/* Assist in file system timestamp tests.
Copyright (C) 2009-2011 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/* Written by Eric Blake , 2009. */
#ifndef GLTEST_NAP_H
# define GLTEST_NAP_H
/* Sleep long enough to notice a timestamp difference on the file
system in the current directory. Assumes that BASE is defined,
and requires that the test module depends on usleep. */
static void
nap (void)
{
static long delay;
if (!delay)
{
/* Initialize only once, by sleeping for 20 milliseconds (needed
since xfs has a quantization of about 10 milliseconds, even
though it has a granularity of 1 nanosecond, and since NTFS
has a default quantization of 15.25 milliseconds, even though
it has a granularity of 100 nanoseconds). If the seconds
differ, repeat the test one more time (in case we crossed a
quantization boundary on a file system with 1 second
resolution). If we can't observe a difference in only the
nanoseconds, then fall back to 1 second if the time is odd,
and 2 seconds (needed for FAT) if time is even. */
struct stat st1;
struct stat st2;
ASSERT (close (creat (BASE "tmp", 0600)) == 0);
ASSERT (stat (BASE "tmp", &st1) == 0);
ASSERT (unlink (BASE "tmp") == 0);
delay = 20000;
usleep (delay);
ASSERT (close (creat (BASE "tmp", 0600)) == 0);
ASSERT (stat (BASE "tmp", &st2) == 0);
ASSERT (unlink (BASE "tmp") == 0);
if (st1.st_mtime != st2.st_mtime)
{
/* Seconds differ, give it one more shot. */
st1 = st2;
usleep (delay);
ASSERT (close (creat (BASE "tmp", 0600)) == 0);
ASSERT (stat (BASE "tmp", &st2) == 0);
ASSERT (unlink (BASE "tmp") == 0);
}
if (! (st1.st_mtime == st2.st_mtime
&& get_stat_mtime_ns (&st1) < get_stat_mtime_ns (&st2)))
delay = (st1.st_mtime & 1) ? 1000000 : 2000000;
}
usleep (delay);
}
#endif /* GLTEST_NAP_H */