On Thu, Aug 10, 2006 at 05:16:17PM +0200, Divacky Roman wrote:
> hi
>
> I am doing this:
>
> (pseudocode)
> LIST_FOREACH_SAFE(em, &td_em->shared->threads, threads, tmp_em) {
>
> kill(em, SIGKILL);
> }
>
> kill(SIGKILL) calls exit() which calls my exit_hook()
>
> my exit_hook() does LIST_REMOVE(em, threads).
>
> the problem is that this is not synchronous so I am getting a panic by
> INVARIANTS
> that "Bad link elm prev->next != elm". This is because I list 1st item in the
> list
> I call kill on it, then process 2nd list, then scheduler preempts my code and
> calls
> exit() on the first proc which removes the first entry and bad things happen.
>
> I see this possible solutions:
>
> make this synchronous, it can be done by something like:
>
> ....
> kill(em, SIGKILL);
> wait_for_proc_to_vanish();
>
> pls. tell me what do you think about this solution and if its correct what is
> the wait_for_proc_to_vanish()
>
> maybe there's some better solution, pls tell me.It sounds like you need a lock protecting the list. If you held it over the whole loop you could signal all processes before the exit_hook could remove any. -- Brooks
pgpAjMc3UpCa2.pgp
Description: PGP signature
