Re: linuxthreads and tid testing

Eric Paire (e.paire@opengroup.org)
Fri, 30 Jul 1999 09:12:29 +0200


> Eric PAIRE <eric.paire@ri.silicomp.com> writes:
>
> > I don't really understand why a kernel patch is needed to have a uniq
> > PID for a thread. I would have implemented a getpid() in the libpthread
> > (hiding the getpid() from libc), as well as a getppid().
>
> And how do you handle things like credentials? These data structures
> are filled by the kernel. Send such a package from a thread and the
> receiver will see the PID of the thread, and not the manager.
>
> There are certainly other situations like this. An only-user-level
> solution cannot work.
>
Don't you think that this should be the purpose of the CLONE_PID flag ?
With this flag, all system calls returning the current pid would return
the pid of the last clone() call without this flag set, except getpid()
(in order to get a standard way to get the actual kernel pid of a
CLONE_PID thread, and because this could be hidden by the libpthread).

-Eric
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ Eric PAIRE
Web : http://www.ri.silicomp.com/~paire | Group SILICOMP - Research Institute
Email: eric.paire@ri.silicomp.com | 2, avenue de Vignate
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