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Author Simon Biggs
Recipients Simon Biggs, pmpp, serhiy.storchaka, xtreak
Date 2020-04-14.12:39:08
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Hi pmp-p and Serhiy,

I'd be more than happy to attempt a pull request, but I imagine a change
such as this needs to be discussed first, trying not to "rush to make a
patch" (
Also, I doubt I will do a good job of it... but I am more than happy to try.

A note regarding "supercharged full stack pyodide", potentially without
efforts such as upstreaming into CPython and emscripten the relevant
patches, that supercharged full stack may just unfortunately stagnate. See

With respect to blocking when running Python as WASM, I have found running
the WebAssembly CPython within a webworker and signalling data back and
forth causes there to be no UI issues. It ends up being quite a neat set
up. Main down side right now however is the set up is currently going
stale, hence me believing reaching out like this is in the best interests
of Python going forward.


On Tue, 14 Apr 2020 at 18:58, pmp-p <> wrote:

> pmp-p <> added the comment:
> you can add
> *
> -- Python 3.8.x
> (wasm not asm.js, clang-10+ required)
> demo
> CPython can already run in the browser with very little patching, but
> major issues are :
>  - asyncify'ing the whole wasm VM to have pre-emption over cPython's one
> to prevent blocking I/O slows down things *a lot* (10x)
> => (very?) bad user experience.
>  - the size of vm + stdlib  ~ 30 MiB and wasm compilation time.
> => bad user experience on first load or slow connexion.
>  - the lack of threading in wasm MinimumViableProduct specification (but
> this is the browser standard for now), that leads to rewrite bits of stdlib
> ( like eg asyncio module )
> => adding more maintenance burden on stdlib (!)
> i tested them all and my personnal opinion is : I can see no use case that
> would favour "stock" cPython wasm versus a blazing fast MicroPytho (or
> pycopy) wasm flavour or supercharged full stack pyodide.
> ----------
> nosy: +pmpp
> _______________________________________
> Python tracker <>
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Date User Action Args
2020-04-14 12:39:08Simon Biggssetrecipients: + Simon Biggs, pmpp, serhiy.storchaka, xtreak
2020-04-14 12:39:08Simon Biggslinkissue40280 messages
2020-04-14 12:39:08Simon Biggscreate