Ken Brown wrote:
> I don't know what's going on, but it seems clear that pagefile.sys can't
> be used reliably on Cygwin to get a boot time. I wonder if
> get_boot_time should simply bail out on Cygwin and always give a boot
> time of 0. Or do you have a better idea?
I'm committing this workaround.
2024-05-04 Bruno Haible <br...@clisp.org>
readutmp, boot-time: Work around a Cygwin 3.5.3 bug.
Reported by Ken Brown <kbr...@cornell.edu> in
<https://lists.gnu.org/archive/html/bug-gnulib/2024-05/msg00035.html>.
* lib/boot-time-aux.h (get_windows_boot_time): On Cygwin, ignore
pagefile.sys if it appears to be a directory, and use another file as
a fallback.
diff --git a/lib/boot-time-aux.h b/lib/boot-time-aux.h
index a94cdb3f30..7f8c5405e4 100644
--- a/lib/boot-time-aux.h
+++ b/lib/boot-time-aux.h
@@ -304,19 +304,35 @@ get_windows_boot_time (struct timespec *p_boot_time)
Instead, on Windows, the boot time can be retrieved by looking at the
time stamp of a file that (normally) gets touched only during the boot
process, namely C:\pagefile.sys. */
- const char * const boot_touched_file =
- #if defined __CYGWIN__ && !defined _WIN32
- /* It is more portable to use /proc/cygdrive/c than /cygdrive/c. */
- "/proc/cygdrive/c/pagefile.sys"
- #else
- "C:\\pagefile.sys"
- #endif
- ;
- struct stat statbuf;
- if (stat (boot_touched_file, &statbuf) >= 0)
+ const char * const boot_touched_files[] =
{
- *p_boot_time = get_stat_mtime (&statbuf);
- return 0;
+ #if defined __CYGWIN__ && !defined _WIN32
+ /* It is more portable to use /proc/cygdrive/c than /cygdrive/c. */
+ "/proc/cygdrive/c/pagefile.sys",
+ /* A fallback, working around a Cygwin 3.5.3 bug. It has a modification
+ time about 1.5 minutes after the last boot; but that's better than
+ nothing. */
+
"/proc/cygdrive/c/ProgramData/Microsoft/Windows/DeviceMetadataCache/dmrc.idx"
+ #else
+ "C:\\pagefile.sys"
+ #endif
+ };
+ for (idx_t i = 0; i < SIZEOF (boot_touched_files); i++)
+ {
+ const char *filename = boot_touched_files[i];
+ struct stat statbuf;
+ if (stat (filename, &statbuf) >= 0)
+ {
+# if defined __CYGWIN__ && !defined _WIN32
+ /* Work around a Cygwin 3.5.3 bug.
+ <https://cygwin.com/pipermail/cygwin/2024-May/255931.html> */
+ if (!S_ISDIR (statbuf.st_mode))
+# endif
+ {
+ *p_boot_time = get_stat_mtime (&statbuf);
+ return 0;
+ }
+ }
}
return -1;
}
