.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1.  Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2.  Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3.  All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by John Birrell.
.\" 4.  Neither the name of the author nor the names of any co-contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.   IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" %FreeBSD: src/lib/libc_r/man/pthread_once. 3, v 1.6. 2.7 2001/12/17 10:08:26 ru Exp %
.\"
.\" $FreeBSD: doc/ja_JP.eucJP/man/man3/pthread_once. 3, v 1.5 2002/05/18 07:12:56 horikawa Exp $
.Dd April 4, 1996
.Dt PTHREAD_ONCE 3
.Os
.Sh ¸íĪ
.Nm pthread_once
.Nd µ¿ÀûÀÎ ÆÐÅ°ÁöÀÇ ÃʱâÈ­
.Sh ÇÁ·Î±×·¥ ¶óÀ̺귯¸®
.Lb libc_r
.Sh ¼­½Ä
.In pthread.h
.Pp
pthread_once_t
.Fa once_control
= PTHREAD_ONCE_INIT;
.Ft int
.Fn pthread_once "pthread_once_t *once_control" "void (*init_routine)(void)"
.Sh Çؼ³
ÇÁ·Î¼¼½ºÀÇ ¸ðµç thread¿¡ ÀÇÇÑ ÃÖÃÊÀÇ, ÁÖ¾îÁ³´Ù
.Fa once_control
(À»)¸¦ µû¸¥
.Fn pthread_once
ÀÇ È£ÃâÀº,
.Fn init_routine
(À»)¸¦ Àμö ¾øÀ½À¸·Î È£ÃâÇÕ´Ï´Ù.
±× ÈÄ¿¡¼­ÀÇ °°´Ù
.Fa once_control
(À»)¸¦ °¡Áø´Ù
.Fn pthread_once
ÀÇ È£ÃâÀº,
.Fn init_routine
(À»)¸¦ È£ÃâÇÏÁö ¾Ê½À´Ï´Ù.
.Fn pthread_once
(À¸)·ÎºÎÅÍ µ¹¾Æ¿À´Â ½ÃÁ¡¿¡¼­´Â,
.Fn init_routine
ÇÏÁö¸¸ ¿Ï·áÇÏ°í ÀÖ´Â °ÍÀÌ ÇÁ·ÎÅؼǵǰí ÀÖ½À´Ï´Ù.
.Fa once_control
ÆĶó¹ÌÅÍ´Â, °ü·ÃÁöÀ» ¼ö ÀÖ¾ú´ø ÃʱâÈ­ routine°¡ ÀÌ¹Ì ºÒ·Á °¬´ÂÁö ¾î¶°Çß´ÂÁö¸¦
ÆÇ´ÜÇϱâ À§Çؼ­(¶§¹®¿¡) »ç¿ëµË´Ï´Ù.
.Pp
ÇÔ¼ö
.Fn pthread_once
(Àº)´Â Ãë¼Ò Æ÷ÀÎÆ®°¡ ¾Æ´Õ´Ï´Ù.
±×·¸Áö¸¸,
.Fn init_routine
ÇÏÁö¸¸ Ãë¼Ò Æ÷ÀÎÆ®À̹ǷΠ»èÁ¦µÇ¾î
.Fa once_control
ÇÏ
.Fn pthread_once
ÇÏÁö¸¸ Çѹøµµ ºÒ·Á °¡Áö ¾ÊÀº°¡¿Í °°Àº °á°ú°¡ µË´Ï´Ù.
.Pp
Á¤¼ö
.Fa PTHREAD_ONCE_INIT
(Àº)´Â,
.Aq Pa pthread.h
±×¸®°í Á¤Àǵǰí ÀÖ½À´Ï´Ù.
.Pp
.Fa once_control
¿¡ ÀÚµ¿ º¸Á¸ ±â°£ÀÌ ÀÖ´Ù, ¶Ç´Â
.Fa PTHREAD_ONCE_INIT
±×¸®°í ÃʱâÈ­µÇ¾î ÀÖÁö ¾ÊÀº °æ¿ì¿¡´Â,
.Fn pthread_once
ÀÇ µ¿ÀÛÀº ¹ÌÁ¤µµ¸®ÀÔ´Ï´Ù.
.Sh ¹Ýȯ°ª
¹®Á¦°¡ ¾ø´Â °æ¿ì´Â,
.Fn pthread_once
ÇÔ¼ö´Â 0 À» µ¹·ÁÁÝ´Ï´Ù.
¹®Á¦°¡ ÀÖ´Â °æ¿ì´Â, ±× ¿¡·¯¸¦ ³ªÅ¸³»±â À§Çؼ­(¶§¹®¿¡) ¿¡·¯ ¹øÈ£°¡ µ¹·ÁÁÖ¾îÁý´Ï´Ù.
.Sh ¿¡·¯
¾ø½À´Ï´Ù.
.Sh Ç¥ÁØ
.Fn pthread_once
ÇÏ
.St -p1003.1-96
¿¡ ÀûÇÕÇÏ°í ÀÖ½À´Ï´Ù.