Merge pull request #7195 from Citadel-Station-13/upstream-merge-38574

[MIRROR] Global component signals

code/controllers/subsystem/dcs.dm

@@ -0,0 +1,35 @@
+SUBSYSTEM_DEF(dcs)
+	name = "Datum Component System"
+	flags = SS_NO_INIT | SS_NO_FIRE
+
+	var/list/comp_lookup = list()	// A signal:list(components) assoc list
+
+/datum/controller/subsystem/dcs/proc/_SendGlobalSignal(sigtype, list/arguments)
+	. = NONE
+	for(var/i in comp_lookup[sigtype])
+		var/datum/component/comp = i
+		if(!comp.enabled)
+			continue
+		var/datum/callback/CB = comp.signal_procs[sigtype]
+		if(!CB)
+			continue // Should we error from this?
+		. |= CB.InvokeAsync(arglist(arguments))
+
+/datum/controller/subsystem/dcs/proc/RegisterSignal(datum/component/comp, sigtype)
+	if(!comp_lookup[sigtype])
+		comp_lookup[sigtype] = list()
+	
+	comp_lookup[sigtype][comp] = TRUE
+
+/datum/controller/subsystem/dcs/proc/UnregisterSignal(datum/component/comp, list/sigtypes)
+	if(!length(sigtypes))
+		sigtypes = list(sigtypes)
+	for(var/sigtype in sigtypes)
+		switch(length(comp_lookup[sigtype]))
+			if(1)
+				comp_lookup -= sigtype
+			if(2 to INFINITY)
+				comp_lookup[sigtype] -= comp
+
+/datum/controller/subsystem/dcs/Recover()
+	comp_lookup = SSdcs.comp_lookup