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 */
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() */
48 time_t msg_rtime; /* time of last msgrcv() */
50 time_t msg_ctime; /* time of last msgctl() */
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 name of the structure type or the name of an
63 * instance of the structure...
66 long mtype; /* message type (+ve integer) */
67 char mtext[1]; /* message body */
73 * Based on the configuration parameters described in an SVR2 (yes, two)
74 * config(1m) man page.
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).
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 */
90 extern struct msginfo msginfo;
95 #include <sys/cdefs.h>
99 int msgctl(int, int, struct msqid_ds *);
100 int msgget(key_t, int);
101 int msgsnd(int, void *, size_t, int);
102 int msgrcv(int, void*, size_t, long, int);
106 #endif /* !_SYS_MSG_H_ */