Originální popis anglicky:
sys/mman.h - memory management declarations
Návod, kniha: POSIX Programmer's Manual
#include <sys/mman.h>
The
<sys/mman.h> header shall be supported if the implementation
supports 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 sequentially from
lower addresses to higher addresses.
- POSIX_MADV_RANDOM
-
The application expects to access the specified range in a random
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.
None.
None.
None.
<sys/types.h> , the System Interfaces volume of
IEEE Std 1003.1-2001,
mlock(),
mlockall(),
mmap(),
mprotect(),
msync(),
munlock(),
munlockall(),
munmap(),
posix_mem_offset(),
posix_typed_mem_get_info(),
posix_typed_mem_open(),
shm_open(),
shm_unlink()
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
.
