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[Balazs Scheidler]

> > parent:
> > 	wait until term signal arrives
> >
> > child:
> > 	initialize config
> > 	send SIGTERM to parent
> 
> Maybe I'm missing something, but why don't you initialize the config
> *before* forking? Then all the parent needs to do is exit.... (I assume you
> set the parent's SIGCHLD handler to ignore and that the child removes itself
> from the parent's process group.... though even that you can do before
> forking.)

Because initialization may mean something that cannot be inherited by
fork(), for instance door support may create threads etc.

I background the child using the following function:

void go_background()
{
        pid_t pid;

        pid = fork();
        if (pid == 0) {
                return;
        }
        else if (pid == -1) {
                werror("Cannot fork(), (%z)\n", strerror(errno));
                exit(1);
        }
        signal(SIGTERM, sig_term);
        while (sigtermrecvd == 0)
                pause();
        exit(0);
}

The child then initializes config and calls the following code:

        if (do_fork) {
                set_error_internal();
                close(0);
                close(1);
                close(2);
                setsid();
                kill(getppid(), SIGTERM);
        }

I don't understand everything about process groups, process leaders and
such, but this should work IMHO. If you have a better idea, please don't
hesitate to tell me.

-- 
Bazsi
PGP key: http://www.balabit.hu/pgpkey.txt, or finger bazsi@balabit.hu