NAME

epoll_event, epoll_data, epoll_data_t - epoll event

LIBRARY

Standard C library (libc)

#include <sys/epoll.h>

struct epoll_event {
    uint32_t      events;  /* Epoll events */
    epoll_data_t  data;    /* User data variable */
};

union epoll_data {
    void     *ptr;
    int       fd;
    uint32_t  u32;
    uint64_t  u64;
};

typedef union epoll_data  epoll_data_t;

The epoll_event structure specifies data that the kernel should save and return when the corresponding file descriptor becomes ready.

The Linux kernel headers also provide this type, with a slightly different definition:

#include <linux/eventpoll.h>
struct epoll_event {
    __poll_t  events;
    __u64     data;
};

Linux.