diff options
Diffstat (limited to 'src/basic/time-util.c')
| -rw-r--r-- | src/basic/time-util.c | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/src/basic/time-util.c b/src/basic/time-util.c index c16460a198..edd9179cb8 100644 --- a/src/basic/time-util.c +++ b/src/basic/time-util.c @@ -47,15 +47,12 @@ static clockid_t map_clock_id(clockid_t c) { /* Some more exotic archs (s390, ppc, …) lack the "ALARM" flavour of the clocks. Thus, clock_gettime() will * fail for them. Since they are essentially the same as their non-ALARM pendants (their only difference is * when timers are set on them), let's just map them accordingly. This way, we can get the correct time even on - * those archs. - * - * Also, older kernels don't support CLOCK_BOOTTIME: fall back to CLOCK_MONOTONIC. */ + * those archs. */ switch (c) { - case CLOCK_BOOTTIME: case CLOCK_BOOTTIME_ALARM: - return clock_boottime_or_monotonic (); + return CLOCK_BOOTTIME; case CLOCK_REALTIME_ALARM: return CLOCK_REALTIME; @@ -1083,22 +1080,31 @@ bool timezone_is_valid(const char *name) { return true; } -clockid_t clock_boottime_or_monotonic(void) { - static clockid_t clock = -1; - int fd; - - if (clock != -1) - return clock; - - fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC); - if (fd < 0) - clock = CLOCK_MONOTONIC; - else { - safe_close(fd); - clock = CLOCK_BOOTTIME; +bool clock_boottime_supported(void) { + static int supported = -1; + + /* Note that this checks whether CLOCK_BOOTTIME is available in general as well as available for timerfds()! */ + + if (supported < 0) { + int fd; + + fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC); + if (fd < 0) + supported = false; + else { + safe_close(fd); + supported = true; + } } - return clock; + return supported; +} + +clockid_t clock_boottime_or_monotonic(void) { + if (clock_boottime_supported()) + return CLOCK_BOOTTIME; + else + return CLOCK_MONOTONIC; } int get_timezone(char **tz) { |