udp发送完消息后要关闭端口描述符

最新推荐文章于 2022-07-13 20:57:23 发布

原创最新推荐文章于 2022-07-13 20:57:23 发布 · 1.5k 阅读

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在UDP通信中，如果不关闭发送消息后的端口描述符，可能导致第二次尝试通信时无法正常接收数据，甚至线程被挂住。正确做法是在发送完毕后记得关闭端口描述符。

int get_osd_oob_list(struct osd_node onode, struct list_head *head)
{
	printf("\nEntering %s ", __func__);
	char message[4096];
	char oob_receive_buf[8192];
	int ret, m_type, valid_len;
	int failure_time = 0;
	int socket_descriptor;
	struct sockaddr_in sin;
	int sin_len;
	int port = OSD_RECEIVE_RESULT_PORT;
	int is_cur_osd = (onode.osd_no == current_osd_no) ? 1:0;
	CACHE_INFO("This time being processed osd_node is: no:%d and name %s and current restarted osdno:%d",\
		onode.osd_no, onode.osd_address, current_osd_no);
	CACHE_INFO("+++++++++In line%d and is_cur_osd :%d", __LINE__, is_cur_osd);
	if(onode.osd_no == current_osd_no)
		is_cur_osd = 1;
	CACHE_INFO("++++++++++++++++IN line%d and is_cur_osd :%d", __LINE__, is_cur_osd);
	memset(&sin, 0, sizeof(sin));
	sin.sin_family=AF_INET;
	sin.sin_addr.s_addr=htonl(INADDR_ANY);
	sin.sin_port=htons(port);
	sin_len=sizeof(sin);
	socket_descriptor=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
	bind(socket_descriptor,(struct sockaddr *)&sin,sizeof(sin));
	
	*(uint32_t *) &message[0] = OOB_SCAN;
	memcpy(&message[4], current_osd_ip, 20); 
	send_osd_message(onode.osd_address, OSD_RECEIVE_CMD_PORT, message, 24);
	printf("\nIn %s and line:%d and read oob info cmd is sent to osd:%s", __func__, __LINE__, onode.osd_address);
	
	while(1){
		if(recvfrom(socket_descriptor,oob_receive_buf, sizeof(oob_receive_buf),0,(struct sockaddr *)&sin,&sin_len)){
			m_type = get_ntohl_be(&oob_receive_buf[0]);
			if(m_type!=OOB_DATA){
				CACHE_DEBUG("Invalid data because the data type is not OOB_DATA...");
				failure_time++;
				if(failure_time > 2)
					break;
				else
					continue;
			}
			valid_len = get_ntohl_be(&oob_receive_buf[4]);
			if(!valid_len){
				CACHE_INFO("No more valid oob info on node %s and goto next step... ", onode.osd_address);
				break;
			}
			CACHE_INFO("Received oob info len:%d", valid_len);
			if(valid_len % OOB_LEN != 0)
				CACHE_DEBUG("Something is wrong with the oob data len...");
			ret = oob_data_process(oob_receive_buf+8, valid_len, head, is_cur_osd);
		}//if
	}
	
	close(socket_descriptor);
	printf("\nLeaving %s ...\n\n", __func__);
	return 0;
}

按如下调用上述函数，在忘记close(socket_descriptor);的时候，第二次进入上述函数，无法正常接收数据，线程挂住！

for(i=0; i< related_osd_table->osd_count; i++){
	printf("\nTo get osd oob list %d", i);
	ret = get_osd_oob_list(related_osd_table->osd[i], &osd_oobinfo_list[i]);
}