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| // echo_single.c — 单连接 Echo Server
// 编译：gcc -std=c11 -O2 echo_single.c -luring -o echo_single
#include <liburing.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#define BUF_SIZE 1024
// 请求类型枚举
enum EventType {
EVENT_ACCEPT = 0,
EVENT_READ = 1,
EVENT_WRITE = 2,
};
int main()
{
int listenFd = socket(AF_INET, SOCK_STREAM, 0);
int opt = 1;
setsockopt(listenFd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
struct sockaddr_in addr = {
.sin_family = AF_INET,
.sin_port = htons(9000),
.sin_addr.s_addr = INADDR_ANY,
};
bind(listenFd, (struct sockaddr *)&addr, sizeof(addr));
listen(listenFd, 128);
struct io_uring ring;
io_uring_queue_init(32, &ring, 0);
// 提交 accept 请求
struct io_uring_sqe *sqe = io_uring_get_sqe(&ring);
io_uring_prep_accept(sqe, listenFd, NULL, NULL, 0);
// 用 user_data 编码事件类型
io_uring_sqe_set_data64(sqe, EVENT_ACCEPT);
io_uring_submit(&ring);
char buf[BUF_SIZE];
int clientFd = -1;
printf("Echo Server 监听端口 9000...\n");
while (1) {
struct io_uring_cqe *cqe;
io_uring_wait_cqe(&ring, &cqe);
__u64 eventType = io_uring_cqe_get_data64(cqe);
switch (eventType) {
case EVENT_ACCEPT: {
clientFd = cqe->res;
if (clientFd < 0) {
fprintf(stderr, "accept 失败: %s\n", strerror(-clientFd));
break;
}
printf("新连接: fd=%d\n", clientFd);
// 提交 recv 请求
sqe = io_uring_get_sqe(&ring);
io_uring_prep_recv(sqe, clientFd, buf, BUF_SIZE, 0);
io_uring_sqe_set_data64(sqe, EVENT_READ);
io_uring_submit(&ring);
break;
}
case EVENT_READ: {
if (cqe->res <= 0) {
// 连接关闭或出错
printf("连接关闭 (fd=%d)\n", clientFd);
close(clientFd);
// 重新提交 accept
sqe = io_uring_get_sqe(&ring);
io_uring_prep_accept(sqe, listenFd, NULL, NULL, 0);
io_uring_sqe_set_data64(sqe, EVENT_ACCEPT);
io_uring_submit(&ring);
break;
}
int bytesRead = cqe->res;
printf("收到 %d 字节: %.*s", bytesRead, bytesRead, buf);
// 提交 send 请求（回显数据）
sqe = io_uring_get_sqe(&ring);
io_uring_prep_send(sqe, clientFd, buf, bytesRead, 0);
io_uring_sqe_set_data64(sqe, EVENT_WRITE);
io_uring_submit(&ring);
break;
}
case EVENT_WRITE: {
if (cqe->res < 0) {
fprintf(stderr, "send 失败: %s\n", strerror(-cqe->res));
close(clientFd);
break;
}
printf("回显 %d 字节\n", cqe->res);
// send 完成后，继续 recv
sqe = io_uring_get_sqe(&ring);
io_uring_prep_recv(sqe, clientFd, buf, BUF_SIZE, 0);
io_uring_sqe_set_data64(sqe, EVENT_READ);
io_uring_submit(&ring);
break;
}
}
io_uring_cqe_seen(&ring, cqe);
}
io_uring_queue_exit(&ring);
close(listenFd);
return 0;
}
// 测试：
// 终端1: ./echo_single
// 终端2: nc localhost 9000
// 输入 "hello"
// 收到 "hello"
|