linux recv非阻塞

#include <sys/epoll.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>

// ... 其他代码 ...

int set_nonblocking(int fd) {
    int flags = fcntl(fd, F_GETFL, 0);
    if (flags == -1) return -1;
    flags |= O_NONBLOCK;
    return fcntl(fd, F_SETFL, flags);
}

int main() {
    int sockfd = ...; // 创建并连接套接字
    set_nonblocking(sockfd);

    int epollfd = epoll_create1(0);
    struct epoll_event event;
    event.events = EPOLLIN;
    event.data.fd = sockfd;
    epoll_ctl(epollfd, EPOLL_CTL_ADD, sockfd, &event);

    while (1) {
        struct epoll_event events[10];
        int n = epoll_wait(epollfd, events, 10, -1);
        for (int i = 0; i < n; i++) {
            if (events[i].data.fd == sockfd) {
                char buf[1024];
                while (1) {
                    ssize_t count = recv(sockfd, buf, sizeof(buf), 0);
                    if (count == -1) {
                        if (errno == EAGAIN || errno == EWOULDBLOCK) break;
                        perror("recv");
                        break;
                    } else if (count == 0) {
                        printf("Connection closed
");
                        return 0;
                    } else {
                        // 处理接收到的数据
                        printf("Received data: %s
", buf);
                    }
                }
            }
        }
    }

    close(epollfd);
    close(sockfd);
    return 0;
}