glibc/bits/shm.h

/* Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef _SYS_SHM_H
# error "Never include <bits/shm.h> directly; use <sys/shm.h> instead."
#endif

#include <sys/types.h>

/* Flags for `shmat'.  */
#define SHM_RDONLY	010000		/* attach read-only else read-write */
#define SHM_RND		020000		/* round attach address to SHMLBA */
#define SHM_REMAP	040000		/* take-over region on attach */

/* Commands for `shmctl'.  */
#define SHM_LOCK	11		/* lock segment (root only) */
#define SHM_UNLOCK	12		/* unlock segment (root only) */


/* Data structure describing a set of semaphores.  */
struct shmid_ds
  {
    struct ipc_perm sem_perm;		/* operation permission struct */
    int shm_segsz;			/* size of segment in bytes */
    __time_t sem_atime;			/* time of last shmat() */
    __time_t sem_dtime;			/* time of last shmdt() */
    __time_t sem_ctime;			/* time of last change by shmctl() */
    __pid_t shm_cpid;			/* pid of creator */
    __pid_t shm_lpid;			/* pid of last shmop */
    unsigned short int shm_nattch;	/* number of current attaches */
  };