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 /*
  30  * Request the handling of system wakeup events so as to prevent system suspends
  31  * from happening while those events are being processed.
  32  *
  33  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
  34  * re-allowed until epoll_wait is called again after consuming the wakeup
  35  * event(s).
  36  *
  37  * Requires CAP_BLOCK_SUSPEND
  38  */
  39 #define EPOLLWAKEUP (1 << 29)
  40
  41 /* Set the One Shot behaviour for the target file descriptor */
  42 #define EPOLLONESHOT (1 << 30)
  43
  44 /* Set the Edge Triggered behaviour for the target file descriptor */
  45 #define EPOLLET (1 << 31)
  46
  47 /*
  48  * On x86-64 make the 64bit structure have the same alignment as the
  49  * 32bit structure. This makes 32bit emulation easier.
  50  *
  51  * UML/x86_64 needs the same packing as x86_64
  52  */
  53 #ifdef __x86_64__
  54 #define EPOLL_PACKED __attribute__((packed))
  55 #else
  56 #define EPOLL_PACKED
  57 #endif
  58
  59 struct epoll_event {
  60         __u32 events;
  61         __u64 data;
  62 } EPOLL_PACKED;
  63
  64 #ifdef CONFIG_PM_SLEEP
  65 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  66 {
  67         if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
  68                 epev->events &= ~EPOLLWAKEUP;
  69 }
  70 #else
  71 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  72 {
  73         epev->events &= ~EPOLLWAKEUP;
  74 }
  75 #endif
  76 #endif /* _UAPI_LINUX_EVENTPOLL_H */