On Wed, 1 Jun 2022 08:19:54 +0000
Mattias Rönnblom <mattias.ronnb...@ericsson.com> wrote:
> On 2022-06-01 00:45, Stephen Hemminger wrote:
> > On Mon, 23 May 2022 16:23:46 +0200
> > Mattias Rönnblom <mattias.ronnb...@ericsson.com> wrote:
> >
> >> +/**
> >> + * The RTE seqcount type.
> >> + */
> >> +typedef struct {
> >> + uint32_t sn; /**< A sequence number for the protected data. */
> >> +} rte_seqcount_t;
> >
> > Don't need structure for only one element.
> >
>
> The struct adds a degree of type safety, with no run-time cost.
Makes sense.
>
> > typedef uint32_t rte_seqcount_t;
> >
> > + if (unlikely(begin_sn != end_sn))
> > + return true;
> > +
> > + return false;
> >
> > Prefer to avoid conditional if possible (compiler will optimize it as):
> >
> > return begin_sn == end_sn;
>
> Is this a readability argument, or a performance one?
>
> The compiler might use the unlikely hint to do something useful, like
> avoiding a branch in the common case.
It is a matter of taste. I always prefer writing the smallest (within reason)
amount of code as possible. And my preference is to do things with declarative
and data statements rather than conditionals.
