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The C and C++ Include Header Files

cat -n /usr/include/x86_64-linux-gnu/bits/shm.h

     1	/* Copyright (C) 1995-2026 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/wordsize.h>
    24	#include <bits/shmlba.h>
    25	
    26	/* Permission flag for shmget.  */
    27	#define SHM_R		0400		/* or S_IRUGO from <linux/stat.h> */
    28	#define SHM_W		0200		/* or S_IWUGO from <linux/stat.h> */
    29	
    30	/* Flags for `shmat'.  */
    31	#define SHM_RDONLY	010000		/* attach read-only else read-write */
    32	#define SHM_RND		020000		/* round attach address to SHMLBA */
    33	#define SHM_REMAP	040000		/* take-over region on attach */
    34	#define SHM_EXEC	0100000		/* execution access */
    35	
    36	/* Commands for `shmctl'.  */
    37	#define SHM_LOCK	11		/* lock segment (root only) */
    38	#define SHM_UNLOCK	12		/* unlock segment (root only) */
    39	
    40	__BEGIN_DECLS
    41	
    42	/* Type to count number of attaches.  */
    43	typedef __syscall_ulong_t shmatt_t;
    44	
    45	#include <bits/types/struct_shmid_ds.h>
    46	#include <bits/types/struct_shmid64_ds.h>
    47	
    48	#ifdef __USE_MISC
    49	
    50	/* ipcs ctl commands */
    51	# define SHM_STAT 	13
    52	# define SHM_INFO 	14
    53	# define SHM_STAT_ANY	15
    54	
    55	/* shm_mode upper byte flags */
    56	# define SHM_DEST	01000	/* segment will be destroyed on last detach */
    57	# define SHM_LOCKED	02000   /* segment will not be swapped */
    58	# define SHM_HUGETLB	04000	/* segment is mapped via hugetlb */
    59	# define SHM_NORESERVE	010000	/* don't check for reservations */
    60	
    61	/* When SHM_HUGETLB is set, bits [26:31] encode the log2 of the huge page size.
    62	   The following definitions are associated with this huge page size encoding.
    63	   It is responsibility of the application to know which sizes are supported on
    64	   the running system.  See shmget(2) man page for details.  */
    65	
    66	#define SHM_HUGE_SHIFT	26
    67	#define SHM_HUGE_MASK	0x3f
    68	
    69	#define SHM_HUGE_16KB	(14 << SHM_HUGE_SHIFT)
    70	#define SHM_HUGE_64KB	(16 << SHM_HUGE_SHIFT)
    71	#define SHM_HUGE_512KB	(19 << SHM_HUGE_SHIFT)
    72	#define SHM_HUGE_1MB	(20 << SHM_HUGE_SHIFT)
    73	#define SHM_HUGE_2MB	(21 << SHM_HUGE_SHIFT)
    74	#define SHM_HUGE_8MB	(23 << SHM_HUGE_SHIFT)
    75	#define SHM_HUGE_16MB	(24 << SHM_HUGE_SHIFT)
    76	#define SHM_HUGE_32MB	(25 << SHM_HUGE_SHIFT)
    77	#define SHM_HUGE_256MB	(28 << SHM_HUGE_SHIFT)
    78	#define SHM_HUGE_512MB	(29 << SHM_HUGE_SHIFT)
    79	#define SHM_HUGE_1GB	(30 << SHM_HUGE_SHIFT)
    80	#define SHM_HUGE_2GB	(31 << SHM_HUGE_SHIFT)
    81	#define SHM_HUGE_16GB	(34U << SHM_HUGE_SHIFT)
    82	
    83	struct	shminfo
    84	  {
    85	    __syscall_ulong_t shmmax;
    86	    __syscall_ulong_t shmmin;
    87	    __syscall_ulong_t shmmni;
    88	    __syscall_ulong_t shmseg;
    89	    __syscall_ulong_t shmall;
    90	    __syscall_ulong_t __glibc_reserved1;
    91	    __syscall_ulong_t __glibc_reserved2;
    92	    __syscall_ulong_t __glibc_reserved3;
    93	    __syscall_ulong_t __glibc_reserved4;
    94	  };
    95	
    96	struct shm_info
    97	  {
    98	    int used_ids;
    99	    __syscall_ulong_t shm_tot;	/* total allocated shm */
   100	    __syscall_ulong_t shm_rss;	/* total resident shm */
   101	    __syscall_ulong_t shm_swp;	/* total swapped shm */
   102	    __syscall_ulong_t swap_attempts;
   103	    __syscall_ulong_t swap_successes;
   104	  };
   105	
   106	#endif /* __USE_MISC */
   107	
   108	__END_DECLS