bsd/sys/msg.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*      $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $      */
  26
  27 /*
  28  * SVID compatible msg.h file
  29  *
  30  * Author:  Daniel Boulet
  31  *
  32  * Copyright 1993 Daniel Boulet and RTMX Inc.
  33  *
  34  * This system call was implemented by Daniel Boulet under contract from RTMX.
  35  *
  36  * Redistribution and use in source forms, with and without modification,
  37  * are permitted provided that this entire comment appears intact.
  38  *
  39  * Redistribution in binary form may occur without any restrictions.
  40  * Obviously, it would be nice if you gave credit where credit is due
  41  * but requiring it would be too onerous.
  42  *
  43  * This software is provided ``AS IS'' without any warranties of any kind.
  44  */
  45
  46 #ifndef _SYS_MSG_H_
  47 #define _SYS_MSG_H_
  48
  49 #include <sys/appleapiopts.h>
  50
  51 #ifdef __APPLE_API_UNSTABLE
  52 #include <sys/ipc.h>
  53
  54
  55 /*
  56  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
  57  * are as defined by the SV API Intel 386 Processor Supplement.
  58  */
  59
  60 #define MSG_NOERROR     010000          /* don't complain about too long msgs */
  61
  62 struct msqid_ds {
  63         struct  ipc_perm msg_perm;      /* msg queue permission bits */
  64         struct  msg *msg_first; /* first message in the queue */
  65         struct  msg *msg_last;  /* last message in the queue */
  66         u_long  msg_cbytes;     /* number of bytes in use on the queue */
  67         u_long  msg_qnum;       /* number of msgs in the queue */
  68         u_long  msg_qbytes;     /* max # of bytes on the queue */
  69         pid_t   msg_lspid;      /* pid of last msgsnd() */
  70         pid_t   msg_lrpid;      /* pid of last msgrcv() */
  71         time_t  msg_stime;      /* time of last msgsnd() */
  72         long    msg_pad1;
  73         time_t  msg_rtime;      /* time of last msgrcv() */
  74         long    msg_pad2;
  75         time_t  msg_ctime;      /* time of last msgctl() */
  76         long    msg_pad3;
  77         long    msg_pad4[4];
  78 };
  79
  80 struct msg {
  81         struct  msg *msg_next;  /* next msg in the chain */
  82         long    msg_type;       /* type of this message */
  83                                 /* >0 -> type of this message */
  84                                 /* 0 -> free header */
  85         u_short msg_ts;         /* size of this message */
  86         short   msg_spot;       /* location of start of msg in buffer */
  87 };
  88
  89 /*
  90  * Structure describing a message.  The SVID doesn't suggest any
  91  * particular name for this structure.  There is a reference in the
  92  * msgop man page that reads "The structure mymsg is an example of what
  93  * this user defined buffer might look like, and includes the following
  94  * members:".  This sentence is followed by two lines equivalent
  95  * to the mtype and mtext field declarations below.  It isn't clear
  96  * if "mymsg" refers to the naem of the structure type or the name of an
  97  * instance of the structure...
  98  */
  99 struct mymsg {
 100         long    mtype;          /* message type (+ve integer) */
 101         char    mtext[1];       /* message body */
 102 };
 103
 104 /*
 105  * Based on the configuration parameters described in an SVR2 (yes, two)
 106  * config(1m) man page.
 107  *
 108  * Each message is broken up and stored in segments that are msgssz bytes
 109  * long.  For efficiency reasons, this should be a power of two.  Also,
 110  * it doesn't make sense if it is less than 8 or greater than about 256.
 111  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
 112  * two between 8 and 1024 inclusive (and panic's if it isn't).
 113  */
 114 struct msginfo {
 115         int     msgmax,         /* max chars in a message */
 116                 msgmni,         /* max message queue identifiers */
 117                 msgmnb,         /* max chars in a queue */
 118                 msgtql,         /* max messages in system */
 119                 msgssz,         /* size of a message segment (see notes above) */
 120                 msgseg;         /* number of message segments */
 121 };
 122 #ifdef KERNEL
 123 extern struct msginfo   msginfo;
 124
 125 #ifndef MSGSSZ
 126 #define MSGSSZ  8               /* Each segment must be 2^N long */
 127 #endif
 128 #ifndef MSGSEG
 129 #define MSGSEG  2048            /* must be less than 32767 */
 130 #endif
 131 #define MSGMAX  (MSGSSZ*MSGSEG)
 132 #ifndef MSGMNB
 133 #define MSGMNB  2048            /* max # of bytes in a queue */
 134 #endif
 135 #ifndef MSGMNI
 136 #define MSGMNI  40
 137 #endif
 138 #ifndef MSGTQL
 139 #define MSGTQL  40
 140 #endif
 141
 142 /*
 143  * macros to convert between msqid_ds's and msqid's.
 144  * (specific to this implementation)
 145  */
 146 #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
 147 #define MSQID_IX(id)    ((id) & 0xffff)
 148 #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
 149
 150 /*
 151  * The rest of this file is specific to this particular implementation.
 152  */
 153
 154
 155 /*
 156  * Stuff allocated in machdep.h
 157  */
 158 struct msgmap {
 159         short   next;           /* next segment in buffer */
 160                                 /* -1 -> available */
 161                                 /* 0..(MSGSEG-1) -> index of next segment */
 162 };
 163
 164 extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
 165 extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
 166 extern struct msg *msghdrs;     /* MSGTQL msg headers */
 167 extern struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
 168
 169 #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
 170
 171 #endif /* KERNEL */
 172
 173 #ifndef KERNEL
 174 #include <sys/cdefs.h>
 175
 176 __BEGIN_DECLS
 177 int msgsys __P((int, ...));
 178 int msgctl __P((int, int, struct msqid_ds *));
 179 int msgget __P((key_t, int));
 180 int msgsnd __P((int, void *, size_t, int));
 181 int msgrcv __P((int, void*, size_t, long, int));
 182 __END_DECLS
 183 #endif /* !KERNEL */
 184
 185 #endif /* __APPLE_API_UNSTABLE */
 186 #endif /* !_SYS_MSG_H_ */