'\" t
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.\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
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.\" Japanese Version Copyright (c) 2006 Akihiro MOTOKI all rights reserved.
.\" Translated 2006-03-13, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2006-07-20, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.36
.\" Updated 2009-02-23, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v3.19
.\"
.\"WORD:	message queue descriptor	å塼һ
.\"WORD:	message queue description	å塼
.\"
.TH MQ_OVERVIEW 7 2009-02-25 "Linux" "Linux Programmer's Manual"
.SH ̾
mq_overview \- POSIX å塼γ
.SH 
POSIX å塼Ѥȡץ֤
åηǤΥǡΤԤȤǤ롣
 API  System V å塼 API
.RB ( msgget (2),
.BR msgsnd (2),
.BR msgrcv (2)
ʤ) ȤϰۤʤΤƱͤεǽ󶡤롣

å塼κȥץ
.BR mq_open (3)
ȤäƹԤδؿ
.I å塼һ (message queue descriptor)
.RI ( mqd_t )
֤ʹߤΥǤϡץ󤵤줿å塼
.I å塼һ
ȤäƻȤ롣
ƥå塼
.I /somename
η̾Ƕ̤뤳ȤǤ롣
̾ϡ
.B NAME_MAX
(ʤ 255) ʸ NULL ü줿ʸǡ
åǻϤޤꡢåʳʸ 1 ʸʾ³Ǥ롣
.BR mq_open (3)
Ʊ̾ϤȤǡ2ĤΥץƱΥ塼
뤳ȤǤ롣

åΥ塼ؤ
.BR mq_send (3)

.BR mq_receive (3)
ȤäƹԤץ塼λѤ򽪤Ȥˤϡ
.BR mq_close (3)
Ȥäƥ塼򥯥롣塼ϤפȤʤäˤϡ
.BR mq_unlink (3)
Ȥäƥ塼Ǥ롣塼°
.BR mq_getattr (3)
ǼǤ (¤Ϥ뤬)
.BR mq_setattr (3)
ѹǤ롣
.BR mq_notify (3)
ȤȤǡΥ塼ؤΥåƱ
Τ褦׵᤹뤳ȤǤ롣

å塼һҤ
.I "ץå塼 (open message queue description)"
ؤλȤǤ
.RB ( open (2)
⻲)
.BR fork (2)
¹ԸϡҥץϿƥץΥå塼һҤΥԡѾ롣
εһҤϡƥץб뵭һҤƱץå塼
Ҥ򻲾ȤƤ롣ƥץȻҥץб뵭һҤϡե饰
.RI ( mq_flags )
ͭ롣ʤʤ顢ե饰ϥץå塼Ҥ
ϢդƤ뤫Ǥ롣

ƥåˤϤ줾
.I ͥ (priority)
ꡢåμץؤϾ
ͥ٤ι⤤å˹Ԥ롣
åͥ٤ 0 (ͥ) 
.I sysconf(_SC_MQ_PRIO_MAX)\ -\ 1
(ͥ) ͤġ
Linux Ǥϡ
.I sysconf(_SC_MQ_PRIO_MAX)
 32768 ֤
POSIX.1-2001 ׵ᤵƤΤ 0  31 ޤǤͥ٤
뤳ȤǤꡢˤäƤϤϰϤͥ٤
бƤʤ
.PP
λĤǤϡPOSIX å塼 Linux μξܺ
ˤĤ롣
.SS 饤֥ꥤ󥿥եȥƥॳ
ۤȤɤξ硢嵭
.B mq_*()
饤֥ꥤ󥿥եϡƱ̾βؤΥƥॳ
ȤäƼƤ롣ȤߤˤƤϤޤʤΤ
ʲɽ˼
.in +4n
.TS
lB lB
l l.
Library interface	System call
mq_close(3)	close(2)
mq_getattr(3)	mq_getsetattr(2)
mq_notify(3)	mq_notify(2)
mq_open(3)	mq_open(2)
mq_receive(3)	mq_timedreceive(2)
mq_send(3)	mq_timedsend(2)
mq_setattr(3)	mq_getsetattr(2)
mq_timedreceive(3)	mq_timedreceive(2)
mq_timedsend(3)	mq_timedsend(2)
mq_unlink(3)	mq_unlink(2)
.TE
.in
.SS С
Linux Ǥ POSIX å塼ϥͥ 2.6.6 ʹߤǥݡȤƤ롣
glibc ǤϥС 2.3.4 ʹߤǥݡȤƤ롣
.SS ͥ
POSIX å塼ΥݡȤϡͥ (configuration)
ץ
.B CONFIG_POSIX_MQUEUE
ǽǤ롣ΥץϥǥեȤǤͭǤ롣
.SS ³
POSIX å塼ϥͥݻ롣
.BR mq_unlink (3)
ǺʤСå塼
ƥबåȥ󤵤ޤ¸ߤ³롣
.SS 
POSIX å塼 API Ѥץ
.I cc \-lrt
ǥѥ뤷ꥢ륿饤֥
.I librt
ȥ󥯤ʤФʤʤ
.SS /proc 󥿥ե
ʲΥ󥿥եȤäơPOSIX å塼񤹤륫ͥ
̤¤뤳ȤǤ롣
.TP
.I /proc/sys/fs/mqueue/msg_max
ΥեȤäơĤΥ塼åκ
ͤ򻲾ȤѹǤ롣ͤϡ
.BR mq_open (3)
Ϥ
.I attr\->mq_maxmsg
ФͤȤƵǽ롣
.I msg_max
ΥǥեͤӺǾͤ 10 Ǥ;
¤ϡߤθ͡
.RB ( HARD_MAX )

.IR "(131072\ /\ sizeof(void\ *))"
(Linux/86 Ǥ 32768) Ǥ롣
ξ¤øץ
.RB ( CAP_SYS_RESOURCE )
Ǥ̵뤵뤬ߤθͤˤ¤
ɤʾˤǤŬѤ롣
.TP
.I /proc/sys/fs/mqueue/msgsize_max
ΥեȤäơåκ祵ξͤ	
ȤѹǤ롣	
ͤϡ	
.BR mq_open (3)	
Ϥ	
.I attr\->mq_msgsize
ФͤȤƵǽ롣	
.I msgsize_max	
ΥǥեͤӺǾͤ 8192 ХȤǤ;	
¤
.B INT_MAX
(Linux/86 Ǥ 2147483647) Ǥ롣	
ξ¤øץ	
.RB ( CAP_SYS_RESOURCE )	
Ǥ̵뤵롣
.TP
.I /proc/sys/fs/mqueue/queues_max
ΥեȤäơ뤳ȤǤå塼ο	
Ф륷ƥΤǤ¤򻲾ȤѹǤ롣	
٤ξ¤ãȡå塼ǤΤ	
øץ	
.RB ( CAP_SYS_RESOURCE )	
Ȥʤ롣	
.I queues_max	
Υǥեͤ 256 Ǥꡢ	
0  INT_MAX ϰϤǤդͤѹ뤳ȤǤ롣
.SS ꥽
꥽
.B RLIMIT_MSGQUEUE
ϡץμ UID бå塼񤹤
֤̤Фƾ¤ꤹ롣
.BR getrlimit (2)
򻲾ȡ
.SS å塼ե륷ƥΥޥ
Linux Ǥϡå塼ϲۥե륷ƥ˺
(¾μǤƱͤεǽ󶡤ƤΤ⤢뤬
ܺ٤ϰäƤ)
ʲΥޥɤȤȤǡΥե륷ƥޥȤǤ:
.in +4n
.nf

.RB "$" " mkdir /dev/mqueue"
.RB "$" " mount \-t mqueue none /dev/mqueue"

.fi
.in
ޥȤǥ쥯ȥΥƥåӥå (sticky bit) 
ưŪ˥Ȥʤ롣

å塼ե륷ƥΥޥȸϡեФ
̾Ȥޥ (㤨
.BR ls (1)

.BR rm (1))
ȤäơƥΥå塼ɽ
Ǥ롣

ǥ쥯ȥγƥեƤ 1ԤǤꡢ
塼˴ؤɽ롣
.in +4n
.nf

.RB "$" " ls /dev/mqueue/mymq"
QSIZE:129     NOTIFY:2    SIGNO:0    NOTIFY_PID:8260
.RB "$" " mount \-t mqueue none /dev/mqueue"

.fi
.in
ƥեɤξܺ٤ϰʲ̤Ǥ:
.TP
.B QSIZE
塼äƤåιץХȿ
.TP
.B NOTIFY_PID
ͤ 0 ʳξ硢ͤ PID ĥץ
.BR mq_notify (3)
ȤäơƱΥåΤԤ褦ꤷȤ򼨤
ɤΤ褦ΤԤ뤫ϡʲΥեɤˤꤵ롣
.TP
.B NOTIFY
ˡ:
0 
.BR SIGEV_SIGNAL ;
1 
.BR SIGEV_NONE ;
2 
.B SIGEV_THREAD
.TP
.B SIGNO
.B SIGEV_SIGNAL
˻Ѥ륷ʥֹ档
.SS å塼һҤΥݡ
Linux Ǥϡå塼һҤϼºݤϥե뵭һ (file descriptor)
Ǥꡢ
.BR select (2),
.BR poll (2),
.BR epoll (7)
Ȥäƴƻ뤹뤳ȤǤ롣
εǽΰܿϤʤ
.SH 
POSIX.1-2001.
.SH 
System V å塼
.RB ( msgget (2),
.BR msgsnd (2),
.BR msgrcv (2)
ʤ) ϥץ֤ǥåꤹ뤿θŤ API Ǥ롣
POSIX å塼 System V å塼⤦ޤ
߷פ줿󥿥ե󶡤Ƥ롣
ǡPOSIX å塼 System V å塼٤
ѤǤ륷ƥबʤ (äˡŤƥǤϾʤ)

ߤΤȤ (С 2.6.26 )
Linux  POSIX å塼Ф륢ꥹ (ACL) 
бƤʤ
.SH 
ƼΥå塼ؿѤ㤬
.BR mq_notify (3)
˵ܤƤ롣
.SH Ϣ
.BR getrlimit (2),
.BR mq_getsetattr (2),
.BR poll (2),
.BR select (2),
.BR mq_close (3),
.BR mq_getattr (3),
.BR mq_notify (3),
.BR mq_open (3),
.BR mq_receive (3),
.BR mq_send (3),
.BR mq_unlink (3),
.BR epoll (7)