CFDate.c

// taken from https://opensource.apple.com/source/CF/CF-855.17/CFDate.c
CFAbsoluteTime CFAbsoluteTimeGetCurrent(void) {
    CFAbsoluteTime ret;
    struct timeval tv;
    gettimeofday(&tv, NULL); // http://linux.die.net/man/2/gettimeofday
    ret = (CFTimeInterval)tv.tv_sec - kCFAbsoluteTimeIntervalSince1970;
    ret += (1.0E-6 * (CFTimeInterval)tv.tv_usec);
    return ret;
}