bits/msq.h

   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 #error "Never use <bits/msq.h> directly; include <sys/msg.h> instead."
  20 #endif
  21
  22 #include <bits/types.h>
  23
  24 /* Define options for message queue functions.  */
  25 #define MSG_NOERROR     010000  /* no error if message is too big */
  26
  27 /* Types used in the structure definition.  */
  28 typedef unsigned short int msgqnum_t;
  29 typedef unsigned short int msglen_t;
  30
  31
  32 /* Structure of record for one message inside the kernel.
  33    The type `struct __msg' is opaque.  */
  34 struct msqid_ds
  35 {
  36   struct ipc_perm msg_perm;     /* structure describing operation permission */
  37   __time_t msg_stime;           /* time of last msgsnd command */
  38   __time_t msg_rtime;           /* time of last msgrcv command */
  39   __time_t msg_ctime;           /* time of last change */
  40   msgqnum_t msg_qnum;           /* number of messages currently on queue */
  41   msglen_t msg_qbytes;          /* max number of bytes allowed on queue */
  42   __pid_t msg_lspid;            /* pid of last msgsnd() */
  43   __pid_t msg_lrpid;            /* pid of last msgrcv() */
  44 };