Re: POSIX message queues

[Jamie Lokier <jamie@shareable.org>]

Jakub Jelinek wrote:
> > Speaking of librt - I should not have to link in pthreads and the
> > run-time overhead associated with it (locking stdio etc.) just so I
> > can use shm_open().  Any chance of fixing this?
> 
> That overhead is mostly gone in current glibcs (when using NPTL):
> a) e.g. locking is done unconditionally even when libpthread is not present
>    (it is just lock cmpxchgl, inlined)
> b) things like cancellation aware syscall wrappers for cancellable syscalls
>    and various other things are only done after first pthread_create has
>    been called, it doesn't matter whether libpthread is loaded or not

That's good.  I still don't like linking in pthreads when I'm not
using threads or any thread-using services, so I'll continue to use a
non-libc version of shm_open() in my own programs, particularly the
ones which use clone() directly.

Why isn't shm_open() simply part of libc?

-- Jamie