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From: Jacob Todd <jaketodd422@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] file descriptor leak
Date: Tue, 16 Feb 2016 10:56:55 -0500	[thread overview]
Message-ID: <CAB8pEY7voFuqkE1LU_9KCsYPE86bk0JP=9nR+Crq=f9UOL=5Qw@mail.gmail.com> (raw)
In-Reply-To: <8FB7CBFD-7334-4F9F-8C71-571DEF9FAD31@ar.aichi-u.ac.jp>

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I've had this problem too, I have yet to resolve it.
On Feb 16, 2016 10:54 AM, "arisawa" <arisawa@ar.aichi-u.ac.jp> wrote:

> Hello,
>
> I have observed warning messages from dns server:
> dns 30792: warning process exceeded 100 file descriptors
> dns 30888: warning process exceeded 200 file descriptors
> …
>
> probably the file descriptor leak comes from dnresolve.c
>
> udpquery(Query *qp, char *mntpt, int depth, int patient, int inns)
> {
>         …
>                         msg = system(open("/dev/null", ORDWR), "outside");
>         …
> }
>
> char *
> system(int fd, char *cmd)
> {
>         int pid, p, i;
>         static Waitmsg msg;
>
>         if((pid = fork()) == -1)
>                 sysfatal("fork failed: %r");
>         else if(pid == 0){
>                 dup(fd, 0);
>                 close(fd);
>                 for (i = 3; i < 200; i++)
>                         close(i);               /* don't leak fds */
>                 execl("/bin/rc", "rc", "-c", cmd, nil);
>                 sysfatal("exec rc: %r");
>         }
>         for(p = waitpid(); p >= 0; p = waitpid())
>                 if(p == pid)
>                         return msg.msg;
>         return "lost child";
> }
>
> fd is lost if pid > 0
>
> my server is running on 9front. however both 9atom and bell-labs use same
> routine.
>
> Kenji Arisawa
>
>
>
>

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  reply	other threads:[~2016-02-16 15:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-16 15:52 arisawa
2016-02-16 15:56 ` Jacob Todd [this message]
2016-02-16 16:42   ` lucio
2016-02-16 17:05     ` Jacob Todd
2016-02-16 17:17     ` Charles Forsyth
2016-02-16 18:01 ` cinap_lenrek
2016-02-16 21:05   ` erik quanstrom
2016-02-16 21:16   ` Charles Forsyth
2016-02-17  2:19     ` cinap_lenrek
2016-02-22  5:18     ` erik quanstrom
2016-02-16 22:24 ` Charles Forsyth
2016-02-17  1:13   ` arisawa
2016-02-17  1:22     ` cinap_lenrek

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