glibc/bits/shm.h

57 lines
2.0 KiB
C

/* Copyright (C) 1995-2022 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_SHM_H
# error "Never include <bits/shm.h> directly; use <sys/shm.h> instead."
#endif
#include <bits/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) */
__BEGIN_DECLS
/* Segment low boundary address multiple. */
#define SHMLBA (__getpagesize ())
extern int __getpagesize (void) __THROW __attribute__ ((__const__));
/* Type to count number of attaches. */
typedef unsigned short int shmatt_t;
/* Data structure describing a shared memory segment. */
struct shmid_ds
{
struct ipc_perm shm_perm; /* operation permission struct */
size_t shm_segsz; /* size of segment in bytes */
__time_t shm_atime; /* time of last shmat() */
__time_t shm_dtime; /* time of last shmdt() */
__time_t shm_ctime; /* time of last change by shmctl() */
__pid_t shm_cpid; /* pid of creator */
__pid_t shm_lpid; /* pid of last shmop */
shmatt_t shm_nattch; /* number of current attaches */
};
__END_DECLS