Are min() and max() thread-safe?

Hendrik van Rooyen hendrik at
Thu Sep 17 14:34:28 CEST 2009

On Thursday 17 September 2009 12:57:18 Carl Banks wrote:
> On Sep 17, 2:18 am, Hendrik van Rooyen <hend... at>
> wrote:

> When running min or max on a list of ints, there is probably no
> occasion for the function to release the GIL.  If a thread doesn't
> release the GIL no other Python threads can run.  This behavior may be
> rotten, but it's totally expected.

The lack of concurrency was not what I was complaining about,  but the second 
case that just quietly freaked out when I made the list of ints large.

I have subsequently seen that it is red herring in this context though, as it 
is some memory problem - the crash  comes during the list creation, and has 
nothing to do with the min/max processing.  One can demo it by simply trying 
to create a big list at the interactive prompt, and after a while you get 
the "Killed" message.

a = range(100000000)   does it for me on my machine.

- Hendrik

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