使用Linux系统函数构建高性能TCP服务器的详细步骤

int server_fd = socket(AF_INET, SOCK_STREAM, 0);
if (server_fd == -1) {
    perror("socket creation failed");
    exit(EXIT_FAILURE);
}

struct sockaddr_in address;
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY; // 监听所有网络接口
address.sin_port = htons(PORT); // 端口号转换网络字节序

if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
    perror("bind failed");
    exit(EXIT_FAILURE);
}

if (listen(server_fd, 3) < 0) {
    perror("listen failed");
    exit(EXIT_FAILURE);
}

int addrlen = sizeof(address);
int new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen);
if (new_socket < 0) {
    perror("accept failed");
    exit(EXIT_FAILURE);
}

struct epoll_event ev, events[MAX_EVENTS];
int epoll_fd = epoll_create1(0);

ev.events = EPOLLIN;
ev.data.fd = server_fd;
epoll_ctl(epoll_fd, EPOLL_CTL_ADD, server_fd, &ev);

while(1) {
    int nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);
    for (int n = 0; n < nfds; ++n) {
        if (events[n].data.fd == server_fd) {
            // 处理新连接
        } else {
            // 处理客户端数据
        }
    }
}

typedef struct {
    int fd;
    char name[32];
    time_t connect_time;
} ClientInfo;

ClientInfo clients[MAX_CLIENTS];
int client_count = 0;

// 安全读取示例
ssize_t safe_recv(int sockfd, void *buf, size_t len) {
    ssize_t n = recv(sockfd, buf, len, 0);
    if (n <= 0) {
        if (n == 0) {
            // 连接关闭
        } else if (errno == EINTR) {
            // 被信号中断，重试
            return safe_recv(sockfd, buf, len);
        } else {
            // 真实错误
            perror("recv error");
        }
    }
    return n;
}