Re: [dpdk-dev] [PATCH] eal/linux: fix return after alarm registration failure

[Thomas Monjalon <thomas@monjalon.net>]

26/06/2019 13:43, Burakov, Anatoly:
> On 26-Jun-19 12:39 PM, David Marchand wrote:
> > On Wed, Jun 26, 2019 at 1:36 PM Thomas Monjalon <thomas@monjalon.net> wrote:
> > 
> >> 26/06/2019 13:20, David Marchand:
> >>> On Wed, Jun 26, 2019 at 12:41 PM Thomas Monjalon <thomas@monjalon.net>
> >>> wrote:
> >>>
> >>>> When adding an alarm, if an error happen when registering
> >>>> the common alarm callback, it is not considered as a major failure.
> >>>> The alarm is then inserted in the list.
> >>>> However it was returning an error code after inserting the alarm.
> >>>>
> >>>> The error code is reset to 0 so the behaviour and the return code
> >>>> are consistent.
> >>>> Other return code related lines are cleaned up for easier
> >> understanding.
> >>>>
> >> [...]
> >>>> --- a/lib/librte_eal/linux/eal/eal_alarm.c
> >>>> +++ b/lib/librte_eal/linux/eal/eal_alarm.c
> >>>>          if (!handler_registered) {
> >>>> -               ret |= rte_intr_callback_register(&intr_handle,
> >>>> +               ret = rte_intr_callback_register(&intr_handle,
> >>>>                                  eal_alarm_callback, NULL);
> >>>> -               handler_registered = (ret == 0) ? 1 : 0;
> >>>> +               if (ret == 0)
> >>>> +                       handler_registered = 1;
> >>>> +               else
> >>>> +                       /* not fatal, callback can be registered later
> >> */
> >>>> +                       ret = 0;
> >>>>          }
> >>>
> >>> Well, then it means that you don't want to touch ret at all.
> >>> How about:
> >>> if (rte_intr_callback_register(&intr_handle,
> >>>                                 eal_alarm_callback, NULL) == 0)
> >>>          handler_registered = 1;
> >>>
> >>> ?
> >>
> >> Too much simple :)
> >>
> >> I think we try to avoid calling a function in a "if"
> >> per coding style.
> >> And my proposal has the benefit of offering a comment
> >> about the non-fatal error.
> >>
> > 
> > /* not fatal, callback can be registered later */
> > if (rte_intr_callback_register(&intr_handle,
> >                                eal_alarm_callback, NULL) == 0)
> >         handler_registered = 1;
> > 
> 
> I prefer the original. It's more explicit and conveys the intention 
> better. Did i break the tie? :)

I was going to send a v2 with David's suggestion.
Now I'm confused.