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/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 35 /*!!! In the kernel implementation, both msg_first and msg_last 36 * have 'struct msg*' type. 37 * In the userland implementation, a pointer to a msg is useless 38 * because each message queue is mapped at different addresses in 39 * the process space address so my choice was to use indexes. 40 */ 41 struct msg; 42 43 struct msqid_ds { 44 struct ipc_perm msg_perm; /* msg queue permission bits */ 45 struct msg *msg_first; /* first message in the queue. */ 46 struct msg *msg_last; /* last message in the queue. */ 47 u_long msg_cbytes; /* number of bytes in use on the queue */ 48 u_long msg_qnum; /* number of msgs in the queue */ 49 u_long msg_qbytes; /* max # of bytes on the queue */ 50 pid_t msg_lspid; /* pid of last msgsnd() */ 51 pid_t msg_lrpid; /* pid of last msgrcv() */ 52 time_t msg_stime; /* time of last msgsnd() */ 53 long msg_pad1; 54 time_t msg_rtime; /* time of last msgrcv() */ 55 long msg_pad2; 56 time_t msg_ctime; /* time of last msgctl() */ 57 long msg_pad3; 58 long msg_pad4[4]; 59 }; 60 61 /* 62 * Structure describing a message. The SVID doesn't suggest any 63 * particular name for this structure. There is a reference in the 64 * msgop man page that reads "The structure mymsg is an example of what 65 * this user defined buffer might look like, and includes the following 66 * members:". This sentence is followed by two lines equivalent 67 * to the mtype and mtext field declarations below. It isn't clear 68 * if "mymsg" refers to the naem of the structure type or the name of an 69 * instance of the structure... 70 */ 71 struct mymsg { 72 long mtype; /* message type (+ve integer) */ 73 char mtext[1]; /* message body */ 74 }; 75 76 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 77 78 /* 79 * Based on the configuration parameters described in an SVR2 (yes, two) 80 * config(1m) man page. 81 * 82 * Each message is broken up and stored in segments that are msgssz bytes 83 * long. For efficiency reasons, this should be a power of two. Also, 84 * it doesn't make sense if it is less than 8 or greater than about 256. 85 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 86 * two between 8 and 1024 inclusive (and panic's if it isn't). 87 */ 88 struct msginfo { 89 int msgmax, /* max chars in a message */ 90 msgmni, /* max message queue identifiers */ 91 msgmnb, /* max chars in a queue */ 92 msgtql, /* max messages in system */ 93 msgssz, /* size of a message segment (see notes above) */ 94 msgseg; /* number of message segments */ 95 }; 96 #endif 97 98 #ifdef _KERNEL 99 extern struct msginfo msginfo; 100 #endif 101 102 #ifndef _KERNEL 103 104 #include <sys/cdefs.h> 105 106 __BEGIN_DECLS 107 int msgctl (int, int, struct msqid_ds *); 108 int msgget (key_t, int); 109 int msgsnd (int, const void *, size_t, int); 110 int msgrcv (int, void *, size_t, long, int); /* XXX should return ssize_t */ 111 __END_DECLS 112 #endif 113 114 #endif /* !_SYS_MSG_H_ */ 115