gistfile1.txt

#include <zmq.hpp>
#include <stdio.h>
#include <stdint.h>

int main () 
{
    zmq::context_t context (1);

    zmq::socket_t s (context, ZMQ_DEALER);
    uint64_t hwm = 1;
    s.setsockopt (ZMQ_HWM, &hwm, sizeof (uint64_t));
    s.bind ("tcp://*:11132");

    zmq::pollitem_t items [1];
    items [0].socket  = s;
    items [0].fd      = 0;
    items [0].events  = ZMQ_POLLIN | ZMQ_POLLOUT;
    items [0].revents = 0;

    while (true)
    {
        int rc = zmq::poll (&items [0], 1, -1);
        assert (rc > 0);

        // ACK coming in
        if (items [0].revents & ZMQ_POLLIN) {
            zmq::message_t msg;
            s.recv (&msg);
            static int got_ack = 0;
            got_ack++;
            printf ("Got ACK: %d\n", got_ack); 
        }

        // Sending messages out
        if (items [0].revents & ZMQ_POLLOUT) {
            while (true)
            {
                zmq::message_t msg (10);
                if (!s.send (msg, ZMQ_NOBLOCK))
                    break;
            }
        }
    }

    return 0;
}