posix_memalign(3) [mojave man page]

POSIX_MEMALIGN(3)					   BSD Library Functions Manual 					 POSIX_MEMALIGN(3)

NAME

     posix_memalign -- aligned memory allocation

SYNOPSIS

     #include <stdlib.h>

     int
     posix_memalign(void **memptr, size_t alignment, size_t size);

DESCRIPTION

     The posix_memalign() function allocates size bytes of memory such that the allocation's base address is an exact multiple of alignment, and
     returns the allocation in the value pointed to by memptr.

     The requested alignment must be a power of 2 at least as large as sizeof(void *).

     Memory that is allocated via posix_memalign() can be used as an argument in subsequent calls to realloc(3), reallocf(3), and free(3).  (Note
     however, that the allocation returned by realloc(3) or reallocf(3) is not guaranteed to preserve the original alignment).

NOTES

     posix_memalign() should be used judiciously as the algorithm that realizes the alignment constraint can incur significant memory overhead.

RETURN VALUES

     The posix_memalign() function returns the value 0 if successful; otherwise it returns an error value.

ERRORS

     The posix_memalign() function will fail if:

     [EINVAL]		The alignment parameter is not a power of 2 at least as large as sizeof(void *).

     [ENOMEM]		Memory allocation error.

SEE ALSO

     free(3), malloc(3), realloc(3), reallocf(3), valloc(3), malloc_zone_memalign(3)

STANDARDS

     The posix_memalign() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').

BSD
								   April 9, 2008							       BSD

POSIX_MEMALIGN(3P)					     POSIX Programmer's Manual						POSIX_MEMALIGN(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       posix_memalign - aligned memory allocation (ADVANCED REALTIME)

SYNOPSIS

       #include <stdlib.h>

       int posix_memalign(void **memptr, size_t alignment, size_t size);

DESCRIPTION

       The posix_memalign() function shall allocate size bytes aligned on a boundary specified by alignment, and shall return  a  pointer  to  the
       allocated  memory  in  memptr.  The value of alignment shall be a multiple of sizeof( void *), that is also a power of two. Upon successful
       completion, the value pointed to by memptr shall be a multiple of alignment.

       The free() function shall deallocate memory that has previously been allocated by posix_memalign().

RETURN VALUE

       Upon successful completion, posix_memalign() shall return zero; otherwise, an error number shall be returned to indicate the error.

ERRORS

       The posix_memalign() function shall fail if:

       EINVAL The value of the alignment parameter is not a power of two multiple of sizeof( void *).

       ENOMEM There is insufficient memory available with the requested alignment.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The posix_memalign() function is part of the Advisory Information option and need not be provided on all implementations.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       free(), malloc(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- 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							POSIX_MEMALIGN(3P)