On Wed, Jul 29, 2026 at 11:05:55PM +0900, Alexandre Courbot wrote:
[...]
> > + /// Get the value, or populate it if it's missing.
> > + ///
> > + /// This method is useful to avoid spinning on the internal atomic
> > state. If all writers call
> > + /// this method with the same lock, then they are synchronized with
> > each other and it's
> > + /// guaranteed that no caller will attempt to invoke
> > [`SetOnce::populate`] more than once.
> > + pub fn try_get_or_populate<F, E, U, B>(&self, lock: &lock::Lock<U, B>,
> > f: F) -> Result<&T, E>
>
> From the API perspective, this still leaves the option of calling the
> method concurrently with different locks. What happens in this case?
>
Calling this function with different locks is not a correctness issue
(SetOnce::populate() already handle the synchronization). User may want
to synchronize different groups of writers with different locks.
Regards,
Boqun
> > + where
> > + B: lock::Backend,
> > + F: FnOnce() -> Result<T, E>,
> > + {
> > + if let Some(value) = self.as_ref() {
> > + return Ok(value);
> > + }
> > +
> > + let mut to_insert = f()?;
[...]
