Re: [PATCHv6 0/8] fetch submodules in parallel

From: Stefan Beller <sbeller@google.com>
Date: Oct 1, 2015, 19:03 UTC
Message-ID: <CAGZ79kb7Td6v16Ypfp7Uzgh+eLf26Mdwuy6=eMQwkPJdBdMUng@mail.gmail.com>
In-Reply-To: <560D81B7.6090304@ramsayjones.plus.com>

On Thu, Oct 1, 2015 at 11:55 AM, Ramsay Jones <ramsay@ramsayjones.plus.com> wrote:

Show 18 quoted lines

> Hi Stefan,
>
>>
>> -     if (!pp->get_next_task(pp->data,
>> +     if (!pp->get_next_task(&pp->children[i].data,
>>                              &pp->children[i].process,
>> -                            &pp->children[i].err))
>> +                            &pp->children[i].err,
>> +                            pp->data))
>>               return 1;
>
> ... the above hunk caught my eye. I don't know that it matters that
> much, but since you have reordered parameters on some functions, should
> pp->get_next_task() take the 'task_cb' as the last parameter, rather than
> the first?
>
> I have not looked at the final result yet (just the interdiff), so please
> just ignore the above if I've missed something obvious. :-D

Well I reordered such that "passive" arguments come last, i.e. the cookies for consumption. In this specific case we ask get_next_task to fill in the cookie if desired. Unlike all the other cookie passing this is a double void pointer, so even syntactically we have a difference to other cookie passing around.

If you look at the function definitions in the header, you find the arguments ordered as

  (Active/unique arguments for that function, child process, error
buffer, cookies for consumption)

That said, I find a few things I need to improve. pp->children[i].data, may want to be initialized to NULL before we ask get_next_task to fill in a cookie. If get_next_task decides not to, we have a clear default.

The call to run_processes_parallel may be reordered to its original order again, as we pass in a cookie actively. (int n, int *cb, callbacks...)

>
> ATB,
> Ramsay Jones
>