struct timespec end_time;
    struct timespec current_time;

    double shocktimesec_s = floor(shocktimesec);
    double shocktimesec_ns = (shocktimesec - floor(shocktimesec)) * 1e9;

    clock_gettime(CLOCK_MONOTONIC, &end_time);

    if ((end_time.tv_nsec + shocktimesec_ns ) < 1.00) {
        end_time.tv_sec = end_time.tv_sec + shocktimesec_s;
        end_time.tv_nsec = end_time.tv_nsec + shocktimesec_ns;
    } else {
        end_time.tv_sec = end_time.tv_sec + shocktimesec_s + 1;
        end_time.tv_nsec = (end_time.tv_nsec + shocktimesec_ns) - 1;
    }

    long double end_time_value = end_time.tv_sec + (end_time.tv_nsec / 1e9);

    long double current_time_value = 0;

    do {

        // do stuff here!

        clock_gettime(CLOCK_MONOTONIC, &current_time);

        current_time_value = current_time.tv_sec + (current_time.tv_nsec / 1e9);
        printf("current time: %f", current_time_value);
        printf("end time: %f", end_time_value);




        } while (current_time_value < end_time_value);