time_diff_in_msec
real_time = time_diff_in_msec(hdl->start_time, end_time);
hdl->total_time += time_diff_in_msec(start_time, end_time);
hdl->total_time += time_diff_in_msec(hdl->start_time, end_time);
hdl->total_time += time_diff_in_msec(hdl->start_time, end_time);