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.TH POSIX_MEMALIGN "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH 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.

.SH NAME

posix_memalign

\(em aligned memory allocation

(\fBADVANCED REALTIME\fP)

.SH SYNOPSIS

.LP

.nf

#include <stdlib.h>

.P

int posix_memalign(void **\fImemptr\fP, size_t \fIalignment\fP, size_t \fIsize\fP);

.fi

.SH DESCRIPTION

The

\fIposix_memalign\fR()

function shall allocate

.IR size

bytes aligned on a boundary specified by

.IR alignment ,

and shall return a pointer to the allocated memory in

.IR memptr .

The value of

.IR alignment

shall be a power of two multiple of

.IR sizeof (\c

.BR "void *" ).

.P

Upon successful completion, the value pointed to by

.IR memptr

shall be a multiple of

.IR alignment .

.P

If the size of the space requested is 0, the behavior is

implementation-defined; the value returned in

.IR memptr

shall be either a null pointer or a unique pointer.

.P

The

\fIfree\fR()

function shall deallocate memory that has previously been allocated by

\fIposix_memalign\fR().

.SH "RETURN VALUE"

Upon successful completion,

\fIposix_memalign\fR()

shall return zero; otherwise, an error number shall be returned to

indicate the error.

.SH ERRORS

The

\fIposix_memalign\fR()

function shall fail if:

.TP

.BR EINVAL

The value of the alignment parameter is not a power of two multiple of

.IR sizeof (\c

.BR "void *" ).

.TP

.BR ENOMEM

There is insufficient memory available with the requested alignment.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

The

\fIposix_memalign\fR()

function is part of the Advisory Information option and need not be

provided on all implementations.

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.IR "\fIfree\fR\^(\|)",

.IR "\fImalloc\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<stdlib.h>\fP"

.SH 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 .