rt.py

from cffi import FFI

ffi = FFI()

ffi.cdef("""
typedef long int time_t;

struct timespec {
    time_t tv_sec;
    long tv_nsec;
};

int gettime(struct timespec *);
""")

lib = ffi.verify("""
#include <time.h>
#include <mach/clock.h>
#include <mach/mach.h>

int gettime(struct timespec* ts) {
    clock_serv_t cclock;
    mach_timespec_t mts;
    host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &cclock);
    clock_get_time(cclock, &mts);
    mach_port_deallocate(mach_task_self(), cclock);
    ts->tv_sec = mts.tv_sec;
    ts->tv_nsec = mts.tv_nsec;
    return 0;
};
""")

def gettime():
    ts = ffi.new('struct timespec *')
    lib.gettime(ts)
    return (ts.tv_sec * 1000000000) + ts.tv_nsec