1/* Copyright (C) 1997-2025 Free Software Foundation, Inc.
 2   This file is part of the GNU C Library.
 3
 4   The GNU C Library is free software; you can redistribute it and/or
 5   modify it under the terms of the GNU Lesser General Public
 6   License as published by the Free Software Foundation; either
 7   version 2.1 of the License, or (at your option) any later version.
 8
 9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, see
16   <https://www.gnu.org/licenses/>.  */
17
18#ifndef _SYS_POLL_H
19# error "Never use <bits/poll.h> directly; include <sys/poll.h> instead."
20#endif
21
22/* Event types that can be polled for.  These bits may be set in `events'
23   to indicate the interesting event types; they will appear in `revents'
24   to indicate the status of the file descriptor.  */
25#define POLLIN		0x001		/* There is data to read.  */
26#define POLLPRI		0x002		/* There is urgent data to read.  */
27#define POLLOUT		0x004		/* Writing now will not block.  */
28
29#if defined __USE_XOPEN || defined __USE_XOPEN2K8
30/* These values are defined in XPG4.2.  */
31# define POLLRDNORM	0x040		/* Normal data may be read.  */
32# define POLLRDBAND	0x080		/* Priority data may be read.  */
33# define POLLWRNORM	0x100		/* Writing now will not block.  */
34# define POLLWRBAND	0x200		/* Priority data may be written.  */
35#endif
36
37#ifdef __USE_GNU
38/* These are extensions for Linux.  */
39# define POLLMSG	0x400
40# define POLLREMOVE	0x1000
41# define POLLRDHUP	0x2000
42#endif
43
44/* Event types always implicitly polled for.  These bits need not be set in
45   `events', but they will appear in `revents' to indicate the status of
46   the file descriptor.  */
47#define POLLERR		0x008		/* Error condition.  */
48#define POLLHUP		0x010		/* Hung up.  */
49#define POLLNVAL	0x020		/* Invalid polling request.  */