threads/101323: fork(2) in threaded programs broken.

[Daniel Eischen]

The following reply was made to PR threads/101323; it has been noted by GNATS.

From: Daniel Eischen <deischen at freebsd.org>
To: Poul-Henning Kamp <phk at phk.freebsd.dk>
Cc: FreeBSD-gnats-submit at freebsd.org, freebsd-threads at freebsd.org
Subject: Re: threads/101323: fork(2) in threaded programs broken.
Date: Thu, 3 Aug 2006 16:19:29 -0400 (EDT)

 On Thu, 3 Aug 2006, Poul-Henning Kamp wrote:
 
 > In message <Pine.GSO.4.64.0608031558540.13543 at sea.ntplx.net>, Daniel Eischen wr
 > ites:
 >
 >
 >> There's no easy way to hold all library locks.  They are
 >> littered in libc and libpthread and the application doesn't
 >> have access to them.  You would have to teach libc to
 >> record these locks and export a function to lib<thread>
 >> to lock and unlock these them.
 >
 > I would be perfectly happy if libpthread would just at the very
 > least release the locks it specifically grabs for the fork.
 >
 > There's a big difference between giving it a sensible shot and
 > downright sabotaging it the way we do currently.
 
 Actually, I would prefer to emit an error message of the
 form:
 
    "fork() from a threaded process is not defined by POSIX"
 
 and purposefully segfault ;-)
 
 > Anyway, apart from the view from the theoretical high ground and
 > the fact that POSIX doesn't actually say anything helpful here, are
 > there any objections to the fix I proposed ?
 
 For that one specific change, no objection.  I have an
 objection to enabling the NOTYET in thr_kern.c without
 having an overall solution for libc as well.
 
 -- 
 DE