1/* Compatibility definitions for System V `poll' interface.
2 Copyright (C) 1994-2020 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
56#ifdef __USE_GNU
57/* Like poll, but before waiting the threads signal mask is replaced
58 with that specified in the fourth parameter. For better usability,
59 the timeout value is specified using a TIMESPEC object.
60
61 This function is a cancellation point and therefore not marked with
62 __THROW. */
63extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
64 const struct timespec *__timeout,
65 const __sigset_t *__ss);
66#endif
67
68__END_DECLS
69
70
71/* Define some inlines helping to catch common problems. */
72#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
73# include <bits/poll2.h>
74#endif
75
76#endif /* sys/poll.h */
77

source code of include/x86_64-linux-gnu/sys/poll.h