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:reply-to:subject:to:references:from:message-id :date:mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=PObXujsyC6M1uMjN T1Ri2JIwNMGZ82g9+vz8v3BtBDPxt5qLVujfWHYo4HlxPOvn5XIrrQT1RQxqr/qZ ZEIp8nN+A8nAobQtS2/Okzee11AvExuciksuxX9hgLc6F7DzYsIHdGXnllPGtdm9 oHE3bbA4wwW01lbXGhvKaUHYvpY= 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:reply-to:subject:to:references:from:message-id :date:mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=d0UduuGJYc4qrScsJMCDtm NO/UE=; b=FnM4o92TimffMf3rGw2lYHMQIx80Ll3DH2bIcx97rydg7RCvbioDeX /8fgJ/Sgf/GOaIyyFVDAAKQ0Q+E1IEKh1+OuUem+vdb/8TJ0U1MP6S3rPcEpFz/v cbemRIis3sJhNH6qoD5K0wWJn7fIt5Q6P+bu28Cg2+40oj6tjVkY4= Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , 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-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy=canada, Canada, calgary, SYSTEM X-HELO: smtp-out-no.shaw.ca X-Authority-Analysis: v=2.3 cv=Tai4SyYh c=1 sm=1 tr=0 a=MVEHjbUiAHxQW0jfcDq5EA==:117 a=MVEHjbUiAHxQW0jfcDq5EA==:17 a=IkcTkHD0fZMA:10 a=Yiq6MpJl8BZHHIEplY4A:9 a=QEXdDO2ut3YA:10 Reply-To: Brian DOT Inglis AT SystematicSw DOT ab DOT ca Subject: Re: Odd hang in python waiting for child; strace wakes hung process? To: cygwin AT cygwin DOT com References: <877eq5fedf DOT fsf AT Rainer DOT invalid>

<20180322165908 DOT GI6761 AT calimero DOT vinschen DOT de> <20180325102422 DOT GC14026 AT calimero DOT vinschen DOT de> From: Brian Inglis Message-ID: <721b2e8a-96e5-647e-022e-c9c42f1f8363@SystematicSw.ab.ca> Date: Sun, 25 Mar 2018 12:11:56 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180325102422.GC14026@calimero.vinschen.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfA2M8z18tyHBIGuqWd4RJNYx19ND5KhYp6fHFA207dBK6HUUu9ENtw9KXNFxHd9dcE1nWOqDP1WVmRfa6tnH/pBLM5IuT4imqJoeCuvS703CyQLN+bQq 7E0rlHrWjva1uuH1dkJmHuUss5PTQC3tYCx/wZnc2as6VVloxk/OMH3k/oQ3eXGJQXoypiF+CoiGGQ== X-IsSubscribed: yes On 2018-03-25 04:24, Corinna Vinschen wrote: > On Mar 23 19:21, Brian Inglis wrote: >> On 2018-03-22 10:59, Corinna Vinschen wrote: >>> On Mar 21 23:41, Brian Inglis wrote: >>>> On 2018-03-21 16:07, Dan Kegel wrote: >>>>> On Wed, Mar 21, 2018 at 11:54 AM, Achim Gratz wrote: >>>>>> Well, with the sporadic hanging/defunct processes at work my routine is >>>>>> to send CONT to all Cygwin processes, then HUP/KILL to anything that's >>>>>> still not live or gone and then another round of CONT. This works >>>>>> _most_ of the time, anything more stubborn I /bin/kill -f usually. >>>>> >>>>> Since I wrote, both bots hung again. This time I verified: >>>>> 0) both had the defunct git process as expected >>>>> 1) kill -CONT the-pid doesn't do anything, nor does kill -9. It's truly wedged. >>>>> 2) the process stays in its spin hang until you ^C strace -p the-pid >>>>> 3) ^C-ing the strace causes the process to terminate (strace alone doesn't) >>>>> 4) taskkill /pid the-task /f also kills the process successfully. >>>>> >>>>> So I could write a script that watched for defunct git processes >>>>> and taskkilled their parent. Build jobs would fail, but at least >>>>> the bot would stay up. Of course it would be much nicer if >>>>> the cygwin python process didn't get wedged. >>>>> >>>>> Alternately, I suppose I could try running native python... >>>>> or cygwin's python3... but dangit, kill -9 should work. >>>> >>>> Seems to be looping on access failure to a Windows mailslot; not sure what this >>>> feature is normally used for: dmesg/syslog messages/AF_UNIX sockets? >>> >>> /dev/kmsg is implemented using a mailslot under the hood. This >>> feature is only used to log exceptions and for nothing else since >>> nobody ever found another reason to use it for. >>> >>> It would be interesting to learn if the perl hangs have the same reason. >>> >>> I guess we can simply remove /dev/kmsg support completely and drop >>> the mailslot code. I'm pretty sure nobody would miss it. Hardly >>> anybody knows it exists... >> >> Is /dev/log implemented the same way? > > No. /dev/log is a AF_UNIX socket. > >> Looks like syslog-ng stopped working around the last upgrade: >> >> $ cat /var/log/syslog-ng.log >> Error reading serialized data; error='Error reading file (short read)' >> Persistent configuration file is in invalid format, ignoring; >> Error binding socket; addr='AF_UNIX(/dev/log)', error='Address already in use (112)' > > rm -rf /dev/log $ ll /dev/log && /bin/rm -f /dev/log && ll /dev/log -rw-rw-rw- 1 SYSTEM SYSTEM 54 Nov 24 20:59 /dev/log ls: cannot access '/dev/log': No such file or directory [start services] $ cyg-srv-status.sh cron Running cygserver Running sendmail Running sshd Running syslog-ng Running Thank you very much! -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada -- 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