msg.h revision 92719 
1/* $FreeBSD: head/sys/sys/msg.h 92719 2002-03-19 20:18:42Z alfred $ */
2/*	$NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $	*/
3
4/*
5 * SVID compatible msg.h file
6 *
7 * Author:  Daniel Boulet
8 *
9 * Copyright 1993 Daniel Boulet and RTMX Inc.
10 *
11 * This system call was implemented by Daniel Boulet under contract from RTMX.
12 *
13 * Redistribution and use in source forms, with and without modification,
14 * are permitted provided that this entire comment appears intact.
15 *
16 * Redistribution in binary form may occur without any restrictions.
17 * Obviously, it would be nice if you gave credit where credit is due
18 * but requiring it would be too onerous.
19 *
20 * This software is provided ``AS IS'' without any warranties of any kind.
21 */
22
23#ifndef _SYS_MSG_H_
24#define _SYS_MSG_H_
25
26#include <sys/ipc.h>
27
28/*
29 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
30 * are as defined by the SV API Intel 386 Processor Supplement.
31 */
32
33#define MSG_NOERROR	010000		/* don't complain about too long msgs */
34
35struct msg;
36
37struct msqid_ds {
38	struct	ipc_perm msg_perm;	/* msg queue permission bits */
39	struct	msg *msg_first;	/* first message in the queue */
40	struct	msg *msg_last;	/* last message in the queue */
41	u_long	msg_cbytes;	/* number of bytes in use on the queue */
42	u_long	msg_qnum;	/* number of msgs in the queue */
43	u_long	msg_qbytes;	/* max # of bytes on the queue */
44	pid_t	msg_lspid;	/* pid of last msgsnd() */
45	pid_t	msg_lrpid;	/* pid of last msgrcv() */
46	time_t	msg_stime;	/* time of last msgsnd() */
47	long	msg_pad1;
48	time_t	msg_rtime;	/* time of last msgrcv() */
49	long	msg_pad2;
50	time_t	msg_ctime;	/* time of last msgctl() */
51	long	msg_pad3;
52	long	msg_pad4[4];
53};
54
55/*
56 * Structure describing a message.  The SVID doesn't suggest any
57 * particular name for this structure.  There is a reference in the
58 * msgop man page that reads "The structure mymsg is an example of what
59 * this user defined buffer might look like, and includes the following
60 * members:".  This sentence is followed by two lines equivalent
61 * to the mtype and mtext field declarations below.  It isn't clear
62 * if "mymsg" refers to the naem of the structure type or the name of an
63 * instance of the structure...
64 */
65struct mymsg {
66	long	mtype;		/* message type (+ve integer) */
67	char	mtext[1];	/* message body */
68};
69
70#ifdef _KERNEL
71
72/*
73 * Based on the configuration parameters described in an SVR2 (yes, two)
74 * config(1m) man page.
75 *
76 * Each message is broken up and stored in segments that are msgssz bytes
77 * long.  For efficiency reasons, this should be a power of two.  Also,
78 * it doesn't make sense if it is less than 8 or greater than about 256.
79 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
80 * two between 8 and 1024 inclusive (and panic's if it isn't).
81 */
82struct msginfo {
83	int	msgmax,		/* max chars in a message */
84		msgmni,		/* max message queue identifiers */
85		msgmnb,		/* max chars in a queue */
86		msgtql,		/* max messages in system */
87		msgssz,		/* size of a message segment (see notes above) */
88		msgseg;		/* number of message segments */
89};
90extern struct msginfo	msginfo;
91#endif
92
93#ifndef _KERNEL
94
95#include <sys/cdefs.h>
96
97__BEGIN_DECLS
98int msgsys(int, ...);
99int msgctl(int, int, struct msqid_ds *);
100int msgget(key_t, int);
101int msgsnd(int, void *, size_t, int);
102int msgrcv(int, void*, size_t, long, int);
103__END_DECLS
104#endif
105
106#endif /* !_SYS_MSG_H_ */
107