Re: __{read,write}_once

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

David Holland <dholland-tech%netbsd.org@localhost> wrote:
>  > I see the potential source of confusion, but just think about: what
>  > could "atomic" possibly mean for loads or stores?  A load is just a
>  > load, there is no RMW cycle, conceptually; inter-locking the operation
>  > does not make sense.  For anybody who attempts to reason about this,
>  > it should not be too confusing, plus there are man pages.
> 
> ...that it's not torn.
> 
> As far as names... there are increasingly many slightly different
> types of atomic and semiatomic operations.
> 
> I think it would be helpful if someone came up with a comprehensive
> naming scheme for all of them (including ones we don't currently have
> that we're moderately likely to end up with later...)

Yes, the meaning of "atomic" has different flavours and describes different
set of properties in different fields (operating systems vs databases vs
distributed systems vs ...) and, as we can see, even within the fields.

Perhaps not ideal, but "atomic loads/stores" and "relaxed" are already the
dominant terms.  I think it is pointless to attempt to reinvent the wheel
here.  It is terminology used by C11 (and C++11) and accepted by various
technical literature and, at this point, by academia (if you look at the
recent papers on memory models -- it's pretty much settled).  These terms
are not too bad; it could be worse; and this bit is certainly not the worst
part of C11.  So, I would just move on.

-- 
Mindaugas