Ports /tg controller optimizations

https://github.com/tgstation/tgstation/pull/31092 - Fixes subsystems not returning a qdel hint
https://github.com/tgstation/tgstation/pull/31494 - In which the stoner one gets stoned and tries to address tick contention... again
https://github.com/tgstation/tgstation/pull/31950 - Removes an empty New()
https://github.com/tgstation/tgstation/pull/31951 - Logs subsystem shutdowns

code/__defines/_tick.dm

@@ -1,5 +1,5 @@
 #define TICK_LIMIT_RUNNING 80
-#define TICK_LIMIT_TO_RUN 78
+#define TICK_LIMIT_TO_RUN 70
 #define TICK_LIMIT_MC 70
 #define TICK_LIMIT_MC_INIT_DEFAULT 98
 

code/__defines/math.dm

@@ -8,3 +8,7 @@
 //for when you need a reliable time number that doesn't depend on byond time.
 #define REALTIMEOFDAY (world.timeofday + (MIDNIGHT_ROLLOVER * MIDNIGHT_ROLLOVER_CHECK))
 #define MIDNIGHT_ROLLOVER_CHECK ( rollovercheck_last_timeofday != world.timeofday ? update_midnight_rollover() : midnight_rollovers )
+
+#define CEILING(x, y) ( -round(-(x) / (y)) * (y) )
+// round() acts like floor(x, 1) by default but can't handle other values
+#define FLOOR(x, y) ( round((x) / (y)) * (y) )

code/_helpers/mobs.dm

@@ -182,7 +182,7 @@ Proc for attack log creation, because really why not
 	var/starttime = world.time
 	. = 1
 	while (world.time < endtime)
-		sleep(1)
+		stoplag(1)
 		if (progress)
 			progbar.update(world.time - starttime)
 		if(!user || !target)
@@ -229,7 +229,7 @@ Proc for attack log creation, because really why not
 	var/starttime = world.time
 	. = 1
 	while (world.time < endtime)
-		sleep(1)
+		stoplag(1)
 		if (progress)
 			progbar.update(world.time - starttime)
 

code/_helpers/time.dm

@@ -13,6 +13,12 @@
 #define TimeOfGame (get_game_time())
 #define TimeOfTick (TICK_USAGE*0.01*world.tick_lag)
 
+#define TICK *world.tick_lag
+#define TICKS *world.tick_lag
+
+#define DS2TICKS(DS) (DS/world.tick_lag)	// Convert deciseconds to ticks
+#define TICKS2DS(T) (T TICKS) 				// Convert ticks to deciseconds
+
 /proc/get_game_time()
 	var/global/time_offset = 0
 	var/global/last_time = 0
@@ -111,13 +117,21 @@ var/round_start_time = 0
 
 //Increases delay as the server gets more overloaded,
 //as sleeps aren't cheap and sleeping only to wake up and sleep again is wasteful
-#define DELTA_CALC max(((max(TICK_USAGE, world.cpu) / 100) * max(Master.sleep_delta,1)), 1)
+#define DELTA_CALC max(((max(TICK_USAGE, world.cpu) / 100) * max(Master.sleep_delta-1,1)), 1)
 
-/proc/stoplag()
+//returns the number of ticks slept
+/proc/stoplag(initial_delay)
+	if (!Master || !(Master.current_runlevel & RUNLEVELS_DEFAULT))
+		sleep(world.tick_lag)
+		return 1
+	if (!initial_delay)
+		initial_delay = world.tick_lag
 	. = 0
-	var/i = 1
+	var/i = DS2TICKS(initial_delay)
 	do
-		. += round(i*DELTA_CALC)
+		. += CEILING(i*DELTA_CALC, 1)
 		sleep(i*world.tick_lag*DELTA_CALC)
 		i *= 2
 	while (TICK_USAGE > min(TICK_LIMIT_TO_RUN, Master.current_ticklimit))
+
+#undef DELTA_CALC

code/controllers/master.dm

@@ -12,7 +12,7 @@ var/datum/controller/master/Master = new()
 	name = "Master"
 
 	// Are we processing (higher values increase the processing delay by n ticks)
-	var/processing = 1
+	var/processing = TRUE
 	// How many times have we ran
 	var/iteration = 0
 
@@ -27,7 +27,7 @@ var/datum/controller/master/Master = new()
 	var/init_time
 	var/tickdrift = 0
 
-	var/sleep_delta
+	var/sleep_delta = 1
 
 	var/make_runtime = 0
 
@@ -77,7 +77,9 @@ var/datum/controller/master/Master = new()
 	sortTim(subsystems, /proc/cmp_subsystem_init)
 	reverseRange(subsystems)
 	for(var/datum/controller/subsystem/ss in subsystems)
+		log_world("Shutting down [ss.name] subsystem...")
 		ss.Shutdown()
+	log_world("Shutdown complete")
 
 // Returns 1 if we created a new mc, 0 if we couldn't due to a recent restart,
 //	-1 if we encountered a runtime trying to recreate it
@@ -91,7 +93,7 @@ var/datum/controller/master/Master = new()
 	var/delay = 50 * ++Master.restart_count
 	Master.restart_timeout = world.time + delay
 	Master.restart_clear = world.time + (delay * 2)
-	Master.processing = 0 //stop ticking this one
+	Master.processing = FALSE //stop ticking this one
 	try
 		new/datum/controller/master()
 	catch
@@ -267,35 +269,45 @@ var/datum/controller/master/Master = new()
 
 	iteration = 1
 	var/error_level = 0
-	var/sleep_delta = 0
+	var/sleep_delta = 1
 	var/list/subsystems_to_check
 	//the actual loop.
+
 	while (1)
 		tickdrift = max(0, MC_AVERAGE_FAST(tickdrift, (((REALTIMEOFDAY - init_timeofday) - (world.time - init_time)) / world.tick_lag)))
+		var/starting_tick_usage = TICK_USAGE
 		if (processing <= 0)
 			current_ticklimit = TICK_LIMIT_RUNNING
 			sleep(10)
 			continue
 
-		//if there are mutiple sleeping procs running before us hogging the cpu, we have to run later
-		//	because sleeps are processed in the order received, so longer sleeps are more likely to run first
-		if (TICK_USAGE > TICK_LIMIT_MC)
-			sleep_delta += 2
+		//Anti-tick-contention heuristics:
+		//if there are mutiple sleeping procs running before us hogging the cpu, we have to run later.
+		//	(because sleeps are processed in the order received, longer sleeps are more likely to run first)
+		if (starting_tick_usage > TICK_LIMIT_MC) //if there isn't enough time to bother doing anything this tick, sleep a bit.
+			sleep_delta *= 2
 			current_ticklimit = TICK_LIMIT_RUNNING * 0.5
-			sleep(world.tick_lag * (processing + sleep_delta))
+			sleep(world.tick_lag * (processing * sleep_delta))
 			continue
 
-		sleep_delta = MC_AVERAGE_FAST(sleep_delta, 0)
-		if (last_run + (world.tick_lag * processing) > world.time)
-			sleep_delta += 1
-		if (TICK_USAGE > (TICK_LIMIT_MC*0.5))
+		//Byond resumed us late. assume it might have to do the same next tick
+		if (last_run + CEILING(world.tick_lag * (processing * sleep_delta), world.tick_lag) < world.time)
 			sleep_delta += 1
 
+		sleep_delta = MC_AVERAGE_FAST(sleep_delta, 1) //decay sleep_delta
+
+		if (starting_tick_usage > (TICK_LIMIT_MC*0.75)) //we ran 3/4 of the way into the tick
+			sleep_delta += 1
+
+		//debug
 		if (make_runtime)
 			var/datum/controller/subsystem/SS
 			SS.can_fire = 0
+
 		if (!Failsafe || (Failsafe.processing_interval > 0 && (Failsafe.lasttick+(Failsafe.processing_interval*5)) < world.time))
 			new/datum/controller/failsafe() // (re)Start the failsafe.
+
+		//now do the actual stuff
 		if (!queue_head || !(iteration % 3))
 			var/checking_runlevel = current_runlevel
 			if(cached_runlevel != checking_runlevel)
@@ -312,6 +324,7 @@ var/datum/controller/master/Master = new()
 			subsystems_to_check = current_runlevel_subsystems
 		else
 			subsystems_to_check = tickersubsystems
+
 		if (CheckQueue(subsystems_to_check) <= 0)
 			if (!SoftReset(tickersubsystems, runlevel_sorted_subsystems))
 				log_world("MC: SoftReset() failed, crashing")
@@ -342,8 +355,10 @@ var/datum/controller/master/Master = new()
 		iteration++
 		last_run = world.time
 		src.sleep_delta = MC_AVERAGE_FAST(src.sleep_delta, sleep_delta)
-		current_ticklimit = TICK_LIMIT_RUNNING - (TICK_LIMIT_RUNNING * 0.25) //reserve the tail 1/4 of the next tick for the mc.
-		sleep(world.tick_lag * (processing + sleep_delta))
+		current_ticklimit = TICK_LIMIT_RUNNING
+		if (processing * sleep_delta <= world.tick_lag)
+			current_ticklimit -= (TICK_LIMIT_RUNNING * 0.25) //reserve the tail 1/4 of the next tick for the mc if we plan on running next tick
+		sleep(world.tick_lag * (processing * sleep_delta))
 
 
 

code/controllers/subsystem.dm

@@ -31,8 +31,7 @@
 	var/static/list/failure_strikes //How many times we suspect a subsystem type has crashed the MC, 3 strikes and you're out!
 
 //Do not override
-/datum/controller/subsystem/New()
-	return
+///datum/controller/subsystem/New()
 
 // Used to initialize the subsystem BEFORE the map has loaded
 // Called AFTER Recover if that is called
@@ -66,7 +65,7 @@
 	can_fire = 0
 	flags |= SS_NO_FIRE
 	Master.subsystems -= src
-
+	return ..()
 
 //Queue it to run.
 //	(we loop thru a linked list until we get to the end or find the right point)

code/modules/client/client procs.dm

@@ -296,8 +296,7 @@
 	if (holder)
 		sleep(1)
 	else
-		sleep(5)
-		stoplag()
+		stoplag(5)
 
 /client/proc/last_activity_seconds()
 	return inactivity / 10

code/modules/mob/living/simple_animal/simple_animal.dm

@@ -1165,7 +1165,7 @@
 	//They ran away!
 	else
 		ai_log("AttackTarget() out of range!",3)
-		sleep(1) // Unfortunately this is needed to protect from ClosestDistance() sometimes not updating fast enough to prevent an infinite loop.
+		stoplag(1) // Unfortunately this is needed to protect from ClosestDistance() sometimes not updating fast enough to prevent an infinite loop.
 		handle_stance(STANCE_ATTACK)
 		return 0