Using contextvars in local.py?

[akx]

I noticed local.py has a comment saying

asgiref/asgiref/local.py

Lines 29 to 30 in a90aeb9

	This doesn't use contextvars as it needs to support 3.6. Once it can support
	3.7 only, we can then reimplement the storage more nicely.

which is at odds with the changelog entry for 3.7.0 of this library:

asgiref/CHANGELOG.txt

Lines 14 to 18 in a90aeb9

	3.7.0 (2023-05-23)
	------------------
	* Contextvars are now required for the implementation of Local as Python 3.6
	is now no longer a supported version.

(I noticed sync.py uses contextvars.Context, but local.py doesn't. Maybe there was confusion there?)

Either way, what would be the "nicer storage"? Is someone working on it? :)

[andrewgodwin]

Yeah, we switched sync to use it, but not Local yet. I don't think anyone is actively working on it.

[bluetech]

I looked at this briefly some time ago when looking at Local's performance. IIRC (and I might be misremembering), the difficulty was that contextvars is rooted in a thread local, while Local can be inherited across threads. The semantics are quite different.

[spanezz]

Unless I'm missing something, this seems to be done in d920c3c

However, #473 might be relevant here

[andrewgodwin]

It was indeed done - I will close this as a result, we'll discuss the ramifications elsewhere.