1/* Compatibility definitions for System V `poll' interface.
 2   Copyright (C) 1994-2025 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 Lesser General Public
 7   License as published by the Free Software Foundation; either
 8   version 2.1 of the 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   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; if not, see
17   <https://www.gnu.org/licenses/>.  */
18
19#ifndef	_SYS_POLL_H
20#define	_SYS_POLL_H	1
21
22#include <features.h>
23
24/* Get the platform dependent bits of `poll'.  */
25#include <bits/poll.h>
26#ifdef __USE_GNU
27# include <bits/types/__sigset_t.h>
28# include <bits/types/struct_timespec.h>
29#endif
30
31
32/* Type used for the number of file descriptors.  */
33typedef unsigned long int nfds_t;
34
35/* Data structure describing a polling request.  */
36struct pollfd
37  {
38    int fd;			/* File descriptor to poll.  */
39    short int events;		/* Types of events poller cares about.  */
40    short int revents;		/* Types of events that actually occurred.  */
41  };
42
43
44__BEGIN_DECLS
45
46/* Poll the file descriptors described by the NFDS structures starting at
47   FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
48   an event to occur; if TIMEOUT is -1, block until an event occurs.
49   Returns the number of file descriptors with events, zero if timed out,
50   or -1 for errors.
51
52   This function is a cancellation point and therefore not marked with
53   __THROW.  */
54extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
55    __fortified_attr_access (__write_only__, 1, 2);
56
57#ifdef __USE_GNU
58/* Like poll, but before waiting the threads signal mask is replaced
59   with that specified in the fourth parameter.  For better usability,
60   the timeout value is specified using a TIMESPEC object.
61
62   This function is a cancellation point and therefore not marked with
63   __THROW.  */
64extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
65		  const struct timespec *__timeout,
66		  const __sigset_t *__ss)
67    __fortified_attr_access (__write_only__, 1, 2);
68
69# ifdef __USE_TIME64_REDIRECTS
70#  ifdef __REDIRECT
71extern int __REDIRECT (ppoll, (struct pollfd *__fds, nfds_t __nfds,
72                               const struct timespec *__timeout,
73                               const __sigset_t *__ss),
74                       __ppoll64)
75    __fortified_attr_access (__write_only__, 1, 2);
76#  else
77#  define ppoll __ppoll64
78#  endif
79# endif
80#endif
81
82__END_DECLS
83
84
85/* Define some inlines helping to catch common problems.  */
86#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
87# include <bits/poll2.h>
88#endif
89
90#endif	/* sys/poll.h */