Lwip之TCP客户端示例记录

前言

1. 使用两个线程作为客户端中的收和发
2. 使用线程挂起和线程恢复的api来实现
3. 接收线程必须要保证在处理连接状态才能进行接收。

Demo

//// Created by shchl on 2024/3/8.//#include #include "lwip/api.h"#include "FreeRTOS.h"#include "task.h"#define TCP_CLIENT_RX_BUFSIZE 256static void tcp_client_send(void *);static void tcp_client_rec(void *);static TaskHandle_t client_send_handle;static TaskHandle_t client_rec_handle;static ip_addr_t server_ipaddr, loca_ipaddr;static uint16_t server_port = 8080;static struct netconn *tcp_conn;static uint8_t tcp_client_recvbuf[TCP_CLIENT_RX_BUFSIZE] = {0};    //TCP客户端接收数据缓冲区void create_netconn_tcp_client_thread() {    xTaskCreate((TaskFunction_t) tcp_client_send,                (const char *) "tcp_client_send",                (uint16_t) 256,                (void *) NULL,                (UBaseType_t) 10,                (TaskHandle_t *) &client_send_handle);    xTaskCreate((TaskFunction_t) tcp_client_rec,                (const char *) "tcp_client_rec",                (uint16_t) 256,                (void *) NULL,                (UBaseType_t) 11,                (TaskHandle_t *) &client_rec_handle);}const char *tcp_client_sendbuf = "Apollo STM32F4/F7 NETCONN TCP Client send data\r\n";    //TCP客户端发送数据缓冲区static void tcp_client_send(void *arg) {    err_t err, recv_err;    IP4_ADDR(&server_ipaddr, 192, 168, 8, 2);    while (1) {        tcp_conn = netconn_new(NETCONN_TCP);  //创建一个TCP链接        err = netconn_connect(tcp_conn, &server_ipaddr, server_port);//连接服务器        if (err != ERR_OK) {            netconn_delete(tcp_conn); //返回值不等于ERR_OK,删除tcp_clientconn连接            printf("连接失败....等待重新连接\r\n");            vTaskDelay(1000);            continue;        } else {            vTaskResume(client_rec_handle);/*恢复接收线程*/            printf("连接...ok\r\n");        }        while (1) {            err = netconn_write(tcp_conn, tcp_client_sendbuf, strlen((char *) tcp_client_sendbuf),                                NETCONN_COPY); //发送tcp_server_sentbuf中的数据            if (err != ERR_OK) {                printf("发送失败\r\n");                netconn_close(tcp_conn);                netconn_delete(tcp_conn);                break;            }            vTaskDelay(1000);        }    }}static void tcp_client_rec(void *arg) {    err_t recv_err;    uint32_t data_len;    struct pbuf *q;    struct netbuf *recvbuf;    vTaskSuspend(client_rec_handle); /*挂起自身线程*/    while (1) {        if ((recv_err = netconn_recv(tcp_conn, &recvbuf)) == ERR_OK)  //接收到数据        {            portDISABLE_INTERRUPTS(); //关中断            memset(tcp_client_recvbuf, 0, TCP_CLIENT_RX_BUFSIZE);  //数据接收缓冲区清零            for (q = recvbuf->p; q != NULL; q = q->next)  //遍历完整个pbuf链表            {                //判断要拷贝到TCP_CLIENT_RX_BUFSIZE中的数据是否大于TCP_CLIENT_RX_BUFSIZE的剩余空间，如果大于                //的话就只拷贝TCP_CLIENT_RX_BUFSIZE中剩余长度的数据，否则的话就拷贝所有的数据                if (q->len > (TCP_CLIENT_RX_BUFSIZE - data_len))                    memcpy(tcp_client_recvbuf + data_len, q->payload, (TCP_CLIENT_RX_BUFSIZE - data_len));//拷贝数据                else memcpy(tcp_client_recvbuf + data_len, q->payload, q->len);                data_len += q->len;                if (data_len > TCP_CLIENT_RX_BUFSIZE) break; //超出TCP客户端接收数组,跳出            }            portENABLE_INTERRUPTS(); //关中断            data_len = 0;  //复制完成后data_len要清零。            printf("%s", tcp_client_recvbuf);            netbuf_delete(recvbuf);        } else if (recv_err == ERR_CLSD)  //关闭连接        {            printf("服务器%d.%d.%d.%d断开连接\r\n", 192, 168, 8, 2);            vTaskSuspend(client_rec_handle); /*挂起自身线程*/        }    }}

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