FreeBSD/Linux Kernel Cross Reference
sys/sys/msg.h
1 /* $FreeBSD$ */
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/_types.h>
28 #include <sys/ipc.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 /*
61 * XXX there seems to be no prefix reserved for this header, so the name
62 * "msg" in "struct msg" and the names of all of the nonstandard members
63 * (mainly "msg_pad*) are namespace pollution.
64 */
65
66 struct msqid_ds {
67 struct ipc_perm msg_perm; /* msg queue permission bits */
68 struct msg *msg_first; /* first message in the queue */
69 struct msg *msg_last; /* last message in the queue */
70 msglen_t msg_cbytes; /* number of bytes in use on the queue */
71 msgqnum_t msg_qnum; /* number of msgs in the queue */
72 msglen_t msg_qbytes; /* max # of bytes on the queue */
73 pid_t msg_lspid; /* pid of last msgsnd() */
74 pid_t msg_lrpid; /* pid of last msgrcv() */
75 time_t msg_stime; /* time of last msgsnd() */
76 long msg_pad1;
77 time_t msg_rtime; /* time of last msgrcv() */
78 long msg_pad2;
79 time_t msg_ctime; /* time of last msgctl() */
80 long msg_pad3;
81 long msg_pad4[4];
82 };
83
84 #if __BSD_VISIBLE
85 /*
86 * Structure describing a message. The SVID doesn't suggest any
87 * particular name for this structure. There is a reference in the
88 * msgop man page that reads "The structure mymsg is an example of what
89 * this user defined buffer might look like, and includes the following
90 * members:". This sentence is followed by two lines equivalent
91 * to the mtype and mtext field declarations below. It isn't clear
92 * if "mymsg" refers to the name of the structure type or the name of an
93 * instance of the structure...
94 */
95 struct mymsg {
96 long mtype; /* message type (+ve integer) */
97 char mtext[1]; /* message body */
98 };
99 #endif
100
101 #ifdef _KERNEL
102
103 struct msg {
104 struct msg *msg_next; /* next msg in the chain */
105 long msg_type; /* type of this message */
106 /* >0 -> type of this message */
107 /* 0 -> free header */
108 u_short msg_ts; /* size of this message */
109 short msg_spot; /* location of start of msg in buffer */
110 };
111
112 /*
113 * Based on the configuration parameters described in an SVR2 (yes, two)
114 * config(1m) man page.
115 *
116 * Each message is broken up and stored in segments that are msgssz bytes
117 * long. For efficiency reasons, this should be a power of two. Also,
118 * it doesn't make sense if it is less than 8 or greater than about 256.
119 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
120 * two between 8 and 1024 inclusive (and panic's if it isn't).
121 */
122 struct msginfo {
123 int msgmax, /* max chars in a message */
124 msgmni, /* max message queue identifiers */
125 msgmnb, /* max chars in a queue */
126 msgtql, /* max messages in system */
127 msgssz, /* size of a message segment (see notes above) */
128 msgseg; /* number of message segments */
129 };
130 extern struct msginfo msginfo;
131
132 /*
133 * Kernel wrapper for the user-level structure.
134 */
135 struct msqid_kernel {
136 /*
137 * Data structure exposed to user space.
138 */
139 struct msqid_ds u;
140
141 /*
142 * Kernel-private components of the message queue.
143 */
144 };
145
146 #else /* !_KERNEL */
147
148 __BEGIN_DECLS
149 int msgctl(int, int, struct msqid_ds *);
150 int msgget(key_t, int);
151 /* XXX return value should be ssize_t. */
152 int msgrcv(int, void *, size_t, long, int);
153 int msgsnd(int, const void *, size_t, int);
154 #if __BSD_VISIBLE
155 int msgsys(int, ...);
156 #endif
157 __END_DECLS
158
159 #endif /* _KERNEL */
160
161 #endif /* !_SYS_MSG_H_ */
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