io/sys/poll.h

   1 /* Compatibility definitions for System V `poll' interface.
   2    Copyright (C) 1994, 1996, 1997, 1998 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _SYS_POLL_H
  21 #define _SYS_POLL_H     1
  22
  23 #include <features.h>
  24
  25 /* Get the platform dependent bits of `poll'.  */
  26 #include <bits/poll.h>
  27
  28 __BEGIN_DECLS
  29
  30 /* Data structure describing a polling request.  */
  31 struct pollfd
  32   {
  33     int fd;                     /* File descriptor to poll.  */
  34     short int events;           /* Types of events poller cares about.  */
  35     short int revents;          /* Types of events that actually occurred.  */
  36   };
  37
  38
  39 /* Poll the file descriptors described by the NFDS structures starting at
  40    FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
  41    an event to occur; if TIMEOUT is -1, block until an event occurs.
  42    Returns the number of file descriptors with events, zero if timed out,
  43    or -1 for errors.  */
  44 extern int __poll __P ((struct pollfd *__fds, unsigned long int __nfds,
  45                         int __timeout));
  46 extern int poll __P ((struct pollfd *__fds, unsigned long int __nfds,
  47                       int __timeout));
  48
  49 __END_DECLS
  50
  51 #endif  /* sys/poll.h */