On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-10 11:14 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
POSIX_MEM_OFFSET(P) POSIX_MEM_OFFSET(P)
NAME
posix_mem_offset - find offset and length of a mapped typed memory block (ADVANCED
REALTIME)
SYNOPSIS
#include <sys/mman.h>
int posix_mem_offset(const void *restrict addr, size_t len,
off_t *restrict off, size_t *restrict contig_len,
int *restrict fildes);
DESCRIPTION
The posix_mem_offset() function shall return in the variable pointed to by off a
value that identifies the offset (or location), within a memory object, of the mem-
ory block currently mapped at addr. The function shall return in the variable
pointed to by fildes, the descriptor used (via mmap()) to establish the mapping
which contains addr. If that descriptor was closed since the mapping was estab-
lished, the returned value of fildes shall be -1. The len argument specifies the
length of the block of the memory object the user wishes the offset for; upon
return, the value pointed to by contig_len shall equal either len, or the length of
the largest contiguous block of the memory object that is currently mapped to the
calling process starting at addr, whichever is smaller.
If the memory object mapped at addr is a typed memory object, then if the off and
contig_len values obtained by calling posix_mem_offset() are used in a call to
mmap() with a file descriptor that refers to the same memory pool as fildes (either
through the same port or through a different port), and that was opened with nei-
ther the POSIX_TYPED_MEM_ALLOCATE nor the POSIX_TYPED_MEM_ALLOCATE_CONTIG flag, the
typed memory area that is mapped shall be exactly the same area that was mapped at
addr in the address space of the process that called posix_mem_offset().
If the memory object specified by fildes is not a typed memory object, then the
behavior of this function is implementation-defined.
RETURN VALUE
Upon successful completion, the posix_mem_offset() function shall return zero; oth-
erwise, the corresponding error status value shall be returned.
ERRORS
The posix_mem_offset() function shall fail if:
EACCES The process has not mapped a memory object supported by this function at the
given address addr.
This function shall not return an error code of [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
mmap() , posix_typed_mem_open() , the Base Definitions volume of
IEEE Std 1003.1-2001, <sys/mman.h>
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 .
POSIX 2003 POSIX_MEM_OFFSET(P)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-10 11:14 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)