diff options
| author | Daniel Stone <daniel@fooishbar.org> | 2010-08-27 20:36:37 +1000 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2010-12-27 09:43:44 -0800 |
| commit | 44adb31bfece29260a9bbd9075c9212ebf00d24d (patch) | |
| tree | 630914bb83dc8bf853ad7fbede70fd5fbb43add4 /os | |
| parent | e06fa804009798ea95efa8babaabb0228dfdfe65 (diff) | |
GetTimeInMillis: Use CLOCK_MONOTONIC_COARSE where available
On some systems, using CLOCK_MONOTONIC forces a readback of HPET or some
similarly expensive timer. CLOCK_MONOTONIC_COARSE can alleviate this,
at the cost of negligibly-reduced resolution, so prefer that where we
can.
Signed-off-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Julien Cristau <jcristau@debian.org>
Reviewed-by: Tiago Vignatti <tiago.vignatti@nokia.com>
Diffstat (limited to 'os')
| -rw-r--r-- | os/utils.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/os/utils.c b/os/utils.c index afdff0c5a..18fd91151 100644 --- a/os/utils.c +++ b/os/utils.c @@ -427,7 +427,21 @@ GetTimeInMillis(void) #ifdef MONOTONIC_CLOCK struct timespec tp; - if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) + static clockid_t clockid; + if (!clockid) { +#ifdef CLOCK_MONOTONIC_COARSE + if (clock_getres(CLOCK_MONOTONIC_COARSE, &tp) == 0 && + (tp.tv_nsec / 1000) <= 1000 && + clock_gettime(CLOCK_MONOTONIC_COARSE, &tp) == 0) + clockid = CLOCK_MONOTONIC_COARSE; + else +#endif + if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) + clockid = CLOCK_MONOTONIC; + else + clockid = ~0L; + } + if (clockid != ~0L && clock_gettime(clockid, &tp) == 0) return (tp.tv_sec * 1000) + (tp.tv_nsec / 1000000L); #endif |