1.\" $OpenBSD: posix_memalign.3,v 1.4 2017/05/13 07:11:29 otto Exp $ 2.\" Copyright (C) 2006 Jason Evans <jasone@FreeBSD.org>. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice(s), this list of conditions and the following disclaimer as 10.\" the first lines of this file unmodified other than the possible 11.\" addition of one or more copyright notices. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice(s), this list of conditions and the following disclaimer in 14.\" the documentation and/or other materials provided with the 15.\" distribution. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 18.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE 21.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 24.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 26.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 27.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD: src/lib/libc/stdlib/posix_memalign.3,v 1.3 2007/03/28 04:32:51 jasone Exp $ 30.\" 31.Dd $Mdocdate: May 13 2017 $ 32.Dt POSIX_MEMALIGN 3 33.Os 34.Sh NAME 35.Nm posix_memalign 36.Nd aligned memory allocation 37.Sh SYNOPSIS 38.In stdlib.h 39.Ft int 40.Fn posix_memalign "void **ptr" "size_t alignment" "size_t size" 41.Sh DESCRIPTION 42The 43.Fn posix_memalign 44function allocates 45.Fa size 46bytes of memory such that the allocation's base address is a multiple of 47.Fa alignment , 48and returns the allocation in the value pointed to by 49.Fa ptr . 50.Pp 51The requested 52.Fa alignment 53must be a power of 2 at least as large as 54.Fn sizeof "void *" . 55.Pp 56Memory that is allocated via 57.Fn posix_memalign 58can be used as an argument in subsequent calls to 59.Xr realloc 3 , 60.Xr reallocarray 3 61and 62.Xr free 3 , 63but not 64.Xr recallocarray 3 65and 66.Xr freezero 3 . 67.Sh RETURN VALUES 68The 69.Fn posix_memalign 70function returns the value 0 if successful; otherwise it returns an error value. 71.Sh ERRORS 72The 73.Fn posix_memalign 74function will fail if: 75.Bl -tag -width Er 76.It Bq Er EINVAL 77The 78.Fa alignment 79parameter is not a power of 2 at least as large as 80.Fn sizeof "void *" . 81.It Bq Er ENOMEM 82Memory allocation error. 83.El 84.Sh SEE ALSO 85.Xr free 3 , 86.Xr malloc 3 , 87.Xr realloc 3 88.Sh STANDARDS 89The 90.Fn posix_memalign 91function conforms to 92.St -p1003.1-2001 . 93.Sh HISTORY 94The 95.Fn posix_memalign 96function first appeared in 97.Ox 4.8 . 98