From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.74]) by sourceware.org (Postfix) with ESMTPS id 42CED3844046 for ; Thu, 6 Aug 2020 14:33:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 42CED3844046 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=towo.net Authentication-Results: sourceware.org; spf=none smtp.mailfrom=towo@towo.net Received: from [192.168.178.45] ([95.90.245.244]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.183]) with ESMTPSA (Nemesis) id 1N4z2Y-1kkpCZ2Cyy-010uxn for ; Thu, 06 Aug 2020 16:33:39 +0200 Subject: Re: Race condition hangs on multiple mintty/tcsh? Brad Wetmore To: cygwin@cygwin.com References: <1988bd34-7a17-e70f-bf23-0044f30c8687@towo.net> <1193403444.420395.1596669799506@mail.yahoo.com> <3d594543-c992-a22c-4631-f786cf34f76b@towo.net> <20200806142614.GH1107715@calimero.vinschen.de> From: Thomas Wolff X-Tagtoolbar-Keys: D20200806163336780 Message-ID: Date: Thu, 6 Aug 2020 16:33:36 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200806142614.GH1107715@calimero.vinschen.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:fr4alfx/qRs3kR5CFeSiS6io+TdWMlXyNQkozngCzVFtfKXWw2k PIPn9JmzrBia1vYjr8UGcs2MzJZ3iaD+E9575yIN4yopo/4U9kNHwBIy8xD2H9mOklDEeot JeWlU2OU+ZBUPtRkmYniE6G641QvyibSq/4rWWg75mzAi7erolCr7a9P2s39mBC+E4g7qqN AB/XY5KMmtn9UnCKfVifA== X-UI-Out-Filterresults: notjunk:1;V03:K0:G5EN4vNrK7w=:INB+ObdxYp5592OYI15IZ3 ocD6h4cQ5FQDnjzU2TKsWScj5uVTnqaNRR+Euq8y9Q6I9S2RVmB1ZsSbPnSp/W7hFYZBFEHH/ YV2dku+e3LFqeD/b+GPJ40rSN6oT96iqShTU5sqyU3zpzmAdd6RcXbrvBHKYPmOEw0Y5XGgen 4mCg2SuYOFIRQUpGO6h8RQCkdORv0WTyvZPYVAQzq61X5I3y4dL2H85yYPLE+bRffQdifbMh7 k0oH9eSLmec2qaB2qdDHQNRIUKEKs3xK433GewuNjIzWek6coQ+/nef2thT1H/mu0BZG3uY3r RhfIGE2NjzjMR3TfbZcTdbnJfbpy1+c4ievbJR2G68pSokdjcv8gxS5OYfRbzz/ord85wCagq 7KOQUN9sCp0KTHMR8wFyz9m2EkRX7OuKueWhQ+yeXZmBoWZY/5wm2kNfNuBc/FbsIkOlUi9eV TlxX8E5ggV9Xn6pafjbhbBY4UefH+EyaBEfrzHUk+KC74DCa8auGzrkzAcP11ovGncub8Zx6F AIOP0lDPuN6QDOuZrHpJ8r5vsegEBryWUAaffFUeHeHJ6TL1lackX70xBeN35vLOqhKKmEY4I hCDg2/zQSGSiCwr8FyVdnviB06sbJDBkXq7K9+c/fV+aW01lD/vNItAdhZ31ZuV1XzDFLkp3C MepgFmVL7hlm3R0E0Hz+8iY8BgkN5s6JwVfApKe4+MUcP+PMHslkKLJU8OIH+8WDTR0ZMBq1b F0ID/jWjpr4NS5to7sCQOrE3Rucf/yY8PlfTsnmsEmxQ1Fn4k8E7GcQcf5KVg2gYDdsBHZmeh SYtax8OygCZEPYCfM02npEje+IFuENN6lTZT79tVqKBBQI/FkNsAOfrpvBk+Yc5wdYIYIGI X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Aug 2020 14:33:44 -0000 Am 06.08.2020 um 16:26 schrieb Corinna Vinschen: > On Aug 6 15:31, Thomas Wolff wrote: >> Am 06.08.2020 um 13:46 schrieb Thomas Wolff: >>> Am 06.08.2020 um 01:23 schrieb Kevin Schnitzius via Cygwin: >>>> On Wednesday, August 5, 2020, 06:56:48 PM EDT, Thomas Wolff >>>> wrote: >>>>> Am 04.08.2020 um 12:02 schrieb Thomas Wolff: >>>>>> Am 04.08.2020 um 00:13 schrieb Brad Wetmore via Cygwin: >>>>>>> Hi, >>>>>>> >>>>>>> I generally kick off multiple (10) mintty sessions, and place them >>>>>>> around the screen. >>>>>>> >>>>>>> C:/cygwin64/bin/mintty.exe -i /Cygwin-Terminal.ico \ >>>>>> --position @3 --position 120,0 --size 80x71 /bin/tcsh & >>>>>>> C:/cygwin64/bin/mintty.exe -i /Cygwin-Terminal.ico \ >>>>>>> --position @3 --position 715,0 --size 80x45 /bin/tcsh & >>>>>>> C:/cygwin64/bin/mintty.exe -i /Cygwin-Terminal.ico \ >>>>>>> --position @3 --position 715,660 --size 80x24 /bin/tcsh & >>>>>>> >>>>>>> Within the last 6 months or so, about 2-3 of them would hang and >>>>>>> either mintty/tcsh would not start. I put a "sleep 1" in between each >>>>>>> invocation and that seemed to take care of it. >>>>>>> >>>>>>> With the latest cygwin update, about 8 of them just hang even with >>>>>>> the sleep 1. I put in a "sleep 2", and now everything is coming up >>>>>>> again. >>>>>>> >>>>>>> Not sure if this is a mintty or tcsh issue, but just wondering if >>>>>>> others are seeing this before I start trying to debug this. >>>>>> I can reproduce such behaviour with /bin/bash (easy cross-check), and >>>>>> in fact the shell is running in that case (easy test via `echo > >>>>>> .log`), so I have a vague and unpleasant suspicion it might in fact be >>>>>> related to mintty although I have no idea how that would happen. To be >>>>>> analysed. >>>>> When in this state, on the pty from which mintty receives child process >>>>> output, select() does not report a ready for reading condition; >>>>> could it >>>>> be related to the recent poll/select patch? I could not reproduce it in >>>>> cygwin 3.0.7. >>>> for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ; do >>>> mintty  -i /Cygwin-Terminal.ico  --position @3 --position 120,$i >>>> --size 80x24 /bin/bash & done >>>> >>>> This does not fail for me.  Nor does it fail from cmd or powershell >>>> using a script. >>>> >>>> I tried 3.1.4 and 3.1.6 on Windows 10.  I tried up to 100 instances >>>> of of mintty... >>> Thanks for testing. It is in fact hard to reproduce, maybe also >>> depending on system load (speculating). >>> I could reproduce one case of one of three terminals being unresponsive >>> also with xterm. >> And it also happens if I drop select() from mintty (and use just >> non-blocking read()). >>> Does anybody familiar with pty/select or recent changes have any idea? >> ? > Something with the pseudo console? Can you test w/o pseudo console code, just to check? Hmm, CYGWIN=disable_pcon does not seem to disable ConPTY support for me any more... > > Other than that we probably need some bisecting to find the cause.