sys_mman.h(0p)

1sys_mman.h(0P)             POSIX Programmer's Manual            sys_mman.h(0P)
2
3
4

PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
10

NAME

12       sys/mman.h — memory management declarations
13

SYNOPSIS

15       #include <sys/mman.h>
16

DESCRIPTION

18       The <sys/mman.h> header shall define the following  symbolic  constants
19       for use as protection options:
20
21       PROT_EXEC     Page can be executed.
22
23       PROT_NONE     Page cannot be accessed.
24
25       PROT_READ     Page can be read.
26
27       PROT_WRITE    Page can be written.
28
29       The  <sys/mman.h>  header shall define the following symbolic constants
30       for use as flag options:
31
32       MAP_FIXED     Interpret addr exactly.
33
34       MAP_PRIVATE   Changes are private.
35
36       MAP_SHARED    Share changes.
37
38       The <sys/mman.h> header shall define the following  symbolic  constants
39       for the msync() function:
40
41       MS_ASYNC      Perform asynchronous writes.
42
43       MS_INVALIDATE Invalidate mappings.
44
45       MS_SYNC       Perform synchronous writes.
46
47       The  <sys/mman.h>  header shall define the following symbolic constants
48       for the mlockall() function:
49
50       MCL_CURRENT   Lock currently mapped pages.
51
52       MCL_FUTURE    Lock pages that become mapped.
53
54       The <sys/mman.h> header shall define the symbolic  constant  MAP_FAILED
55       which  shall  have  type void * and shall be used to indicate a failure
56       from the mmap() function .
57
58       If the Advisory  Information  option  is  supported,  the  <sys/mman.h>
59       header  shall  define symbolic constants for the advice argument to the
60       posix_madvise() function as follows:
61
62       POSIX_MADV_DONTNEED
63             The application expects that it will  not  access  the  specified
64             range in the near future.
65
66       POSIX_MADV_NORMAL
67             The  application  has  no  advice  to  give  on its behavior with
68             respect to the specified range. It is the default  characteristic
69             if no advice is given for a range of memory.
70
71       POSIX_MADV_RANDOM
72             The application expects to access the specified range in a random
73             order.
74
75       POSIX_MADV_SEQUENTIAL
76             The application expects to access  the  specified  range  sequen‐
77             tially from lower addresses to higher addresses.
78
79       POSIX_MADV_WILLNEED
80             The application expects to access the specified range in the near
81             future.
82
83       The <sys/mman.h> header shall define the following  symbolic  constants
84       for use as flags for the posix_typed_mem_open() function:
85
86       POSIX_TYPED_MEM_ALLOCATE
87             Allocate on mmap().
88
89       POSIX_TYPED_MEM_ALLOCATE_CONTIG
90             Allocate contiguously on mmap().
91
92       POSIX_TYPED_MEM_MAP_ALLOCATABLE
93             Map on mmap(), without affecting allocatability.
94
95       The  <sys/mman.h>  header  shall  define  the mode_t, off_t, and size_t
96       types as described in <sys_types.h>.
97
98       The <sys/mman.h> header shall define  the  posix_typed_mem_info  struc‐
99       ture, which shall include at least the following member:
100
101
102           size_t  posix_tmi_length  Maximum length which may be allocated
103                                     from a typed memory object.
104
105       The following shall be declared as functions and may also be defined as
106       macros. Function prototypes shall be provided.
107
108
109           int    mlock(const void *, size_t);
110           int    mlockall(int);
111           void  *mmap(void *, size_t, int, int, int, off_t);
112           int    mprotect(void *, size_t, int);
113           int    msync(void *, size_t, int);
114           int    munlock(const void *, size_t);
115           int    munlockall(void);
116           int    munmap(void *, size_t);
117           int    posix_madvise(void *, size_t, int);
118           int    posix_mem_offset(const void *restrict, size_t, off_t *restrict,
119                      size_t *restrict, int *restrict);
120           int    posix_typed_mem_get_info(int, struct posix_typed_mem_info *);
121           int    posix_typed_mem_open(const char *, int, int);
122           int    shm_open(const char *, int, mode_t);
123           int    shm_unlink(const char *);
124
125       The following sections are informative.
126

APPLICATION USAGE

128       None.
129

RATIONALE

131       None.
132

FUTURE DIRECTIONS

134       None.
135

COPYRIGHT

145       Portions  of  this text are reprinted and reproduced in electronic form
146       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
147       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
148       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
149       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
150       event of any discrepancy between this version and the original IEEE and
151       The  Open Group Standard, the original IEEE and The Open Group Standard
152       is the referee document. The original Standard can be  obtained  online
153       at http://www.opengroup.org/unix/online.html .
154
155       Any  typographical  or  formatting  errors that appear in this page are
156       most likely to have been introduced during the conversion of the source
157       files  to  man page format. To report such errors, see https://www.ker‐
158       nel.org/doc/man-pages/reporting_bugs.html .
159
160
161
162IEEE/The Open Group                  2017                       sys_mman.h(0P)