return ((double)timer->stop.tv_sec) - ((double)timer->start.tv_sec) +
((((double)timer->stop.tv_usec) - ((double)timer->start.tv_usec)) / 1000000.0);
return ((double)timer->stop.tv_sec) - ((double)timer->start.tv_sec) +
((((double)timer->stop.tv_usec) - ((double)timer->start.tv_usec)) / 1000000.0);