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 #include <bits/ipctypes.h> 24 25 /* Permission flag for shmget. */ 26 #define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */ 27 #define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */ 28 29 /* Flags for `shmat'. */ 30 #define SHM_RDONLY 010000 /* attach read-only else read-write */ 31 #define SHM_RND 020000 /* round attach address to SHMLBA */ 32 #define SHM_REMAP 040000 /* take-over region on attach */ 33 34 /* Commands for `shmctl'. */ 35 #define SHM_LOCK 11 /* lock segment (root only) */ 36 #define SHM_UNLOCK 12 /* unlock segment (root only) */ 37 38 __BEGIN_DECLS 39 40 /* Segment low boundary address multiple. */ 41 #define SHMLBA (__getpagesize ()) 42 extern int __getpagesize (void) __THROW __attribute__ ((__const__)); 43 44 45 /* Type to count number of attaches. */ 46 typedef unsigned short int shmatt_t; 47 48 /* Data structure describing a shared memory segment. */ 49 struct shmid_ds 50 { 51 struct ipc_perm shm_perm; /* operation permission struct */ 52 size_t shm_segsz; /* size of segment in bytes */ 53 __time_t shm_atime; /* time of last shmat() */ 54 __time_t shm_dtime; /* time of last shmdt() */ 55 __time_t shm_ctime; /* time of last change by shmctl() */ 56 __ipc_pid_t shm_cpid; /* pid of creator */ 57 __ipc_pid_t shm_lpid; /* pid of last shmop */ 58 shmatt_t shm_nattch; /* number of current attaches */ 59 unsigned short int __shm_npages; /* size of segment (pages) */ 60 unsigned long int *__shm_pages; /* array of ptrs to frames -> SHMMAX */ 61 struct __vm_area_struct *__attaches; /* descriptors for attaches */ 62 }; 63 64 #ifdef __USE_MISC 65 66 /* ipcs ctl commands */ 67 # define SHM_STAT 13 68 # define SHM_INFO 14 69 70 /* shm_mode upper byte flags */ 71 # define SHM_DEST 01000 /* segment will be destroyed on last detach */ 72 # define SHM_LOCKED 02000 /* segment will not be swapped */ 73 74 struct shminfo 75 { 76 int shmmax; 77 int shmmin; 78 int shmmni; 79 int shmseg; 80 int shmall; 81 }; 82 83 struct shm_info 84 { 85 int used_ids; 86 unsigned long int shm_tot; /* total allocated shm */ 87 unsigned long int shm_rss; /* total resident shm */ 88 unsigned long int shm_swp; /* total swapped shm */ 89 unsigned long int swap_attempts; 90 unsigned long int swap_successes; 91 }; 92 93 #endif /* __USE_MISC */ 94 95 __END_DECLS 96