bsd/sys/msg.h

   1 /*
   2  * Copyright (c) 2000-2002 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/appleapiopts.h>
  47
  48 #ifdef __APPLE_API_UNSTABLE
  49 #include <sys/ipc.h>
  50
  51
  52 /*
  53  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
  54  * are as defined by the SV API Intel 386 Processor Supplement.
  55  */
  56
  57 #define MSG_NOERROR     010000          /* don't complain about too long msgs */
  58
  59 struct msqid_ds {
  60         struct  ipc_perm msg_perm;      /* msg queue permission bits */
  61         struct  msg *msg_first; /* first message in the queue */
  62         struct  msg *msg_last;  /* last message in the queue */
  63         u_long  msg_cbytes;     /* number of bytes in use on the queue */
  64         u_long  msg_qnum;       /* number of msgs in the queue */
  65         u_long  msg_qbytes;     /* max # of bytes on the queue */
  66         pid_t   msg_lspid;      /* pid of last msgsnd() */
  67         pid_t   msg_lrpid;      /* pid of last msgrcv() */
  68         time_t  msg_stime;      /* time of last msgsnd() */
  69         long    msg_pad1;
  70         time_t  msg_rtime;      /* time of last msgrcv() */
  71         long    msg_pad2;
  72         time_t  msg_ctime;      /* time of last msgctl() */
  73         long    msg_pad3;
  74         long    msg_pad4[4];
  75 };
  76
  77 struct msg {
  78         struct  msg *msg_next;  /* next msg in the chain */
  79         long    msg_type;       /* type of this message */
  80                                 /* >0 -> type of this message */
  81                                 /* 0 -> free header */
  82         u_short msg_ts;         /* size of this message */
  83         short   msg_spot;       /* location of start of msg in buffer */
  84 };
  85
  86 /*
  87  * Structure describing a message.  The SVID doesn't suggest any
  88  * particular name for this structure.  There is a reference in the
  89  * msgop man page that reads "The structure mymsg is an example of what
  90  * this user defined buffer might look like, and includes the following
  91  * members:".  This sentence is followed by two lines equivalent
  92  * to the mtype and mtext field declarations below.  It isn't clear
  93  * if "mymsg" refers to the naem of the structure type or the name of an
  94  * instance of the structure...
  95  */
  96 struct mymsg {
  97         long    mtype;          /* message type (+ve integer) */
  98         char    mtext[1];       /* message body */
  99 };
 100
 101 /*
 102  * Based on the configuration parameters described in an SVR2 (yes, two)
 103  * config(1m) man page.
 104  *
 105  * Each message is broken up and stored in segments that are msgssz bytes
 106  * long.  For efficiency reasons, this should be a power of two.  Also,
 107  * it doesn't make sense if it is less than 8 or greater than about 256.
 108  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
 109  * two between 8 and 1024 inclusive (and panic's if it isn't).
 110  */
 111 struct msginfo {
 112         int     msgmax,         /* max chars in a message */
 113                 msgmni,         /* max message queue identifiers */
 114                 msgmnb,         /* max chars in a queue */
 115                 msgtql,         /* max messages in system */
 116                 msgssz,         /* size of a message segment (see notes above) */
 117                 msgseg;         /* number of message segments */
 118 };
 119 #ifdef KERNEL
 120 extern struct msginfo   msginfo;
 121
 122 #ifndef MSGSSZ
 123 #define MSGSSZ  8               /* Each segment must be 2^N long */
 124 #endif
 125 #ifndef MSGSEG
 126 #define MSGSEG  2048            /* must be less than 32767 */
 127 #endif
 128 #define MSGMAX  (MSGSSZ*MSGSEG)
 129 #ifndef MSGMNB
 130 #define MSGMNB  2048            /* max # of bytes in a queue */
 131 #endif
 132 #ifndef MSGMNI
 133 #define MSGMNI  40
 134 #endif
 135 #ifndef MSGTQL
 136 #define MSGTQL  40
 137 #endif
 138
 139 /*
 140  * macros to convert between msqid_ds's and msqid's.
 141  * (specific to this implementation)
 142  */
 143 #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
 144 #define MSQID_IX(id)    ((id) & 0xffff)
 145 #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
 146
 147 /*
 148  * The rest of this file is specific to this particular implementation.
 149  */
 150
 151
 152 /*
 153  * Stuff allocated in machdep.h
 154  */
 155 struct msgmap {
 156         short   next;           /* next segment in buffer */
 157                                 /* -1 -> available */
 158                                 /* 0..(MSGSEG-1) -> index of next segment */
 159 };
 160
 161 extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
 162 extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
 163 extern struct msg *msghdrs;     /* MSGTQL msg headers */
 164 extern struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
 165
 166 #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
 167
 168 #endif /* KERNEL */
 169
 170 #ifndef KERNEL
 171 #include <sys/cdefs.h>
 172
 173 __BEGIN_DECLS
 174 int msgsys __P((int, ...));
 175 int msgctl __P((int, int, struct msqid_ds *));
 176 int msgget __P((key_t, int));
 177 int msgsnd __P((int, void *, size_t, int));
 178 int msgrcv __P((int, void*, size_t, long, int));
 179 __END_DECLS
 180 #endif /* !KERNEL */
 181
 182 #endif /* __APPLE_API_UNSTABLE */
 183 #endif /* !_SYS_MSG_H_ */