fix typo

to give old, deferrred blocks a chance to time-out.  Needed
because if players aren't currently creating new terrain,
old blocks would never get processed, causing the block log
to only grow rather than eventually run dry (which could result
in very long shutdown times).

init.lua

@@ -76,12 +76,18 @@ local rr = tonumber(minetest.settings:get("biome_lib_queue_run_ratio")) or -100
 biome_lib.queue_run_ratio = 100 - rr
 biome_lib.entries_per_step = math.max(-rr, 1)
 
--- timer runs in microseconds, but I want the user to supply a time in seconds
+-- the timer that manages the block timeout is in microseconds, but the timer
-biome_lib.block_timeout = (tonumber(minetest.settings:get("biome_lib_block_timeout")) or 300) * 1000000
+-- that manages the queue wakeup call has to be in seconds, and works best if
+-- it takes a little longer than the block timeout interval.
+
+local t = tonumber(minetest.settings:get("biome_lib_block_timeout")) or 300
+
+biome_lib.block_timeout = t * 1000000
+biome_lib.block_queue_wakeup_time = t * 1.1
 
 local time_speed = tonumber(minetest.settings:get("time_speed"))
 
-biome_lib.plantlife_seed_diff = 329	-- needs to be global so other mods can see it
+biome_lib.plantlife_seed_diff = 329 -- needs to be global so other mods can see it
 
 local perlin_octaves = 3
 local perlin_persistence = 0.6
@@ -556,6 +562,25 @@ minetest.register_globalstep(function(dtime)
 	end
 end)
 
+-- Periodically wake-up the queue to give old blocks a chance to time-out
+-- if the player isn't currently exploring (i.e. they're just playing in one area)
+
+function biome_lib.wake_up_queue()
+	if #biome_lib.block_recheck_list > 0
+	  and #biome_lib.block_log == 0 then
+		-- we move the second element and not the first because we can't be
+		-- sure if the recheck list's first item is the one currently acted upon
+		-- (else it'd be the first item in the main block log)
+		biome_lib.block_log = table.copy(biome_lib.block_recheck_list)
+		biome_lib.block_recheck_list = {}
+		biome_lib.queue_idle_flag = false
+		biome_lib.dbg("Woke-up the map queue to give old blocks a chance to time-out.", 3)
+	end
+	minetest.after(biome_lib.block_queue_wakeup_time, biome_lib.wake_up_queue)
+end
+
+biome_lib.wake_up_queue()
+
 -- Play out the entire log all at once on shutdown
 -- to prevent unpopulated map areas
 
@@ -773,12 +798,18 @@ if biome_lib.debug_log_level >= 3 then
 
 	function biome_lib.show_pending_block_count()
 		if biome_lib.last_count ~= #biome_lib.block_log then
-			biome_lib.dbg("Pending block count: "..(#biome_lib.block_log + #biome_lib.block_recheck_list), 3)
+			biome_lib.dbg(string.format("Pending block counts - ready to process: %-8icurrently deferred: %i",
+				#biome_lib.block_log, #biome_lib.block_recheck_list), 3)
 			biome_lib.last_count = #biome_lib.block_log
 			biome_lib.queue_idle_flag = false
 		elseif not biome_lib.queue_idle_flag then
-			biome_lib.dbg("Mapblock queue only contains blocks that can't yet be processed.",  3)
+			if #biome_lib.block_recheck_list > 0 then
-			biome_lib.dbg("Idling the queue until new mapblocks show up.",  3)
+				biome_lib.dbg("Mapblock queue only contains blocks that can't yet be processed.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive or the next wake-up call occurs.",  3)
+			else
+				biome_lib.dbg("Mapblock queue has run dry.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive.",  3)
+			end
 			biome_lib.queue_idle_flag = true
 		end
 		minetest.after(1, biome_lib.show_pending_block_count)