LXR linux/include/uapi/linux/eventpoll.h

   1/*
   2 *  include/linux/eventpoll.h ( Efficient event polling implementation )
   3 *  Copyright (C) 2001,...,2006  Davide Libenzi
   4 *
   5 *  This program is free software; you can redistribute it and/or modify
   6 *  it under the terms of the GNU General Public License as published by
   7 *  the Free Software Foundation; either version 2 of the License, or
   8 *  (at your option) any later version.
   9 *
  10 *  Davide Libenzi <davidel@xmailserver.org>
  11 *
  12 */
  13
  14#ifndef _UAPI_LINUX_EVENTPOLL_H
  15#define _UAPI_LINUX_EVENTPOLL_H
  16
  17/* For O_CLOEXEC */
  18#include <linux/fcntl.h>
  19#include <linux/types.h>
  20
  21/* Flags for epoll_create1.  */
  22#define EPOLL_CLOEXEC O_CLOEXEC
  23
  24/* Valid opcodes to issue to sys_epoll_ctl() */
  25#define EPOLL_CTL_ADD 1
  26#define EPOLL_CTL_DEL 2
  27#define EPOLL_CTL_MOD 3
  28
  29/* Set exclusive wakeup mode for the target file descriptor */
  30#define EPOLLEXCLUSIVE (1 << 28)
  31
  32/*
  33 * Request the handling of system wakeup events so as to prevent system suspends
  34 * from happening while those events are being processed.
  35 *
  36 * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
  37 * re-allowed until epoll_wait is called again after consuming the wakeup
  38 * event(s).
  39 *
  40 * Requires CAP_BLOCK_SUSPEND
  41 */
  42#define EPOLLWAKEUP (1 << 29)
  43
  44/* Set the One Shot behaviour for the target file descriptor */
  45#define EPOLLONESHOT (1 << 30)
  46
  47/* Set the Edge Triggered behaviour for the target file descriptor */
  48#define EPOLLET (1 << 31)
  49
  50/* 
  51 * On x86-64 make the 64bit structure have the same alignment as the
  52 * 32bit structure. This makes 32bit emulation easier.
  53 *
  54 * UML/x86_64 needs the same packing as x86_64
  55 */
  56#ifdef __x86_64__
  57#define EPOLL_PACKED __attribute__((packed))
  58#else
  59#define EPOLL_PACKED
  60#endif
  61
  62struct epoll_event {
  63        __u32 events;
  64        __u64 data;
  65} EPOLL_PACKED;
  66
  67#ifdef CONFIG_PM_SLEEP
  68static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  69{
  70        if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
  71                epev->events &= ~EPOLLWAKEUP;
  72}
  73#else
  74static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  75{
  76        epev->events &= ~EPOLLWAKEUP;
  77}
  78#endif
  79#endif /* _UAPI_LINUX_EVENTPOLL_H */
  80