bits/shm.h

   1 /* Copyright (C) 1995, 1996, 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _SYS_SHM_H
  20 # error "Never include <bits/shm.h> directly; use <sys/shm.h> instead."
  21 #endif
  22
  23 #include <sys/types.h>
  24
  25 /* Flags for `shmat'.  */
  26 #define SHM_RDONLY      010000          /* attach read-only else read-write */
  27 #define SHM_RND         020000          /* round attach address to SHMLBA */
  28 #define SHM_REMAP       040000          /* take-over region on attach */
  29
  30 /* Commands for `shmctl'.  */
  31 #define SHM_LOCK        11              /* lock segment (root only) */
  32 #define SHM_UNLOCK      12              /* unlock segment (root only) */
  33
  34
  35 /* Data structure describing a set of semaphores.  */
  36 struct shmid_ds
  37   {
  38     struct ipc_perm sem_perm;           /* operation permission struct */
  39     int shm_segsz;                      /* size of segment in bytes */
  40     __time_t sem_atime;                 /* time of last shmat() */
  41     __time_t sem_dtime;                 /* time of last shmdt() */
  42     __time_t sem_ctime;                 /* time of last change by shmctl() */
  43     __pid_t shm_cpid;                   /* pid of creator */
  44     __pid_t shm_lpid;                   /* pid of last shmop */
  45     unsigned short int shm_nattch;      /* number of current attaches */
  46   };