Re: RFC: Two small remote protocol extensions

Daniel Jacobowitz
2002-05-02T19:34:21Z

On Thu, May 02, 2002 at 12:22:35PM -0700, Kevin Buettner wrote:
> On May 2, 3:14pm, Daniel Jacobowitz wrote:
>
> > Heck, if I can work out a way to do it safely, I intend to do
> > one-thread-stopped-only SVR4 shared library support also.
>
> Can you explain what you mean by this?

I'd like to (where possible; probably not in every circumstance!)
update the shared library information without stopping all threads. At
least glibc's dynamic linker does enough locking on its own (so that
multiple threads calling dlopen() do not trample each other) that when
one thread has stopped it is safe to examine the link maps; I assume
that this is true for other systems which support both threads and
dlopen as well (e.g. Solaris).

As I said in the original message, starting Apache 2 in multithreaded
mode stops all threads every time a module is loaded; that's painful,
since I believe modules can be loaded after server threads have been
created (and on demand, per-request, in some cases). The mod_perl
developers were complaining about the speed hit several months ago.

--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer