Re: [PATCH] Further eliminate POSIX-emulation under LinuxThreads
On Sun, Feb 12, 2012 at 02:16:49PM +0000, Robert Millan wrote:
> El 12 de febrer de 2012 12:42, Niko Tyni <ntyni@debian.org> ha escrit:
> > [crossposted to the Debian GNU/kFreeBSD development list debian-bsd
> > and the Perl 5 development list perl5-porters ]
>
> Thanks for bringing this up.
>
> >> This is also a complete non-issue in practice these days, LinuxThreads
> >> was a Linux 2.4 thread implementation that nobody maintains
> >> anymore[2], all modern Linux distros use NPTL threads which don't
> >> suffer from this discrepancy.
>
> This is not correct. LinuxThreads is only obsolete on GNU/Linux, but
> it is maintained and used on GNU/kFreeBSD because, contrary to what
> its name would indicate, it's a reasonably portable pthread library
> with few kernel-specific dependencies.
>
> However...
>
> > Under POSIX threads the getpid() and getppid() functions return the
> > same values across multiple threads, i.e. threads don't have their own
> > PID's. This is not the case under the obsolete LinuxThreads where each
> > thread has a different PID, so getpid() and getppid() will return
> > different values across threads.
>
> The version of LinuxThreads used on GNU/kFreeBSD has been patched to
> use kFreeBSD (kernel of FreeBSD) thread primitives, and thus future
> releases of Debian GNU/kFreeBSD will no longer be affected by this
> problem.
>
> Debian "Squeeze" release *IS* affected, however. It'd be better if
> you could wait at least until there's a new release before breaking
> compatibility with Squeeze users.
This is now hitting us with the packaging of perl 5.16. Can you provide
a reference which might enable us know which outcome to expect, so that
the test[1] can be updated accordingly?
Cheers,
Dominic.
[1] <http://perl5.git.perl.org/perl.git/blob/7a04c38f6a1f87cc07b6ab6c7778e2a56ca24902:/t/op/getpid.t#l33>
--
Dominic Hargreaves | http://www.larted.org.uk/~dom/
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