Re: SIGSEGV on recursive pthread_join

[Richard Guenther]

On Mon, 5 Jan 2004, Jeroen Dekkers wrote:

> On Mon, Jan 05, 2004 at 05:17:47PM +0100, Richard Guenther wrote:
> > I'm experiencing a weird behavior with the NPTL threads, as that my
> > application (sf.net/projects/glame) segfaults upon invocation of a
> > pthread_join while the main process is currently joining the thread that
> > tries to do the join. I.e.
> >
> >   main:
> >     pthread_join(thread1)
> >
> >   thread1:
> >     pthread_join(thread2)
> >     ...
> >     pthread_join(threadN)
> >
> >   thread2..N:
> >     maybe completed
> >
> > and now as soon as thread1 joins thread2, the pthread_join() in main
> > segfaults! The backtrace is not very helpful, it just shows pthread_join
> > from /lib/tls/libpthread.so.0.  If using a libc with debugging symbols,
> > the failure does _not_ occour!?  All threads were launched by main
> > initially.
>
> You can't join a thread more than once.

I'm not doing this. I'm joining the joining thread ;) I.e. each thread is
exactly joined one time (see the numbering above).

Richard.