Moves adjacent air into the main atmos subsystem (#64559)

We should just straight up not be processing turfs if the adjacent turf
isn't correctly setup

It used to be on a seperate subsystem with a second wait with the idea
of reducing the cost of explosions, but since they're instant now
there's no reason to not just have it on SSair. Gets rid of my excuse
for process_cell runtimes too

code/controllers/subsystem/adjacent_air.dm

@@ -1,41 +0,0 @@
-SUBSYSTEM_DEF(adjacent_air)
-	name = "Atmos Adjacency"
-	flags = SS_BACKGROUND
-	runlevels = RUNLEVEL_GAME | RUNLEVEL_POSTGAME
-	wait = 10
-	priority = FIRE_PRIORITY_ATMOS_ADJACENCY
-	var/list/queue = list()
-
-/datum/controller/subsystem/adjacent_air/stat_entry(msg)
-#ifdef TESTING
-	msg = "P:[length(queue)], S:[GLOB.atmos_adjacent_savings[1]], T:[GLOB.atmos_adjacent_savings[2]]"
-#else
-	msg = "P:[length(queue)]"
-#endif
-	return ..()
-
-/datum/controller/subsystem/adjacent_air/Initialize()
-	while(length(queue))
-		fire(mc_check = FALSE)
-	return ..()
-
-/datum/controller/subsystem/adjacent_air/fire(resumed = FALSE, mc_check = TRUE)
-
-	var/list/queue = src.queue
-
-	while (length(queue))
-		var/turf/currT = queue[1]
-		var/goal = queue[currT]
-		queue.Cut(1,2)
-
-		currT.immediate_calculate_adjacent_turfs()
-		if(goal == MAKE_ACTIVE)
-			SSair.add_to_active(currT)
-		else if(goal == KILL_EXCITED)
-			SSair.add_to_active(currT, TRUE)
-
-		if(mc_check)
-			if(MC_TICK_CHECK)
-				break
-		else
-			CHECK_TICK

code/controllers/subsystem/air.dm

@@ -17,6 +17,7 @@ SUBSYSTEM_DEF(air)
 	var/cost_pipenets = 0
 	var/cost_atmos_machinery = 0
 	var/cost_rebuilds = 0
+	var/cost_adjacent = 0
 
 	var/list/excited_groups = list()
 	var/list/active_turfs = list()
@@ -25,10 +26,12 @@ SUBSYSTEM_DEF(air)
 	var/list/rebuild_queue = list()
 	//Subservient to rebuild queue
 	var/list/expansion_queue = list()
+	/// List of turfs to recalculate adjacent turfs on before processing
+	var/list/adjacent_rebuild = list()
 	/// A list of machines that will be processed when currentpart == SSAIR_ATMOSMACHINERY. Use SSair.begin_processing_machine and SSair.stop_processing_machine to add and remove machines.
 	var/list/obj/machinery/atmos_machinery = list()
-	var/list/pipe_init_dirs_cache = list()
 
+	var/list/pipe_init_dirs_cache = list()
 	//atmos singletons
 	var/list/gas_reactions = list()
 	var/list/atmos_gen
@@ -59,6 +62,7 @@ SUBSYSTEM_DEF(air)
 	msg += "AM:[round(cost_atmos_machinery,1)]|"
 	msg += "AO:[round(cost_atoms, 1)]|"
 	msg += "RB:[round(cost_rebuilds,1)]|"
+	msg += "AJ:[round(cost_adjacent,1)]|"
 	msg += "} "
 	msg += "AT:[active_turfs.len]|"
 	msg += "HS:[hotspots.len]|"
@@ -70,6 +74,7 @@ SUBSYSTEM_DEF(air)
 	msg += "AO:[atom_process.len]|"
 	msg += "RB:[rebuild_queue.len]|"
 	msg += "EP:[expansion_queue.len]|"
+	msg += "AJ:[adjacent_rebuild.len]|"
 	msg += "AT/MS:[round((cost ? active_turfs.len/cost : 0),0.1)]"
 	return ..()
 
@@ -82,6 +87,7 @@ SUBSYSTEM_DEF(air)
 	setup_atmos_machinery()
 	setup_pipenets()
 	setup_turf_visuals()
+	process_adjacent_rebuild()
 	return ..()
 
 
@@ -90,6 +96,16 @@ SUBSYSTEM_DEF(air)
 
 	//Rebuilds can happen at any time, so this needs to be done outside of the normal system
 	cost_rebuilds = 0
+	cost_adjacent = 0
+
+	// We need to have a solid setup for turfs before fire, otherwise we'll get massive runtimes and strange behavior
+	if(length(adjacent_rebuild))
+		timer = TICK_USAGE_REAL
+		process_adjacent_rebuild()
+		//This does mean that the apperent rebuild costs fluctuate very quickly, this is just the cost of having them always process, no matter what
+		cost_adjacent = TICK_USAGE_REAL - timer
+		if(state != SS_RUNNING)
+			return
 
 	// Every time we fire, we want to make sure pipenets are rebuilt. The game state could have changed between each fire() proc call
 	// and anything missing a pipenet can lead to unintended behaviour at worse and various runtimes at best.
@@ -206,6 +222,7 @@ SUBSYSTEM_DEF(air)
 	networks = SSair.networks
 	rebuild_queue = SSair.rebuild_queue
 	expansion_queue = SSair.expansion_queue
+	adjacent_rebuild = SSair.adjacent_rebuild
 	atmos_machinery = SSair.atmos_machinery
 	pipe_init_dirs_cache = SSair.pipe_init_dirs_cache
 	gas_reactions = SSair.gas_reactions
@@ -217,6 +234,26 @@ SUBSYSTEM_DEF(air)
 	currentrun = SSair.currentrun
 	queued_for_activation = SSair.queued_for_activation
 
+/datum/controller/subsystem/air/proc/process_adjacent_rebuild(init = FALSE)
+	var/list/queue = adjacent_rebuild
+
+	while (length(queue))
+		var/turf/currT = queue[1]
+		var/goal = queue[currT]
+		queue.Cut(1,2)
+
+		currT.immediate_calculate_adjacent_turfs()
+		if(goal == MAKE_ACTIVE)
+			add_to_active(currT)
+		else if(goal == KILL_EXCITED)
+			add_to_active(currT, TRUE)
+
+		if(init)
+			CHECK_TICK
+		else
+			if(MC_TICK_CHECK)
+				break
+
 /datum/controller/subsystem/air/proc/process_pipenets(resumed = FALSE)
 	if (!resumed)
 		src.currentrun = networks.Copy()