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Message-ID: <56EB1D2B.4090103@farance.com>
Date: Thu, 17 Mar 2016 17:10:03 -0400
From: Frank Farance <frank@farance.com>
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To: cygwin@cygwin.com
Subject: Re: ctrl-c doesn't reliably kill ping
References: <56E6F25A.7070000@gmx.de>	<56E75B3E.7020102@farance.com>	<54382838.20160315140038@yandex.ru>	<9ee672500661e37c240d30d8413ca0af@mail.kylheku.com>	<56E972EB.9000204@gmail.com>	<CAOC2fq80JudLuzgtg+P-jCG5ZiS0jMNqTE86Tn3ynJm3=6kFSQ@mail.gmail.com>	<f9bfd813b9156f888a1571fb41c3ded5@mail.kylheku.com> <CAD8GWsvgv8e6BmJvximDM5oOKmqR=+EKzrmQXQMNfn612egdug@mail.gmail.com>
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Folks-

Thank you for the thoughtful observations, responses, and suggestions, which I 
will summarize:

- Suggestion #1: Try different DNS settings not using Verizon.
- Suggestion #2: Try different Verizon configuration.
- Suggestion #3: Try Windows version of ping.
- Observation #4: This shouldn't work unless I am administrator (FYI: I've 
configured the cygwin terminal to run as administrator).
- Question #5: Am I running the windows ping?  Answer: Nope, I did "type ping", 
which returned "/usr/bin/ping".

Regarding Verizon, and possibly different settings, my point was not to identify 
flaws in Verizon, I just wanted to give you background on the problem - and I 
believe people understand its nature.  I am well aware of well-known DNS 
servers, such as 8.8.8.8 and 8.8.4.4 -- I am Old School, so I still occasionally 
use the UUNET DNS caches 198.6.1.? to test stuff. :-)

Regarding incompatible ISPs, I believe the program should be robust enough to 
succeed, robust enough to fail, but it shouldn't hang and become non-interruptable.

So from a POSIX compatibility and operating system kernel perspective, I am 
surprised that it is possible to write an application program that gets into an 
non-interruptable state.  In traditional UNIX kernels, it was possible to get 
stuck in a *hard* wait (like local hard drive access), but I don't understand 
how this is possible with ping or any other network application.

Perhaps I don't understand the cygwin signal mechanism and someone can point me 
in the right direction for ping.  Perhaps someone can explain how ping can get 
into this state.

Anyway, as we'd say in standardizing the C programming language, this behavior 
is a "surprise" ... and we should look to eliminate "surprises".

Again, thank you in advance for your help.

-FF


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______________________________________________________________________
Frank Farance, Farance Inc.    T: +1 212 486 4700   M: +1 917 751 2900
mailto:frank@farance.com       http://farance.com
Standards/Products/Services for Information/Communication Technologies

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