1 /* $FreeBSD: src/sys/sys/msg.h,v 1.10.2.1 2000/08/04 22:31:10 peter Exp $ */
2 /* $DragonFly: src/sys/sys/msg.h,v 1.4 2003/08/27 02:03:22 dillon Exp $ */
3 /* $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $ */
6 * SVID compatible msg.h file
8 * Author: Daniel Boulet
10 * Copyright 1993 Daniel Boulet and RTMX Inc.
12 * This system call was implemented by Daniel Boulet under contract from RTMX.
14 * Redistribution and use in source forms, with and without modification,
15 * are permitted provided that this entire comment appears intact.
17 * Redistribution in binary form may occur without any restrictions.
18 * Obviously, it would be nice if you gave credit where credit is due
19 * but requiring it would be too onerous.
21 * This software is provided ``AS IS'' without any warranties of any kind.
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.
34 #define MSG_NOERROR 010000 /* don't complain about too long msgs */
36 /*!!! In the kernel implementation, both msg_first and msg_last
37 * have 'struct msg*' type.
38 * In the userland implementation, a pointer to a msg is useless
39 * because each message queue is mapped at different addresses in
40 * the process space address so my choice was to use indexes.
45 struct ipc_perm msg_perm; /* msg queue permission bits */
46 struct msg *msg_first; /* first message in the queue. */
47 struct msg *msg_last; /* last message in the queue. */
48 u_long msg_cbytes; /* number of bytes in use on the queue */
49 u_long msg_qnum; /* number of msgs in the queue */
50 u_long msg_qbytes; /* max # of bytes on the queue */
51 pid_t msg_lspid; /* pid of last msgsnd() */
52 pid_t msg_lrpid; /* pid of last msgrcv() */
53 time_t msg_stime; /* time of last msgsnd() */
55 time_t msg_rtime; /* time of last msgrcv() */
57 time_t msg_ctime; /* time of last msgctl() */
63 * Structure describing a message. The SVID doesn't suggest any
64 * particular name for this structure. There is a reference in the
65 * msgop man page that reads "The structure mymsg is an example of what
66 * this user defined buffer might look like, and includes the following
67 * members:". This sentence is followed by two lines equivalent
68 * to the mtype and mtext field declarations below. It isn't clear
69 * if "mymsg" refers to the naem of the structure type or the name of an
70 * instance of the structure...
73 long mtype; /* message type (+ve integer) */
74 char mtext[1]; /* message body */
77 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
80 * Based on the configuration parameters described in an SVR2 (yes, two)
81 * config(1m) man page.
83 * Each message is broken up and stored in segments that are msgssz bytes
84 * long. For efficiency reasons, this should be a power of two. Also,
85 * it doesn't make sense if it is less than 8 or greater than about 256.
86 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
87 * two between 8 and 1024 inclusive (and panic's if it isn't).
90 int msgmax, /* max chars in a message */
91 msgmni, /* max message queue identifiers */
92 msgmnb, /* max chars in a queue */
93 msgtql, /* max messages in system */
94 msgssz, /* size of a message segment (see notes above) */
95 msgseg; /* number of message segments */
100 extern struct msginfo msginfo;
105 #include <sys/cdefs.h>
108 int msgsys (int, ...);
109 int msgctl (int, int, struct msqid_ds *);
110 int msgget (key_t, int);
111 int msgsnd (int, void *, size_t, int);
112 int msgrcv (int, void*, size_t, long, int);
116 #endif /* !_SYS_MSG_H_ */