.\" (c) 2001 by John Levon <moz@compsoc.man.ac.uk>
.\" Based in part on GNU libc documentation.
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" License.
.\"
.\" 2001-10-11, 2003-08-22, aeb, added some details
.\"
.\" Japanese Version Copyright (c) 2001 Akihiro MOTOKI
.\"       all rights reserved.
.\" Translated 2001-11-05, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2003-09-05, Akihiro MOTOKI, catch up to v1.60
.\" Updated 2005-11-19, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\"
.\"WORD:	obsolete	ѻߤ줿
.\"WORD:	a multiple of	ܿ
.\"WORD:	a power of two	2 Τ٤
.\"
.TH POSIX_MEMALIGN 3  2007-07-26 "GNU" "Linux Programmer's Manual"
.SH ̾
posix_memalign, memalign, valloc \- 饤Ȥ줿γƤԤ
.SH 
.nf
.B #include <stdlib.h>
.sp
.BI "int posix_memalign(void **" memptr ", size_t " alignment ", size_t " size );
.sp
.B #include <malloc.h>
.sp
.BI "void *valloc(size_t " size );
.BI "void *memalign(size_t " boundary ", size_t " size );
.fi
.sp
.in -4n
glibc εǽޥ׷
.RB ( feature_test_macros (7)
):
.in
.sp
.ad l
.BR posix_memalign ():
_POSIX_C_SOURCE\ >=\ 200112L || _XOPEN_SOURCE\ >=\ 600
.ad b
.SH 
ؿ
.BR posix_memalign ()

.I size
ХȤΥơƤ줿Υɥ쥹
.I "*memptr"
ꤹ롣
Ƥ줿Υɥ쥹
.I "alignment"
ܿˤʤäƤϤǤ롣
.I "alignment"
 2 Τ٤ǡ
.IR "sizeof(void *)"
ܿǤʤФʤʤ

ѻߤ줿ؿǤ
.BR memalign ()
ϡ
.I size
ХȤΥơƤ줿ؤΥݥ󥿤֤
Υɥ쥹
.I "boundary"
ܿˤʤäƤϤǤ롣
.I "boundary"
 2 Τ٤ǤʤФʤʤ

ѻߤ줿ؿǤ
.BR valloc ()

.I size
ХȤΥơƤ줿ؤΥݥ󥿤֤
Υɥ쥹ϥڡܿˤʤäƤϤǤ롣

.I "memalign(sysconf(_SC_PAGESIZE),size)"
Ǥ롣

.\" motoki: be not zeroed äƤɤ̣
3 ĤδؿϤΥꥢԤʤ
.SH ֤
.BR memalign ()

.BR valloc ()
ϳƤ줿ؤΥݥ󥿤֤
Ƥ˼Ԥ NULL ֤

.BR posix_memalign ()
 0 ֤
ԤϼΥ˵ܤ줿顼ͤΤ줫֤
.I errno
ϥåȤʤȤդ뤳ȡ
.SH 顼
.TP
.B EINVAL
.I alignment
ѥ᡼ 2 Τ٤Ǥʤä
.IR "sizeof(void *)"
ܿǤʤä
.TP
.B ENOMEM
׵Τ˽ʬʥ꤬ʤä
.SH С
.BR memalign ()

.BR valloc ()
Ϥ٤Ƥ Linux libc 饤֥ǻѲǽǤ롣
.BR posix_memalign ()
 glibc 2.1.91 ʹߤǻѲǽǤ롣
.SH 
ؿ
.BR valloc ()
 3.0BSD о줷4.3BSD Ǥѻߤ줿ȵܤƤꡢ
SUSv2 ǤϲΤΤȵܤƤ롣
POSIX.1-2001 ˤϤϤ¸ߤʤ
ؿ
.BR memalign ()
 SunOS 4.1.3 о줷4.4BSD ˤϤʤ
ؿ
.BR posix_memalign ()
 POSIX.1d ͳ褹롣
.SS إå
.BR posix_memalign ()
 \fI<stdlib.h>\fP ǹԤȤ˴ؤƤϡ
ΰոפƤ롣

ĤΥƥǤϡ
.BR memalign ()
 \fI<malloc.h>\fP ǤϤʤ \fI<stdlib.h>\fP Ƥ롣

SUSv2 ˤȡ
.BR valloc ()

.I <stdlib.h>
롣
libc4,5  glibc Ǥ
.I <malloc.h>
Ƥꡢ

.I <stdlib.h>
Ǥ뤳Ȥ⤢
(ŪˤϰʲΤ줫ξ:
.B _GNU_SOURCE
Ƥ롢
.B _BSD_SOURCE
Ƥ롢
glibc 
.B _XOPEN_SOURCE_EXTENDED
Ƥ롢
glibc 
.B _XOPEN_SOURCE
 500 꾮ʤͤƤ)
.SH 
¿ΥƥǤϡ饤Ȥ˴ؤ¤롣㤨С
֥åǥХФ쥯 I/O ˻ѤХåեˤ
饤Ȥ˴ؤ¤롣
POSIX Ǥϡɤʥ饤ȤɬפΤ뤿
.I "pathconf(path,_PC_REC_XFER_ALIGN)"
ꤷƤ롣
.BR posix_memalign ()
Ȥȡɬ׾ȤǤ롣

.BR posix_memalign ()

.I alignment
Ǿܺ٤˽Ҥ٤ɬ׾ɤΤ롣
.BR memalign ()

.I boundary
ѥ᡼ɤγǧԤʤ⤷ʤ

POSIX Ǥ
.BR posix_memalign ()
ˤäƳ
.BR free (3)
ȤäƲ뤳ȤǤɬפ롣
ĤΥƥǤ
.BR memalign ()

.BR valloc ()
dzƤ줿Ѥʤ󶡤Ƥʤ
.\" motoki: while ΤĤʤϤǤ
(ʤʤ
.BR free (3)
ϤȤǤΤ
.BR malloc (3)
äݥ󥿤
㤨
.BR memalign ()

.BR malloc (3)
ƤӽФͤ򥢥饤ȤƤޤǤ)
.\" Other systems allow passing the result of
.\" .BR valloc ()
.\" to
.\" .BR free (3),
.\" but not to
.\" .BR realloc (3).
glibc μǤϡ
˽Ҥ٤ 3 ĤδؿΤdz
.BR free (3)
ǺѤ뤳ȤǤ롣

glibc 
.BR malloc (3)
Ͼ 8 ХȤ˥饤Ȥ줿ꥢɥ쥹֤Τǡ
ǽҤ٤ؿɬפˤʤΤ
8 ХȤ礭ʥ饤ȤɬפʾǤ롣
.SH Ϣ
.BR brk (2),
.BR getpagesize (2),
.BR free (3),
.BR malloc (3)