sysvipc/sys/msg.h

   1 /* Copyright (C) 1995-1997,1999,2000,2003,2006,2007,2012
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_MSG_H
  20 #define _SYS_MSG_H
  21
  22 #include <features.h>
  23
  24 #define __need_size_t
  25 #include <stddef.h>
  26
  27 /* Get common definition of System V style IPC.  */
  28 #include <sys/ipc.h>
  29
  30 /* Get system dependent definition of `struct msqid_ds' and more.  */
  31 #include <bits/msq.h>
  32
  33 /* Define types required by the standard.  */
  34 #define __need_time_t
  35 #include <time.h>
  36
  37 #ifndef __pid_t_defined
  38 typedef __pid_t pid_t;
  39 # define __pid_t_defined
  40 #endif
  41
  42 #ifndef __ssize_t_defined
  43 typedef __ssize_t ssize_t;
  44 # define __ssize_t_defined
  45 #endif
  46
  47 /* The following System V style IPC functions implement a message queue
  48    system.  The definition is found in XPG2.  */
  49
  50 #ifdef __USE_GNU
  51 /* Template for struct to be used as argument for `msgsnd' and `msgrcv'.  */
  52 struct msgbuf
  53   {
  54     long int mtype;             /* type of received/sent message */
  55     char mtext[1];              /* text of the message */
  56   };
  57 #endif
  58
  59
  60 __BEGIN_DECLS
  61
  62 /* Message queue control operation.  */
  63 extern int msgctl (int __msqid, int __cmd, struct msqid_ds *__buf) __THROW;
  64
  65 /* Get messages queue.  */
  66 extern int msgget (key_t __key, int __msgflg) __THROW;
  67
  68 /* Receive message from message queue.
  69
  70    This function is a cancellation point and therefore not marked with
  71    __THROW.  */
  72 extern ssize_t msgrcv (int __msqid, void *__msgp, size_t __msgsz,
  73                        long int __msgtyp, int __msgflg);
  74
  75 /* Send message to message queue.
  76
  77    This function is a cancellation point and therefore not marked with
  78    __THROW.  */
  79 extern int msgsnd (int __msqid, const void *__msgp, size_t __msgsz,
  80                    int __msgflg);
  81
  82 __END_DECLS
  83
  84 #endif /* sys/msg.h */