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Re: Odd hang in python waiting for child; strace wakes hung process?
- From: Brian Inglis <Brian dot Inglis at SystematicSw dot ab dot ca>
- To: cygwin at cygwin dot com
- Date: Wed, 21 Mar 2018 23:41:07 -0600
- Subject: Re: Odd hang in python waiting for child; strace wakes hung process?
- References: <CAPF-yOYzTr-jh__S_imaAcdk5Vf4tGD1xFLuTDu4-qsg_+HiCA@mail.gmail.com> <877eq5fedf.fsf@Rainer.invalid> <CAPF-yOb8O+Xhp3yi9wGFFJDvrSA0W24LZ+1adAcga--H7=qaZw@mail.gmail.com>
- Reply-to: Brian dot Inglis at SystematicSw dot ab dot ca
On 2018-03-21 16:07, Dan Kegel wrote:
> On Wed, Mar 21, 2018 at 11:54 AM, Achim Gratz <Stromeko@nexgo.de> 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?
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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