From: Frank Farance <frank@farance.com>
To: cygwin@cygwin.com
Subject: Re: ctrl-c doesn't reliably kill ping
Date: Thu, 17 Mar 2016 21:10:00 -0000 [thread overview]
Message-ID: <56EB1D2B.4090103@farance.com> (raw)
In-Reply-To: <CAD8GWsvgv8e6BmJvximDM5oOKmqR=+EKzrmQXQMNfn612egdug@mail.gmail.com>
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
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next prev parent reply other threads:[~2016-03-17 21:10 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 17:18 ctrl-c doesn't reliably kill applications Björn Stabel
2016-03-14 23:39 ` Kaz Kylheku
2016-03-15 0:46 ` ctrl-c doesn't reliably kill ping Frank Farance
2016-03-15 11:05 ` Andrey Repin
2016-03-15 11:43 ` Adam Dinwoodie
2016-03-16 14:46 ` cyg Simple
2016-03-16 4:56 ` Kaz Kylheku
2016-03-16 11:50 ` Andrey Repin
2016-03-16 14:51 ` cyg Simple
2016-03-16 15:57 ` Michael Enright
2016-03-16 17:33 ` Kaz Kylheku
2016-03-16 18:10 ` Lee
2016-03-17 21:10 ` Frank Farance [this message]
2016-03-17 21:29 ` Marco Atzeri
2016-03-15 15:13 ` Warren Young
2016-03-16 13:25 ` Marco Atzeri
2016-03-17 20:04 ` ctrl-c doesn't reliably kill applications Björn Stabel
2016-04-18 21:38 ` Aaron Digulla
2016-04-19 9:13 ` Corinna Vinschen
2016-04-19 16:30 ` Aaron Digulla
2016-03-16 16:07 ` ctrl-c doesn't reliably kill ping Lee
2016-03-16 16:50 ` Warren Young
2016-03-16 17:52 ` Lee
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