Re: [Qemu-trivial] [PATCH 3/4] pidfile: stop making pidfile error a special case

[Gonglei <arei.gonglei@huawei.com>]

On 2014/10/31 15:41, Michael Tokarev wrote:

> 31.10.2014 10:33, Gonglei wrote:
> []
>>>>> While at it, fix wrong identation in os_daemonize().
>>>>
>>>> s/identation/identification/
>>>
>>> No, the original word was the right one.
>>
>> Sorry, I can't find 'identation' both dictionary and Google.
>> Your meaning 'indentation'?
> 
> Damn.  I missed that one.  It is "indentation" inedeed :)
> (but not identification).
> 
> []
>>>>>              do {
>>>>>                  len = read(fds[0], &status, 1);
>>>>>              } while (len < 0 && errno == EINTR);
>>>>> -            if (len != 1) {
>>>>> -                exit(1);
>>>>> -            }
>>>>
>>>> Does this check need to be removed?
>>>
>>> Yes, because...
>>>>
>>>>> -            else if (status == 1) {
>>>>> -                fprintf(stderr, "Could not acquire pidfile\n");
>>>>> -                exit(1);
>>>>> -            } else {
>>>>> -                exit(0);
>>>>> -            }
>>>>> -            } else if (pid < 0) {
>>>>> -                exit(1);
>>>>> -            }
>>>>> +
>>>>> +            exit(len == 1 && status == 0 ? 0 : 1);
>>>
>>> ...it is checked here, note the 'len == 1' part of the condition.
>>
>> If len != 1, the original code exit with 1, after your changes,
>> it will exit with 0. Right?
> 
> with len != 1, the condition 'len == 1 && status == 0 ? 0 : 1'

Ok. That's will be great if you can modify it
to "(len == 1 && status == 0 ) ? 0 : 1"

Best regards,
-Gonglei

> evaluates to 1.  Maybe I can add a comment here:
> 

> +            /* only exit successfully if our child actually
> +             * wrote a one-byte zero to our pipe */
> +            exit(len == 1 && status == 0 ? 0 : 1);
> 
> See the result at http://git.corpit.ru/?p=qemu.git;a=shortlog;h=refs/heads/trivial-patches-next
> 
> Thanks,
> 
> /mjt