FreeBSD/Linux Kernel Cross Reference
sys/bsd/sys/msg.h

     /*
      * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
      *
      * @APPLE_LICENSE_HEADER_START@
      * 
      * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
      * 
      * This file contains Original Code and/or Modifications of Original Code
      * as defined in and that are subject to the Apple Public Source License
     * Version 2.0 (the 'License'). You may not use this file except in
     * compliance with the License. Please obtain a copy of the License at
     * http://www.opensource.apple.com/apsl/ and read it before using this
     * file.
     * 
     * The Original Code and all software distributed under the License are
     * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
     * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
     * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
     * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
     * Please see the License for the specific language governing rights and
     * limitations under the License.
     * 
     * @APPLE_LICENSE_HEADER_END@
     */
    /*      $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $      */
    
    /*
     * SVID compatible msg.h file
     *
     * Author:  Daniel Boulet
     *
     * Copyright 1993 Daniel Boulet and RTMX Inc.
     *
     * This system call was implemented by Daniel Boulet under contract from RTMX.
     *
     * Redistribution and use in source forms, with and without modification,
     * are permitted provided that this entire comment appears intact.
     *
     * Redistribution in binary form may occur without any restrictions.
     * Obviously, it would be nice if you gave credit where credit is due
     * but requiring it would be too onerous.
     *
     * This software is provided ``AS IS'' without any warranties of any kind.
     */
    
    #ifndef _SYS_MSG_H_
    #define _SYS_MSG_H_
    
    #include <sys/appleapiopts.h>
    
    #ifdef __APPLE_API_UNSTABLE
    #include <sys/ipc.h>
    
    
    /*
     * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
     * are as defined by the SV API Intel 386 Processor Supplement.
     */
    
    #define MSG_NOERROR     010000          /* don't complain about too long msgs */
    
    struct msqid_ds {
            struct  ipc_perm msg_perm;      /* msg queue permission bits */
            struct  msg *msg_first; /* first message in the queue */
            struct  msg *msg_last;  /* last message in the queue */
            u_long  msg_cbytes;     /* number of bytes in use on the queue */
            u_long  msg_qnum;       /* number of msgs in the queue */
            u_long  msg_qbytes;     /* max # of bytes on the queue */
            pid_t   msg_lspid;      /* pid of last msgsnd() */
            pid_t   msg_lrpid;      /* pid of last msgrcv() */
            time_t  msg_stime;      /* time of last msgsnd() */
            long    msg_pad1;
            time_t  msg_rtime;      /* time of last msgrcv() */
            long    msg_pad2;
            time_t  msg_ctime;      /* time of last msgctl() */
            long    msg_pad3;
            long    msg_pad4[4];
    };
    
    struct msg {
            struct  msg *msg_next;  /* next msg in the chain */
            long    msg_type;       /* type of this message */
                                    /* >0 -> type of this message */
                                    /* 0 -> free header */
            u_short msg_ts;         /* size of this message */
            short   msg_spot;       /* location of start of msg in buffer */
    };
    
    /*
     * Structure describing a message.  The SVID doesn't suggest any
     * particular name for this structure.  There is a reference in the
     * msgop man page that reads "The structure mymsg is an example of what
     * this user defined buffer might look like, and includes the following
     * members:".  This sentence is followed by two lines equivalent
     * to the mtype and mtext field declarations below.  It isn't clear
     * if "mymsg" refers to the naem of the structure type or the name of an
     * instance of the structure...
     */
    struct mymsg {
           long    mtype;          /* message type (+ve integer) */
           char    mtext[1];       /* message body */
   };
   
   /*
    * Based on the configuration parameters described in an SVR2 (yes, two)
    * config(1m) man page.
    *
    * Each message is broken up and stored in segments that are msgssz bytes
    * long.  For efficiency reasons, this should be a power of two.  Also,
    * it doesn't make sense if it is less than 8 or greater than about 256.
    * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
    * two between 8 and 1024 inclusive (and panic's if it isn't).
    */
   struct msginfo {
           int     msgmax,         /* max chars in a message */
                   msgmni,         /* max message queue identifiers */
                   msgmnb,         /* max chars in a queue */
                   msgtql,         /* max messages in system */
                   msgssz,         /* size of a message segment (see notes above) */
                   msgseg;         /* number of message segments */
   };
   #ifdef KERNEL
   extern struct msginfo   msginfo;
   
   #ifndef MSGSSZ
   #define MSGSSZ  8               /* Each segment must be 2^N long */
   #endif
   #ifndef MSGSEG
   #define MSGSEG  2048            /* must be less than 32767 */
   #endif
   #define MSGMAX  (MSGSSZ*MSGSEG)
   #ifndef MSGMNB
   #define MSGMNB  2048            /* max # of bytes in a queue */
   #endif
   #ifndef MSGMNI
   #define MSGMNI  40
   #endif
   #ifndef MSGTQL
   #define MSGTQL  40
   #endif
   
   /*
    * macros to convert between msqid_ds's and msqid's.
    * (specific to this implementation)
    */
   #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
   #define MSQID_IX(id)    ((id) & 0xffff)
   #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
   
   /*
    * The rest of this file is specific to this particular implementation.
    */
   
   
   /*
    * Stuff allocated in machdep.h
    */
   struct msgmap {
           short   next;           /* next segment in buffer */
                                   /* -1 -> available */
                                   /* 0..(MSGSEG-1) -> index of next segment */
   };
   
   extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
   extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
   extern struct msg *msghdrs;     /* MSGTQL msg headers */
   extern struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
   
   #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
   
   #endif /* KERNEL */
   
   #ifndef KERNEL
   #include <sys/cdefs.h>
   
   __BEGIN_DECLS
   int msgsys __P((int, ...));
   int msgctl __P((int, int, struct msqid_ds *));
   int msgget __P((key_t, int));
   int msgsnd __P((int, void *, size_t, int));
   int msgrcv __P((int, void*, size_t, long, int));
   __END_DECLS
   #endif /* !KERNEL */
   
   #endif /* __APPLE_API_UNSTABLE */
   #endif /* !_SYS_MSG_H_ */

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