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

[Burakov, Anatoly]

On 26-Jun-19 12:39 PM, David Marchand wrote:
> On Wed, Jun 26, 2019 at 1:36 PM Thomas Monjalon <thomas at monjalon.net> wrote:
> 
>> 26/06/2019 13:20, David Marchand:
>>> On Wed, Jun 26, 2019 at 12:41 PM Thomas Monjalon <thomas at 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? :)

-- 
Thanks,
Anatoly