On 7/10/2018 10:31 AM, David Foster wrote:
Since you're speaking in the past tense and said "but we're not doing it like that", I infer that the notion of a parallel thread was turned down for integration into CPython, as that appears to have been the original goal.
A far as I remember, there was never a formal proposal (PEP). And I just searched PEP 0 for 'parallel'. Hence, no formal rejection, rationale, or thread.
However I am unable to locate a rationale for why that integration was turned down. Was it deemed to be too complex to execute, perhaps in the context of providing C extension compatibility? Was there a desire to see a similar implementation on Linux as well as Windows? Some other reason? Since I presume you were directly involved in the discussions, perhaps you have a link to the relevant thread handy?
As always, there may have been private, off-the-record, informal discussions. -- Terry Jan Reedy