sys_mman.h(0p)

1<sys/mman.h>(0P)           POSIX Programmer's Manual          <sys/mman.h>(0P)
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NAME

6       sys/mman.h - memory management declarations
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SYNOPSIS

9       #include <sys/mman.h>
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DESCRIPTION

12       The  <sys/mman.h>  header shall be supported if the implementation sup‐
13       ports at least one of the following options:
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15        * The Memory Mapped Files option
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17        * The Shared Memory Objects option
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19        * The Process Memory Locking option
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21        * The Memory Protection option
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23        * The Typed Memory Objects option
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25        * The Synchronized Input and Output option
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27        * The Advisory Information option
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29        * The Typed Memory Objects option
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31       If one or more of the Advisory Information,  Memory  Mapped  Files,  or
32       Shared  Memory  Objects options are supported, the following protection
33       options shall be defined:
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35       PROT_READ
36              Page can be read.
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38       PROT_WRITE
39              Page can be written.
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41       PROT_EXEC
42              Page can be executed.
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44       PROT_NONE
45              Page cannot be accessed.
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48       The following flag options shall be defined:
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50       MAP_SHARED
51              Share changes.
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53       MAP_PRIVATE
54              Changes are private.
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56       MAP_FIXED
57              Interpret addr exactly.
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59
60       The following flags shall be defined for msync():
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62       MS_ASYNC
63              Perform asynchronous writes.
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65       MS_SYNC
66              Perform synchronous writes.
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68       MS_INVALIDATE
69              Invalidate mappings.
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71
72       The following symbolic constants shall be defined  for  the  mlockall()
73       function:
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75       MCL_CURRENT
76              Lock currently mapped pages.
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78       MCL_FUTURE
79              Lock pages that become mapped.
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82       The symbolic constant MAP_FAILED shall be defined to indicate a failure
83       from the mmap() function.
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85       If the Advisory Information and  either  the  Memory  Mapped  Files  or
86       Shared  Memory Objects options are supported, values for advice used by
87       posix_madvise() shall be defined as follows:
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89       POSIX_MADV_NORMAL
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91              The application has no advice  to  give  on  its  behavior  with
92              respect to the specified range. It is the default characteristic
93              if no advice is given for a range of memory.
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95       POSIX_MADV_SEQUENTIAL
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97              The application expects to access the  specified  range  sequen‐
98              tially from lower addresses to higher addresses.
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100       POSIX_MADV_RANDOM
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102              The  application expects to access the specified range in a ran‐
103              dom order.
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105       POSIX_MADV_WILLNEED
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107              The application expects to access the  specified  range  in  the
108              near future.
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110       POSIX_MADV_DONTNEED
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112              The  application  expects  that it will not access the specified
113              range in the near future.
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116       The following flags shall be defined for posix_typed_mem_open():
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118       POSIX_TYPED_MEM_ALLOCATE
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120              Allocate on mmap().
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122       POSIX_TYPED_MEM_ALLOCATE_CONTIG
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124              Allocate contiguously on mmap().
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126       POSIX_TYPED_MEM_MAP_ALLOCATABLE
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128              Map on mmap(), without affecting allocatability.
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131       The mode_t, off_t, and size_t types shall be defined  as  described  in
132       <sys/types.h> .
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134       The     <sys/mman.h>     header     shall    define    the    structure
135       posix_typed_mem_info, which includes at least the following member:
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137
138              size_t  posix_tmi_length  Maximum length which may be allocated
139                                        from a typed memory object.
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141       The following shall be declared as functions and may also be defined as
142       macros. Function prototypes shall be provided.
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145              int    mlock(const void *, size_t);
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147
148              int    mlockall(int);
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151              void  *mmap(void *, size_t, int, int, int, off_t);
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153
154              int    mprotect(void *, size_t, int);
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157              int    msync(void *, size_t, int);
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160              int    munlock(const void *, size_t);
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162
163              int    munlockall(void);
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166              int    munmap(void *, size_t);
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168
169              int    posix_madvise(void *, size_t, int);
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172              int    posix_mem_offset(const void *restrict, size_t, off_t *restrict,
173                         size_t *restrict, int *restrict);
174              int    posix_typed_mem_get_info(int, struct posix_typed_mem_info *);
175              int    posix_typed_mem_open(const char *, int, int);
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177
178              int    shm_open(const char *, int, mode_t);
179              int    shm_unlink(const char *);
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181
182       The following sections are informative.
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APPLICATION USAGE

185       None.
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RATIONALE

188       None.
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FUTURE DIRECTIONS

191       None.
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COPYRIGHT

200       Portions of this text are reprinted and reproduced in  electronic  form
201       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
202       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
203       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
204       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
205       event of any discrepancy between this version and the original IEEE and
206       The Open Group Standard, the original IEEE and The Open Group  Standard
207       is  the  referee document. The original Standard can be obtained online
208       at http://www.opengroup.org/unix/online.html .
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212IEEE/The Open Group                  2003                     <sys/mman.h>(0P)