sysvipc/sys/msg.h

   1 /* Copyright (C) 1995-2016 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    <http://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 #define __need_time_t
  34 #include <time.h>
  35
  36 #ifndef __pid_t_defined
  37 typedef __pid_t pid_t;
  38 # define __pid_t_defined
  39 #endif
  40
  41 #ifndef __ssize_t_defined
  42 typedef __ssize_t ssize_t;
  43 # define __ssize_t_defined
  44 #endif
  45
  46 /* The following System V style IPC functions implement a message queue
  47    system.  The definition is found in XPG2.  */
  48
  49 #ifdef __USE_GNU
  50 /* Template for struct to be used as argument for `msgsnd' and `msgrcv'.  */
  51 struct msgbuf
  52   {
  53     __syscall_slong_t mtype;    /* type of received/sent message */
  54     char mtext[1];              /* text of the message */
  55   };
  56 #endif
  57
  58
  59 __BEGIN_DECLS
  60
  61 /* Message queue control operation.  */
  62 extern int msgctl (int __msqid, int __cmd, struct msqid_ds *__buf) __THROW;
  63
  64 /* Get messages queue.  */
  65 extern int msgget (key_t __key, int __msgflg) __THROW;
  66
  67 /* Receive message from message queue.
  68
  69    This function is a cancellation point and therefore not marked with
  70    __THROW.  */
  71 extern ssize_t msgrcv (int __msqid, void *__msgp, size_t __msgsz,
  72                        long int __msgtyp, int __msgflg);
  73
  74 /* Send message to message queue.
  75
  76    This function is a cancellation point and therefore not marked with
  77    __THROW.  */
  78 extern int msgsnd (int __msqid, const void *__msgp, size_t __msgsz,
  79                    int __msgflg);
  80
  81 __END_DECLS
  82
  83 #endif /* sys/msg.h */