3 Memory use optimisations for Lua mapgens

[Festus1965]

I am very sorry,
i struggle with the OOM crash actually read the solutions but dont get sure about before and after!

like the example from here
is it before (i found) Source technic_worldgen/oregen.lua:
changed again and now this 2 lines like shown ... miss understand first, but wondering why "data" instead of "sulfur_buf"
got now better understand and changed, not tested yet.

[BuckarooBanzay]

@paramat am i doing this right?: https://github.com/minetest-mods/technic/pull/484/files

[Kurtzmusch]

what happens when you try to recycle the buffers but the engine is set to generate maps with more than 1 emerge threads? should i make a buffer per thread or will the c++ threads take turns in calling my on_generated? sofar once said that lua is single-threaded, but isnt it possible for the engine to spawn 2 lua instances? if the threads do take turns to call on_generated doesnt this mean that a lua mapgen will be 2 to 4 times slower?( considering that most processors are duo or quad core)

[sfan5]

what happens when you try to recycle the buffers but the engine is set to generate maps with more than 1 emerge threads? [...]

Nothing, your Lua code does not have to concern itself with this.

if the threads do take turns to call on_generated doesnt this mean that a lua mapgen will be 2 to 4 times slower?( considering that most processors are duo or quad core)

That's a weird way to put it, but it's technically true since Lua is single-threaded.