[Python-Dev] SIGCHECK() in longobject.c (original) (raw)

Mark Dickinson dickinsm at gmail.com
Sun Oct 18 22:08:27 CEST 2009

On Sun, Oct 18, 2009 at 9:01 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:

In Objects/longobject.c, there's the SIGCHECK() macro which periodically checks for signals when doing long integer computations (divisions, multiplications). It does so by messing with the PyTicker variable.

It was added in 1991 under the title "Many small changes", and I suppose it was useful back then. However, nowadays long objects are ridiculously fast, witness for example: $ ./py3k/python -m timeit -s "a=eval('3'*10000+'5');b=eval('8'*6000+'7')" "str(a//b)" 1000 loops, best of 3: 1.47 msec per loop Can we remove this check, or are there people doing million-digits calculations they want to interrupt using Control-C ?

Yes, I suspect there are. Though you don't need millions of digits for a single operation to take a noticeable amount of time: try str(10**100000), for example.

Is there a benefit to removing the check?

Mark

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