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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* Copyright (C) 2003 Krzysztof Benedyczak & Michal Wronski
2
3 This program is free software; you can redistribute it and/or
4 modify it under the terms of the GNU Lesser General Public
5 License as published by the Free Software Foundation; either
6 version 2.1 of the License, or (at your option) any later version.
7
8 It is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 Lesser General Public License for more details.
12
13 You should have received a copy of the GNU Lesser General Public
14 License along with this software; if not, write to the Free
15 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
16 02111-1307 USA. */
17
18#ifndef _LINUX_MQUEUE_H
19#define _LINUX_MQUEUE_H
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#define MQ_PRIO_MAX 32768
22/* per-uid limit of kernel memory used by mqueue, in bytes */
23#define MQ_BYTES_MAX 819200
24
25struct mq_attr {
H.J. Lu63159f52013-12-27 14:14:24 -080026 __kernel_long_t mq_flags; /* message queue flags */
27 __kernel_long_t mq_maxmsg; /* maximum number of messages */
28 __kernel_long_t mq_msgsize; /* maximum message size */
29 __kernel_long_t mq_curmsgs; /* number of messages currently queued */
30 __kernel_long_t __reserved[4]; /* ignored for input, zeroed for output */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031};
32
33/*
34 * SIGEV_THREAD implementation:
35 * SIGEV_THREAD must be implemented in user space. If SIGEV_THREAD is passed
36 * to mq_notify, then
37 * - sigev_signo must be the file descriptor of an AF_NETLINK socket. It's not
38 * necessary that the socket is bound.
39 * - sigev_value.sival_ptr must point to a cookie that is NOTIFY_COOKIE_LEN
40 * bytes long.
41 * If the notification is triggered, then the cookie is sent to the netlink
42 * socket. The last byte of the cookie is replaced with the NOTIFY_?? codes:
43 * NOTIFY_WOKENUP if the notification got triggered, NOTIFY_REMOVED if it was
44 * removed, either due to a close() on the message queue fd or due to a
45 * mq_notify() that removed the notification.
46 */
47#define NOTIFY_NONE 0
48#define NOTIFY_WOKENUP 1
49#define NOTIFY_REMOVED 2
50
51#define NOTIFY_COOKIE_LEN 32
52
53#endif