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

NAME
       sys/mman.h - memory management declarations
SYNOPSIS
       #include <sys/mman.h>
DESCRIPTION
       The  <sys/mman.h>  header shall be supported if the implementation sup-
       ports at least one of the following options:
        * The Memory Mapped Files option
        * The Shared Memory Objects option
        * The Process Memory Locking option
        * The Memory Protection option
        * The Typed Memory Objects option
        * The Synchronized Input and Output option
        * The Advisory Information option
        * The Typed Memory Objects option
       If one or more of the Advisory Information,  Memory  Mapped  Files,  or
       Shared  Memory  Objects options are supported, the following protection
       options shall be defined:
       PROT_READ
              Page can be read.
       PROT_WRITE
              Page can be written.
       PROT_EXEC
              Page can be executed.
       PROT_NONE
              Page cannot be accessed.

       The following flag options shall be defined:
       MAP_SHARED
              Share changes.
       MAP_PRIVATE
              Changes are private.
       MAP_FIXED
              Interpret addr exactly.

       The following flags shall be defined for msync():
       MS_ASYNC
              Perform asynchronous writes.
       MS_SYNC
              Perform synchronous writes.
       MS_INVALIDATE
              Invalidate mappings.

       The following symbolic constants shall be defined  for  the  mlockall()
       function:
       MCL_CURRENT
              Lock currently mapped pages.
       MCL_FUTURE
              Lock pages that become mapped.

       The symbolic constant MAP_FAILED shall be defined to indicate a failure
       from the mmap() function.
       If the Advisory Information and  either  the  Memory  Mapped  Files  or
       Shared  Memory Objects options are supported, values for advice used by
       posix_madvise() shall be defined as follows:
       POSIX_MADV_NORMAL
              The application has no advice  to  give  on  its  behavior  with
              respect to the specified range. It is the default characteristic
              if no advice is given for a range of memory.
       POSIX_MADV_SEQUENTIAL
              The application expects to access the  specified  range  sequen-
              tially from lower addresses to higher addresses.
       POSIX_MADV_RANDOM
              The  application expects to access the specified range in a ran-
              dom order.
       POSIX_MADV_WILLNEED
              The application expects to access the  specified  range  in  the
              near future.
       POSIX_MADV_DONTNEED
              The  application  expects  that it will not access the specified
              range in the near future.

       The following flags shall be defined for posix_typed_mem_open():
       POSIX_TYPED_MEM_ALLOCATE
              Allocate on mmap().
       POSIX_TYPED_MEM_ALLOCATE_CONTIG
              Allocate contiguously on mmap().
       POSIX_TYPED_MEM_MAP_ALLOCATABLE
              Map on mmap(), without affecting allocatability.

       The mode_t, off_t, and size_t types shall be defined  as  described  in
       <sys/types.h> .
       The     <sys/mman.h>     header     shall    define    the    structure
       posix_typed_mem_info, which includes at least the following member:

              size_t  posix_tmi_length  Maximum length which may be allocated
                                        from a typed memory object.
       The following shall be declared as functions and may also be defined as
       macros. Function prototypes shall be provided.

              int    mlock(const void *, size_t);

              int    mlockall(int);

              void  *mmap(void *, size_t, int, int, int, off_t);

              int    mprotect(void *, size_t, int);

              int    msync(void *, size_t, int);

              int    munlock(const void *, size_t);

              int    munlockall(void);

              int    munmap(void *, size_t);

              int    posix_madvise(void *, size_t, int);

              int    posix_mem_offset(const void *restrict, size_t, off_t *restrict,
                         size_t *restrict, int *restrict);
              int    posix_typed_mem_get_info(int, struct posix_typed_mem_info *);
              int    posix_typed_mem_open(const char *, int, int);

              int    shm_open(const char *, int, mode_t);
              int    shm_unlink(const char *);

       The following sections are informative.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       <sys/types.h>,  the  System  Interfaces volume of IEEE Std 1003.1-2001,
       mlock(), mlockall(), mmap(), mprotect(), msync(),  munlock(),  munlock-
       all(),    munmap(),   posix_mem_offset(),   posix_typed_mem_get_info(),
       posix_typed_mem_open(), shm_open(), shm_unlink()
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                     <sys/mman.h>(0P)