The 515 MegaPR early downport (#7783)

Co-authored-by: Selis <selis@xynolabs.com>
Co-authored-by: Selis <sirlionfur@hotmail.de>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>
Co-authored-by: SatinIsle <thesatinisle@gmail.com>
Co-authored-by: Heroman <alesha3000@list.ru>
Co-authored-by: Casey <a.roaming.shadow@gmail.com>
Co-authored-by: Raeschen <rycoop29@gmail.com>

code/controllers/configuration.dm

@@ -306,6 +306,18 @@ var/list/gamemode_cache = list()
 
 	var/static/invoke_youtubedl = null
 
+	var/static/asset_transport
+
+	var/static/cache_assets = FALSE
+
+	var/static/save_spritesheets = FALSE
+
+	var/static/asset_simple_preload = FALSE
+
+	var/static/asset_cdn_webroot
+
+	var/static/asset_cdn_url
+
 /datum/configuration/New()
 	var/list/L = subtypesof(/datum/game_mode)
 	for (var/T in L)
@@ -987,6 +999,24 @@ var/list/gamemode_cache = list()
 				if("invoke_youtubedl")
 					config.invoke_youtubedl = value
 
+				if("asset_transport")
+					config.asset_transport = value
+
+				if("cache_assets")
+					config.cache_assets = TRUE
+
+				if("save_spritesheets")
+					config.save_spritesheets = TRUE
+
+				if("asset_simple_preload")
+					config.asset_simple_preload = TRUE
+
+				if("asset_cdn_webroot")
+					config.asset_cdn_webroot = value
+
+				if("asset_cdn_url")
+					config.asset_cdn_url = value
+
 				else
 					log_misc("Unknown setting in configuration: '[name]'")
 

code/controllers/globals.dm

@@ -62,3 +62,5 @@ GLOBAL_REAL(GLOB, /datum/controller/global_vars)
 		var/end_tick = world.time
 		if(end_tick - start_tick)
 			warning("Global [replacetext("[I]", "InitGlobal", "")] slept during initialization!")
+
+	populate_legacy_globals()

code/controllers/master.dm

@@ -281,7 +281,7 @@ GLOBAL_REAL(Master, /datum/controller/master) = new
 	//(higher subsystems will be sooner in the queue, adding them later in the loop means we don't have to loop thru them next queue add)
 	sortTim(tickersubsystems, GLOBAL_PROC_REF(cmp_subsystem_priority))
 	for(var/I in runlevel_sorted_subsystems)
-		sortTim(runlevel_sorted_subsystems, GLOBAL_PROC_REF(cmp_subsystem_priority))
+		sortTim(I, GLOBAL_PROC_REF(cmp_subsystem_priority))
 		I += tickersubsystems
 
 	var/cached_runlevel = current_runlevel

code/controllers/subsystems/asset_loading.dm

@@ -0,0 +1,28 @@
+/// Allows us to lazyload asset datums
+/// Anything inserted here will fully load if directly gotten
+/// So this just serves to remove the requirement to load assets fully during init
+SUBSYSTEM_DEF(asset_loading)
+	name = "Asset Loading"
+	priority = FIRE_PRIORITY_ASSETS
+	flags = SS_NO_INIT
+	runlevels = RUNLEVEL_LOBBY|RUNLEVELS_DEFAULT
+	var/list/datum/asset/generate_queue = list()
+
+/datum/controller/subsystem/asset_loading/fire(resumed)
+	while(length(generate_queue))
+		var/datum/asset/to_load = generate_queue[generate_queue.len]
+
+		to_load.queued_generation()
+
+		if(MC_TICK_CHECK)
+			return
+		generate_queue.len--
+
+/datum/controller/subsystem/asset_loading/proc/queue_asset(datum/asset/queue)
+#ifdef DO_NOT_DEFER_ASSETS
+	stack_trace("We queued an instance of [queue.type] for lateloading despite not allowing it")
+#endif
+	generate_queue += queue
+
+/datum/controller/subsystem/asset_loading/proc/dequeue_asset(datum/asset/queue)
+	generate_queue -= queue

code/controllers/subsystems/assets.dm

@@ -2,17 +2,39 @@ SUBSYSTEM_DEF(assets)
 	name = "Assets"
 	init_order = INIT_ORDER_ASSETS
 	flags = SS_NO_FIRE
-	var/list/cache = list()
+	var/list/datum/asset_cache_item/cache = list()
 	var/list/preload = list()
+	var/datum/asset_transport/transport = new()
 
-/datum/controller/subsystem/assets/Initialize(timeofday)
-	for(var/typepath in typesof(/datum/asset))
-		var/datum/asset/A = typepath
-		if (typepath != initial(A._abstract))
-			get_asset_datum(typepath)
+/datum/controller/subsystem/assets/proc/OnConfigLoad()
+	var/newtransporttype = /datum/asset_transport
+	switch (config.asset_transport)
+		if ("webroot")
+			newtransporttype = /datum/asset_transport/webroot
 
-	preload = cache.Copy() //don't preload assets generated during the round
+	if (newtransporttype == transport.type)
+		return
 
-	for(var/client/C in GLOB.clients)
-		addtimer(CALLBACK(GLOBAL_PROC, GLOBAL_PROC_REF(getFilesSlow), C, preload, FALSE), 10)
-	return ..()
+	var/datum/asset_transport/newtransport = new newtransporttype ()
+	if (newtransport.validate_config())
+		transport = newtransport
+	transport.Load()
+
+
+
+/datum/controller/subsystem/assets/Initialize()
+	OnConfigLoad()
+
+	for(var/type in typesof(/datum/asset))
+		var/datum/asset/A = type
+		if (type != initial(A._abstract))
+			load_asset_datum(type)
+
+	transport.Initialize(cache)
+
+	subsystem_initialized = TRUE
+	return SS_INIT_SUCCESS
+
+/datum/controller/subsystem/assets/Recover()
+	cache = SSassets.cache
+	preload = SSassets.preload

code/controllers/subsystems/garbage.dm

@@ -1,3 +1,26 @@
+/*!
+## Debugging GC issues
+
+In order to debug `qdel()` failures, there are several tools available.
+To enable these tools, define `TESTING` in [_compile_options.dm](https://github.com/tgstation/-tg-station/blob/master/code/_compile_options.dm).
+
+First is a verb called "Find References", which lists **every** refererence to an object in the world. This allows you to track down any indirect or obfuscated references that you might have missed.
+
+Complementing this is another verb, "qdel() then Find References".
+This does exactly what you'd expect; it calls `qdel()` on the object and then it finds all references remaining.
+This is great, because it means that `Destroy()` will have been called before it starts to find references,
+so the only references you'll find will be the ones preventing the object from `qdel()`ing gracefully.
+
+If you have a datum or something you are not destroying directly (say via the singulo),
+the next tool is `QDEL_HINT_FINDREFERENCE`. You can return this in `Destroy()` (where you would normally `return ..()`),
+to print a list of references once it enters the GC queue.
+
+Finally is a verb, "Show qdel() Log", which shows the deletion log that the garbage subsystem keeps. This is helpful if you are having race conditions or need to review the order of deletions.
+
+Note that for any of these tools to work `TESTING` must be defined.
+By using these methods of finding references, you can make your life far, far easier when dealing with `qdel()` failures.
+*/
+
 SUBSYSTEM_DEF(garbage)
 	name = "Garbage"
 	priority = FIRE_PRIORITY_GARBAGE
@@ -5,8 +28,9 @@ SUBSYSTEM_DEF(garbage)
 	flags = SS_POST_FIRE_TIMING|SS_BACKGROUND|SS_NO_INIT
 	runlevels = RUNLEVELS_DEFAULT | RUNLEVEL_LOBBY
 	init_order = INIT_ORDER_GARBAGE
+//	init_stage = INITSTAGE_EARLY
 
-	var/list/collection_timeout = list(2 MINUTES, 10 SECONDS) // deciseconds to wait before moving something up in the queue to the next level
+	var/list/collection_timeout = list(GC_FILTER_QUEUE, GC_CHECK_QUEUE, GC_DEL_QUEUE) // deciseconds to wait before moving something up in the queue to the next level
 
 	//Stat tracking
 	var/delslasttick = 0 // number of del()'s we've done this tick
@@ -26,17 +50,15 @@ SUBSYSTEM_DEF(garbage)
 	var/list/queues
 	#ifdef REFERENCE_TRACKING
 	var/list/reference_find_on_fail = list()
+	#ifdef REFERENCE_TRACKING_DEBUG
+	//Should we save found refs. Used for unit testing
+	var/should_save_refs = FALSE
+	#endif
 	#endif
 
 
 /datum/controller/subsystem/garbage/PreInit()
-	queues = new(GC_QUEUE_COUNT)
-	pass_counts = new(GC_QUEUE_COUNT)
-	fail_counts = new(GC_QUEUE_COUNT)
-	for(var/i in 1 to GC_QUEUE_COUNT)
-		queues[i] = list()
-		pass_counts[i] = 0
-		fail_counts[i] = 0
+	InitQueues()
 
 /datum/controller/subsystem/garbage/stat_entry(msg)
 	var/list/counts = list()
@@ -60,39 +82,48 @@ SUBSYSTEM_DEF(garbage)
 
 /datum/controller/subsystem/garbage/Shutdown()
 	//Adds the del() log to the qdel log file
-	var/list/dellog = list()
+	var/list/del_log = list()
 
 	//sort by how long it's wasted hard deleting
 	sortTim(items, cmp=/proc/cmp_qdel_item_time, associative = TRUE)
 	for(var/path in items)
 		var/datum/qdel_item/I = items[path]
-		dellog += "Path: [path]"
+		var/list/entry = list()
+		del_log[path] = entry
+
 		if (I.qdel_flags & QDEL_ITEM_SUSPENDED_FOR_LAG)
-			dellog += "\tSUSPENDED FOR LAG"
+			entry["SUSPENDED FOR LAG"] = TRUE
 		if (I.failures)
-			dellog += "\tFailures: [I.failures]"
-		dellog += "\tqdel() Count: [I.qdels]"
-		dellog += "\tDestroy() Cost: [I.destroy_time]ms"
+			entry["Failures"] = I.failures
+		entry["qdel() Count"] = I.qdels
+		entry["Destroy() Cost (ms)"] = I.destroy_time
+
 		if (I.hard_deletes)
-			dellog += "\tTotal Hard Deletes: [I.hard_deletes]"
-			dellog += "\tTime Spent Hard Deleting: [I.hard_delete_time]ms"
-			dellog += "\tHighest Time Spent Hard Deleting: [I.hard_delete_max]ms"
+			entry["Total Hard Deletes"] = I.hard_deletes
+			entry["Time Spend Hard Deleting (ms)"] = I.hard_delete_time
+			entry["Highest Time Spend Hard Deleting (ms)"] = I.hard_delete_max
 			if (I.hard_deletes_over_threshold)
-				dellog += "\tHard Deletes Over Threshold: [I.hard_deletes_over_threshold]"
+				entry["Hard Deletes Over Threshold"] = I.hard_deletes_over_threshold
 		if (I.slept_destroy)
-			dellog += "\tSleeps: [I.slept_destroy]"
+			entry["Total Sleeps"] = I.slept_destroy
 		if (I.no_respect_force)
-			dellog += "\tIgnored force: [I.no_respect_force] times"
+			entry["Total Ignored Force"] = I.no_respect_force
 		if (I.no_hint)
-			dellog += "\tNo hint: [I.no_hint] times"
-	text2file(dellog.Join(), "[log_path]-qdel.log")
+			entry["Total No Hint"] = I.no_hint
+		if(LAZYLEN(I.extra_details))
+			entry["Deleted Metadata"] = I.extra_details
+
+	log_debug("", del_log)
 
 /datum/controller/subsystem/garbage/fire()
 	//the fact that this resets its processing each fire (rather then resume where it left off) is intentional.
-	var/queue = GC_QUEUE_CHECK
+	var/queue = GC_QUEUE_FILTER
 
 	while (state == SS_RUNNING)
 		switch (queue)
+			if (GC_QUEUE_FILTER)
+				HandleQueue(GC_QUEUE_FILTER)
+				queue = GC_QUEUE_FILTER+1
 			if (GC_QUEUE_CHECK)
 				HandleQueue(GC_QUEUE_CHECK)
 				queue = GC_QUEUE_CHECK+1
@@ -102,8 +133,21 @@ SUBSYSTEM_DEF(garbage)
 					state = SS_RUNNING
 				break
 
-/datum/controller/subsystem/garbage/proc/HandleQueue(level = GC_QUEUE_CHECK)
-	if (level == GC_QUEUE_CHECK)
+
+
+/datum/controller/subsystem/garbage/proc/InitQueues()
+	if (isnull(queues)) // Only init the queues if they don't already exist, prevents overriding of recovered lists
+		queues = new(GC_QUEUE_COUNT)
+		pass_counts = new(GC_QUEUE_COUNT)
+		fail_counts = new(GC_QUEUE_COUNT)
+		for(var/i in 1 to GC_QUEUE_COUNT)
+			queues[i] = list()
+			pass_counts[i] = 0
+			fail_counts[i] = 0
+
+
+/datum/controller/subsystem/garbage/proc/HandleQueue(level = GC_QUEUE_FILTER)
+	if (level == GC_QUEUE_FILTER)
 		delslasttick = 0
 		gcedlasttick = 0
 	var/cut_off_time = world.time - collection_timeout[level] //ignore entries newer then this
@@ -118,30 +162,33 @@ SUBSYSTEM_DEF(garbage)
 
 	lastlevel = level
 
-	//We do this rather then for(var/refID in queue) because that sort of for loop copies the whole list.
+// 1 from the hard reference in the queue, and 1 from the variable used before this
+#define REFS_WE_EXPECT 2
+
+	//We do this rather then for(var/list/ref_info in queue) because that sort of for loop copies the whole list.
 	//Normally this isn't expensive, but the gc queue can grow to 40k items, and that gets costly/causes overrun.
 	for (var/i in 1 to length(queue))
 		var/list/L = queue[i]
-		if (length(L) < 2)
+		if (length(L) < GC_QUEUE_ITEM_INDEX_COUNT)
 			count++
 			if (MC_TICK_CHECK)
 				return
 			continue
 
-		var/GCd_at_time = L[1]
-		if(GCd_at_time > cut_off_time)
+		var/queued_at_time = L[GC_QUEUE_ITEM_QUEUE_TIME]
+		if(queued_at_time > cut_off_time)
 			break // Everything else is newer, skip them
 		count++
-		var/refID = L[2]
-		var/datum/D
-		D = locate(refID)
 
-		if (!D || D.gc_destroyed != GCd_at_time) // So if something else coincidently gets the same ref, it's not deleted by mistake
+		var/datum/D = L[GC_QUEUE_ITEM_REF]
+
+		// If that's all we've got, send er off
+		if (refcount(D) == REFS_WE_EXPECT)
 			++gcedlasttick
 			++totalgcs
 			pass_counts[level]++
 			#ifdef REFERENCE_TRACKING
-			reference_find_on_fail -= refID //It's deleted we don't care anymore.
+			reference_find_on_fail -= ref(D) //It's deleted we don't care anymore.
 			#endif
 			if (MC_TICK_CHECK)
 				return
@@ -157,22 +204,33 @@ SUBSYSTEM_DEF(garbage)
 		switch (level)
 			if (GC_QUEUE_CHECK)
 				#ifdef REFERENCE_TRACKING
-				if(reference_find_on_fail[refID])
-					INVOKE_ASYNC(D, /datum/proc/find_references)
+				// Decides how many refs to look for (potentially)
+				// Based off the remaining and the ones we can account for
+				var/remaining_refs = refcount(D) - REFS_WE_EXPECT
+				if(reference_find_on_fail[ref(D)])
+					INVOKE_ASYNC(D, TYPE_PROC_REF(/datum,find_references), remaining_refs)
 					ref_searching = TRUE
 				#ifdef GC_FAILURE_HARD_LOOKUP
 				else
-					INVOKE_ASYNC(D, /datum/proc/find_references)
+					INVOKE_ASYNC(D, TYPE_PROC_REF(/datum,find_references), remaining_refs)
 					ref_searching = TRUE
 				#endif
-				reference_find_on_fail -= refID
+				reference_find_on_fail -= ref(D)
 				#endif
 				var/type = D.type
 				var/datum/qdel_item/I = items[type]
 
-				log_world("## TESTING: GC: -- \ref[D] | [type] was unable to be GC'd --")
+				var/message = "## TESTING: GC: -- [ref(D)] | [type] was unable to be GC'd --"
+				message = "[message] (ref count of [refcount(D)])"
+				log_world(message)
+
+				/*var/detail = D.dump_harddel_info()
+				if(detail)
+					LAZYADD(I.extra_details, detail)*/
+
 				#ifdef TESTING
-				for(var/client/admin as anything in GLOB.admins) //Using testing() here would fill the logs with ADMIN_VV garbage
+				for(var/c in GLOB.admins) //Using testing() here would fill the logs with ADMIN_VV garbage
+					var/client/admin = c
 					if(!check_rights_for(admin, R_ADMIN))
 						continue
 					to_chat(admin, "## TESTING: GC: -- [ADMIN_VV(D)] | [type] was unable to be GC'd --")
@@ -204,36 +262,41 @@ SUBSYSTEM_DEF(garbage)
 		queue.Cut(1,count+1)
 		count = 0
 
-/datum/controller/subsystem/garbage/proc/Queue(datum/D, level = GC_QUEUE_CHECK)
+#undef REFS_WE_EXPECT
+
+/datum/controller/subsystem/garbage/proc/Queue(datum/D, level = GC_QUEUE_FILTER)
 	if (isnull(D))
 		return
 	if (level > GC_QUEUE_COUNT)
 		HardDelete(D)
 		return
-	var/gctime = world.time
-	var/refid = "\ref[D]"
+	var/queue_time = world.time
+
+	if (D.gc_destroyed <= 0)
+		D.gc_destroyed = queue_time
 
-	D.gc_destroyed = gctime
 	var/list/queue = queues[level]
-
-	queue[++queue.len] = list(gctime, refid) // not += for byond reasons
+	queue[++queue.len] = list(queue_time, D, D.gc_destroyed) // not += for byond reasons
 
 //this is mainly to separate things profile wise.
 /datum/controller/subsystem/garbage/proc/HardDelete(datum/D)
 	++delslasttick
 	++totaldels
 	var/type = D.type
-	var/refID = "\ref[D]"
+	var/refID = ref(D)
+	var/datum/qdel_item/type_info = items[type]
+	/*var/detail = D.dump_harddel_info()
+	if(detail)
+		LAZYADD(type_info.extra_details, detail)*/
 
 	var/tick_usage = TICK_USAGE
 	del(D)
 	tick_usage = TICK_USAGE_TO_MS(tick_usage)
 
-	var/datum/qdel_item/I = items[type]
-	I.hard_deletes++
-	I.hard_delete_time += tick_usage
-	if (tick_usage > I.hard_delete_max)
-		I.hard_delete_max = tick_usage
+	type_info.hard_deletes++
+	type_info.hard_delete_time += tick_usage
+	if (tick_usage > type_info.hard_delete_max)
+		type_info.hard_delete_max = tick_usage
 	if (tick_usage > highest_del_ms)
 		highest_del_ms = tick_usage
 		highest_del_type_string = "[type]"
@@ -244,15 +307,17 @@ SUBSYSTEM_DEF(garbage)
 		postpone(time)
 	var/threshold = 0.5 // Default, make a config
 	if (threshold && (time > threshold SECONDS))
-		if (!(I.qdel_flags & QDEL_ITEM_ADMINS_WARNED))
-			log_and_message_admins("Error: [type]([refID]) took longer than [threshold] seconds to delete (took [round(time/10, 0.1)] seconds to delete)")
-			I.qdel_flags |= QDEL_ITEM_ADMINS_WARNED
-		I.hard_deletes_over_threshold++
+		if (!(type_info.qdel_flags & QDEL_ITEM_ADMINS_WARNED))
+			log_game("Error: [type]([refID]) took longer than [threshold] seconds to delete (took [round(time/10, 0.1)] seconds to delete)")
+			message_admins("Error: [type]([refID]) took longer than [threshold] seconds to delete (took [round(time/10, 0.1)] seconds to delete).")
+			type_info.qdel_flags |= QDEL_ITEM_ADMINS_WARNED
+		type_info.hard_deletes_over_threshold++
 		var/overrun_limit = 0 // Default, make a config
-		if (overrun_limit && I.hard_deletes_over_threshold >= overrun_limit)
-			I.qdel_flags |= QDEL_ITEM_SUSPENDED_FOR_LAG
+		if (overrun_limit && type_info.hard_deletes_over_threshold >= overrun_limit)
+			type_info.qdel_flags |= QDEL_ITEM_SUSPENDED_FOR_LAG
 
 /datum/controller/subsystem/garbage/Recover()
+	InitQueues() //We first need to create the queues before recovering data
 	if (istype(SSgarbage.queues))
 		for (var/i in 1 to SSgarbage.queues.len)
 			queues[i] |= SSgarbage.queues[i]
@@ -271,79 +336,85 @@ SUBSYSTEM_DEF(garbage)
 	var/no_hint = 0 //!Number of times it's not even bother to give a qdel hint
 	var/slept_destroy = 0 //!Number of times it's slept in its destroy
 	var/qdel_flags = 0 //!Flags related to this type's trip thru qdel.
+	var/list/extra_details //!Lazylist of string metadata about the deleted objects
 
 /datum/qdel_item/New(mytype)
 	name = "[mytype]"
 
-
 /// Should be treated as a replacement for the 'del' keyword.
 ///
 /// Datums passed to this will be given a chance to clean up references to allow the GC to collect them.
-/proc/qdel(datum/D, force=FALSE, ...)
-	if(!istype(D))
-		del(D)
+/proc/qdel(datum/to_delete, force = FALSE)
+	if(!istype(to_delete))
+		del(to_delete)
 		return
 
-	var/datum/qdel_item/I = SSgarbage.items[D.type]
-	if (!I)
-		I = SSgarbage.items[D.type] = new /datum/qdel_item(D.type)
-	I.qdels++
+	var/datum/qdel_item/trash = SSgarbage.items[to_delete.type]
+	if (isnull(trash))
+		trash = SSgarbage.items[to_delete.type] = new /datum/qdel_item(to_delete.type)
+	trash.qdels++
 
-	if(isnull(D.gc_destroyed))
-		if (SEND_SIGNAL(D, COMSIG_PARENT_PREQDELETED, force)) // Give the components a chance to prevent their parent from being deleted
+	if(!isnull(to_delete.gc_destroyed))
+		if(to_delete.gc_destroyed == GC_CURRENTLY_BEING_QDELETED)
+			CRASH("[to_delete.type] destroy proc was called multiple times, likely due to a qdel loop in the Destroy logic")
+		return
+
+	if (SEND_SIGNAL(to_delete, COMSIG_PARENT_PREQDELETED, force)) // Give the components a chance to prevent their parent from being deleted
+		return
+
+	to_delete.gc_destroyed = GC_CURRENTLY_BEING_QDELETED
+	var/start_time = world.time
+	var/start_tick = world.tick_usage
+	SEND_SIGNAL(to_delete, COMSIG_PARENT_QDELETING, force) // Let the (remaining) components know about the result of Destroy
+	var/hint = to_delete.Destroy(force) // Let our friend know they're about to get fucked up.
+
+	if(world.time != start_time)
+		trash.slept_destroy++
+	else
+		trash.destroy_time += TICK_USAGE_TO_MS(start_tick)
+
+	if(isnull(to_delete))
+		return
+
+	switch(hint)
+		if (QDEL_HINT_QUEUE) //qdel should queue the object for deletion.
+			SSgarbage.Queue(to_delete)
+		if (QDEL_HINT_IWILLGC)
+			to_delete.gc_destroyed = world.time
 			return
-		D.gc_destroyed = GC_CURRENTLY_BEING_QDELETED
-		var/start_time = world.time
-		var/start_tick = world.tick_usage
-		SEND_SIGNAL(D, COMSIG_PARENT_QDELETING, force) // Let the (remaining) components know about the result of Destroy
-		var/hint = D.Destroy(arglist(args.Copy(2))) // Let our friend know they're about to get fucked up.
-		if(world.time != start_time)
-			I.slept_destroy++
-		else
-			I.destroy_time += TICK_USAGE_TO_MS(start_tick)
-		if(!D)
-			return
-		switch(hint)
-			if (QDEL_HINT_QUEUE) //qdel should queue the object for deletion.
-				SSgarbage.Queue(D)
-			if (QDEL_HINT_IWILLGC)
-				D.gc_destroyed = world.time
+		if (QDEL_HINT_LETMELIVE) //qdel should let the object live after calling destory.
+			if(!force)
+				to_delete.gc_destroyed = null //clear the gc variable (important!)
 				return
-			if (QDEL_HINT_LETMELIVE) //qdel should let the object live after calling destory.
-				if(!force)
-					D.gc_destroyed = null //clear the gc variable (important!)
-					return
-				// Returning LETMELIVE after being told to force destroy
-				// indicates the objects Destroy() does not respect force
-				#ifdef TESTING
-				if(!I.no_respect_force)
-					testing("WARNING: [D.type] has been force deleted, but is \
-						returning an immortal QDEL_HINT, indicating it does \
-						not respect the force flag for qdel(). It has been \
-						placed in the queue, further instances of this type \
-						will also be queued.")
-				#endif
-				I.no_respect_force++
-
-				SSgarbage.Queue(D)
-			if (QDEL_HINT_HARDDEL) //qdel should assume this object won't gc, and queue a hard delete
-				SSgarbage.Queue(D, GC_QUEUE_HARDDELETE)
-			if (QDEL_HINT_HARDDEL_NOW) //qdel should assume this object won't gc, and hard del it post haste.
-				SSgarbage.HardDelete(D)
-			#ifdef REFERENCE_TRACKING
-			if (QDEL_HINT_FINDREFERENCE) //qdel will, if REFERENCE_TRACKING is enabled, display all references to this object, then queue the object for deletion.
-				SSgarbage.Queue(D)
-				D.find_references()
-			if (QDEL_HINT_IFFAIL_FINDREFERENCE) //qdel will, if REFERENCE_TRACKING is enabled and the object fails to collect, display all references to this object.
-				SSgarbage.Queue(D)
-				SSgarbage.reference_find_on_fail["\ref[D]"] = TRUE
+			// Returning LETMELIVE after being told to force destroy
+			// indicates the objects Destroy() does not respect force
+			#ifdef TESTING
+			if(!trash.no_respect_force)
+				testing("WARNING: [to_delete.type] has been force deleted, but is \
+					returning an immortal QDEL_HINT, indicating it does \
+					not respect the force flag for qdel(). It has been \
+					placed in the queue, further instances of this type \
+					will also be queued.")
 			#endif
-			else
-				#ifdef TESTING
-				if(!I.no_hint)
-					testing("WARNING: [D.type] is not returning a qdel hint. It is being placed in the queue. Further instances of this type will also be queued.")
-				#endif
-				I.no_hint++
-				SSgarbage.Queue(D)
-	else if(D.gc_destroyed == GC_CURRENTLY_BEING_QDELETED)
-		CRASH("[D.type] destroy proc was called multiple times, likely due to a qdel loop in the Destroy logic")
+			trash.no_respect_force++
+
+			SSgarbage.Queue(to_delete)
+		if (QDEL_HINT_HARDDEL) //qdel should assume this object won't gc, and queue a hard delete
+			SSgarbage.Queue(to_delete, GC_QUEUE_HARDDELETE)
+		if (QDEL_HINT_HARDDEL_NOW) //qdel should assume this object won't gc, and hard del it post haste.
+			SSgarbage.HardDelete(to_delete)
+		#ifdef REFERENCE_TRACKING
+		if (QDEL_HINT_FINDREFERENCE) //qdel will, if REFERENCE_TRACKING is enabled, display all references to this object, then queue the object for deletion.
+			SSgarbage.Queue(to_delete)
+			INVOKE_ASYNC(to_delete, TYPE_PROC_REF(/datum, find_references))
+		if (QDEL_HINT_IFFAIL_FINDREFERENCE) //qdel will, if REFERENCE_TRACKING is enabled and the object fails to collect, display all references to this object.
+			SSgarbage.Queue(to_delete)
+			SSgarbage.reference_find_on_fail[ref(to_delete)] = TRUE
+		#endif
+		else
+			#ifdef TESTING
+			if(!trash.no_hint)
+				testing("WARNING: [to_delete.type] is not returning a qdel hint. It is being placed in the queue. Further instances of this type will also be queued.")
+			#endif
+			trash.no_hint++
+			SSgarbage.Queue(to_delete)

code/controllers/subsystems/overlays.dm

@@ -77,23 +77,31 @@ SUBSYSTEM_DEF(overlays)
 	var/list/result = list()
 	var/icon/icon = subject.icon
 	for (var/atom/entry as anything in sources)
-		if (!entry)
-			continue
-		else if (istext(entry))
-			result += GetStateAppearance(icon, entry)
-		else if (isicon(entry))
-			result += GetIconAppearance(entry)
-		else
-			if (isloc(entry))
-				if (entry.flags & OVERLAY_QUEUED)
-					entry.ImmediateOverlayUpdate()
-			if (!ispath(entry))
-				result += entry.appearance
-			else
-				var/image/image = entry
-				result += image.appearance
+		AppearanceListEntry(entry, result, icon)
 	return result
 
+//Fixes runtime with overlays present in 515
+/datum/controller/subsystem/overlays/proc/AppearanceListEntry(var/atom/entry,var/list/result,var/icon/icon)
+	if (!entry)
+		return
+	else if(islist(entry))
+		var/list/entry_list = entry
+		for(var/entry_item in entry_list)
+			AppearanceListEntry(entry_item)
+	else if (istext(entry))
+		result += GetStateAppearance(icon, entry)
+	else if (isicon(entry))
+		result += GetIconAppearance(entry)
+	else
+		if (isloc(entry))
+			if (entry.flags & OVERLAY_QUEUED)
+				entry.ImmediateOverlayUpdate()
+		if (!ispath(entry))
+			if(entry.appearance)
+				result += entry.appearance
+		else
+			var/image/image = entry
+			result += image.appearance
 
 /// Enqueues the atom for an overlay update if not already queued
 /atom/proc/QueueOverlayUpdate()