[CRIU] [PATCH v2] zdtm: test -- Add trivial poll() timeout test

[Cyrill Gorcunov]

On Wed, Mar 18, 2015 at 01:49:43PM +0300, Andrew Vagin wrote:
> > +
> > +		task_waiter_complete(&t, 1);
> > +		delta = 5;
> > +		while (futex_get(f) != 1) {
> 
> We can use test_go() here

Ah, thanks, completely forget that we've this helper.

> 
> > +			ret = poll(ufds, 2, delta * 1000);
> > +			show_pollfd(ufds, 2);
> > +			if (ret) {
> > +				err("Poll-2 returned %d (events?!)", ret);
> > +				exit(1);
> > +			}
> > +		}
> > +
> > +		task_waiter_wait4(&t, 2);
> 
> Why do we need this synchronization?

Well, with test_go (and futex underneath) this become redundant, thanks.

> > +
> > +		show_timestamp("Stop", time2.tv_sec, time2.tv_usec);
> > +		show_timestamp("Diff", time2.tv_sec - time1.tv_sec,
> > +			       time2.tv_usec - time1.tv_usec);
> > +		if ((time2.tv_sec - time1.tv_sec) > delta) {
> 
> We can call poll a few time in a loop and the test should not fail in
> this case.

Not really sure I follow here. How it's different from a single poll call?
I mean we're testing that poll get not screwed on timeout after restore,
why one poll call is not enough here?

> > +	test_daemon();
> > +	test_waitsig();
> > +
> > +	futex_set(f, 1);
> 
> kill(pid, SIGTERM);

sure, thanks