xref: /dragonfly/sys/sys/msg.h (revision e6d22e9b)
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 #include <machine/stdint.h>
29 
30 /*
31  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
32  * are as defined by the SV API Intel 386 Processor Supplement.
33  */
34 
35 #define	MSG_NOERROR	010000		/* don't complain about too long msgs */
36 
37 typedef	unsigned long	msglen_t;
38 typedef	unsigned long	msgqnum_t;
39 
40 #ifndef _PID_T_DECLARED
41 typedef	__pid_t		pid_t;
42 #define	_PID_T_DECLARED
43 #endif
44 
45 #ifndef _SIZE_T_DECLARED
46 typedef	__size_t	size_t;
47 #define	_SIZE_T_DECLARED
48 #endif
49 
50 #ifndef _SSIZE_T_DECLARED
51 typedef	__ssize_t	ssize_t;
52 #define	_SSIZE_T_DECLARED
53 #endif
54 
55 #ifndef _TIME_T_DECLARED
56 typedef	__time_t	time_t;
57 #define	_TIME_T_DECLARED
58 #endif
59 
60 /*!!! In the kernel implementation, both msg_first and msg_last
61  * have 'struct msg*' type.
62  * In the userland implementation, a pointer to a msg is useless
63  * because each message queue is mapped at different addresses in
64  * the process space address so my choice was to use indexes.
65  */
66 struct msg;
67 
68 struct msqid_ds {
69 	struct	ipc_perm msg_perm;	/* msg queue permission bits */
70 	struct	msg *msg_first;	/* first message in the queue. */
71 	struct	msg *msg_last;	/* last message in the queue. */
72 	msglen_t msg_cbytes;	/* number of bytes in use on the queue */
73 	msgqnum_t msg_qnum;	/* number of msgs in the queue */
74 	msglen_t msg_qbytes;	/* max # of bytes on the queue */
75 	pid_t	msg_lspid;	/* pid of last msgsnd() */
76 	pid_t	msg_lrpid;	/* pid of last msgrcv() */
77 	time_t	msg_stime;	/* time of last msgsnd() */
78 	long	msg_pad1;
79 	time_t	msg_rtime;	/* time of last msgrcv() */
80 	long	msg_pad2;
81 	time_t	msg_ctime;	/* time of last msgctl() */
82 	long	msg_pad3;
83 	long	msg_pad4[4];
84 };
85 
86 #if __BSD_VISIBLE
87 /*
88  * Structure describing a message.  The SVID doesn't suggest any
89  * particular name for this structure.  There is a reference in the
90  * msgop man page that reads "The structure mymsg is an example of what
91  * this user defined buffer might look like, and includes the following
92  * members:".  This sentence is followed by two lines equivalent
93  * to the mtype and mtext field declarations below.  It isn't clear
94  * if "mymsg" refers to the naem of the structure type or the name of an
95  * instance of the structure...
96  */
97 struct mymsg {
98 	long	mtype;		/* message type (+ve integer) */
99 	char	mtext[1];	/* message body */
100 };
101 #endif
102 
103 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
104 
105 /*
106  * Based on the configuration parameters described in an SVR2 (yes, two)
107  * config(1m) man page.
108  *
109  * Each message is broken up and stored in segments that are msgssz bytes
110  * long.  For efficiency reasons, this should be a power of two.  Also,
111  * it doesn't make sense if it is less than 8 or greater than about 256.
112  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
113  * two between 8 and 1024 inclusive (and panic's if it isn't).
114  */
115 struct msginfo {
116 	int	msgmax,		/* max chars in a message */
117 		msgmni,		/* max message queue identifiers */
118 		msgmnb,		/* max chars in a queue */
119 		msgtql,		/* max messages in system */
120 		msgssz,		/* size of a message segment (see notes above) */
121 		msgseg;		/* number of message segments */
122 };
123 #endif
124 
125 #ifdef _KERNEL
126 extern struct msginfo	msginfo;
127 #else
128 __BEGIN_DECLS
129 int	msgctl(int, int, struct msqid_ds *);
130 int	msgget(key_t, int);
131 int	msgsnd(int, const void *, size_t, int);
132 int	msgrcv(int, void *, size_t, long, int); /* XXX should return ssize_t */
133 __END_DECLS
134 #endif
135 
136 #endif /* !_SYS_MSG_H_ */
137