test-utimens: avoid spurious failure

Fixes a spurious failure on ext3, with one-second resolution,
now that ctime effects are being tested for inequality.

* tests/test-chown.h (nap): Factor...
* tests/nap.h: ...into new file.
* tests/test-lchown.h (nap): Avoid duplication.
* tests/test-utimens-common.h (nap): Use shared implementation,
necessary on file systems with 1-second resolution.
* modules/chown-tests (Files): Include new file.
* modules/fdutimensat-tests (Files): Likewise.
* modules/futimens-tests (Files): Likewise.
* modules/lchown-tests (Files): Likewise.
* modules/openat-tests (Files): Likewise.
* modules/utimens-tests (Files): Likewise.
* modules/utimensat-tests (Files): Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 4 insertions, 23 deletions

diff --git a/tests/test-utimens-common.h b/tests/test-utimens-common.h
index 707971abe4..30fd886748 100644
--- a/tests/test-utimens-common.h
+++ b/tests/test-utimens-common.h
@@ -24,10 +24,14 @@
 # include <string.h>
 # include <unistd.h>
 
+/* Gnulib modules.  */
 # include "stat-time.h"
 # include "timespec.h"
 # include "utimecmp.h"
 
+/* Gnulib test header.  */
+# include "nap.h"
+
 enum {
   BILLION = 1000 * 1000 * 1000,
 
@@ -44,29 +48,6 @@ enum {
                           : 0)
 };
 
-/* Sleep long enough to cross a timestamp quantization boundary on
-   most known systems with subsecond timestamp resolution.  For
-   example, ext4 has a quantization of 10 milliseconds, but a
-   resolution of 1 nanosecond.  Likewise, NTFS has a quantization as
-   slow as 15.25 milliseconds, but a resolution of 100 nanoseconds.
-   This is necessary on systems where creat or utimens with NULL
-   rounds down to the quantization boundary, but where gettime and
-   hence utimensat can inject timestamps between quantization
-   boundaries.  By ensuring we cross a boundary, we are less likely to
-   confuse utimecmp for two times that would round to the same
-   quantization boundary but are distinct based on resolution.  */
-static void
-nap (void)
-{
-  /* Systems that lack usleep also lack subsecond timestamps, and have
-     a quantization boundary equal to the resolution.  Our usage of
-     utimecmp allows equality, so no need to waste 980 milliseconds
-     if the replacement usleep rounds to 1 second.  */
-# if HAVE_USLEEP
-  usleep (20 * 1000); /* 20 milliseconds.  */
-# endif
-}
-
 # if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
 /* Skip ctime tests on native Windows, since it is either a copy of
    mtime or birth time (depending on the file system), rather than a