epoll_data_t(3type)

epoll_data_t3type

Epoll event

Part of epoll_event(3type).

Usage

#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;

Library

Standard C library (libc)

Overview

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

Versions

C library/kernel differences

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;
};

Releases

3 releases since Debian 12 (Bookworm); the text changed 2 times.