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Re: Signal SIGINT ignored during socket.accept

From Marko Rauhamaa <marko@pacujo.net>
Newsgroups comp.lang.python
Subject Re: Signal SIGINT ignored during socket.accept
Date 2015-09-11 17:00 +0300
Organization A noiseless patient Spider
Message-ID <87k2rxqcn5.fsf@elektro.pacujo.net> (permalink)
References (2 earlier) <msskh1$j00$1@dont-email.me> <mailman.337.1441913195.8327.python-list@python.org> <msso49$28e$1@dont-email.me> <mailman.348.1441936893.8327.python-list@python.org> <msum6c$hv$1@reader1.panix.com>

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Grant Edwards <invalid@invalid.invalid>:

> On 2015-09-11, Chris Angelico <rosuav@gmail.com> wrote:
>> This is what I meant when I said you would be polling. Effectively,
>> you wake up your program every half-second, check if Ctrl-C has been
>> pressed, and if it hasn't, you go back to sleep again. This is pretty
>> inefficient.
>
> Though it offends one's engineering sensibilities[1], it's just not
> that inefficient. I'd bet money you won't even be able to measure the
> difference in CPU usage. Waking up twice per second and immediately
> calling select() again on any hardware/OS built in the past 50 years
> is going completely negligible (as long as you can ignore the smell).
>
> Even waking up ten times per second won't be noticeable.
>
> Waking up every millisecond or two might be noticeable.

It can add up. In particular, it can prevent the CPU from staying in the
low-power mode, especially on battery-powered devices.

  <URL: https://lwn.net/Articles/549580/>

Another environment where such polling circuses can actually overwhelm a
CPU is virtual machines. When dozens or hundreds of VMs are each polling
left and right, the host may not get much actual work done.


Marko

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Thread

Signal SIGINT ignored during socket.accept "James Harris" <james.harris.1@gmail.com> - 2015-09-10 19:24 +0100
  Re: Signal SIGINT ignored during socket.accept Chris Angelico <rosuav@gmail.com> - 2015-09-11 04:36 +1000
    Re: Signal SIGINT ignored during socket.accept "James Harris" <james.harris.1@gmail.com> - 2015-09-10 20:11 +0100
      Re: Signal SIGINT ignored during socket.accept Chris Angelico <rosuav@gmail.com> - 2015-09-11 05:26 +1000
        Re: Signal SIGINT ignored during socket.accept "James Harris" <james.harris.1@gmail.com> - 2015-09-10 21:12 +0100
          Re: Signal SIGINT ignored during socket.accept Chris Angelico <rosuav@gmail.com> - 2015-09-11 12:01 +1000
            Re: Signal SIGINT ignored during socket.accept Grant Edwards <invalid@invalid.invalid> - 2015-09-11 13:50 +0000
              Re: Signal SIGINT ignored during socket.accept Marko Rauhamaa <marko@pacujo.net> - 2015-09-11 17:00 +0300
              Re: Signal SIGINT ignored during socket.accept Chris Angelico <rosuav@gmail.com> - 2015-09-12 00:27 +1000
              Re: Signal SIGINT ignored during socket.accept "James Harris" <james.harris.1@gmail.com> - 2015-09-11 18:14 +0100
                Re: Signal SIGINT ignored during socket.accept "James Harris" <james.harris.1@gmail.com> - 2015-09-12 00:15 +0100

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