#include <bits/types/struct_timeval.h>

double interval_to_ms(struct timeval const *t)
{
    return (double)t->tv_sec * 1000.0 + (double)t->tv_usec / 1000.0;
}

double get_interval(struct timeval const *start, struct timeval const *stop)
{
    return interval_to_ms(stop) - interval_to_ms(start);
}