[PATCH] make flapping smbcontrol test more informative

[Jeremy Allison]

On Tue, Feb 27, 2018 at 07:11:18AM +1300, Gary Lockyer via samba-technical wrote:
> Ouch this was added for the pre-fork process model work and it was
> intended to catch gross failures in the start up.
> 
> So it could just be limited to just the prefork test environments,
> currently only addc_no_ntlm.
> 
> My preference though would be to get it working for the standard model
> as well, but I'm unsure how to do this. Any thoughts, suggestions.

If you've got a TOC/TOU race it's difficult to see
how this test can survive in its current form.

To make it reliable you must eliminate the race,
and irpc_all_servers() is only ever going to
get you a 'snapshot' of processes available to
ping.

> On 25/02/18 22:35, Ralph Böhme via samba-technical wrote:
> > On Sun, Feb 25, 2018 at 09:07:06PM +1300, Douglas Bagnall via samba-technical wrote:
> >> And then I thought: with multi-process fork-on-demand LDAP, we should
> >> expect a race between listing the processes and pinging them. They 
> >> disappear all the time.
> >>
> >>         processes = self.msg_ctx.irpc_all_servers()
> >>         for p in processes:
> >>             for id in p.ids:
> >>                 if p.name != "samba":
> >>                     self.check_run("%s %d %s" % (COMMAND, id.pid, PING),
> >>                                    msg="trying to ping %s" % p.name)
> >>
> >> so I was wrong here:
> >>
> >>>>> This is a canary, I suspect -- the test itself is sound (sort of),
> >>
> >> the test is not sound.
> > 
> > hehe, ouch! Good catch! :)
> > 
> > -slow
> > 
>