Async all the things that were blocking.

[gwww]

Remove blocking errors that are showing up in Home Assistant. See home-assistant/core#119084

[bdraco]

Note that Home Assistant only checks for open calls, once you find one, please make sure all the read/writes that happen after the open call are also happening in the executor since Home Assistant never checks read/write calls and you will likely never find them again otherwise (and the problem will be much harder to find).

[gwww]

Is there an way to tell if read/writes are happening? This code is buried deep in the pillow library - hard to know where reads might be happening. Trying to brut force it at the moment looking through code.

[gwww]

Switched to draft PR until can figure out read/writes.

[bdraco]

strace is usually the best way to verify if a read or write syscall is happening and in which thread

[gwww]

A few more changes to encapsulate all the PIL calls. While this looks like a big change it is mostly just moving blocks of code around and so that the PIL call could all be put into a single function that is run_in_executor.

[gwww]

I've consolidated all the run_in_executor calls down to 2. I'd get rid of the last one but the code complexity is risky for (at least me) to change.

Really, really ready for review! Thanks for your comments @bdraco! Super helpful!

[bdraco]

Looks like its async safe now 👍

At least I don't see anything obvious that is a problem, but its always hard to tell without doing the strace to see where the I/O happens if you don't know all the code in the underlying library (PIL), which I don't

[michaeldavie]

Thanks @gwww!