utimensat-tests, etc.: try to fix some races Problem reported by Bernhard Voelker in <http://lists.gnu.org/archive/html/bug-gnulib/2013-04/msg00071.html>. I don't know whether this patch fixes that race condition, but it fixes *some* race conditions, so it should be a win. * modules/chown-tests (Depends-on): * modules/fchownat-tests (Depends-on): * modules/fdutimensat-tests (Depends-on): * modules/futimens-tests (Depends-on): * modules/lchown-tests (Depends-on): * modules/stat-time-tests (Depends-on): * modules/utimens-tests (Depends-on): * modules/utimensat-tests (Depends-on): Depend on nanosleep, not usleep. * modules/chown-tests (test_chown_LDADD): * modules/lchown-tests (test_lchown_LDADD): * modules/stat-time-tests (test_stat_time_LDADD): New macro. * modules/fchownat-tests (test_fchownat_LDADD): * modules/fdutimensat-tests (test_fdutimensat_LDADD): * modules/futimens-tests (test_futimens_LDADD): * modules/utimens-tests (test_utimens_LDADD): * modules/utimensat-tests (test_utimensat_LDADD): Add $(LIB_NANOSLEEP). * modules/stat-time-tests (Files): Add tests/nap.h. * tests/nap.h: Include <limits.h>, for INT_MAX. (lt_mtime): Remove. (diff_timespec): New function. (get_stat): Rename from get_mtime. All callers changed. (nap_works): Determine the needed delay by inspecting the file system's timestamp jumps; this should be more reliable. Look at both mtime and ctime, and take the maximum of the two jumps. (nap_works, guess_delay): Return a nanosecond cound, not a microsecond count. All callers changed. (nap_works, nap): Use nanosleep, not usleep. Check for nanosleep failure. (nap): Multiply the guess by 1.125, to accommodate the case where the file system's clock is a bit slower than nanosleep's clock. * tests/test-stat-time.c (BASE): New macro. Include nap.h. (nap): Remove; nap.h now defines this. This removes a duplicate implementation of 'nap'.