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
  62 struct epoll_event {
  63         __u32 events;
  64         __u64 data;
  65 } EPOLL_PACKED;
  66
  67 #ifdef CONFIG_PM_SLEEP
  68 static 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
  74 static 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 */