epoll.h源码：

/* Copyright (C) 2002-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>.  */
#ifndef	_SYS_EPOLL_H
#define	_SYS_EPOLL_H	1
#include <stdint.h>
#include <sys/types.h>
/* Get __sigset_t.  */
#include <bits/sigset.h>
#ifndef __sigset_t_defined
# define __sigset_t_defined
typedef __sigset_t sigset_t;
#endif
/* Get the platform-dependent flags.  */
#include <bits/epoll.h>
#ifndef __EPOLL_PACKED
# define __EPOLL_PACKED
#endif
enum EPOLL_EVENTS
{
EPOLLIN = 0x001,
#define EPOLLIN EPOLLIN
EPOLLPRI = 0x002,
#define EPOLLPRI EPOLLPRI
EPOLLOUT = 0x004,
#define EPOLLOUT EPOLLOUT
EPOLLRDNORM = 0x040,
#define EPOLLRDNORM EPOLLRDNORM
EPOLLRDBAND = 0x080,
#define EPOLLRDBAND EPOLLRDBAND
EPOLLWRNORM = 0x100,
#define EPOLLWRNORM EPOLLWRNORM
EPOLLWRBAND = 0x200,
#define EPOLLWRBAND EPOLLWRBAND
EPOLLMSG = 0x400,
#define EPOLLMSG EPOLLMSG
EPOLLERR = 0x008,
#define EPOLLERR EPOLLERR
EPOLLHUP = 0x010,
#define EPOLLHUP EPOLLHUP
EPOLLRDHUP = 0x2000,
#define EPOLLRDHUP EPOLLRDHUP
EPOLLWAKEUP = 1u << 29,
#define EPOLLWAKEUP EPOLLWAKEUP
EPOLLONESHOT = 1u << 30,
#define EPOLLONESHOT EPOLLONESHOT
EPOLLET = 1u << 31
#define EPOLLET EPOLLET
};
/* Valid opcodes ( "op" parameter ) to issue to epoll_ctl().  */
#define EPOLL_CTL_ADD 1	/* Add a file descriptor to the interface.  */
#define EPOLL_CTL_DEL 2	/* Remove a file descriptor from the interface.  */
#define EPOLL_CTL_MOD 3	/* Change file descriptor epoll_event structure.  */
typedef union epoll_data
{
void *ptr;
int fd;
uint32_t u32;
uint64_t u64;
} epoll_data_t;
struct epoll_event
{
uint32_t events;	/* Epoll events */
epoll_data_t data;	/* User data variable */
} __EPOLL_PACKED;
__BEGIN_DECLS
/* Creates an epoll instance.  Returns an fd for the new instance.
The "size" parameter is a hint specifying the number of file
descriptors to be associated with the new instance.  The fd
returned by epoll_create() should be closed with close().  */
extern int epoll_create (int __size) __THROW;
/* Same as epoll_create but with an FLAGS parameter.  The unused SIZE
parameter has been dropped.  */
extern int epoll_create1 (int __flags) __THROW;
/* Manipulate an epoll instance "epfd". Returns 0 in case of success,
-1 in case of error ( the "errno" variable will contain the
specific error code ) The "op" parameter is one of the EPOLL_CTL_*
constants defined above. The "fd" parameter is the target of the
operation. The "event" parameter describes which events the caller
is interested in and any associated user data.  */
extern int epoll_ctl (int __epfd, int __op, int __fd,
struct epoll_event *__event) __THROW;
/* Wait for events on an epoll instance "epfd". Returns the number of
triggered events returned in "events" buffer. Or -1 in case of
error with the "errno" variable set to the specific error code. The
"events" parameter is a buffer that will contain triggered
events. The "maxevents" is the maximum number of events to be
returned ( usually size of "events" ). The "timeout" parameter
specifies the maximum wait time in milliseconds (-1 == infinite).
This function is a cancellation point and therefore not marked with
__THROW.  */
extern int epoll_wait (int __epfd, struct epoll_event *__events,
int __maxevents, int __timeout);
/* Same as epoll_wait, but the thread's signal mask is temporarily
and atomically replaced with the one provided as parameter.
This function is a cancellation point and therefore not marked with
__THROW.  */
extern int epoll_pwait (int __epfd, struct epoll_event *__events,
int __maxevents, int __timeout,
const __sigset_t *__ss);
__END_DECLS
#endif /* sys/epoll.h */