Re: speed up test-stat-time

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

According to Eric Blake on 10/9/2009 12:06 PM:
> Multiple calls to sleep(2) add up fast!  I've especially noticed it while 
> working on my utimensat series, where repeatedly running 'make check' stalls 
> on 
> this test.  Unless you are insane enough to run on FAT, or unlucky enough to 
> be 
> on mingw (since I didn't want to drag in a dependency on xnanosleep just for 
> this test), this patch gives an order-of-magnitude speedup to test-stat-time.

And in testing it, I came across spurious failures on at least Darwin's
NFS client, where mtime is rather bogus until a sync().  I'm pushing this:

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAkrQAw8ACgkQ84KuGfSFAYAFWQCgpHBmL9ctcYWnHR3ghhK1qvxW
0pAAnRHqZEpfX7q4oqUXX2K58VOwXq4A
=oYbS
-----END PGP SIGNATURE-----

>From 9b77fe9ec434d890feccddf665540e4a53aa6972 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Fri, 9 Oct 2009 21:09:38 -0600
Subject: [PATCH] test-stat-time: port to buggy NFS clients

On darwin, the NFS client reports mtime with st_sec==-1 and st_nsec
monotonically increasing per transaction until the next sync();
but sync() is expensive, so it is easier to just skip this part
of the test if mtime is nowhere near ctime.

* tests/test-stat-time.c (main) [W32]: Reduce ifdefs.
(test_ctime): Also skip test if mtime and ctime are skewed.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog              |    4 ++++
 tests/test-stat-time.c |   18 ++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index d5ec7c3..49ac4cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2009-10-09  Eric Blake  <address@hidden>

+       test-stat-time: port to buggy NFS clients
+       * tests/test-stat-time.c (main) [W32]: Reduce ifdefs.
+       (test_ctime): Also skip test if mtime and ctime are skewed.
+
        futimens: new module
        * modules/futimens: New file.
        * lib/futimens.c (futimens): Likewise.
diff --git a/tests/test-stat-time.c b/tests/test-stat-time.c
index 77b99a4..3759024 100644
--- a/tests/test-stat-time.c
+++ b/tests/test-stat-time.c
@@ -186,10 +186,21 @@ test_mtime (const struct stat *statinfo, struct timespec 
*modtimes)
     }
 }

-#if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+/* Skip the ctime tests on native Windows platforms, because their
+   st_ctime is either the same as st_mtime (plus or minus an offset)
+   or set to the file _creation_ time, and is not influenced by rename
+   or chmod.  */
+# define test_ctime ((void) 0)
+#else
 static void
 test_ctime (const struct stat *statinfo)
 {
+  /* On some buggy NFS clients, mtime and ctime are disproportionately
+     skewed from one another.  Skip this test in that case.  */
+  if (statinfo[0].st_mtime != statinfo[0].st_ctime)
+    return;
+
   /* mtime(stamp2) < ctime(renamed) */
   ASSERT (statinfo[2].st_mtime < statinfo[1].st_ctime
           || (statinfo[2].st_mtime == statinfo[1].st_ctime
@@ -246,12 +257,7 @@ main ()
   cleanup (0);
   prepare_test (statinfo, modtimes);
   test_mtime (statinfo, modtimes);
-  /* Skip the ctime tests on native Windows platforms, because there st_ctime
-     is either the same as st_mtime (plus or minus an offset) or set to the
-     file _creation_ time, and is not influenced by rename or chmod.  */
-#if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
   test_ctime (statinfo);
-#endif
   test_birthtime (statinfo, modtimes, birthtimes);

   cleanup (0);
-- 
1.6.5.rc1