1/* 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
21#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 {
26	__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 */
31};
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
54