epoll_wait总是设置EPOLLOUT位

c
#include <stdio.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include <unistd.h>
#define MAX_EVENTS 10
int mAIn() {
    int epoll_fd;
    struct epoll_event events[MAX_EVENTS];
    // 创建一个epoll实例
    epoll_fd = epoll_create1(0);
    if (epoll_fd == -1) {
        perror("epoll_create1");
        exit(EXIT_FAILURE);
    }
    // 添加标准输出文件描述符到epoll的事件集合中
    struct epoll_event event;
    event.events = EPOLLOUT;
    event.data.fd = STDOUT_FILENO;
    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, STDOUT_FILENO, &event) == -1) {
        perror("epoll_ctl");
        exit(EXIT_FAILURE);
    }
    // 等待EPOLLOUT事件的发生
    int num_events = epoll_wAIt(epoll_fd, events, MAX_EVENTS, -1);
    if (num_events == -1) {
        perror("epoll_wAIt");
        exit(EXIT_FAILURE);
    }
    // 处理EPOLLOUT事件
    for (int i = 0; i < num_events; i++) {</p>        if (events[i].events & EPOLLOUT) {
            printf("EPOLLOUT event occurred on file descriptor %d\n", events[i].data.fd);
        }
    }
    close(epoll_fd);
    return 0;
}