Doc tests action takes too long

[Privat33r-dev]

Issue

Usually doctest's action's [Run documentation doctest¹ job takes around 12 minutes² to execute. Most of this time is taken by the internal framework doctest.py³. The issue is caused by unparallelized execution of tests.

Solution

Since the tests are not interconnected (between different doc files), they can be easily parallelized. I suggest using ProcessPoolExecutor that will be suitable to "bypass" GIL (assuming that tasks are CPU-bound). Github runners have 4 cores available⁴, so, potentially, it can speed up execution by up to 4 times.

@AlexWaygood @erlend-aasland

Footnotes

1. https://github.com/python/cpython/blob/7ac933e2609b2ef9b08ccf9c815b682b0e1ede2a/.github/workflows/reusable-docs.yml#L108 ↩

2. https://github.com/python/cpython/actions/runs/8922903843/job/24506021604 ↩

3. https://github.com/python/cpython/blob/main/Lib/doctest.py ↩

4. https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories ↩

[erlend-aasland]

Sounds good; do you have a PR ready? :)

[Privat33r-dev]

I was waiting for a feedback because I might've missed something :) My schedule is a bit tight lately, but I will try to find a time to implement it (hopefully in a week or two).