xref: /dragonfly/sys/sys/msg.h (revision 38b720cd)
1 /* $FreeBSD: src/sys/sys/msg.h,v 1.10.2.1 2000/08/04 22:31:10 peter Exp $ */
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/cdefs.h>
27 #include <sys/ipc.h>
28 
29 /*
30  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
31  * are as defined by the SV API Intel 386 Processor Supplement.
32  */
33 
34 #define	MSG_NOERROR	010000		/* don't complain about too long msgs */
35 
36 typedef	unsigned long	msglen_t;
37 typedef	unsigned long	msgqnum_t;
38 
39 #ifndef _PID_T_DECLARED
40 typedef	__pid_t		pid_t;
41 #define	_PID_T_DECLARED
42 #endif
43 
44 #ifndef _SIZE_T_DECLARED
45 typedef	__size_t	size_t;
46 #define	_SIZE_T_DECLARED
47 #endif
48 
49 #ifndef _SSIZE_T_DECLARED
50 typedef	__ssize_t	ssize_t;
51 #define	_SSIZE_T_DECLARED
52 #endif
53 
54 #ifndef _TIME_T_DECLARED
55 typedef	__time_t	time_t;
56 #define	_TIME_T_DECLARED
57 #endif
58 
59 /*!!! In the kernel implementation, both msg_first and msg_last
60  * have 'struct msg*' type.
61  * In the userland implementation, a pointer to a msg is useless
62  * because each message queue is mapped at different addresses in
63  * the process space address so my choice was to use indexes.
64  */
65 struct msg;
66 
67 struct msqid_ds {
68 	struct	ipc_perm msg_perm;	/* msg queue permission bits */
69 	struct	msg *msg_first;	/* first message in the queue. */
70 	struct	msg *msg_last;	/* last message in the queue. */
71 	msglen_t msg_cbytes;	/* number of bytes in use on the queue */
72 	msgqnum_t msg_qnum;	/* number of msgs in the queue */
73 	msglen_t msg_qbytes;	/* max # of bytes on the queue */
74 	pid_t	msg_lspid;	/* pid of last msgsnd() */
75 	pid_t	msg_lrpid;	/* pid of last msgrcv() */
76 	time_t	msg_stime;	/* time of last msgsnd() */
77 	long	msg_pad1;
78 	time_t	msg_rtime;	/* time of last msgrcv() */
79 	long	msg_pad2;
80 	time_t	msg_ctime;	/* time of last msgctl() */
81 	long	msg_pad3;
82 	long	msg_pad4[4];
83 };
84 
85 #if __BSD_VISIBLE
86 /*
87  * Structure describing a message.  The SVID doesn't suggest any
88  * particular name for this structure.  There is a reference in the
89  * msgop man page that reads "The structure mymsg is an example of what
90  * this user defined buffer might look like, and includes the following
91  * members:".  This sentence is followed by two lines equivalent
92  * to the mtype and mtext field declarations below.  It isn't clear
93  * if "mymsg" refers to the naem of the structure type or the name of an
94  * instance of the structure...
95  */
96 struct mymsg {
97 	long	mtype;		/* message type (+ve integer) */
98 	char	mtext[1];	/* message body */
99 };
100 #endif
101 
102 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
103 
104 /*
105  * Based on the configuration parameters described in an SVR2 (yes, two)
106  * config(1m) man page.
107  *
108  * Each message is broken up and stored in segments that are msgssz bytes
109  * long.  For efficiency reasons, this should be a power of two.  Also,
110  * it doesn't make sense if it is less than 8 or greater than about 256.
111  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
112  * two between 8 and 1024 inclusive (and panic's if it isn't).
113  */
114 struct msginfo {
115 	int	msgmax,		/* max chars in a message */
116 		msgmni,		/* max message queue identifiers */
117 		msgmnb,		/* max chars in a queue */
118 		msgtql,		/* max messages in system */
119 		msgssz,		/* size of a message segment (see notes above) */
120 		msgseg;		/* number of message segments */
121 };
122 #endif
123 
124 #ifdef _KERNEL
125 extern struct msginfo	msginfo;
126 #else
127 __BEGIN_DECLS
128 int	msgctl(int, int, struct msqid_ds *);
129 int	msgget(key_t, int);
130 int	msgsnd(int, const void *, size_t, int);
131 int	msgrcv(int, void *, size_t, long, int); /* XXX should return ssize_t */
132 __END_DECLS
133 #endif
134 
135 #endif /* !_SYS_MSG_H_ */
136