Re: [PATCH v4] gc: reject if another gc is running, unless --force is given

From: Andreas Schwab <schwab@linux-m68k.org>
Date: Aug 10, 2013, 07:11 UTC
Message-ID: <m238qiyq8q.fsf@linux-m68k.org>
In-Reply-To: <CACsJy8D8EHpPGrc8MZnpvmh1j1LDudoZ0OO-zyfuDmhwLJqNsA@mail.gmail.com>

Duy Nguyen <pclouds@gmail.com> writes:

Show 11 quoted lines

> On Fri, Aug 9, 2013 at 11:29 PM, Andres Perera <andres.p@zoho.com> wrote:
>> On Thu, Aug 8, 2013 at 6:35 AM, Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote:
>>> +       uintmax_t pid;
>>
>> pid_t is always an signed type, therefore unintmax_t does not make
>> sense as a catch all value
>
> I only catch real process id. In practice we don't have processes with
> negative pid_t, do we? I can't find any document about this, but at
> least waitpid seems to treat negative pid (except -1) just as an
> indicator while the true pid is the positive counterpart.

Negative pids are used for denoting process groups in various interfaces. No process can have a negative pid.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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