On Thu, Nov 23, 2023 at 4:17 PM Ruediger Pluem <rpl...@apache.org> wrote:
>
> On 11/23/23 3:53 PM, Yann Ylavic wrote:
> >
> > As for the 64bit atomics vs APR version dance, it's because the former
> > are not available before apr-1.7 and likely not reliable before 1.7.4
> > (at least for some architectures where builtins are not available). In
> > any case we need a fallback for apr < 1.7, but maybe to keep this
> > simpler we should fall back to non-atomics (as before) in this case.
> > It all looks over complicated for the feature, but I can't think of
> > something simpler and still correct..
>
> Understood.
>
> I am asking because I guess I am hit now by races in the byrequests LB
> with the worker->s->lbstatus.
> I probably want to look for a way to solve this in a more generic way
> for various shared worker fields.
lbstatus is an int so the 32bit apr_atomic API could do I think.
Maybe we need some ap_atomic_{int,long,size_t,..}_*() helpers for
system dependent widths. It preferably would be implemented in APR but
in the meantime we could have something in httpd already.
What we should avoid IMO is needing 64bit atomics on 32bit systems
(because we'd have to reimplement the mutexes etc), but apart from
that I think we can wrap anything using the existing apr atomics.
Regards;
Yann.
