Update

- Creates a global list of items which have pwr_drain() called every powernet tick
- Makes powersink use this list
- Adds scheck

code/controllers/Processes/machinery.dm

@@ -22,8 +22,11 @@
 
 		powernets.Remove(powerNetwork)
 
-	for(var/obj/item/device/powersink/S in processing_objects)
+	// Currently only used by powersinks. These items get priority processed before machinery
-		S.drain()
+	for(var/obj/item/I in processing_power_items)
+		if(!I.pwr_drain()) // 0 = Process Kill, remove from processing list.
+			processing_power_items.Remove(I)
+		scheck()
 
 	for(var/obj/machinery/M in machines)
 		if(M && !M.gcDestroyed)

code/game/objects/items.dm

@@ -599,4 +599,7 @@ modules/mob/living/carbon/human/life.dm if you die, you will be zoomed out.
 		if(!cannotzoom)
 			usr.visible_message("[zoomdevicename ? "[usr] looks up from the [src.name]" : "[usr] lowers the [src.name]"].")
 
-	return
+	return
+
+/obj/item/proc/pwr_drain()
+	return 0 // Process Kill

code/game/objects/items/devices/powersink.dm

@@ -27,6 +27,7 @@
 
 /obj/item/device/powersink/Destroy()
 	processing_objects.Remove(src)
+	processing_power_items.Remove(src)
 	..()
 
 /obj/item/device/powersink/attackby(var/obj/item/I, var/mob/user)
@@ -49,6 +50,7 @@
 		else
 			if (mode == 2)
 				processing_objects.Remove(src) // Now the power sink actually stops draining the station's power if you unhook it. --NeoFite
+				processing_power_items.Remove(src)
 			anchored = 0
 			mode = 0
 			src.visible_message("<span class='notice'>[user] detaches [src] from the cable!</span>")
@@ -71,25 +73,27 @@
 			mode = 2
 			icon_state = "powersink1"
 			processing_objects.Add(src)
+			processing_power_items.Add(src)
 		if(2)  //This switch option wasn't originally included. It exists now. --NeoFite
 			src.visible_message("<span class='notice'>[user] deactivates [src]!</span>")
 			mode = 1
 			set_light(0)
 			icon_state = "powersink0"
 			processing_objects.Remove(src)
+			processing_power_items.Remove(src)
 
-/obj/item/device/powersink/proc/drain()
+/obj/item/device/powersink/pwr_drain()
 	if(!attached)
-		return
+		return 0
 
 	if(drained_this_tick)
-		return
+		return 1
 	drained_this_tick = 1
 
 	var/drained = 0
 
 	if(!PN)
-		return
+		return 1
 
 	set_light(12)
 	PN.trigger_warning()
@@ -110,6 +114,7 @@
 					A.cell.use(drain_val * CELLRATE)
 					drained += drain_val
 	power_drained += drained
+	return 1
 
 
 /obj/item/device/powersink/process()

code/global.dm

@@ -8,6 +8,7 @@ var/global/obj/effect/datacore/data_core = null
 var/global/list/all_areas                = list()
 var/global/list/machines                 = list()
 var/global/list/processing_objects       = list()
+var/global/list/processing_power_items   = list()
 var/global/list/active_diseases          = list()
 var/global/list/med_hud_users            = list() // List of all entities using a medical HUD.
 var/global/list/sec_hud_users            = list() // List of all entities using a security HUD.