How to use timerfd properly?

I use timerfd with zmq.

How can I use timerfd_create and timerfd_set to wait one second for the timer (https://man7.org/linux/man-pages/man2/timerfd_create.2.html)?

I have looked through the link but I still do not get how I can initilize a timer that waits one second per tick with create and set. This is exactly my task:

We start a timer with timerfd_create(), which is 1 / sec. ticking. When setting a timer with timer_set_(..) acounter is simply incremented, which is decremented with every tick. When the counter reaches 0, the timerhas expired.

In this project we have a function timer _ set _(), where the timer is set with the function timerfd_create and timerfd_settimer(). I hope you can help me.

This is my progress (part of my code):

    struct itimerspec timerValue;    g_items[n].socket = nullptr;     g_items[n].events = ZMQ_POLLIN;    g_items[n].fd = timerfd_create(CLOCK_REALTIME, 0);    if(g_items[n].fd == -1 ){        printf("timerfd_create() failed: errno=%d\n", errno);        return -1;    }      timerValue.it_value.tv_sec = 1;    timerValue.it_value.tv_nsec = 0;    timerValue.it_interval.tv_sec = 1;    timerValue.it_interval.tv_nsec = 0;    timerfd_settime(g_items[n].fd,  0, &timerValue, NULL);