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 $ */
5 * SVID compatible msg.h file
7 * Author: Daniel Boulet
9 * Copyright 1993 Daniel Boulet and RTMX Inc.
11 * This system call was implemented by Daniel Boulet under contract from RTMX.
13 * Redistribution and use in source forms, with and without modification,
14 * are permitted provided that this entire comment appears intact.
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.
20 * This software is provided ``AS IS'' without any warranties of any kind.
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.
33 #define MSG_NOERROR 010000 /* don't complain about too long msgs */
35 typedef unsigned long msglen_t;
36 typedef unsigned long msgqnum_t;
38 /*!!! In the kernel implementation, both msg_first and msg_last
39 * have 'struct msg*' type.
40 * In the userland implementation, a pointer to a msg is useless
41 * because each message queue is mapped at different addresses in
42 * the process space address so my choice was to use indexes.
47 struct ipc_perm msg_perm; /* msg queue permission bits */
48 struct msg *msg_first; /* first message in the queue. */
49 struct msg *msg_last; /* last message in the queue. */
50 msglen_t msg_cbytes; /* number of bytes in use on the queue */
51 msgqnum_t msg_qnum; /* number of msgs in the queue */
52 msglen_t msg_qbytes; /* max # of bytes on the queue */
53 pid_t msg_lspid; /* pid of last msgsnd() */
54 pid_t msg_lrpid; /* pid of last msgrcv() */
55 time_t msg_stime; /* time of last msgsnd() */
57 time_t msg_rtime; /* time of last msgrcv() */
59 time_t msg_ctime; /* time of last msgctl() */
65 * Structure describing a message. The SVID doesn't suggest any
66 * particular name for this structure. There is a reference in the
67 * msgop man page that reads "The structure mymsg is an example of what
68 * this user defined buffer might look like, and includes the following
69 * members:". This sentence is followed by two lines equivalent
70 * to the mtype and mtext field declarations below. It isn't clear
71 * if "mymsg" refers to the naem of the structure type or the name of an
72 * instance of the structure...
75 long mtype; /* message type (+ve integer) */
76 char mtext[1]; /* message body */
79 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
82 * Based on the configuration parameters described in an SVR2 (yes, two)
83 * config(1m) man page.
85 * Each message is broken up and stored in segments that are msgssz bytes
86 * long. For efficiency reasons, this should be a power of two. Also,
87 * it doesn't make sense if it is less than 8 or greater than about 256.
88 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
89 * two between 8 and 1024 inclusive (and panic's if it isn't).
92 int msgmax, /* max chars in a message */
93 msgmni, /* max message queue identifiers */
94 msgmnb, /* max chars in a queue */
95 msgtql, /* max messages in system */
96 msgssz, /* size of a message segment (see notes above) */
97 msgseg; /* number of message segments */
102 extern struct msginfo msginfo;
107 #include <sys/cdefs.h>
110 int msgctl(int, int, struct msqid_ds *);
111 int msgget(key_t, int);
112 int msgsnd(int, const void *, size_t, int);
113 int msgrcv(int, void *, size_t, long, int); /* XXX should return ssize_t */
117 #endif /* !_SYS_MSG_H_ */