I compile zeromq c++ source code with pgm source code in visual code 2019, and get zeromq lib.Then I config my multicast environment, but the program failed in joining multicast.my code is :
void* context = zmq_ctx_new(); void* socket = zmq_socket(context, ZMQ_SUB); zmq_setsockopt(socket, ZMQ_SUBSCRIBE, "", 0); zmq_setsockopt(socket, ZMQ_RATE, &RATE, sizeof(RATE)); const int32_t RCVBUF_SIZE = 1342177280; zmq_setsockopt(socket, ZMQ_RCVHWM, &RCVBUF_SIZE, sizeof(RCVBUF_SIZE)); const int32_t SNDBUF_SIZE = 1342177280; zmq_setsockopt(socket, ZMQ_SNDHWM, &SNDBUF_SIZE, sizeof(SNDBUF_SIZE)); // example: "epgm://192.168.65.132;224.0.22.1:9210" const std::string protocol = "epgm"; int rc = zmq_connect( socket, (protocol +"://" + local_ip +";" + multicast_addr).c_str());`When debugging it, I found it failed in :
`int rc = pgm_receiver->init (udp_encapsulation, _addr->address.c_str ()); (from file session_base.cpp)`continuing the debugging process, it returns -1 here:
`retval = setsockopt (s, recv_level, MCAST_JOIN_GROUP, (const char*)gr, sizeof(struct group_req));(from file sockaddr.c89.c)`How can I resolve this issue?
the reason and the solution