Ports tgstation/tgstation#40577 - Makes /datum/gas_mixture/share() roughly 5% faster by removing fairly useless abstraction, also contains a small boost to pipelines

code/modules/atmospherics/gasmixtures/gas_mixture.dm

@@ -29,6 +29,7 @@ GLOBAL_LIST_INIT(gaslist_cache, init_gaslist_cache())
 	var/last_share = 0
 	var/list/reaction_results
 	var/list/analyzer_results //used for analyzer feedback - not initialized until its used
+	var/gc_share = FALSE // Whether to call garbage_collect() on the sharer during shares, used for immutable mixtures
 
 /datum/gas_mixture/New(volume)
 	gases = new
@@ -143,9 +144,6 @@ GLOBAL_LIST_INIT(gaslist_cache, init_gaslist_cache())
 	//Performs air sharing calculations between two gas_mixtures assuming only 1 boundary length
 	//Returns: amount of gas exchanged (+ if sharer received)
 
-/datum/gas_mixture/proc/after_share(datum/gas_mixture/sharer)
-	//called on share's sharer to let it know it just got some gases
-
 /datum/gas_mixture/proc/temperature_share(datum/gas_mixture/sharer, conduction_coefficient)
 	//Performs temperature sharing calculations (via conduction) between two gas_mixtures assuming only 1 boundary length
 	//Returns: new temperature of the sharer
@@ -343,7 +341,8 @@ GLOBAL_LIST_INIT(gaslist_cache, init_gaslist_cache())
 	if(length(cached_gases ^ sharer_gases)) //if all gases were present in both mixtures, we know that no gases are 0
 		garbage_collect(cached_gases - sharer_gases) //any gases the sharer had, we are guaranteed to have. gases that it didn't have we are not.
 		sharer.garbage_collect(sharer_gases - cached_gases) //the reverse is equally true
-	sharer.after_share(src, atmos_adjacent_turfs)
+	if (initial(sharer.gc_share))
+		sharer.garbage_collect()
 	if(temperature_delta > MINIMUM_TEMPERATURE_TO_MOVE || abs(moved_moles) > MINIMUM_MOLES_DELTA_TO_MOVE)
 		var/our_moles
 		TOTAL_MOLES(cached_gases,our_moles)
@@ -351,9 +350,6 @@ GLOBAL_LIST_INIT(gaslist_cache, init_gaslist_cache())
 		TOTAL_MOLES(sharer_gases,their_moles)
 		return (temperature_archived*(our_moles + moved_moles) - sharer.temperature_archived*(their_moles - moved_moles)) * R_IDEAL_GAS_EQUATION / volume
 
-/datum/gas_mixture/after_share(datum/gas_mixture/sharer, atmos_adjacent_turfs = 4)
-	return
-
 /datum/gas_mixture/temperature_share(datum/gas_mixture/sharer, conduction_coefficient, sharer_temperature, sharer_heat_capacity)
 	//transfer of thermal energy (via conduction) between self and sharer
 	if(sharer)

code/modules/atmospherics/gasmixtures/immutable_mixtures.dm

@@ -3,6 +3,7 @@
 
 /datum/gas_mixture/immutable
 	var/initial_temperature
+	gc_share = TRUE
 
 /datum/gas_mixture/immutable/New()
 	..()
@@ -23,9 +24,6 @@
 	. = ..(sharer, 0)
 	garbage_collect()
 
-/datum/gas_mixture/immutable/after_share()
-	garbage_collect()
-
 /datum/gas_mixture/immutable/react()
 	return 0 //we're immutable.
 

code/modules/atmospherics/machinery/datum_pipeline.dm

@@ -221,13 +221,16 @@
 		if(!P)
 			continue
 		GL += P.return_air()
-		for(var/obj/machinery/atmospherics/components/binary/valve/V in P.other_atmosmch)
+		for(var/atmosmch in P.other_atmosmch)
-			if(V.on)
+			if (istype(atmosmch, /obj/machinery/atmospherics/components/binary/valve))
-				PL |= V.parents[1]
+				var/obj/machinery/atmospherics/components/binary/valve/V = atmosmch
-				PL |= V.parents[2]
+				if(V.on)
-		for(var/obj/machinery/atmospherics/components/unary/portables_connector/C in P.other_atmosmch)
+					PL |= V.parents[1]
-			if(C.connected_device)
+					PL |= V.parents[2]
-				GL += C.portableConnectorReturnAir()
+			else if (istype(atmosmch, /obj/machinery/atmospherics/components/unary/portables_connector))
+				var/obj/machinery/atmospherics/components/unary/portables_connector/C = atmosmch
+				if(C.connected_device)
+					GL += C.portableConnectorReturnAir()
 
 	var/total_thermal_energy = 0
 	var/total_heat_capacity = 0