Re: rte_atomic_*_explicit

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Thu, Jan 25, 2024 at 11:10:47PM +0100, Morten Brørup wrote:
> > From: Mattias Rönnblom [mailto:hofors@lysator.liu.se]
> > Sent: Thursday, 25 January 2024 19.54
> > 
> > Why do rte_stdatomic.h functions have the suffix "_explicit"?
> > Especially
> > since there aren't any wrappers for the implicit variants.
> > 
> > More to type, more to read.
> 
> They have the "_explicit" suffix to make their names similar to those in stdatomic.h.
> 
> You might consider their existence somewhat temporary until C11 stdatomics can be fully phased in, so there's another argument for similar names. (This probably does not happen as long as compilers generate slower code for C11 stdatomics than with their atomic built-ins.)

yes, there was feedback at the time it was.

* we should *not* have non-explicit versions of the macros
* the atomic generic functions should be named to match C11 standard
  with a rte_ prefix.

> 
> > 
> > When was this API introduced? Shouldn't it say "experimental"
> > somewhere?
> 
> They were introduced as part of the migration to C11.
> I suppose they were not marked experimental because they replaced something we didn't want anymore (the compiler built-ins for atomics, e.g. __atomic_load_n()). I don't recall if we discussed experimental marking or not.

i don't think we discussed it since they're wrapper macros.

> 
> 
> Reverse paper trail:
> https://git.dpdk.org/dpdk/log/lib/eal/include/rte_stdatomic.h
> https://patchwork.dpdk.org/project/dpdk/patch/1692738045-32363-2-git-send-email-roretzla@linux.microsoft.com/
> https://patchwork.dpdk.org/project/dpdk/patch/1692738045-32363-2-git-send-email-roretzla@linux.microsoft.com/
>