1/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#ifndef _SYS_MSG_H
19#define _SYS_MSG_H
20
21#include <features.h>
22
23#define __need_size_t
24#include <stddef.h>
25
26/* Get common definition of System V style IPC. */
27#include <sys/ipc.h>
28
29/* Get system dependent definition of `struct msqid_ds' and more. */
30#include <bits/msq.h>
31
32/* Define types required by the standard. */
33#include <bits/types/time_t.h>
34
35#ifndef __pid_t_defined
36typedef __pid_t pid_t;
37# define __pid_t_defined
38#endif
39
40#ifndef __ssize_t_defined
41typedef __ssize_t ssize_t;
42# define __ssize_t_defined
43#endif
44
45/* The following System V style IPC functions implement a message queue
46 system. The definition is found in XPG2. */
47
48#ifdef __USE_GNU
49/* Template for struct to be used as argument for `msgsnd' and `msgrcv'. */
50struct msgbuf
51 {
52 __syscall_slong_t mtype; /* type of received/sent message */
53 char mtext[1]; /* text of the message */
54 };
55#endif
56
57
58__BEGIN_DECLS
59
60/* Message queue control operation. */
61#ifndef __USE_TIME_BITS64
62extern int msgctl (int __msqid, int __cmd, struct msqid_ds *__buf) __THROW;
63#else
64# ifdef __REDIRECT_NTH
65extern int __REDIRECT_NTH (msgctl,
66 (int __msqid, int __cmd, struct msqid_ds *__buf),
67 __msgctl64);
68# else
69# define msgctl __msgctl64
70# endif
71#endif
72
73/* Get messages queue. */
74extern int msgget (key_t __key, int __msgflg) __THROW;
75
76/* Receive message from message queue.
77
78 This function is a cancellation point and therefore not marked with
79 __THROW. */
80extern ssize_t msgrcv (int __msqid, void *__msgp, size_t __msgsz,
81 long int __msgtyp, int __msgflg);
82
83/* Send message to message queue.
84
85 This function is a cancellation point and therefore not marked with
86 __THROW. */
87extern int msgsnd (int __msqid, const void *__msgp, size_t __msgsz,
88 int __msgflg);
89
90__END_DECLS
91
92#endif /* sys/msg.h */
93

source code of include/x86_64-linux-gnu/sys/msg.h