bsd/sys/msg.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $      */
  23
  24 /*
  25  * SVID compatible msg.h file
  26  *
  27  * Author:  Daniel Boulet
  28  *
  29  * Copyright 1993 Daniel Boulet and RTMX Inc.
  30  *
  31  * This system call was implemented by Daniel Boulet under contract from RTMX.
  32  *
  33  * Redistribution and use in source forms, with and without modification,
  34  * are permitted provided that this entire comment appears intact.
  35  *
  36  * Redistribution in binary form may occur without any restrictions.
  37  * Obviously, it would be nice if you gave credit where credit is due
  38  * but requiring it would be too onerous.
  39  *
  40  * This software is provided ``AS IS'' without any warranties of any kind.
  41  */
  42
  43 #ifndef _SYS_MSG_H_
  44 #define _SYS_MSG_H_
  45
  46 #include <sys/ipc.h>
  47
  48 /*
  49  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
  50  * are as defined by the SV API Intel 386 Processor Supplement.
  51  */
  52
  53 #define MSG_NOERROR     010000          /* don't complain about too long msgs */
  54
  55 struct msqid_ds {
  56         struct  ipc_perm msg_perm;      /* msg queue permission bits */
  57         struct  msg *msg_first; /* first message in the queue */
  58         struct  msg *msg_last;  /* last message in the queue */
  59         u_long  msg_cbytes;     /* number of bytes in use on the queue */
  60         u_long  msg_qnum;       /* number of msgs in the queue */
  61         u_long  msg_qbytes;     /* max # of bytes on the queue */
  62         pid_t   msg_lspid;      /* pid of last msgsnd() */
  63         pid_t   msg_lrpid;      /* pid of last msgrcv() */
  64         time_t  msg_stime;      /* time of last msgsnd() */
  65         long    msg_pad1;
  66         time_t  msg_rtime;      /* time of last msgrcv() */
  67         long    msg_pad2;
  68         time_t  msg_ctime;      /* time of last msgctl() */
  69         long    msg_pad3;
  70         long    msg_pad4[4];
  71 };
  72
  73 struct msg {
  74         struct  msg *msg_next;  /* next msg in the chain */
  75         long    msg_type;       /* type of this message */
  76                                 /* >0 -> type of this message */
  77                                 /* 0 -> free header */
  78         u_short msg_ts;         /* size of this message */
  79         short   msg_spot;       /* location of start of msg in buffer */
  80 };
  81
  82 /*
  83  * Structure describing a message.  The SVID doesn't suggest any
  84  * particular name for this structure.  There is a reference in the
  85  * msgop man page that reads "The structure mymsg is an example of what
  86  * this user defined buffer might look like, and includes the following
  87  * members:".  This sentence is followed by two lines equivalent
  88  * to the mtype and mtext field declarations below.  It isn't clear
  89  * if "mymsg" refers to the naem of the structure type or the name of an
  90  * instance of the structure...
  91  */
  92 struct mymsg {
  93         long    mtype;          /* message type (+ve integer) */
  94         char    mtext[1];       /* message body */
  95 };
  96
  97 /*
  98  * Based on the configuration parameters described in an SVR2 (yes, two)
  99  * config(1m) man page.
 100  *
 101  * Each message is broken up and stored in segments that are msgssz bytes
 102  * long.  For efficiency reasons, this should be a power of two.  Also,
 103  * it doesn't make sense if it is less than 8 or greater than about 256.
 104  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
 105  * two between 8 and 1024 inclusive (and panic's if it isn't).
 106  */
 107 struct msginfo {
 108         int     msgmax,         /* max chars in a message */
 109                 msgmni,         /* max message queue identifiers */
 110                 msgmnb,         /* max chars in a queue */
 111                 msgtql,         /* max messages in system */
 112                 msgssz,         /* size of a message segment (see notes above) */
 113                 msgseg;         /* number of message segments */
 114 };
 115 #ifdef KERNEL
 116 extern struct msginfo   msginfo;
 117
 118 #ifndef MSGSSZ
 119 #define MSGSSZ  8               /* Each segment must be 2^N long */
 120 #endif
 121 #ifndef MSGSEG
 122 #define MSGSEG  2048            /* must be less than 32767 */
 123 #endif
 124 #define MSGMAX  (MSGSSZ*MSGSEG)
 125 #ifndef MSGMNB
 126 #define MSGMNB  2048            /* max # of bytes in a queue */
 127 #endif
 128 #ifndef MSGMNI
 129 #define MSGMNI  40
 130 #endif
 131 #ifndef MSGTQL
 132 #define MSGTQL  40
 133 #endif
 134
 135 /*
 136  * macros to convert between msqid_ds's and msqid's.
 137  * (specific to this implementation)
 138  */
 139 #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
 140 #define MSQID_IX(id)    ((id) & 0xffff)
 141 #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
 142
 143 /*
 144  * The rest of this file is specific to this particular implementation.
 145  */
 146
 147
 148 /*
 149  * Stuff allocated in machdep.h
 150  */
 151 struct msgmap {
 152         short   next;           /* next segment in buffer */
 153                                 /* -1 -> available */
 154                                 /* 0..(MSGSEG-1) -> index of next segment */
 155 };
 156
 157 extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
 158 extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
 159 extern struct msg *msghdrs;     /* MSGTQL msg headers */
 160 extern struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
 161
 162 #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
 163
 164 #endif /* KERNEL */
 165
 166 #ifndef KERNEL
 167 #include <sys/cdefs.h>
 168
 169 __BEGIN_DECLS
 170 int msgsys __P((int, ...));
 171 int msgctl __P((int, int, struct msqid_ds *));
 172 int msgget __P((key_t, int));
 173 int msgsnd __P((int, void *, size_t, int));
 174 int msgrcv __P((int, void*, size_t, long, int));
 175 __END_DECLS
 176 #endif /* !KERNEL */
 177
 178 #endif /* !_SYS_MSG_H_ */