ref: 40dc39bf7d8d17a84d6a2a427ca7facd8b2cb66b
dir: /sys/src/ape/lib/ap/gen/clock.c/
#include <time.h>
#include <sys/times.h>
clock_t
clock(void)
{
struct tms t;
if(times(&t) == (clock_t)-1)
return (clock_t)-1;
return t.tms_utime+t.tms_stime;
}