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Re: python reliability with EINTR handling in general modules

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On Wed, 1 Feb 2012 23:25:36 -0800 (PST), oleg korenevich
<void.of.time@gmail.com> wrote:


>Thanks for help. In first case all vars is python integers, maybe
>math.floor is redundant, but i'm afraid that same error with math
>module call will occur in other places of app, where math is needed.
>Strange thing here is that math library call is not a system call, and
>strange exception ValueError (all values have right values) and why in
>braces i have (4, Interruted system call).
>
	math.floor() may still be a system call of some sort if access to
the math processor requires synchronization between processes (that is,
the math processor/registers are maintained as a separate structure
apart from the task status during process switches). {Yes -- that is a
wild hypothesis}

	Or perhaps you haven't enabled the full math support in the runtime
-- from http://uclibc.org/FAQ.html

       >In other cases, uClibc leaves certain features (such as full C99
Math library support, wordexp, IPV6, and RPC support) disabled by
default. 

FYI: uClibc 9.33 has been released -- might be worth checking the change
logs to see if something might apply to the problems.

>For second case: if python really does some slow system call from
>module os, why it doesn't handle EINTR and not restart call. Is
>SA_RESTART flag in signal can be solution? But how i can set this
>flag? By placing flag for signal handler in c extension (or ctypes
>manipulation)?

	Note that it is identifying "firmware" as the system call (If I
understand the nature of the traceback). Is "firmware" a real file
system directory or some virtual entry that translates into scanning the
hardware/ROM for information. (If it isn't obvious, I'm not an OS
internals expert -- though I was able to get around in DEC (Open)VMS
back in the 90s).

	What has me curious is: WHAT signal is being seen that is
interrupting the system call.
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
        wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

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python reliability with EINTR handling in general modules oleg korenevich <void.of.time@gmail.com> - 2012-02-01 06:15 -0800
  Re: python reliability with EINTR handling in general modules Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-02-01 11:07 -0500
    Re: python reliability with EINTR handling in general modules oleg korenevich <void.of.time@gmail.com> - 2012-02-01 23:25 -0800
      Re: python reliability with EINTR handling in general modules Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-02-02 11:34 -0500
        Re: python reliability with EINTR handling in general modules Mel Wilson <mwilson@the-wire.com> - 2012-02-02 14:42 -0500

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