.\" Page by b.hubert - may be freely modified and distributed
.\"
.\" Niki A. Rahimi (LTC Security Development, narahimi@us.ibm.com)
.\" added ERRORS section.
.\"
.\" Modified 2004-06-17 mtk
.\" Modified 2004-10-07 aeb, added FUTEX_REQUEUE, FUTEX_CMP_REQUEUE
.\"
.\" Japanese Version Copyright(C) 2003 Suzuki Takashi
.\"         all rights reserved.
.\" Translated Fri Oct 24 10:37:10 JST 2003
.\"         by Suzuki Takashi.
.\" Updated & Modified Sat Feb  5 14:28:53 JST 2005
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>
.\"
.\"WORD: integer                int ѿ
.\"WORD: sleep                  Ԥ
.\"WORD: wake                   
.\"WORD: wake up                
.\"
.TH FUTEX 2 "2004-10-07" "Linux 2.6.7" "Linux Programmer's Manual"
.SH "̾"
futex \- ®桼֥åΥƥॳ
.SH ""
.nf
.sp
.B "#include <linux/futex.h>"
.sp
.B "#include <sys/time.h>"
.sp
.BI "int futex(int *" uaddr ", int " op ", int " val \
", const struct timespec *" timeout ,
.br
.BI "          int *" uaddr2 ", int " val3 );
.\" int *? void *? u32 *?
.fi
.SH ""
.PP
.BR futex ()
ƥॳϡ
ꤷɥ쥹ͤѹΤץबԤļʤ
Υɥ쥹ФԵΥץ wake () ʤ󶡤
(ץۤʤƱФ륢ɥ쥹ƱǤϤʤ⤷ʤ
ͥϰۤʤ֤˥ޥåפ줿Ʊ
.BR futex ()
ǻȤ褦ǥޥåפ)
ŵŪˤϡfutex 
.BR futex (7)
˵Ƥ褦ˡ
ͭΥå礹νΤѤ롣
.PP
.BR futex (7)
桼֤Ƕʤλʤä硢
ͥۤ뤿˥ƥॳƤɬפ롣
ۤȤΤϡƤӽФץ sleep (Ԥ) ꡢȿФ
Ԥץ wake ꤹ뤳Ȥ̣롣
.PP
δؿƤӽФץ
.BR futex (7)
˵ҤƤ륻ޥƥ¤Ǥ뤳Ȥ׵ᤵ롣
ΥޥƥˤϰܿԲǽʥ֥̿񤯤Ȥޤޤ롣
ΤȤϸ futex Υ桼ΤۤȤɤϼºݤϥ饤֥κԤǤꡢ
̥ץꥱγȯԤǤϤʤȤȤǤ롣
.PP
.I uaddr
ϡ󥿤Ǽ롢
饤Ȥ·ä int ѿؤƤɬפ롣
¹Ԥ
.I op
ѥ᡼𤷤ơ
.I val
ȤȤϤ롣
.PP
ߤΤȤ 5 ĤƤ:
.TP
.B FUTEX_WAIT
 futex ɥ쥹
.I uaddr
˻ꤵ줿
.I val
ޤǼƤ뤫ɤԲʬǸڤ
sleep ֤
 futex ɥ쥹Ф FUTEX_WAKE ¹ԤΤԤġ
.I timeout
 NULL Ǥʤ硢Ƥ
Ԥ֤κͤɽNULL ξ̵ɽ

.I uaddr2

.I val3
̵뤵롣

.BR futex (7)
˾Ȥ餷碌ȡθƤӽФ
ȤΥǥȤ (ɽ) ˤʤä˼¹Ԥ졢
̤Υץ futex  FUTEX_WAKE ¹Ԥޤ
sleep 롣
.TP
.B FUTEX_WAKE
Ǥϻꤷ futex ɥ쥹ФԤ֤
(ʤ FUTEX_WAIT )  \fIval\fR ĤΥץ wake 롣

.IR timeout ,
.IR uaddr2 ,
.I val3
̵뤵롣

\fBfutex\fR(4) ˾Ȥ餷碌ȡ

ȤΥ󥯥ȤԤץȽ
futex ͤ 1 ꤵ줿 (ѲǽǤ뤳Ȥɽ) ˼¹Ԥ롣
.TP
.B FUTEX_FD
Ʊ wake б뤿ᡢϥեǥץ futex 
ϢŤ롣
.\" .BR poll (2)
.\" ŬƤ롣
̤Υץ FUTEX_WAKE ¹Ԥȡ
ץ
.I val
Ϥ줿ʥֹΥʥ롣
ƤӽФץϻѸ塢֤줿եǥץ
ʤФʤʤ

.IR timeout ,
.IR uaddr2 ,
.I val3
̵뤵롣

֤ɻߤ뤿ᡢƤӽФץ FUTEX_FD ֤ä
futex  up 줿ɤǧʤФʤʤ
.TP
.BR FUTEX_REQUEUE " (Linux 2.5.70 ʹ)"
ϡ
FUTEX_WAKE ȤƤơ wake ƤƤΥץ
¾ futex ɬפˡ
ֽäη˽ (thundering herd)׸̤򤱤뤿Ƴ줿
θƤӽФ
.I val
ĤΥץ wake ɥ쥹
.I uaddr2
 futex ԤäƤ¾ƤΥץ٥塼ˤ롣

.I timeout

.I val3
̵뤵롣
.TP
.BR FUTEX_CMP_REQUEUE " (Linux 2.6.7 ʹ)"
.\"Osato: 
.\"Osato: intended 褯ʬʤ
.\"Osato: 
ΰդ FUTEX_REQUEUE Ȥ˶礬뤿ᡢ
FUTEX_CMP_REQUEUE Ƴ줿
 FUTEX_REQUEUE ȻƤ뤬
.I uaddr

.I val3
ޤݻƤ뤫ǽ˥å롣
ݻƤʤ硢顼 EAGAIN ֤롣

.I timeout
̵뤵롣
.SH "֤"
.PP
ɤ¹Ԥ줿ˤäơ֤ͤϰۤʤ̣ġ
.TP
.B FUTEX_WAIT
ץ \fIFUTEX_WAKE\fR θƤӽФ wake  0 ֤
ॢȤξ硢ETIMEOUT ֤롣
futex ꤵ줿ͤʤ硢EWOULDBLOCK ֤롣
ʥ (ޤ¾ε wake ˤä) EINTR ֤
.TP
.B FUTEX_WAKE
wake ץο֤
.TP
.B FUTEX_FD
futex ˴ϢŤ줿ʥեǥץ֤
.TP
.B FUTEX_REQUEUE
wake ץο֤
.TP
.B FUTEX_CMP_REQUEUE
wake ץο֤
.SH "顼"
.TP
.B EACCES
futex ɤ߹ߥʤä
.TP
.B EAGAIN
FUTEX_CMP_REQUEUE ͽʤ futex ͤĤä
(϶򼨤Ƥ뤫⤷ʤ
ξϰ FUTEX_WAKE Ȥ)
.TP
.B EFAULT
桼֤
.I timeout
ξݤ˥顼ȯ
.TP
.B EINVAL
Ƥʤޤϥڡ饤Ȥǥ顼ȯ
.TP
.B ENFILE
ץ󤵤Ƥեƥ¤ã
.SH ""
.PP
֤ futex ϥɥ桼ưפ˻ȤȤΤǤ복ǰȤ
տޤ줿ΤǤϤʤ
Ԥϡ֥˴Ƥꡢʲ˵󤲤 futex 桼֥饤֥
ɤ߽Ƥ뤳Ȥ׵ᤵ롣
.\" .SH ""
.\" .PP
.\" futex  Hubertus Franke (IBM Thomas J. Watson Research Center),
.\" Matthew Kirkwood, Ingo Molnar (Red Hat),
.\" Rusty Russell (IBM Linux Technology Center) ߷פ
.\" Υڡ bert hubert 
.SH С
.PP
ǽ futex б Linux 2.5.7 Ȥ߹ޤ줿
嵭ΥޥƥȤϰۤʤ롣
ǼƤ륻ޥƥ
4 ĤΰΥƥॳϡLinux 2.5.40 Ƴ줿
Linux 2.5.70 Ǥ 1 Ĥΰɲä줿
Linux 2.6.7 Ǥ 6 ܤΰɲä줿
ϱs390 ƥ̤ΤΤǤ롣
.SH 
.\"Omotoki: Minux  Linux  typo ?
Υƥॳ Linux ȼǤ롣
.SH Ϣ
.PP
.BR futex (7), 
`Fuss, Futexes and Furwocks: Fast Userlevel Locking in Linux'
(proceedings of the Ottawa Linux Symposium 2002), 
futex λ饤֥, futex-*.tar.bz2
<URL:ftp://ftp.nl.kernel.org:/pub/linux/kernel/people/rusty/>.