Async environment for mods to do concurrent tasks (#11131)

builtin/async/game.lua

@@ -0,0 +1,46 @@
+core.log("info", "Initializing asynchronous environment (game)")
+
+local function pack2(...)
+	return {n=select('#', ...), ...}
+end
+
+-- Entrypoint to run async jobs, called by C++
+function core.job_processor(func, params)
+	local retval = pack2(func(unpack(params, 1, params.n)))
+
+	return retval
+end
+
+-- Import a bunch of individual files from builtin/game/
+local gamepath = core.get_builtin_path() .. "game" .. DIR_DELIM
+
+dofile(gamepath .. "constants.lua")
+dofile(gamepath .. "item_s.lua")
+dofile(gamepath .. "misc_s.lua")
+dofile(gamepath .. "features.lua")
+dofile(gamepath .. "voxelarea.lua")
+
+-- Transfer of globals
+do
+	assert(core.transferred_globals)
+	local all = core.deserialize(core.transferred_globals, true)
+	core.transferred_globals = nil
+
+	-- reassemble other tables
+	all.registered_nodes = {}
+	all.registered_craftitems = {}
+	all.registered_tools = {}
+	for k, v in pairs(all.registered_items) do
+		if v.type == "node" then
+			all.registered_nodes[k] = v
+		elseif v.type == "craftitem" then
+			all.registered_craftitems[k] = v
+		elseif v.type == "tool" then
+			all.registered_tools[k] = v
+		end
+	end
+
+	for k, v in pairs(all) do
+		core[k] = v
+	end
+end