bpo-34060: Report system load when running test suite for Windows

[ammaraskar]

See the bpo ticket for more technical details on the implementation and otherwise.

https://bugs.python.org/issue34060

[jkloth]

A quick note on the LOADAVG_FACTOR_1F and SAMPLING_INTERVAL; that given dampening factor is for a sample rate of 5 seconds. SAMPLING_INTERVAL should really be changed to 5 or re-run the equation with the different interval.

[ammaraskar]

Thanks again Jeremy, I changed the interval to 5 to be more in line with the Linux scheduler.

[vstinner]

Please move the assignment on a separated line. Same comments for other assignments in if().

[vstinner]

Hum. It seems like you allocate a resource, but never release it.

I would suggest to create an object which keeps track of these resources and release them later. getloadavg() would be a method of that object.

[ammaraskar]

Would it be acceptable to do it in the module's m_free function? I was initially thinking of doing something similar but thought that would create a lot of extra code and complexity for an internal API with one use case.

[vstinner]

I dislike using m_free() for that.

[ammaraskar]

Also, I don't think this actually needs a NEWS entry right? It relates to cpython build process and doesn't actually affect the language. Could you mark it with the skip news label if so?

[zooba]

What extra runtime dependencies does this add to python38.dll (use dumpbin /imports python38.dll and grab the DLL filenames)?

Also, winapi methods are public, if undocumented (since they are supposed to reflect the Windows API calls directly, so that documentation should suffice). If you really want an internal test suite helper it should go in its own extension module with a _ prefix.

(Haven't looked too closely at the implementation yet, but when I do, it will be with the view that it is a public API change. Unless you rework it into its own module first.)

[zooba]

(Edited above post). Let me take that back - was thinking of winreg module, not the _winapi module. But it still should be treated as a publicly usable API with all the robustness guarantees unless it's in its own module, since it will be used.

[ammaraskar]

Aah yeah I think you have a good point, _winapi despite being undocumented is being consumed by end users https://github.com/search?p=1&q=import+_winapi&type=Code

I think making it its own module would be a bit overkilll so I'll clean up the API anticipating some public usage.

[ammaraskar]

Closed in favor of #8357

Thank you @csabella 😄