Concurrent issue with Industrial Upgrade

[coco875]

Describe the bug
Softlock

To Reproduce
Steps to reproduce the behavior:

1. have c2me, industrial upgrade (and chunky to help provocate the softlock)
2. generate chunk
3. see that it no longer generate

Expected behavior
that it work normally

Runtime info (please complete the following information):

• OS: Linux
• Minecraft version: 1.21.1
• Mod version: 0.3.0+alpha.0.88

Crash reports / logs
https://mclo.gs/JiaBBVM

Other mods
Industrial Upgrade

Checklist

• I am using the official version of the mod.
• I tried the latest development version but the issue persists.
• I searched for similar open issues and could not find an existing bug report on this.

Additional context
ZelGimi/industrialupgrade#200

[ishland]

Not our issue. The whole worldgen process assumes that no modifications are made to globally visible state, and chunks outside of the write radius.

They will have to remove all globally mutable state from their worldgen code, such as these and this, and pass the around in some other ways.

[ZelGimi]

Crash occurs in a stage

[ZelGimi]

error here:

Default ore generation from Minecraft (there is no error):

[ishland]

As explained, all globally mutable state must be removed for it to work.

[InitAuther97]

Crash occurs in a stage

These are likely not to fail if the code has respected Vanilla chunk write radius for FEATURE stage (which is 1, and after me checking, writing to a radius of 12 at any position should be fine).
In Vanilla, feature placement is run on a single worker thread. C2ME makes all stages concurrent and involves thread-safe concerns for the code. We have manually guaranteed that Vanilla code is working correct.
I do notice that some static collections are involved in feature placement process.It is necessary to make these collections thread-safe. Otherwise, in a multi-threaded environment, the result is pretty unpredictable.