c++ - 为什么 ZeroMQ PGM 多播没有收到多播消息？ ( C++, Windows )

Question

环境设置:
- 多播发送和接收应用程序都在同一台机器上运行

我正在将 ZeroMQ 多播与 OpenPGM 支持集成，但在我的示例代码下方遇到问题。

即“未收到多播消息” 在接收器应用程序中。如果我做错了，请纠正我。也无法找到关于 ZeroMQ PGM 多播要求的适当示例。

// ZMQ_pgm_receive.cpp : 
//
//Headers
#include "stdafx.h"
#include "zmq.h"
#include <iostream>
#include <windows.h>

std::string fullurl = "pgm://eth0;239.255.0.1:30001";
static int roundtrip_count = 50;
static size_t message_size = 4;

int _tmain(int argc, _TCHAR* argv[])
{
    void *ctx = NULL,
         *s = NULL;
    int con;
    int i;

    ctx = zmq_init (1);
    if (!ctx) {
        printf ("error in zmq_init: %s\n", zmq_strerror (errno));
        return -1;
    }

    s = zmq_socket (ctx, ZMQ_SUB);
    if (!s) {
        printf ("error in zmq_socket: %s\n", zmq_strerror (errno));
        return -1;
    }


    con = zmq_bind(socket, fullurl.c_str()); 
    if (con == 0) {
        printf ("error in zmq_bind: %s\n", zmq_strerror (errno));
        return -1;
    }
    zmq_msg_t msg;

    int rc = zmq_msg_init (&msg);
    if (rc != 0) {
        printf ("error in zmq_msg_init: %s\n", zmq_strerror (errno));
        return -1;
    }

    for (i = 0; i != roundtrip_count; i++) {

        rc = zmq_recvmsg (s, &msg, 0);
        if (rc < 0) {
            printf ("error in zmq_recvmsg: %s\n", zmq_strerror (errno));
            return -1;
        }
        printf("message received\n");

        if (zmq_msg_size (&msg) != message_size) {
            printf ("message of incorrect size received\n");
            return -1;
        }
        Sleep(1000);

    }

    rc = zmq_msg_close (&msg);
    if (rc != 0) {
        printf ("error in zmq_msg_close: %s\n", zmq_strerror (errno));
        return -1;
    }

    rc = zmq_close (s);
    if (rc != 0) {
        printf ("error in zmq_close: %s\n", zmq_strerror (errno));
        return -1;
    }
    /*rc = zmq_ctx_term (ctx);
    if (rc != 0) {
        printf ("error in zmq_ctx_term: %s\n", zmq_strerror (errno));
        return -1;
    }
ctx = NULL;
*/

return 0;
}

---

// ZMQ_pgm_send.cpp :
//
#include "stdafx.h"
#include "zmq.h"
#include <iostream>
#include <windows.h>

std::string fullurl = "pgm://eth0;239.255.0.1:30001";    
static int roundtrip_count = 50;
static size_t message_size = 4;

int _tmain(int argc, _TCHAR* argv[])
{
    void *ctx = NULL,
         *s = NULL;
    int con;
    int i;

    ctx = zmq_init (1);
    if (!ctx) {
        printf ("error in zmq_init: %s\n", zmq_strerror (errno));
        return -1;
    }

    s = zmq_socket (ctx, ZMQ_PUB);
    if (!s) {
        printf ("error in zmq_socket: %s\n", zmq_strerror (errno));
        return -1;
    }

    con = zmq_connect(socket, fullurl.c_str()); 
    if (con == 0) {
        printf ("error in zmq_connect: %s\n", zmq_strerror (errno));
        return -1;
    }
    zmq_msg_t msg;

    int rc = zmq_msg_init_size (&msg,message_size);
    if (rc != 0) {
        printf ("error in zmq_msg_init: %s\n", zmq_strerror (errno));
        return -1;
    }

    memset(zmq_msg_data (&msg),'A', message_size ); 
    for (i = 0; i != roundtrip_count; i++) {

        rc = zmq_sendmsg (s, &msg, 0);
        if (rc < 0) {
            printf ("error in zmq_sendmsg: %s\n", zmq_strerror (errno));
            return -1;
        }
    }

    rc = zmq_msg_close (&msg);
    if (rc != 0) {
        printf ("error in zmq_msg_close: %s\n", zmq_strerror (errno));
        return -1;
    }

    rc = zmq_close (s);
    if (rc != 0) {
        printf ("error in zmq_close: %s\n", zmq_strerror (errno));
        return -1;
    }
    /*rc = zmq_ctx_term (ctx);
    if (rc != 0) {
        printf ("error in zmq_ctx_term: %s\n", zmq_strerror (errno));
        return -1;
    }
    ctx = NULL;
    */

    return 0;
}

如果我做错了，请指正。

Answer 1

解决了上面评论中提出的[Step 0]，
一个应该
检测

缺少ZMQ_SUBSCRIBE设置，因此SUB端过滤所有流量

ZMQ_SUBSCRIBE: Establish message filter

The ZMQ_SUBSCRIBE option shall establish a new message filter on a ZMQ_SUB socket. Newly created ZMQ_SUB sockets shall filter out all incoming messages, therefore you should call this option to establish an initial message filter.

An empty option_value of length zero shall subscribe to all incoming messages. A non-empty option_value shall subscribe to all messages beginning with the specified prefix. Multiple filters may be attached to a single ZMQ_SUB socket, in which case a message shall be accepted if it matches at least one filter.

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无论如何，欢迎并享受这些用于分布式系统计算的智能工具!