Mercurial > hg > octave-kai > gnulib-hg
changeset 12153:4443f8be082f
test-stat-time: avoid more spurious failures
On xfs, although timestamps can have a full nanosecond resolution,
successive file actions appear to be quantized to approximately
10 millisecond windows. Running with just 1 ms delays could
cause two actions to fall in the same window, leading to sporadic
failures on a fast enough machine. Slow down to prevent this.
On ext2, timestamps only have 1 second resolution, but if the
first timestamp was made at 1.95 and the second at 2.10, then
the two files appear 1 second apart, and the shorter delay was
used, causing spurious failures. Require that the observable
difference lie within the same second, using a second try if
necessary, to prevent this.
* tests/test-stat-time.c (nap): Wait for 15ms rather than 2ms, for
xfs; and avoid race if the two timestamps cross quantization edge.
Signed-off-by: Eric Blake <ebb9@byu.net>
| author | Eric Blake <ebb9@byu.net> |
|---|---|
| date | Sat, 10 Oct 2009 08:04:41 -0600 |
| parents | 64131ac8b004 |
| children | 70f5bc44922b |
| files | ChangeLog tests/test-stat-time.c |
| diffstat | 2 files changed, 23 insertions(+), 7 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2009-10-10 Eric Blake <ebb9@byu.net> + test-stat-time: avoid more spurious failures + * tests/test-stat-time.c (nap): Wait for 15ms rather than 2ms, for + xfs; and avoid race if the two timestamps cross quantization edge. + relocatable: prefer 'file system' over 'filesystem' * m4/relocatable-lib.m4 (gl_RELOCATABLE_NOP): Use AS_HELP_STRING. (gl_RELOCATABLE_LIBRARY_BODY): Fix spelling.
--- a/tests/test-stat-time.c +++ b/tests/test-stat-time.c @@ -104,19 +104,31 @@ static long delay; if (!delay) { - /* Initialize only once, by sleeping for 1 millisecond. If that - was enough to observe a difference, then we are set; - otherwise fall back to 2 seconds. */ + /* Initialize only once, by sleeping for 15 milliseconds (needed + since xfs has a quantization of about 10 milliseconds, even + though it has a granularity of 1 nanosecond). 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 2 seconds. */ struct stat st1; struct stat st2; ASSERT (stat ("t-stt-stamp1", &st1) == 0); ASSERT (unlink ("t-stt-stamp1") == 0); - usleep (delay = 1000); + usleep (delay = 15000); create_file ("t-stt-stamp1"); ASSERT (stat ("t-stt-stamp1", &st2) == 0); - if (! (st1.st_mtime < st2.st_mtime - || (st1.st_mtime == st2.st_mtime - && get_stat_mtime_ns (&st1) < get_stat_mtime_ns (&st2)))) + if (st1.st_mtime != st2.st_mtime) + { + /* Seconds differ, give it one more shot. */ + st1 = st2; + ASSERT (unlink ("t-stt-stamp1") == 0); + usleep (delay); + create_file ("t-stt-stamp1"); + ASSERT (stat ("t-stt-stamp1", &st2) == 0); + } + if (! (st1.st_mtime == st2.st_mtime + && get_stat_mtime_ns (&st1) < get_stat_mtime_ns (&st2))) delay = 2000000; } usleep (delay);