blob: 33083189dfd9e7d95ebee1c799e9cb2786121282 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
#ifndef TIME_OSX_H
#define TIME_OSX_H
/*
* clock_gettime()
*
* OS X doesn't implement the clock_gettime() POSIX interface, but does
* provide a monotonic clock through mach_absolute_time(). On i386 and
* x86_64 architectures this clock is in nanosecond units, but not so on
* other devices. mach_timebase_info() provides the conversion parameters.
*
*/
#include <time.h> /* struct timespec */
#include <errno.h> /* errno EINVAL */
#include <sys/time.h> /* TIMEVAL_TO_TIMESPEC struct timeval gettimeofday(3) */
#include <mach/mach_time.h> /* mach_timebase_info_data_t mach_timebase_info() mach_absolute_time() */
#define CLOCK_REALTIME 0
#define CLOCK_VIRTUAL 1
#define CLOCK_PROF 2
#define CLOCK_MONOTONIC 3
static mach_timebase_info_data_t clock_timebase = {
.numer = 1, .denom = 1,
}; /* clock_timebase */
void clock_gettime_init(void) __attribute__((constructor));
void clock_gettime_init(void) {
if (mach_timebase_info(&clock_timebase) != KERN_SUCCESS)
__builtin_abort();
} /* clock_gettime_init() */
static int clock_gettime(int clockid, struct timespec *ts) {
switch (clockid) {
case CLOCK_REALTIME: {
struct timeval tv;
if (0 != gettimeofday(&tv, 0))
return -1;
TIMEVAL_TO_TIMESPEC(&tv, ts);
return 0;
}
case CLOCK_MONOTONIC: {
unsigned long long abt;
abt = mach_absolute_time();
abt = abt * clock_timebase.numer / clock_timebase.denom;
ts->tv_sec = abt / 1000000000UL;
ts->tv_nsec = abt % 1000000000UL;
return 0;
}
default:
errno = EINVAL;
return -1;
} /* switch() */
} /* clock_gettime() */
#endif /* TIME_OSX_H */
|
