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Subject: Re: Problem with zombie processes
To: cygwin AT cygwin DOT com
References: <CAOTD34bHSDJErA0B8Qt8Zqi54ciV5ZpRJdTa_pGs9Mp2PERsuw AT mail DOT gmail DOT com> <58A3598F DOT 2020405 AT maxrnd DOT com> <CAOTD34Z7VM=6=Ss_gCLS97c4sFNpnaT-+RgJq+xme-VyWYbbpw AT mail DOT gmail DOT com>
From: Mark Geisert <mark AT maxrnd DOT com>
Message-ID: <58A773C9.1080905@maxrnd.com>
Date: Fri, 17 Feb 2017 14:06:01 -0800
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Erik Bray wrote:
> On Tue, Feb 14, 2017 at 8:25 PM, Mark Geisert <XXXX AT XXXXXX DOT XXX> wrote:

Please don't quote raw email addresses.  We try to avoid feeding spammers.

>> Erik Bray wrote:
>>>
>>> The attached Python script
>>
>> ??
>
> D'oh!  Here is the script.  It at least demonstrates the problem.
>
[...]

Thanks!  Running this script repeatedly on my system (Win7, 2 cores / 4 HT 
threads) showed no differences between your Test 1 and Test 2.  Each Test 
concludes in one of three ways, seemingly randomly: (1) read of /proc/<pid>/stat 
succeeds and process status is displayed, (2) read fails with Python IOError, 
(3) read apparently succeeds but there's no process data displayed.

An strace of your script shows Python itself is calling wait4() to reap the 
child process.  So, as Doug suggested on another thread, the script's actions 
are just subject to the whims of process scheduling and vary from run to run.

..mark




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