1 /* Definitions for BSD-style memory management.
2 Copyright (C) 1994-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #ifndef _SYS_MMAN_H
20 #define _SYS_MMAN_H 1
21
22 #include <features.h>
23 #include <bits/types.h>
24 #define __need_size_t
25 #include <stddef.h>
26
27 #ifndef __off_t_defined
28 # ifndef __USE_FILE_OFFSET64
29 typedef __off_t off_t;
30 # else
31 typedef __off64_t off_t;
32 # endif
33 # define __off_t_defined
34 #endif
35
36 #ifndef __mode_t_defined
37 typedef __mode_t mode_t;
38 # define __mode_t_defined
39 #endif
40
41 #include <bits/mman.h>
42
43 /* Return value of `mmap' in case of an error. */
44 #define MAP_FAILED ((void *) -1)
45
46 __BEGIN_DECLS
47 /* Map addresses starting near ADDR and extending for LEN bytes. from
48 OFFSET into the file FD describes according to PROT and FLAGS. If ADDR
49 is nonzero, it is the desired mapping address. If the MAP_FIXED bit is
50 set in FLAGS, the mapping will be at ADDR exactly (which must be
51 page-aligned); otherwise the system chooses a convenient nearby address.
52 The return value is the actual mapping address chosen or MAP_FAILED
53 for errors (in which case `errno' is set). A successful `mmap' call
54 deallocates any previous mapping for the affected region. */
55
56 #ifndef __USE_FILE_OFFSET64
57 extern void *mmap (void *__addr, size_t __len, int __prot,
58 int __flags, int __fd, __off_t __offset) __THROW;
59 #else
60 # ifdef __REDIRECT_NTH
61 extern void * __REDIRECT_NTH (mmap,
62 (void *__addr, size_t __len, int __prot,
63 int __flags, int __fd, __off64_t __offset),
64 mmap64);
65 # else
66 # define mmap mmap64
67 # endif
68 #endif
69 #ifdef __USE_LARGEFILE64
70 extern void *mmap64 (void *__addr, size_t __len, int __prot,
71 int __flags, int __fd, __off64_t __offset) __THROW;
72 #endif
73
74 /* Deallocate any mapping for the region starting at ADDR and extending LEN
75 bytes. Returns 0 if successful, -1 for errors (and sets errno). */
76 extern int munmap (void *__addr, size_t __len) __THROW;
77
78 /* Change the memory protection of the region starting at ADDR and
79 extending LEN bytes to PROT. Returns 0 if successful, -1 for errors
80 (and sets errno). */
81 extern int mprotect (void *__addr, size_t __len, int __prot) __THROW;
82
83 /* Synchronize the region starting at ADDR and extending LEN bytes with the
84 file it maps. Filesystem operations on a file being mapped are
85 unpredictable before this is done. Flags are from the MS_* set.
86
87 This function is a cancellation point and therefore not marked with
88 __THROW. */
89 extern int msync (void *__addr, size_t __len, int __flags);
90
91 #ifdef __USE_MISC
92 /* Advise the system about particular usage patterns the program follows
93 for the region starting at ADDR and extending LEN bytes. */
94 extern int madvise (void *__addr, size_t __len, int __advice) __THROW;
95 #endif
96 #ifdef __USE_XOPEN2K
97 /* This is the POSIX name for this function. */
98 extern int posix_madvise (void *__addr, size_t __len, int __advice) __THROW;
99 #endif
100
101 /* Guarantee all whole pages mapped by the range [ADDR,ADDR+LEN) to
102 be memory resident. */
103 extern int mlock (const void *__addr, size_t __len) __THROW;
104
105 /* Unlock whole pages previously mapped by the range [ADDR,ADDR+LEN). */
106 extern int munlock (const void *__addr, size_t __len) __THROW;
107
108 /* Cause all currently mapped pages of the process to be memory resident
109 until unlocked by a call to the `munlockall', until the process exits,
110 or until the process calls `execve'. */
111 extern int mlockall (int __flags) __THROW;
112
113 /* All currently mapped pages of the process' address space become
114 unlocked. */
115 extern int munlockall (void) __THROW;
116
117 #ifdef __USE_MISC
118 /* mincore returns the memory residency status of the pages in the
119 current process's address space specified by [start, start + len).
120 The status is returned in a vector of bytes. The least significant
121 bit of each byte is 1 if the referenced page is in memory, otherwise
122 it is zero. */
123 extern int mincore (void *__start, size_t __len, unsigned char *__vec)
124 __THROW;
125 #endif
126
127 #ifdef __USE_GNU
128 /* Remap pages mapped by the range [ADDR,ADDR+OLD_LEN) to new length
129 NEW_LEN. If MREMAP_MAYMOVE is set in FLAGS the returned address
130 may differ from ADDR. If MREMAP_FIXED is set in FLAGS the function
131 takes another parameter which is a fixed address at which the block
132 resides after a successful call. */
133 extern void *mremap (void *__addr, size_t __old_len, size_t __new_len,
134 int __flags, ...) __THROW;
135
136 /* Remap arbitrary pages of a shared backing store within an existing
137 VMA. */
138 extern int remap_file_pages (void *__start, size_t __size, int __prot,
139 size_t __pgoff, int __flags) __THROW;
140 #endif
141
142
143 /* Open shared memory segment. */
144 extern int shm_open (const char *__name, int __oflag, mode_t __mode);
145
146 /* Remove shared memory segment. */
147 extern int shm_unlink (const char *__name);
148
149 /* System-specific extensions. */
150 #include <bits/mman_ext.h>
151
152 __END_DECLS
153
154 #endif /* sys/mman.h */