linux epoll原理

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

#define MAX_EVENTS 10

int main() {
    int epoll_fd = epoll_create1(0);
    if (epoll_fd == -1) {
        perror("epoll_create1");
        return 1;
    }

    struct epoll_event event;
    event.events = EPOLLIN;
    event.data.fd = STDIN_FILENO;

    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, STDIN_FILENO, &event) == -1) {
        perror("epoll_ctl");
        close(epoll_fd);
        return 1;
    }

    struct epoll_event events[MAX_EVENTS];
    while (1) {
        int n = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);
        if (n == -1) {
            perror("epoll_wait");
            break;
        }

        for (int i = 0; i < n; i++) {
            if (events[i].data.fd == STDIN_FILENO) {
                char buf[1024];
                ssize_t len = read(STDIN_FILENO, buf, sizeof(buf));
                if (len > 0) {
                    buf[len] = '\0';
                    printf("Read input: %s
", buf);
                }
            }
        }
    }

    close(epoll_fd);
    return 0;
}