X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:message-id:references
	:in-reply-to:content-type:content-id:content-transfer-encoding
	:mime-version; q=dns; s=default; b=jTnvroElInfn6zUwioPU8GICBBcRC
	W/srYk6iyJ8Wl6U/HKAmJWx31fwkBtfe+xtkhbtRCuwGo3UVU2OmfUyvt0kWXLiM
	jM+rU+gizDb30iS2AlvxSnorN+xVgIEByD5BLrl/3auciwosB2QXH3iAlud+/if8
	321+E1SeycEVDo=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:message-id:references
	:in-reply-to:content-type:content-id:content-transfer-encoding
	:mime-version; s=default; bh=QFGW3p9GON3RrBRQly4LLOAEqO4=; b=xCZ
	MB1jXcC/ozoA7Q8qAgrG2BrdKjfINFstML3KgCSvShIDLhrxf/DRqbpnHekybiIl
	Tsm1ctdSvjInZvsnyPLdUOZY6g9DoYDyYC7MRLsAoUBYG30JGC8D9qhLWSTAmF0U
	S+R4C7kMtg4xWyIyZ6Lyd+nOeRhcs5lOqHfZsPlE=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Spam-SWARE-Status:	No, score=-9.0 required=5.0 tests=AWL,BAYES_00,MIME_BASE64_BLANKS,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.1 spammy=Ken, row, communication
X-HELO:	NAM05-CO1-obe.outbound.protection.outlook.com
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cornell.edu; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=t3aWzfzfKSNl3P9ShxSQVUVndpzI2PxBEghOMXthuDM=; b=eAzUtBfVnoVQOqaWP6Pz4ciPQcpVD4mb065VQLNHERtLqfZUWmOaryD91CcJykGiX13A+EWYKDdZLUThP2vRrQiG52bdcgYx352SzYRyxOrF9dg+YtSTMsHHbspK/LVxr55djsSicFybYOdfsDEQk/ZWdr/6yBlhQGfFYWnXkYI=
From:	Ken Brown <kbrown AT cornell DOT edu>
To:	"cygwin AT cygwin DOT com" <cygwin AT cygwin DOT com>
Subject:	Re: Fork problems on master branch
Date:	Sun, 9 Jun 2019 16:51:31 +0000
Message-ID:	<87e7b7f9-e1e5-92f2-c036-961dcc8c06f0@cornell.edu>
References:	<330c76fd-af22-beb9-08b6-707c73df3b75 AT cornell DOT edu>
In-Reply-To:	<330c76fd-af22-beb9-08b6-707c73df3b75@cornell.edu>
user-agent:	Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0
authentication-results:	spf=none (sender IP is ) smtp.mailfrom=kbrown AT cornell DOT edu;
x-ms-exchange-purlcount:	1
x-ms-oob-tlc-oobclassifiers:	OLM:9508;
received-spf:	None (protection.outlook.com: cornell.edu does not designate permitted sender hosts)
x-ms-exchange-senderadcheck:	1
MIME-Version:	1.0
X-MS-Exchange-CrossTenant-mailboxtype:	HOSTED
X-MS-Exchange-CrossTenant-userprincipalname:	ksb2 AT cornell DOT edu
X-IsSubscribed:	yes
X-MIME-Autoconverted:	from base64 to 8bit by delorie.com id x59GqBQe028782

On 6/8/2019 3:44 PM, Ken Brown wrote:
> Earlier today I reported on the cygwin-patches list a fork problem with a
> cygwin1.dll built from the master branch of the Cygwin source repo.  See
> https://cygwin.com/ml/cygwin-patches/2019-q2/msg00155.html.  A bisection showed
> that commit f03ea8e1 was the first bad commit for the problem being discussed there.
> 
> I've just run into a second fork problem for which I think the same commit is
> the first bad one.  I can't be positive, because the problem is sporadic, so I
> might have marked some bad commits as good if I didn't run the test enough times.
> 
> The test case for this (attached) is one that I used when testing my new FIFO
> code.  Normally I run this program in one terminal and type
> 
>     echo blah > /tmp/myfifo
> 
> in a second terminal.  For the present purposes, however, you can skip the
> second part and simply terminate fifo_fork_test with C-c.
> 
> In my testing, I found that running the test program would yield "read: Bad
> address" about 1 out of 10 times.  Occasionally I would get "read: Communication
> error on send" instead.  Both error messages indicate a problem with the child
> process reading from an fd inherited from the parent.

Never mind.  This seems to be a bug in my recently added FIFO code.  I just 
never before ran my test many times in a row, so I never saw the error before.

Sorry for the noise.

Ken

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -