msg.h revision 2836
1/* $Id: msg.h,v 1.1 1994/09/13 14:47:34 dfr 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/ipc.h> 27 28/* 29 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct 30 * are as defined by the SV API Intel 386 Processor Supplement. 31 */ 32 33#define MSG_NOERROR 010000 /* don't complain about too long msgs */ 34 35struct msqid_ds { 36 struct ipc_perm msg_perm; /* msg queue permission bits */ 37 struct msg *msg_first; /* first message in the queue */ 38 struct msg *msg_last; /* last message in the queue */ 39 u_long msg_cbytes; /* number of bytes in use on the queue */ 40 u_long msg_qnum; /* number of msgs in the queue */ 41 u_long msg_qbytes; /* max # of bytes on the queue */ 42 pid_t msg_lspid; /* pid of last msgsnd() */ 43 pid_t msg_lrpid; /* pid of last msgrcv() */ 44 time_t msg_stime; /* time of last msgsnd() */ 45 long msg_pad1; 46 time_t msg_rtime; /* time of last msgrcv() */ 47 long msg_pad2; 48 time_t msg_ctime; /* time of last msgctl() */ 49 long msg_pad3; 50 long msg_pad4[4]; 51}; 52 53struct msg { 54 struct msg *msg_next; /* next msg in the chain */ 55 long msg_type; /* type of this message */ 56 /* >0 -> type of this message */ 57 /* 0 -> free header */ 58 u_short msg_ts; /* size of this message */ 59 short msg_spot; /* location of start of msg in buffer */ 60}; 61 62/* 63 * Structure describing a message. The SVID doesn't suggest any 64 * particular name for this structure. There is a reference in the 65 * msgop man page that reads "The structure mymsg is an example of what 66 * this user defined buffer might look like, and includes the following 67 * members:". This sentence is followed by two lines equivalent 68 * to the mtype and mtext field declarations below. It isn't clear 69 * if "mymsg" refers to the naem of the structure type or the name of an 70 * instance of the structure... 71 */ 72struct mymsg { 73 long mtype; /* message type (+ve integer) */ 74 char mtext[1]; /* message body */ 75}; 76 77/* 78 * Based on the configuration parameters described in an SVR2 (yes, two) 79 * config(1m) man page. 80 * 81 * Each message is broken up and stored in segments that are msgssz bytes 82 * long. For efficiency reasons, this should be a power of two. Also, 83 * it doesn't make sense if it is less than 8 or greater than about 256. 84 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 85 * two between 8 and 1024 inclusive (and panic's if it isn't). 86 */ 87struct msginfo { 88 int msgmax, /* max chars in a message */ 89 msgmni, /* max message queue identifiers */ 90 msgmnb, /* max chars in a queue */ 91 msgtql, /* max messages in system */ 92 msgssz, /* size of a message segment (see notes above) */ 93 msgseg; /* number of message segments */ 94}; 95#ifdef KERNEL 96extern struct msginfo msginfo; 97 98#ifndef MSGSSZ 99#define MSGSSZ 8 /* Each segment must be 2^N long */ 100#endif 101#ifndef MSGSEG 102#define MSGSEG 2048 /* must be less than 32767 */ 103#endif 104#undef MSGMAX /* ALWAYS compute MGSMAX! */ 105#define MSGMAX (MSGSSZ*MSGSEG) 106#ifndef MSGMNB 107#define MSGMNB 2048 /* max # of bytes in a queue */ 108#endif 109#ifndef MSGMNI 110#define MSGMNI 40 111#endif 112#ifndef MSGTQL 113#define MSGTQL 40 114#endif 115 116/* 117 * macros to convert between msqid_ds's and msqid's. 118 * (specific to this implementation) 119 */ 120#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000)) 121#define MSQID_IX(id) ((id) & 0xffff) 122#define MSQID_SEQ(id) (((id) >> 16) & 0xffff) 123 124/* 125 * The rest of this file is specific to this particular implementation. 126 */ 127 128 129/* 130 * Stuff allocated in machdep.h 131 */ 132struct msgmap { 133 short next; /* next segment in buffer */ 134 /* -1 -> available */ 135 /* 0..(MSGSEG-1) -> index of next segment */ 136}; 137 138char *msgpool; /* MSGMAX byte long msg buffer pool */ 139struct msgmap *msgmaps; /* MSGSEG msgmap structures */ 140struct msg *msghdrs; /* MSGTQL msg headers */ 141struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */ 142 143#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */ 144 145#endif /* KERNEL */ 146 147#ifndef KERNEL 148#include <sys/cdefs.h> 149 150__BEGIN_DECLS 151int msgsys __P((int, ...)); 152int msgctl __P((int, int, struct msqid_ds *)); 153int msgget __P((key_t, int)); 154int msgsnd __P((int, void *, size_t, int)); 155int msgrcv __P((int, void*, size_t, long, int)); 156__END_DECLS 157#endif /* !KERNEL */ 158 159#endif /* !_SYS_MSG_H_ */ 160