dest.c: Use monotonic time for cups_enum_dest #1084
Conversation
Patch written by Adam Williamson. `gettimeofday()` is vulnerable to clock jumps, so it is better to use `clock_gettime()` to avoid issues with libcups if system changes clock, f.e. in Live CDs.
| t->t = GetTickCount(); | ||
| #elif HAVE_CLOCK_MONOTONIC | ||
| clock_gettime(CLOCK_MONOTONIC, &t->t); | ||
| #elif __sun |
There was a problem hiding this comment.
Let's not bother with Solaris-specific functions. We don't have any Solaris testing resources.
| cups_gettimeofday(_cups_time_t *t) | ||
| { | ||
| #if _WIN32 | ||
| t->t = GetTickCount(); |
There was a problem hiding this comment.
Need to use GetTickCount64, otherwise we have a 49 day wrap problem.
| typedef struct _cups_time_s | ||
| { | ||
| #if _WIN32 | ||
| DWORD t; |
There was a problem hiding this comment.
I'd actually like to do away with this kind of structure here - let's just use a double to return "elapsed time" and then we can use simple math operations portably across platforms.
| @@ -448,6 +450,22 @@ AC_DEFINE_UNQUOTED([CUPS_DEFAULT_SYSTEM_AUTHKEY], ["$CUPS_DEFAULT_SYSTEM_AUTHKEY | |||
| AC_SUBST([CUPS_SYSTEM_AUTHKEY]) | |||
| AC_SUBST([INSTALLXPC]) | |||
|
|
|||
| dnl Check if monotonic clock is available | |||
| AC_MSG_CHECKING([for monotonic clock]) | |||
| AC_LINK_IFELSE([AC_LANG_PROGRAM([ | |||
There was a problem hiding this comment.
It should be enough to check that CLOCK_MONOTONIC is defined. CUPS requires POSIX compliance.
| @@ -224,6 +224,8 @@ AC_COMPILE_IFELSE([ | |||
| dnl See if we have the removefile(3) function for securely removing files | |||
| AC_CHECK_FUNCS([removefile]) | |||
|
|
|||
| dnl See if | |||
| #if _WIN32 | ||
| t->t = GetTickCount(); | ||
| #elif HAVE_CLOCK_MONOTONIC | ||
| clock_gettime(CLOCK_MONOTONIC, &t->t); |
There was a problem hiding this comment.
Even if CLOCK_MONOTONIC is defined, that doesn't mean that the platform will support that clock. Check for a non-zero return and fallback on gettimeofday when it fails.
|
[master 0350eba] Add cupsGetClock API. Also in libcups repository. |
Patch written by Adam Williamson.
gettimeofday()is vulnerable to clock jumps, so it is better to useclock_gettime()to avoid issues with libcups if system changes clock, f.e. in Live CDs.