int gettime(struct timespec *tp)
{
static struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
/* Find out clock resolution. Will only be retrieved on first call */
if (!res.tv_sec && !res.tv_nsec) {
clock_getres(CLOCK_REALTIME, &res);
/* Clock resolution is lower than expected (1ns) */
assert(res.tv_nsec == 1);
}
/* Get wall-clock time */
return clock_gettime(CLOCK_REALTIME, tp);
}
/* OS X hasn't defined POSIX clocks, but clock_get_time() */
#elif defined HAVE_CLOCK_GET_TIME
int gettime(struct timespec *tp)
{
static struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
clock_serv_t cclock;
host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
/* Find out clock resolution. Will only be retrieved on first call */
if (!res.tv_sec && !res.tv_nsec) {
natural_t attribute[4];
mach_msg_type_number_t count = sizeof(attribute)/sizeof(natural_t);
clock_get_attributes(cclock, CLOCK_GET_TIME_RES,
(clock_attr_t) &attribute, &count);
/* Clock resolution is lower than expected (1ns) */
assert(attribute[0] > 1);
}
mach_timespec_t mts;
kern_return_t rc = clock_get_time(cclock, &mts);
mach_port_deallocate(mach_task_self(), cclock);
tp->tv_sec = mts.tv_sec;
tp->tv_nsec = mts.tv_nsec;
return (rc == KERN_SUCCESS ? 0 : -1);
}
static Sint64
mach_clock_getres(ErtsMachClock *clk)
{
kern_return_t kret;
natural_t attr[1];
mach_msg_type_number_t cnt;
cnt = sizeof(attr);
kret = clock_get_attributes(clk->srv,
CLOCK_GET_TIME_RES,
(clock_attr_t) attr,
&cnt);
if (kret != KERN_SUCCESS || cnt != 1) {
erl_exit(ERTS_ABORT_EXIT,
"clock_get_attributes(%s, _) failed\n",
clk->name);
}
return (Sint64) attr[0];
}
