dccifd: restart after signal 6

On Fri, Jun 05, 2009 at 09:52:05PM +0000, Vernon Schryver wrote:
> > From: MrC <lists-dcc@cappella.us>
> 
> > As expected, this is the result of a kill(2) call.
> >
> > #0  0xbbaf923f in kill () from /usr/lib/libc.so.12
> > #1  0xbbb95a64 in abort () from /usr/lib/libc.so.12
> > #2  0xbbbdc60c in __res_state () from /usr/lib/libpthread.so.0
> > #3  0x0806b9ca in dcc_res_delays (budget=4) at get_port.c:476
> > #4  0x080660f2 in dcc_clnt_rdy (emsg=0xb91fff50 "", ctxt=0x80c9000, 
> > clnt_fgs=8 '\b') at clnt_send.c:1740
> > #5  0x080544dc in clnt_resolve_thread (arg=0x0) at clnt_threaded.c:394
> > #6  0xbbbe562d in pthread_join () from /usr/lib/libpthread.so.0
> > #7  0xbbb1aa2c in swapcontext () from /usr/lib/libc.so.12
> 
> Now that you mention it, I saw an instance of it a week or two ago,
> but hoped it was a fluke.  I've been unable to reproduce it then or today.
> 
> That's an ugly one, because it's not in my code.
> This is the relevant part of my get_port.c:
> 
> 	if (!dcc_host_locked)
> 		dcc_logbad(EX_SOFTWARE, "dcc_get_host() not locked");
> 
> 	/* get the current value */
> 	if (!(_res.options & RES_INIT))
> 		res_init();
> 
> dcc_logbad() calls abort() after syslog().
> Because I assume the resolver is not thread safe and check that it's
> locked, it can't be a simple, valid locking problem.
> 
> I guess I'll have to look for NetBSD's version of the resolver library
> to see what NetBSD has done to it.  There are no abort() calls in the
> FreeBSD 7.1 version of res_state.c

	# find /usr/src/ -name 'res_state*'
	/usr/src/lib/libc/resolv/res_state.c
	/usr/src/lib/libpthread/res_state.c
	# grep -ri abort\( /usr/src/lib/libc/resolv/res_state.c 
	# grep -ri abort\( /usr/src/lib/libpthread/res_state.c 
		abort();



   Petar Bogdanovic