that it is not unsound.`

For conditional variables, wait() is clearly going to release the mutex 
to wait for someone else so the surprise factor is much less.  Having it 
return a new guard would be closer to std::sync::Condvar::wait, but it'd 
add churn and I'm not sure how much you all care about consistency with 
std.  std has the extra constraint of poisoned locks so it doesn't 
really have a choice.

Paolo

> Of course, that doesn't mean we can't change it. Condvar could be
> updated to use ownership in that way, and doing say may be a good
> idea.