Test case which demonstrates the "Assertion failed: nbytes == sizeof (command_t)" occuring on orderly shutdown.

gistfile1.c

#include <zmq.h>
#include <assert.h>
#include <signal.h>

static void* ctx = NULL;

void handle_signal(int sig)
{
    void* push = zmq_socket(ctx, ZMQ_PUSH);
    zmq_connect(push, "inproc://CONTROL-SOCKET");
    
    zmq_msg_t message;
    zmq_msg_init(&message);
    zmq_send(push, &message, 0);
    
    zmq_msg_close(&message);
    zmq_close(push);
}

int main(int argc, char const* argv[])
{    
    // Setup signal handling
    struct sigaction action;
    action.sa_handler = handle_signal;
    action.sa_flags = 0;

    sigemptyset(&action.sa_mask);
    sigaction(SIGINT,  &action, NULL);
    sigaction(SIGTERM, &action, NULL);

    // Setup ZMQ
    ctx = zmq_init(1);
    int rc = 0;

    void* router = zmq_socket(ctx, ZMQ_ROUTER);
    assert(router != NULL);
    rc = zmq_bind(router, "tcp://*:4567");
    assert(rc == 0);

    void* puller = zmq_socket(ctx, ZMQ_PULL);
    assert(puller != NULL);
    rc = zmq_bind(puller, "inproc://CONTROL-SOCKET");
    assert(rc == 0);
    
    zmq_pollitem_t poll_item[4];
    poll_item[0].socket = puller;
    poll_item[0].fd = 0;
    poll_item[0].events = ZMQ_POLLIN;
    poll_item[0].revents = 0;
    
    // Loop
    int keep_looping = 1;
    while (keep_looping)
    {
        zmq_poll(poll_item, 1, 100000);
        
        if (poll_item[0].revents & ZMQ_POLLIN)
        {
            zmq_msg_t message;
            zmq_msg_init(&message);
            zmq_recv(puller, &message, 0);
            zmq_msg_close(&message);
            
            keep_looping = 0;
        }
    }
    
    // Terminate
    zmq_close(puller);
    zmq_close(router);

    zmq_term(ctx);
    
    return 0;
}