Date: Fri, 21 Dec 2012 14:36:20 -0500
From: Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Intermittent failures retrieving process exit codes - snapshot test requested
Message-ID: <20121221193620.GA29203@ednor.casa.cgf.cx>
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On Fri, Dec 21, 2012 at 06:02:19PM +0100, Corinna Vinschen wrote:
>On Dec 21 11:10, Christopher Faylor wrote:
>> On Fri, Dec 21, 2012 at 11:32:41AM +0100, Corinna Vinschen wrote:
>> >Maybe the signal thread should really not exit by itself, but just
>> >wait until the TerminateThread is called.  Chris?
>> 
>> If the analysis is correct, that just fixes one symptom doesn't it?
>> There are potentially many threads running in any Cygwin program
>> and it sounds like any one of them could trigger this.
>
>Right.  I guess the question is how to synchronize things so that the
>thread calling TerminateProcess is actually the last one, making sure
>its return value is used.
>
>Maybe the NtQueryInformationThread(ThreadAmILastThread) call is of some
>help.  Or we have to keep all thread IDs of the self-started threads
>available to terminate them explicitely at process exit.

I checked in a complicated fix for this problem which only affected
Cygwin-created threads.  But, then, I thought about another riskier but
simpler fix.  That version is now in CVS and I'm generating a new
snapshot with it.

I tested this lightly on Windows 7 and 32-bit XP but it would be nice to
hear if multi-threaded things like X work on other platforms too.

If you test a snapshot, note that I'm still tracking down Ken Brown's
reporte emacs regression in recent snapshots so that will still be
broken.

cgf

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