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 corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAMEposix_memalign — aligned memory allocation (ADVANCED REALTIME)
int posix_memalign(void **memptr, size_t alignment, size_t size);
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 implementa‐
tion-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().
Upon successful completion, posix_memalign() shall return zero; other‐
wise, an error number shall be returned to indicate the error.
The posix_memalign() function shall fail if:
EINVAL The value of the alignment parameter is not a power of two mul‐
tiple of sizeof(void *).
ENOMEM There is insufficient memory available with the requested align‐
The following sections are informative.
The posix_memalign() function is part of the Advisory Information
option and need not be provided on all implementations.
SEE ALSOfree(), malloc()
The Base Definitions volume of POSIX.1‐2008, <stdlib.h>
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 Electri‐
cal 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
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IEEE/The Open Group 2013 POSIX_MEMALIGN(3P)