sys/sys/msg.h

   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 $      */
   3
   4 /*
   5  * SVID compatible msg.h file
   6  *
   7  * Author:  Daniel Boulet
   8  *
   9  * Copyright 1993 Daniel Boulet and RTMX Inc.
  10  *
  11  * This system call was implemented by Daniel Boulet under contract from RTMX.
  12  *
  13  * Redistribution and use in source forms, with and without modification,
  14  * are permitted provided that this entire comment appears intact.
  15  *
  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.
  19  *
  20  * This software is provided ``AS IS'' without any warranties of any kind.
  21  */
  22
  23 #ifndef _SYS_MSG_H_
  24 #define _SYS_MSG_H_
  25
  26 #include <sys/cdefs.h>
  27 #include <sys/ipc.h>
  28
  29 /*
  30  * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
  31  * are as defined by the SV API Intel 386 Processor Supplement.
  32  */
  33
  34 #define MSG_NOERROR     010000          /* don't complain about too long msgs */
  35
  36 typedef unsigned long   msglen_t;
  37 typedef unsigned long   msgqnum_t;
  38
  39 #ifndef _PID_T_DECLARED
  40 typedef __pid_t         pid_t;
  41 #define _PID_T_DECLARED
  42 #endif
  43
  44 #ifndef _SIZE_T_DECLARED
  45 typedef __size_t        size_t;
  46 #define _SIZE_T_DECLARED
  47 #endif
  48
  49 #ifndef _SSIZE_T_DECLARED
  50 typedef __ssize_t       ssize_t;
  51 #define _SSIZE_T_DECLARED
  52 #endif
  53
  54 #ifndef _TIME_T_DECLARED
  55 typedef __time_t        time_t;
  56 #define _TIME_T_DECLARED
  57 #endif
  58
  59 /*!!! In the kernel implementation, both msg_first and msg_last
  60  * have 'struct msg*' type.
  61  * In the userland implementation, a pointer to a msg is useless
  62  * because each message queue is mapped at different addresses in
  63  * the process space address so my choice was to use indexes.
  64  */
  65 struct msg;
  66
  67 struct msqid_ds {
  68         struct  ipc_perm msg_perm;      /* msg queue permission bits */
  69         struct  msg *msg_first; /* first message in the queue. */
  70         struct  msg *msg_last;  /* last message in the queue. */
  71         msglen_t msg_cbytes;    /* number of bytes in use on the queue */
  72         msgqnum_t msg_qnum;     /* number of msgs in the queue */
  73         msglen_t msg_qbytes;    /* max # of bytes on the queue */
  74         pid_t   msg_lspid;      /* pid of last msgsnd() */
  75         pid_t   msg_lrpid;      /* pid of last msgrcv() */
  76         time_t  msg_stime;      /* time of last msgsnd() */
  77         long    msg_pad1;
  78         time_t  msg_rtime;      /* time of last msgrcv() */
  79         long    msg_pad2;
  80         time_t  msg_ctime;      /* time of last msgctl() */
  81         long    msg_pad3;
  82         long    msg_pad4[4];
  83 };
  84
  85 #if __BSD_VISIBLE
  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 #endif
 101
 102 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
 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 #endif
 123
 124 #ifdef _KERNEL
 125 extern struct msginfo   msginfo;
 126 #else
 127 __BEGIN_DECLS
 128 int     msgctl(int, int, struct msqid_ds *);
 129 int     msgget(key_t, int);
 130 int     msgsnd(int, const void *, size_t, int);
 131 int     msgrcv(int, void *, size_t, long, int); /* XXX should return ssize_t */
 132 __END_DECLS
 133 #endif
 134
 135 #endif /* !_SYS_MSG_H_ */