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 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 */ 93