[linuxjm/LDP_man-pages.git] / release / man3 / mq_notify.3

'\" t
.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
.\"
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.\" 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.\" manual page may be incorrect or out-of-date.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.
.\"
.\" Japanese Version Copyright (c) 2006 Akihiro MOTOKI all rights reserved.
.\" Translated 2006-07-31, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2010-04-18, Akihiro MOTOKI, LDP v3.24
.\"
.TH MQ_NOTIFY 3 2009-09-15 "Linux" "Linux Programmer's Manual"
.SH ̾Á°
mq_notify \- ¥á¥Ã¥»¡¼¥¸ÅþÃå»þ¤ËÄÌÃΤò¹Ô¤¦¤è¤¦ÅÐÏ¿¤¹¤ë
.SH ½ñ¼°
.nf
.B #include <mqueue.h>
.sp
.BI "mqd_t mq_notify(mqd_t " mqdes ", const struct sigevent *" notification );
.fi
.sp
\fI\-lrt\fP ¤Ç¥ê¥ó¥¯¤¹¤ë¡£
.SH ÀâÌÀ
.BR mq_notify ()
¤ò»È¤¦¤È¡¢¥Ç¥£¥¹¥¯¥ê¥×¥¿
.I mqdes
¤Ç»²¾È¤µ¤ì¤ë¶õ¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤Ë¿·¤·¤¯¥á¥Ã¥»¡¼¥¸¤¬ÅþÃ夷¤¿»þ¤Ë
ÈóƱ´ü¤ÎÄÌÃÎ (notification) ¤ÎÇÛÁ÷¤¬¹Ô¤ï¤ì¤ë¤è¤¦¤ËÅÐÏ¿¤·¤¿¤ê¡¢
¤½¤Î²ò½ü¤ò¹Ô¤Ã¤¿¤ê¤Ç¤­¤ë¡£

.I notification
°ú¤­¿ô¤Ï
.I sigevent
¹½Â¤ÂΤؤΥݥ¤¥ó¥¿¤Ç¤¢¤ë¡£
.I sigevent
¹½Â¤ÂΤϰʲ¼¤Î¤è¤¦¤Ê´¶¤¸¤ÇÄêµÁ¤µ¤ì¤Æ¤¤¤ë:
.in +4n
.nf

union sigval {          /* Data passed with notification */
    int     sival_int;         /* Integer value */
    void   *sival_ptr;         /* Pointer value */
};

struct sigevent {
    int          sigev_notify; /* Notification method */
    int          sigev_signo;  /* Notification signal */
    union sigval sigev_value;  /* Data passed with
                                  notification */
    void       (*sigev_notify_function) (union sigval);
                               /* Function for thread
                                  notification */
    void        *sigev_notify_attributes;
                               /* Thread function attributes */
};
.fi
.in
.PP
.I notification
¤¬ NULL ¤Ç¤Ê¤¤¥Ý¥¤¥ó¥¿¤Ç¤¢¤ì¤Ð¡¢
.BR mq_notify ()
¤Ï¥á¥Ã¥»¡¼¥¸ÄÌÃΤò¼õ¤±¼è¤ë¤è¤¦¤Ë¸Æ¤Ó½Ð¤·¸µ¤Î¥×¥í¥»¥¹¤òÅÐÏ¿¤¹¤ë¡£
.I notification
¤¬»Ø¤¹
.I sigevent
¤Î
.I sigev_notify
¥Õ¥£¡¼¥ë¥É¤Ï¡¢¤É¤Î¤è¤¦¤ÊÄÌÃΤò¹Ô¤¦¤Î¤«¤ò»ØÄꤹ¤ë¡£
¤³¤Î¥Õ¥£¡¼¥ë¥É¤Ï°Ê²¼¤ÎÃͤΤ¤¤º¤ì¤«¤ò»ý¤Ä¡£
.TP
.B SIGEV_NONE
¡Ö¶õ¤Î (null)¡×¤ÎÄÌÃÎ: ¸Æ¤Ó½Ð¤·¸µ¤Î¥×¥í¥»¥¹¤òÄÌÃΤΰ¸Àè¤È¤·¤ÆÅÐÏ¿¤¹¤ë¤¬¡¢
¼ÂºÝ¤Ë¤Ï¥á¥Ã¥»¡¼¥¸¤¬ÅþÃ夷¤¿»þ¤ËÄÌÃΤÏÁ÷¤é¤ì¤Ê¤¤¡£
.\" When is SIGEV_NONE useful?
.TP
.B SIGEV_SIGNAL
.I sigev_signo
¤Ç»ØÄꤵ¤ì¤¿¥·¥°¥Ê¥ë¤òÁ÷¤Ã¤Æ¡¢¥×¥í¥»¥¹¤ËÄÌÃΤ¹¤ë¡£
.BR sigaction (2)
¤Î
.B SA_SIGINFO
¥Õ¥é¥°¤Ç¥·¥°¥Ê¥ë¥Ï¥ó¥É¥é¤òÅÐÏ¿¤·¤Æ¤¤¤ë¾ì¹ç¡¢
¤½¤Î¥·¥°¥Ê¥ë¥Ï¥ó¥É¥é¤Ç¥·¥°¥Ê¥ë¤¬Ê᪤µ¤ì¤¿¾ì¹ç¤Ë¤Ï¡¢
¥·¥°¥Ê¥ë¥Ï¥ó¥É¥é¤ÎÂèÆó°ú¤­¿ô¤È¤·¤ÆÅϤµ¤ì¤ë
.I siginfo_t
¹½Â¤ÂΤγƥե£¡¼¥ë¥É¤Ï°Ê²¼¤Î¤è¤¦¤ËÀßÄꤵ¤ì¤ë¡£
.I si_code
¤Ë¤Ï
.B SI_MESGQ
¤¬¡¢
.I si_signo
¤Ë¤Ï¥·¥°¥Ê¥ëÈֹ椬¡¢
.I si_value
¤Ë¤Ï
.I notification\->sigev_value
¤Ç»ØÄꤷ¤¿Ãͤ¬ÀßÄꤵ¤ì¤ë¡£
.\" I don't know of other implementations that set
.\" si_pid and si_uid -- MTK
.I si_pid
¤Ë¤Ï¥á¥Ã¥»¡¼¥¸¤òÁ÷¿®¤·¤¿¥×¥í¥»¥¹¤Î PID ¤¬¡¢
.I si_uid
¤Ë¤ÏÁ÷¿®¥×¥í¥»¥¹¤Î¼Â¥æ¡¼¥¶ ID ¤¬ÀßÄꤵ¤ì¤ë¡£
.BR sigwaitinfo (2)
¤ò»È¤Ã¤Æ¥·¥°¥Ê¥ë¤ò¼õ¿®¤¹¤ë¾ì¹ç¤â¡¢Æ±¤¸¾ðÊó¤¬ÆÀ¤é¤ì¤ë¡£
.TP
.B SIGEV_THREAD
¿·¤·¤¤¥¹¥ì¥Ã¥É¤Î³«»Ï´Ø¿ô¤È¤·¤Æ
.I notification\->sigev_thread_function
¤òµ¯Æ°¤¹¤ë¤³¤È¤ÇÄÌÃΤò¹Ô¤¦¡£
µ¯Æ°»þ¤Î´Ø¿ô¤Î°ú¤­¿ô¤È¤·¤Æ¤Ï
.I notification\->sigev_value
¤À¤±¤¬ÅϤµ¤ì¤ë¡£
.I notification\->sigev_notify_attributes
¤Ï¡¢NULL °Ê³°¤Î¾ì¹ç¡¢
¤½¤Î¥¹¥ì¥Ã¥É¤Î°À­¤òÄêµÁ¤¹¤ë
.I pthread_attr_t
¹½Â¤ÂΤؤΥݥ¤¥ó¥¿¤È¤Ê¤Ã¤Æ¤¤¤ëɬÍפ¬¤¢¤ë
.RB ( pthread_attr_init (3)
»²¾È)¡£
.PP
°ì¤Ä¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤«¤éÄÌÃΤò¼õ¿®¤¹¤ë¤è¤¦¤ËÅÐÏ¿¤Ç¤­¤ë¥×¥í¥»¥¹¤Ï
°ì¤Ä¤À¤±¤Ç¤¢¤ë¡£

.I notification
¤¬ NULL ¤Ç¡¢¤«¤Ä¸Æ¤Ó½Ð¤·¸µ¤Î¥×¥í¥»¥¹¤¬¤³¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤«¤é¤Î
ÄÌÃΤò¼õ¿®¤¹¤ë¤Ë¸½ºßÅÐÏ¿¤·¤Æ¤¤¤ë¾ì¹ç¡¢ÅÐÏ¿¤òºï½ü¤¹¤ë¡£
¤³¤ì°Ê¹ß¡¢ÊÌ¤Î¥×¥í¥»¥¹¤¬¤³¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤«¤éÄÌÃΤò¼õ¿®¤¹¤ë¤è¤¦¤Ë
ÅÐÏ¿¤Ç¤­¤ë¤è¤¦¤Ë¤Ê¤ë¡£

¥á¥Ã¥»¡¼¥¸ÄÌÃΤϡ¢¤½¤ì¤Þ¤Ç¶õ¤Î¥­¥å¡¼¤Ë¿·¤·¤¤¥á¥Ã¥»¡¼¥¸¤¬ÅþÃ夷¤¿
¾ì¹ç¤Ë¤Î¤ß¹Ô¤ï¤ì¤ë¡£
.BR mq_notify ()
¤¬¸Æ¤Ó½Ð¤µ¤ì¤¿»þ¤Ë¤½¤Î¥­¥å¡¼¤¬¶õ¤Ç¤Ê¤¤¾ì¹ç¡¢
¤½¤Î¥­¥å¡¼¤¬¶õ¤Ë¤Ê¤ê¡¢¤½¤Î¸å¿·¤·¤¤¥á¥Ã¥»¡¼¥¸¤¬ÅþÃ夷¤¿»þ¤Ë
½é¤á¤ÆÄÌÃΤ¬¹Ô¤ï¤ì¤ë¤³¤È¤Ë¤Ê¤ë¡£

ÊÌ¤Î¥×¥í¥»¥¹¤ä¥¹¥ì¥Ã¥É¤¬
.BR mq_receive (3)
¤ò»È¤Ã¤Æ¡¢¶õ¤Î¥­¥å¡¼¤«¤é¥á¥Ã¥»¡¼¥¸¤ÎÆɤ߽Ф·¤òÂԤäƤ¤¤ë¾ì¹ç¡¢
¥á¥Ã¥»¡¼¥¸ÄÌÃΤÎÅÐÏ¿¤ÏÁ´¤Æ̵»ë¤µ¤ì¤ë¡£
¥á¥Ã¥»¡¼¥¸¤Ï
.BR mq_receive (3)
¤ò¸Æ¤Ó½Ð¤·¤Æ¤¤¤ë¥×¥í¥»¥¹¤ä¥¹¥ì¥Ã¥É¤ËÇÛÁ÷¤µ¤ì¡¢
¥á¥Ã¥»¡¼¥¸ÄÌÃΤÎÅÐÏ¿¤Ï¸úÎϤò»ý¤Ã¤¿¤Þ¤Þ¤È¤Ê¤ë¡£

ÄÌÃΤϰìÅÙ¤À¤±¹Ô¤ï¤ì¤ë¡£ÄÌÃΤ¬Á÷¤é¤ì¤¿¸å¤Ï¡¢ÄÌÃÎÍ×µá¤ÎÅÐÏ¿¤Ïºï½ü¤µ¤ì¡¢
ÊÌ¤Î¥×¥í¥»¥¹¤¬¥á¥Ã¥»¡¼¥¸ÄÌÃΤò¼õ¿®¤¹¤ë¤è¤¦¤ËÅÐÏ¿¤Ç¤­¤ë¤è¤¦¤Ë¤Ê¤ë¡£
ÄÌÃΤò¼õ¤±¤¿¥×¥í¥»¥¹¤¬¼¡¤ÎÄÌÃΤâ¼õ¿®¤·¤¿¤¤¾ì¹ç¤Ï¡¢
.BR mq_notify ()
¤ò»È¤Ã¤Æ¤½¤Î¸å¤ÎÄÌÃΤâ¼õ¤±¤ë¤è¤¦¤ËÍ׵᤹¤ë¤³¤È¤¬¤Ç¤­¤ë¡£
.BR mq_notify ()
¤òºÆÅٸƤӽФ¹¤Î¤Ï¡¢Æɤ߽Ф·¤Æ¤¤¤Ê¤¤¥á¥Ã¥»¡¼¥¸¤òÁ´ÉôÆɤ߽Ф·¤Æ
¥­¥å¡¼¤¬¶õ¤Ë¤Ê¤ëÁ°¤Ë¤¹¤Ù¤­¤Ç¤¢¤ë
(¥­¥å¡¼¤«¤é¤Î¥á¥Ã¥»¡¼¥¸Æɤ߽Ф·¤ò¥­¥å¡¼¤¬¶õ¤Ë¤Ê¤Ã¤¿»þ¤Ë
Ää»ß (block) ¤»¤º¤Ë¹Ô¤¦¤Ë¤Ï¡¢¥­¥å¡¼¤òÈóÄä»ß¥â¡¼¥É (non-blocking mode)
¤ËÀßÄꤷ¤Æ¤ª¤¯¤È¤è¤¤)¡£
.SH ÊÖ¤êÃÍ
À®¸ù¤¹¤ë¤È¡¢
.BR mq_notify ()
¤Ï 0 ¤òÊÖ¤¹¡£¥¨¥é¡¼¤Î¾ì¹ç¡¢\-1 ¤òÊÖ¤·¡¢
.I errno
¤ò¥¨¥é¡¼¤ò¼¨¤¹ÃͤËÀßÄꤹ¤ë¡£
.SH ¥¨¥é¡¼
.TP
.B EBADF
.I mqdes
¤Ë»ØÄꤵ¤ì¤¿¥Ç¥£¥¹¥¯¥ê¥×¥¿¤¬ÉÔÀµ¤Ç¤¢¤ë¡£
.TP
.B EBUSY
ÊÌ¤Î¥×¥í¥»¥¹¤¬¤¹¤Ç¤Ë
¤³¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤ËÂФ¹¤ëÄÌÃΤò¼õ¿®¤¹¤ë¤è¤¦¤ËÅÐÏ¿¤·¤Æ¤¤¤ë¡£
.TP
.B EINVAL
.I notification\->sigev_notify
¤¬µö²Ä¤µ¤ì¤¿ÃͤΤ¤¤º¤ì¤Ç¤â¤Ê¤¤¡£¤â¤·¤¯¤Ï
.I notification\->sigev_notify
¤¬
.B SIGEV_SIGNAL
¤À¤¬
.I notification\->sigev_signo
¤¬Í­¸ú¤Ê¥·¥°¥Ê¥ëÈÖ¹æ¤Ç¤Ï¤Ê¤¤¡£
.TP
.B ENOMEM
ɬÍפʥá¥â¥ê¤¬¤Ê¤«¤Ã¤¿¡£
.PP
POSIX.1-2008 ¤Ç¤Ï¡¢
.I notifications
¤¬ NULL ¤Ç¡¢¸Æ¤Ó½Ð¤·¸µ¤Î¥×¥í¥»¥¹¤¬¥­¥å¡¼
.I mqdes
¤Ë´Ø¤¹¤ëÄÌÃΤò¼õ¿®¤¹¤ë¤è¤¦¤ËÅÐÏ¿¤µ¤ì¤Æ¤¤¤Ê¤¤¾ì¹ç¡¢¥¨¥é¡¼
.B EINVAL
¤òÀ¸À®¤¹¤ë¤è¤¦¤Ê¼ÂÁõ¤ò¹Ô¤Ã¤Æ¤â¡Ö¤è¤¤¡×¤³¤È¤Ë¤Ê¤Ã¤Æ¤¤¤ë¡£
.\" Linux ¤Î¼ÂÁõ¤Ç¤Ï EINVAL ¤ÏÀ¸À®¤µ¤ì¤Ê¤¤
.SH ½àµò
POSIX.1-2001.
.SH Îã
°Ê²¼¤Î¥×¥í¥°¥é¥à¤Ï¡¢
¥³¥Þ¥ó¥É¥é¥¤¥ó°ú¤­¿ô¤Ç»ØÄꤵ¤ì¤¿Ì¾Á°¤Î¥á¥Ã¥»¡¼¥¸¥­¥å¡¼¤Ø¤Î
ÄÌÃÎÍ×µá¤òÅÐÏ¿¤·¡¢ÄÌÃΤϥ¹¥ì¥Ã¥É¤ÎºîÀ®¤Ë¤è¤Ã¤Æ¹Ô¤ï¤ì¤ë¡£
¤½¤Î¥¹¥ì¥Ã¥É¤Ï¡¢¤½¤Î¥­¥å¡¼¤«¤é¥á¥Ã¥»¡¼¥¸¤ò°ì¤ÄÆɤ߽Ф·¤Æ¤«¤é¡¢
¥×¥í¥»¥¹¤ò½ªÎ»¤¹¤ë´Ø¿ô¤ò¼Â¹Ô¤¹¤ë¡£
.nf

#include <pthread.h>
#include <mqueue.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define handle_error(msg) \\
    do { perror(msg); exit(EXIT_FAILURE); } while (0)

static void                     /* ¥¹¥ì¥Ã¥É³«»Ï´Ø¿ô */
tfunc(union sigval sv)
{
    struct mq_attr attr;
    ssize_t nr;
    void *buf;
    mqd_t mqdes = *((mqd_t *) sv.sival_ptr);

    /* ºÇÂç¥á¥Ã¥»¡¼¥¸¥µ¥¤¥º¤ò·èÄꤷ¡¢
       ¥á¥Ã¥»¡¼¥¸¼õ¿®ÍѤΥХåե¡¤ò³ÎÊݤ¹¤ë */

    if (mq_getattr(mqdes, &attr) == \-1)
        handle_error("mq_getattr");
    buf = malloc(attr.mq_msgsize);
    if (buf == NULL)
        handle_error("malloc");

    nr = mq_receive(mqdes, buf, attr.mq_msgsize, NULL);
    if (nr == \-1)
        handle_error("mq_receive");

    printf("Read %ld bytes from MQ\\n", (long) nr);
    free(buf);
    exit(EXIT_SUCCESS);         /* ¥×¥í¥»¥¹¤ò½ªÎ»¤¹¤ë */
}

int
main(int argc, char *argv[])
{
    mqd_t mqdes;
    struct sigevent not;

    if (argc != 2) {
        fprintf(stderr, "Usage: %s <mq-name>\\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    mqdes = mq_open(argv[1], O_RDONLY);
    if (mqdes == (mqd_t) \-1)
        handle_error("mq_open");

    not.sigev_notify = SIGEV_THREAD;
    not.sigev_notify_function = tfunc;
    not.sigev_notify_attributes = NULL;
    not.sigev_value.sival_ptr = &mqdes;   /* ¥¹¥ì¥Ã¥É´Ø¿ô¤ËÅϤ¹°ú¤­¿ô */
    if (mq_notify(mqdes, &not) == \-1)
        handle_error("mq_notify");

    pause();    /* ¥×¥í¥»¥¹¤Ï¥¹¥ì¥Ã¥É´Ø¿ô¤Ë¤è¤ê½ªÎ»¤µ¤ì¤ë */
}
.fi
.SH ´ØÏ¢¹àÌÜ
.BR mq_close (3),
.BR mq_getattr (3),
.BR mq_open (3),
.BR mq_receive (3),
.BR mq_send (3),
.BR mq_unlink (3),
.BR mq_overview (7)