glibc (2.38)
1 /* Copyright (C) 1995-2023 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
36 typedef __pid_t pid_t;
37 # define __pid_t_defined
38 #endif
39
40 #ifndef __ssize_t_defined
41 typedef __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'. */
50 struct 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
62 extern int msgctl (int __msqid, int __cmd, struct msqid_ds *__buf) __THROW;
63 #else
64 # ifdef __REDIRECT_NTH
65 extern 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. */
74 extern 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. */
80 extern 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. */
87 extern int msgsnd (int __msqid, const void *__msgp, size_t __msgsz,
88 int __msgflg);
89
90 __END_DECLS
91
92 #endif /* sys/msg.h */
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