blue11

Everything looks like Eastern Europe in the 80s, except that, as many people noted already, nobody is smiling.

Well, that much is obvious. But if you are going to truncate, you should be consistent. Always truncate towards 0, not sometimes towards 0 and sometimes towards infinity.

Sorry to nitpick, but I believe the time difference code has an error of 1 millisecond 25% of the time:

    int64_t delta = tv2->tv_sec - tv1->tv_sec;
    return delta * 1000 + (tv2->tv_usec - tv1->tv_usec) / 1000;

One way to fix it is:

    int64_t deltasec = tv2->tv_sec - tv1->tv_sec - 1;
    int64_t deltausec = tv2->tv_usec - tv1->tv_usec + 1000000;
    return deltasec * 1000 + deltausec / 1000;