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From: Ken Brown <kbrown AT cornell DOT edu>
To: "cygwin AT cygwin DOT com" <cygwin AT cygwin DOT com>
Subject: Re: Fork problems on master branch
Date: Sun, 9 Jun 2019 16:51:31 +0000
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On 6/8/2019 3:44 PM, Ken Brown wrote:
> Earlier today I reported on the cygwin-patches list a fork problem with a
> cygwin1.dll built from the master branch of the Cygwin source repo.  See
> https://cygwin.com/ml/cygwin-patches/2019-q2/msg00155.html.  A bisection showed
> that commit f03ea8e1 was the first bad commit for the problem being discussed there.
> 
> I've just run into a second fork problem for which I think the same commit is
> the first bad one.  I can't be positive, because the problem is sporadic, so I
> might have marked some bad commits as good if I didn't run the test enough times.
> 
> The test case for this (attached) is one that I used when testing my new FIFO
> code.  Normally I run this program in one terminal and type
> 
>     echo blah > /tmp/myfifo
> 
> in a second terminal.  For the present purposes, however, you can skip the
> second part and simply terminate fifo_fork_test with C-c.
> 
> In my testing, I found that running the test program would yield "read: Bad
> address" about 1 out of 10 times.  Occasionally I would get "read: Communication
> error on send" instead.  Both error messages indicate a problem with the child
> process reading from an fd inherited from the parent.

Never mind.  This seems to be a bug in my recently added FIFO code.  I just 
never before ran my test many times in a row, so I never saw the error before.

Sorry for the noise.

Ken

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