fix flood lights te issues

[Pilzinsel64]

After a long time of mysterious errors we were finally able to reproduce the issues and finally fix them. Not sure if the code here is best-practice, so feel free to correct me.

From the commit message:

• This can happen probably because the new TE will not be created fast enough after we set the block (or whatever).
• This fix finally works on our production server.
• It also fixes a ConcurentModificationException by using a copy of the actual sources list while it can be updated at updateAllSources

[wlhlm]

Do you know what causes the CME? What are the different threads accessing sources in parallel here? ArrayList.addAll() is not thread-safe either, you can still run into CMEs during that. I feel like some synchronization is necessary if parallel access is unavoidable.

[Cardinalstars]

Is this going to work between server and client? As far as I understand using world.setTileEntity needs to have something special to go along with it when updating the tile entity in the description packet (because I can't remember if the descriptionPacket will create the tileEntity if it doesn't exist on the client side). I need to look into this more later when I get home. Also, I'm not sure if this code runs on server and client.

[Pilzinsel64]

Do you know what causes the CME

@wlhlm There are two possible sources. One is the due setTileEntity call I added and another one is at RemoveTileEntity.

Both are called after I clone the list. I just want to iterate a local copy of the state of before.

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Is this going to work between server and client?

@Cardinalstars It works between server and client, yes. Tested this mainly on server my private prod and also on a backup server.

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The main reason why I made it like it is is just that after setBlock the TileEntity isn't available yet (which leads to an "Can not cast to XXX error" at this point) and I need a quick fix for the prod server. Feel free to suggest a better way (or make a better fix, I'm just developing on MC mods / with Java casual).

[Pilzinsel64]

Closing this as the main issue seems to still be present. God I hate that ...

The main issue seems to be that Ender IO lights and Flood Lights are incompatible with each other. Means, if you place a EIO light in the near of a Flood light, you will get a server crash at some point. Both want to spread out their light TEs and both overwrite each other on loading the chunk.

Also, in combination with a light on the edge of a chunk, it crashes too.

I'm going to make a bug report as soon as I got a fully reproduceable example. Someone else need to get into this, this is absolutely out of my scope due missing time.