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'.

8 files changed, 18 insertions, 13 deletions

diff --git a/modules/chown-tests b/modules/chown-tests
index 467046de64..58b9656821 100644
--- a/modules/chown-tests
+++ b/modules/chown-tests
@@ -9,7 +9,7 @@ Depends-on:
 ignore-value
 lstat
 mgetgroups
-usleep
+nanosleep
 stat-time
 stdbool
 symlink
@@ -20,3 +20,4 @@ AC_CHECK_FUNCS_ONCE([getegid])
 Makefile.am:
 TESTS += test-chown
 check_PROGRAMS += test-chown
+test_chown_LDADD = $(LDADD) $(LIB_NANOSLEEP)
diff --git a/modules/fchownat-tests b/modules/fchownat-tests
index 1b79d47f55..7b9991e6c6 100644
--- a/modules/fchownat-tests
+++ b/modules/fchownat-tests
@@ -9,9 +9,9 @@ tests/macros.h
 Depends-on:
 ignore-value
 mgetgroups
+nanosleep
 openat-h
 progname
-usleep
 stat-time
 symlink
 
@@ -21,4 +21,4 @@ AC_CHECK_FUNCS_ONCE([getegid])
 Makefile.am:
 TESTS += test-fchownat
 check_PROGRAMS += test-fchownat
-test_fchownat_LDADD = $(LDADD) @LIBINTL@
+test_fchownat_LDADD = $(LDADD) $(LIB_NANOSLEEP) @LIBINTL@
diff --git a/modules/fdutimensat-tests b/modules/fdutimensat-tests
index 9e3e77979a..a77ada4f06 100644
--- a/modules/fdutimensat-tests
+++ b/modules/fdutimensat-tests
@@ -10,10 +10,10 @@ tests/macros.h
 Depends-on:
 fcntl-h
 ignore-value
+nanosleep
 openat
 timespec
 dup
-usleep
 utimecmp
 
 configure.ac:
@@ -21,4 +21,5 @@ configure.ac:
 Makefile.am:
 TESTS += test-fdutimensat
 check_PROGRAMS += test-fdutimensat
-test_fdutimensat_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) @LIBINTL@
+test_fdutimensat_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) \
+  $(LIB_NANOSLEEP) @LIBINTL@
diff --git a/modules/futimens-tests b/modules/futimens-tests
index a0bfb0b215..a1948eb2bb 100644
--- a/modules/futimens-tests
+++ b/modules/futimens-tests
@@ -10,9 +10,9 @@ Depends-on:
 gettext
 fcntl-h
 ignore-value
+nanosleep
 timespec
 dup
-usleep
 utimecmp
 
 configure.ac:
@@ -20,4 +20,4 @@ configure.ac:
 Makefile.am:
 TESTS += test-futimens
 check_PROGRAMS += test-futimens
-test_futimens_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) @LIBINTL@
+test_futimens_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) $(LIB_NANOSLEEP) @LIBINTL@
diff --git a/modules/lchown-tests b/modules/lchown-tests
index 47aec96f6e..d7288fea6c 100644
--- a/modules/lchown-tests
+++ b/modules/lchown-tests
@@ -8,7 +8,7 @@ tests/macros.h
 Depends-on:
 ignore-value
 mgetgroups
-usleep
+nanosleep
 stat-time
 stdbool
 symlink
@@ -19,3 +19,4 @@ AC_CHECK_FUNCS_ONCE([getegid])
 Makefile.am:
 TESTS += test-lchown
 check_PROGRAMS += test-lchown
+test_lchown_LDADD = $(LDADD) $(LIB_NANOSLEEP)
diff --git a/modules/stat-time-tests b/modules/stat-time-tests
index 2e72444b29..18843de5a6 100644
--- a/modules/stat-time-tests
+++ b/modules/stat-time-tests
@@ -1,13 +1,15 @@
 Files:
 tests/test-stat-time.c
 tests/macros.h
+tests/nap.h
 
 Depends-on:
+nanosleep
 time
-usleep
 
 configure.ac:
 
 Makefile.am:
 TESTS += test-stat-time
 check_PROGRAMS += test-stat-time
+test_stat_time_LDADD = $(LDADD) $(LIB_NANOSLEEP)
diff --git a/modules/utimens-tests b/modules/utimens-tests
index 8c9160b020..76dad1b93b 100644
--- a/modules/utimens-tests
+++ b/modules/utimens-tests
@@ -11,9 +11,9 @@ Depends-on:
 dup
 gettext
 ignore-value
+nanosleep
 symlink
 timespec
-usleep
 utimecmp
 
 configure.ac:
@@ -21,4 +21,4 @@ configure.ac:
 Makefile.am:
 TESTS += test-utimens
 check_PROGRAMS += test-utimens
-test_utimens_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) @LIBINTL@
+test_utimens_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) $(LIB_NANOSLEEP) @LIBINTL@
diff --git a/modules/utimensat-tests b/modules/utimensat-tests
index 6acfe89ad6..09e5cb15bf 100644
--- a/modules/utimensat-tests
+++ b/modules/utimensat-tests
@@ -9,8 +9,8 @@ tests/macros.h
 
 Depends-on:
 ignore-value
+nanosleep
 timespec
-usleep
 utimecmp
 
 configure.ac:
@@ -18,4 +18,4 @@ configure.ac:
 Makefile.am:
 TESTS += test-utimensat
 check_PROGRAMS += test-utimensat
-test_utimensat_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) @LIBINTL@
+test_utimensat_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME) $(LIB_NANOSLEEP) @LIBINTL@