rtthread使用kawaii-mqtt加EC20联网，mqtt被服务器踢下线的情况下无法自动重连

发布于 2023-05-26 16:32:40 浏览：743 订阅该版

1 个回答

红枫认证专家 2023-05-27

这家伙很懒，什么也没写！

#### 是有你说的这个问题，需要应用层做定期检测和断线后的重连处理。下面是我用过的一段处理代码，供参考。

```c
static void mqtt_app_wait_net_link_up(void)
{
    while(1)
    {
        struct netdev * netdev = netdev_get_by_family(AF_AT);
        if (netdev && netdev_is_link_up(netdev))
        {
            break;
        }
        rt_thread_mdelay(1000);
    }
}

static bool mqtt_app_exit_chk(void)
{
    return (mqtt_app_reset_flag || (mqtt_app_client->mqtt_client_state != CLIENT_STATE_CONNECTED));
}

static void mqtt_app_running(void)
{
    mqtt_app_fail_cnt = 0;
    mqtt_app_reset_flag = false;
    mqtt_client_t *client = mqtt_app_client = mqtt_lease();
    if(client == RT_NULL)
    {
        LOG_E("mqtt client lease fail.");
        rt_thread_mdelay(1000);
        return;
    }
    
    mqtt_app_wait_net_link_up();

mqtt_log_init();

mqtt_app_config(client);

while(1)
    {
        if (mqtt_connect(client) == KAWAII_MQTT_SUCCESS_ERROR)
        {
            break;
        }
        rt_thread_mdelay(3 * 1000);
    }

data_set_online_status(true);

if (mqtt_app_topic_subscribe_all(client))
    {
        while (1) 
        {   
            rt_thread_mdelay(200); 
            if (mqtt_app_exit_chk())
            {
                break;
            }                                                      
            mqtt_app_evt_rep_chk();
            mqtt_app_time_rep_chk(); 
        }
    }
    
    data_set_online_status(false);
    mqtt_disconnect(client);
    mqtt_release(client);
}

static void mqtt_app_thread_entry(void *args)
{
    mqtt_app_evt_rep_queue_init();
    
    while(1)
    {
        mqtt_app_running();
    }
}
```

cheung 2023-05-28

实事求是

红枫 2023-05-29

这家伙很懒，什么也没写！

cheung 2023-05-29

实事求是

红枫 2023-05-29

这家伙很懒，什么也没写！

cheung 2023-05-30

实事求是

现在我这边更改了sal_socket和mqttclient
mqttclient.c 文件中的 mqtt_read_packet 函数更改如下：
```c
    /* 1. read the header byte.  This has the packet type in it */
    rc = network_read(c->mqtt_network, c->mqtt_read_buf, len, platform_timer_remain(timer));
    if (rc != len)
	{
        /* connection has been broken by server */
		if (rc < 0)
		{
            network_release(c->mqtt_network);
            mqtt_set_client_state(c, CLIENT_STATE_DISCONNECTED);

RETURN_ERROR(MQTT_NOT_CONNECT_ERROR);
		}
		else
			RETURN_ERROR(MQTT_NOTHING_TO_READ_ERROR);
	}
```

at_socket.c 文件中的 at_recvfrom 函数更改如下：

```c
            /* get receive buffer to receiver ring buffer */
            rt_mutex_take(sock->recv_lock, RT_WAITING_FOREVER);
            recv_len = at_recvpkt_get(&(sock->recvpkt_list), (char *) mem, len);
            rt_mutex_release(sock->recv_lock);
            if (recv_len > 0)
            {
                break;
            }
            else
            {
                /* we have no data to receive but are woken up,
                    which means the socket have been closed. */
                errno = EIO;
                result = -1;
                if (sock->state == AT_SOCKET_CLOSED)
                {
                    result = -1;
                    errno = EIO;
                }
                else
                {
                    result = 0;
                    errno = ENODATA;
                }
                
                goto __exit;
            }
```

[@红枫](https://club.rt-thread.org/u/84f1782df43c8f19)