FYI In the PEP 540, I didn't try to elaborate on each design change, but I
wrote a very short version history at the end:
https://www.python.org/dev/peps/pep-0540/#version-history
Maybe something like that would help for the PEP 567?
Victor
Le 17 janv. 2018 8:26 PM, "Guido van Rossum" <gvanros...@gmail.com> a
écrit :
> Perhaps you can update the PEP with a summary of the rejected ideas from
> this thread?
>
> On Jan 17, 2018 7:23 AM, "Yury Selivanov" <yselivanov...@gmail.com> wrote:
>
>> On Wed, Jan 17, 2018 at 6:03 AM, Antoine Pitrou <solip...@pitrou.net>
>> wrote:
>> > On Tue, 16 Jan 2018 17:18:06 -0800
>> > Nathaniel Smith <n...@pobox.com> wrote:
>> >> On Tue, Jan 16, 2018 at 5:06 PM, Yury Selivanov <
>> yselivanov...@gmail.com> wrote:
>> >> >
>> >> > I think it would be a very fragile thing In practice: if you have
>> even
>> >> > one variable in the context that isn't pickleable, your code that
>> uses
>> >> > a ProcessPool would stop working. I would defer Context
>> pickleability
>> >> > to 3.8+.
>> >>
>> >> There's also a more fundamental problem: you need some way to match up
>> >> the ContextVar objects across the two processes, and right now they
>> >> don't have an attached __module__ or __qualname__.
>> >
>> > They have a name, though. So perhaps the name could serve as a unique
>> > identifier? Instead of being serialized as a bunch of ContextVars, the
>> > Context would then be serialized as a {name: value} dict.
>>
>> One of the points of the ContextVar design is to avoid having unique
>> identifiers requirement. Names can clash which leads to data being
>> lost. If you prohibit them from clashing, then if libraries A and B
>> happen to use the same context variable name—you can't use them both
>> in your projects. And without enforcing name uniqueness, your
>> approach to serialize context as a dict with string keys won't work.
>>
>> I like Nathaniel's idea to explicitly enable ContextVars pickling
>> support on a per-var basis. Unfortunately we don't have time to
>> seriously consider and debate (and implement!) this idea in time
>> before the 3.7 freeze.
>>
>> In the meanwhile, given that Context objects are fully introspectable,
>> users can implement their own ad-hoc solutions for serializers or
>> cross-process execution.
>>
>> Yury
>> _______________________________________________
>> Python-Dev mailing list
>> Python-Dev@python.org
>> https://mail.python.org/mailman/listinfo/python-dev
>> Unsubscribe: https://mail.python.org/mailman/options/python-dev/guido%
>> 40python.org
>>
>
> _______________________________________________
> Python-Dev mailing list
> Python-Dev@python.org
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: https://mail.python.org/mailman/options/python-dev/
> victor.stinner%40gmail.com
>
>
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
