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In-Reply-To: <8FB7CBFD-7334-4F9F-8C71-571DEF9FAD31@ar.aichi-u.ac.jp>
References: <8FB7CBFD-7334-4F9F-8C71-571DEF9FAD31@ar.aichi-u.ac.jp>
Date: Tue, 16 Feb 2016 10:56:55 -0500
Message-ID: <CAB8pEY7voFuqkE1LU_9KCsYPE86bk0JP=9nR+Crq=f9UOL=5Qw@mail.gmail.com>
From: Jacob Todd <jaketodd422@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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Subject: Re: [9fans] file descriptor leak
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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
> =E2=80=A6
>
> probably the file descriptor leak comes from dnresolve.c
>
> udpquery(Query *qp, char *mntpt, int depth, int patient, int inns)
> {
>         =E2=80=A6
>                         msg =3D system(open("/dev/null", ORDWR), "outside=
");
>         =E2=80=A6
> }
>
> char *
> system(int fd, char *cmd)
> {
>         int pid, p, i;
>         static Waitmsg msg;
>
>         if((pid =3D fork()) =3D=3D -1)
>                 sysfatal("fork failed: %r");
>         else if(pid =3D=3D 0){
>                 dup(fd, 0);
>                 close(fd);
>                 for (i =3D 3; i < 200; i++)
>                         close(i);               /* don't leak fds */
>                 execl("/bin/rc", "rc", "-c", cmd, nil);
>                 sysfatal("exec rc: %r");
>         }
>         for(p =3D waitpid(); p >=3D 0; p =3D waitpid())
>                 if(p =3D=3D 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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<p dir=3D"ltr">I&#39;ve had this problem too, I have yet to resolve it.</p>
<div class=3D"gmail_quote">On Feb 16, 2016 10:54 AM, &quot;arisawa&quot; &l=
t;<a href=3D"mailto:arisawa@ar.aichi-u.ac.jp">arisawa@ar.aichi-u.ac.jp</a>&=
gt; wrote:<br type=3D"attribution"><blockquote class=3D"gmail_quote" style=
=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<b=
r>
<br>
I have observed warning messages from dns server:<br>
dns 30792: warning process exceeded 100 file descriptors<br>
dns 30888: warning process exceeded 200 file descriptors<br>
=E2=80=A6<br>
<br>
probably the file descriptor leak comes from dnresolve.c<br>
<br>
udpquery(Query *qp, char *mntpt, int depth, int patient, int inns)<br>
{<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =E2=80=A6<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 msg =3D system(open(&quot;/dev/null&quot;, ORDWR), &quot;outside=
&quot;);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =E2=80=A6<br>
}<br>
<br>
char *<br>
system(int fd, char *cmd)<br>
{<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 int pid, p, i;<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 static Waitmsg msg;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 if((pid =3D fork()) =3D=3D -1)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 sysfatal(&quot;fork=
 failed: %r&quot;);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 else if(pid =3D=3D 0){<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 dup(fd, 0);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 for (i =3D 3; i &lt=
; 200; i++)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 close(i);=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0=
/* don&#39;t leak fds */<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 execl(&quot;/bin/rc=
&quot;, &quot;rc&quot;, &quot;-c&quot;, cmd, nil);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 sysfatal(&quot;exec=
 rc: %r&quot;);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 for(p =3D waitpid(); p &gt;=3D 0; p =3D waitpid=
())<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 if(p =3D=3D pid)<br=
>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 return msg.msg;<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 return &quot;lost child&quot;;<br>
}<br>
<br>
fd is lost if pid &gt; 0<br>
<br>
my server is running on 9front. however both 9atom and bell-labs use same r=
outine.<br>
<br>
Kenji Arisawa<br>
<br>
<br>
<br>
</blockquote></div>

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