Author Bharatsolanki
Recipients Bharatsolanki, eric.smith, tim.peters
Date 2020-03-19.06:51:52
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In-reply-to <1584564938.32.0.139491584701.issue40005@roundup.psfhosted.org>
Content
Hi Tim,

Thank you for clearing that up.

I ran the same code in 2.7 and 3.7 on Windows, Its showing the same error.
Yes, Its running in Linux-y systems. It depends on OS.

Regards,
Bharat

On Thu, Mar 19, 2020 at 2:25 AM Tim Peters <report@bugs.python.org> wrote:

>
> Tim Peters <tim@python.org> added the comment:
>
> u1 is a global _only_ in a process that runs `function()`, which declares
> u1 global and assigns it a value.  You have no sane expectation that a
> worker process (none of which run `function()`) will know anything about it.
>
> Are you sure you're running 2.7 and 3.7 on the same machine?  It's
> impossible that this code ever "worked" under Windows, but it might under
> Linux-y systems, which use `fork()` to create worker processes.
>
> The traceback you showed was obviously run under Windows.  Under Python
> 2.7.11 on Windows, I get the same kind of error:
>
> NameError: global name 'u1' is not defined
>
> This is the code:
>
> from multiprocessing import Pool
> import traceback
>
> class Utils:
>     def __init__(self):
>        self.count = 10
>
> def function():
>     global u1
>     u1 = Utils()
>     l1 = range(3)
>     process_pool = Pool(1)
>     try:
>         process_pool.map(add, l1, 1)
>         process_pool.close()
>         process_pool.join()
>     except Exception as e:
>         process_pool.terminate()
>         process_pool.join()
>         print(traceback.format_exc())
>         print(e)
>
> def add(num):
>      total = num + u1.count
>      print(total)
>
> if __name__ == "__main__":
>     function()
>
> ----------
> nosy: +tim.peters
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue40005>
> _______________________________________
>
History
Date User Action Args
2020-03-19 06:51:53Bharatsolankisetrecipients: + Bharatsolanki, tim.peters, eric.smith
2020-03-19 06:51:53Bharatsolankilinkissue40005 messages
2020-03-19 06:51:53Bharatsolankicreate