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 corresponding 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 power of two multiple of sizeof( void *).

Upon successful completion, the value pointed to by memptr shall be a multiple of alignment.

If the size of the space requested is 0, the behavior is implementation-defined; the value returned in memptr shall be either a null pointer or a unique pointer.

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 POSIX.1-2008, <stdlib.h>

COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html . Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .