DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=ZMnxQfhgR3f1fZ999WT36QiOgslxPKtNdkAv9oa+/IatKN6wdN0UH
	l9lfikOx9TgfFljOKzhQk6NeCVfwpsKxnhD+j/IDvbezsmnPLG7royq02jFtMfZn
	aZhDly46UKxpK4tuKQchuqpJ+bojvKw6p65jZonF3WSg5S3nRbeCf8=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Date: Mon, 2 Nov 2015 15:30:23 +0100
From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: Randomly hang when compiling Cygwin on Cygwin on Wine
Message-ID: <20151102143023.GC963@calimero.vinschen.de>
Reply-To: cygwin@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
References: <CALd+sZS-EbkUMgmRCyJUK0LCMo6zydzB1rbM9iZFrAcnbfHCRQ@mail.gmail.com> <CALd+sZTRVMuLjwZMjxN6f6JvTtax5rJAUuk_SMXvcQzMzxhirA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;	protocol="application/pgp-signature"; boundary="t0UkRYy7tHLRMCai"
Content-Disposition: inline
In-Reply-To: <CALd+sZTRVMuLjwZMjxN6f6JvTtax5rJAUuk_SMXvcQzMzxhirA@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)

--t0UkRYy7tHLRMCai
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Nov  2 03:08, Qian Hong wrote:
> Update:
>=20
> I have another case of hang:
>=20
> ?(1)-+-bash(1419290)
>      |-bash(1419318)---make(1423770)---sh(1423783)---sh(1423838)
>      |-mintty(1249269)---bash(1249277)
>      |-mintty(47)---bash(55)---bash(1132827)---make(1139169)---sh(1139182=
)---make(1139234)---sh(1206695)---sh(1206721)---make(1206764)---sh(1206770)=
---make(1206783)---perl(1249042)
>      |-mintty(596773)---bash(596790)---pstree(1423865)
>      `-mintty(1417449)---bash(1417457)
>=20
>=20
> $ ps aux | grep 1249042
>   1249042 1206783 1132827    1249050  pty0      197608   Oct 31 /usr/bin/=
perl
>   1249077 1249042 1132827    1249092  pty0      197608   Oct 31
> /usr/bin/nm <defunct>
>=20
>=20
>=20
> Here the process perl(1249042) is waiting for a pipe, while its child
> process nm(1249077) is in the status "defunct". nm(1249077) appears in
> output of `ps aux`, but doesn't appear in output of `pstree -p -l`.
>=20
> Is there any case, where a child process can exit unexpected, but the
> parent process still incorrectly wait for the child process forever?

I don't answer this question conclusively before consulting my lawyer.
It *might* be possible.  See fhandler_base_overlapped::close(),
fhandler_base_overlapped::check_later() and flush_async_io(), all three
in fhandler.cc.

No, I'm not happy with using overlapped IO for pipes.  I'd prefer to use
nonblocking pipes instead, but the most required resource to fix this,
which is least available, is time :(


Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--t0UkRYy7tHLRMCai
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=nHpR
-----END PGP SIGNATURE-----

--t0UkRYy7tHLRMCai--