On Wed, Feb 4, 2009 at 11:09 AM, Mladen Turk <mturk@apache.org> wrote:
Hi,

I would like to commit this module to trunk.
It's a watchdog module that creates a worker threads
either in parent, child via an API, and it's not for
standalone use, but for other module usage like
mod_heartbeat, probably mod_jk and others that need
maintenance threads.

It seems scary to me to have the MPM parent on Unix forking children while a separate thread in that same process is running arbitrary code.  Surprising problems can crop up when this arbitrary code is in certain states (maybe a mutex gets inherited in held state by the new MPM child?)

I once had a rather harsh quote on this topic from Ulrich Drepper taped to my office wall amidst TCP/IP diagrams and definitions of C's break and continue in very large print, but sadly it has gone missing. 

However, I just found another one which should suffice:

* Ulrich Drepper <drepper@redhat.com> [030910 15:41]:
> Aidan Van Dyk wrote:
>
> > The particular problem I'm seeing is with syslog_lock.
>
> The standard doesn't guarantee that any functions but exec works after
> fork in a multi-threaded program.

That doesn't match the profile of an MPM child process ;)