kernel - Refactor the kernel message buffer code
[dragonfly.git] / sys / sys / msgbuf.h
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1/*
2 * Copyright (c) 1981, 1984, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)msgbuf.h 8.1 (Berkeley) 6/2/93
34 * $FreeBSD: src/sys/sys/msgbuf.h,v 1.14.2.1 2001/01/16 12:26:21 phk Exp $
4abcbc58 35 * $DragonFly: src/sys/sys/msgbuf.h,v 1.6 2006/09/30 20:03:44 swildner Exp $
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36 */
37
38#ifndef _SYS_MSGBUF_H_
39#define _SYS_MSGBUF_H_
40
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41#ifndef _SYS_TYPES_H_
42#include <sys/types.h>
43#endif
44
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45/*
46 * NOTE! The indices are not masked against msg_size. All accessors
47 * must mask the indices against msg_size to get actual buffer
48 * indexes. For relative block sizes, simple subtraction can be
49 * used using unsigned integers.
50 */
984263bc 51struct msgbuf {
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52#define MSG_MAGIC 0x063064
53#define MSG_OMAGIC 0x063062
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54 unsigned int msg_magic;
55 unsigned int msg_size; /* size of buffer area */
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56 unsigned int msg_bufx; /* write index - kernel */
57 unsigned int msg_bufr; /* base index - kernel */
984263bc 58 char * msg_ptr; /* pointer to buffer */
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59 unsigned int msg_bufl; /* read index - log device */
60 unsigned int msg_unused01;
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61};
62
63#ifdef _KERNEL
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64extern int msgbuftrigger;
65extern struct msgbuf *msgbufp;
b153f746 66void msgbufinit (void *ptr, size_t size);
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67
68#if !defined(MSGBUF_SIZE)
c8b47640 69#define MSGBUF_SIZE 131072
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70#endif
71
72#endif
73
74#endif