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 /*!!! In the kernel implementation, both msg_first and msg_last
36 * have 'struct msg*' type.
37 * In the userland implementation, a pointer to a msg is useless
38 * because each message queue is mapped at different addresses in
39 * the process space address so my choice was to use indexes.
44 struct ipc_perm msg_perm; /* msg queue permission bits */
45 struct msg *msg_first; /* first message in the queue. */
46 struct msg *msg_last; /* last message in the queue. */
47 u_long msg_cbytes; /* number of bytes in use on the queue */
48 u_long msg_qnum; /* number of msgs in the queue */
49 u_long msg_qbytes; /* max # of bytes on the queue */
50 pid_t msg_lspid; /* pid of last msgsnd() */
51 pid_t msg_lrpid; /* pid of last msgrcv() */
52 time_t msg_stime; /* time of last msgsnd() */
54 time_t msg_rtime; /* time of last msgrcv() */
56 time_t msg_ctime; /* time of last msgctl() */
62 * Structure describing a message. The SVID doesn't suggest any
63 * particular name for this structure. There is a reference in the
64 * msgop man page that reads "The structure mymsg is an example of what
65 * this user defined buffer might look like, and includes the following
66 * members:". This sentence is followed by two lines equivalent
67 * to the mtype and mtext field declarations below. It isn't clear
68 * if "mymsg" refers to the naem of the structure type or the name of an
69 * instance of the structure...
72 long mtype; /* message type (+ve integer) */
73 char mtext[1]; /* message body */
76 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
79 * Based on the configuration parameters described in an SVR2 (yes, two)
80 * config(1m) man page.
82 * Each message is broken up and stored in segments that are msgssz bytes
83 * long. For efficiency reasons, this should be a power of two. Also,
84 * it doesn't make sense if it is less than 8 or greater than about 256.
85 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
86 * two between 8 and 1024 inclusive (and panic's if it isn't).
89 int msgmax, /* max chars in a message */
90 msgmni, /* max message queue identifiers */
91 msgmnb, /* max chars in a queue */
92 msgtql, /* max messages in system */
93 msgssz, /* size of a message segment (see notes above) */
94 msgseg; /* number of message segments */
99 extern struct msginfo msginfo;
104 #include <sys/cdefs.h>
107 int msgctl (int, int, struct msqid_ds *);
108 int msgget (key_t, int);
109 int msgsnd (int, const void *, size_t, int);
110 int msgrcv (int, void *, size_t, long, int); /* XXX should return ssize_t */
114 #endif /* !_SYS_MSG_H_ */