1 /* Copyright (C) 1995-2022 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_SHM_H 19 # error "Never include <bits/shm.h> directly; use <sys/shm.h> instead." 20 #endif 21 22 #include <bits/types.h> 23 24 /* Flags for `shmat'. */ 25 #define SHM_RDONLY 010000 /* attach read-only else read-write */ 26 #define SHM_RND 020000 /* round attach address to SHMLBA */ 27 #define SHM_REMAP 040000 /* take-over region on attach */ 28 29 /* Commands for `shmctl'. */ 30 #define SHM_LOCK 11 /* lock segment (root only) */ 31 #define SHM_UNLOCK 12 /* unlock segment (root only) */ 32 33 __BEGIN_DECLS 34 35 /* Segment low boundary address multiple. */ 36 #define SHMLBA (__getpagesize ()) 37 extern int __getpagesize (void) __THROW __attribute__ ((__const__)); 38 39 40 /* Type to count number of attaches. */ 41 typedef unsigned short int shmatt_t; 42 43 /* Data structure describing a shared memory segment. */ 44 struct shmid_ds 45 { 46 struct ipc_perm shm_perm; /* operation permission struct */ 47 size_t shm_segsz; /* size of segment in bytes */ 48 __time_t shm_atime; /* time of last shmat() */ 49 __time_t shm_dtime; /* time of last shmdt() */ 50 __time_t shm_ctime; /* time of last change by shmctl() */ 51 __pid_t shm_cpid; /* pid of creator */ 52 __pid_t shm_lpid; /* pid of last shmop */ 53 shmatt_t shm_nattch; /* number of current attaches */ 54 }; 55 56 __END_DECLS 57