Combined unit and weapon slow update loops.

Fix #4862
If a unit was inserted during the unit slowUpdate process, between
activeSlowUpdateWeapon and activeSlowUpdateUnit, it caused them to diverge
(because the new unit had its weapons slowupdated instead of another
unit).
Then when the activeSlowUpdateWeapon was deleted, the iterator wasn't
advanced (since the test only checks activeSlowUpdateUnit).

rts/Sim/Units/UnitHandler.cpp

@@ -37,7 +37,6 @@ CR_REG_METADATA(CUnitHandler, (
 	CR_MEMBER(idPool),
 	CR_MEMBER(unitsToBeRemoved),
 	CR_IGNORED(activeSlowUpdateUnit),
-	CR_IGNORED(activeSlowUpdateWeapon),
 	CR_MEMBER(maxUnits),
 	CR_MEMBER(maxUnitRadius),
 	CR_POSTLOAD(PostLoad)
@@ -49,7 +48,6 @@ void CUnitHandler::PostLoad()
 {
 	// reset any synced stuff that is not saved
 	activeSlowUpdateUnit = activeUnits.end();
-	activeSlowUpdateWeapon = activeUnits.end();
 }
 
 
@@ -77,7 +75,6 @@ CUnitHandler::CUnitHandler()
 	idPool.Expand(0, units.size());
 
 	activeSlowUpdateUnit = activeUnits.end();
-	activeSlowUpdateWeapon = activeUnits.end();
 	airBaseHandler = new CAirBaseHandler();
 }
 
@@ -142,7 +139,6 @@ void CUnitHandler::DeleteUnitNow(CUnit* delUnit)
 {
 	if (activeSlowUpdateUnit != activeUnits.end() && delUnit == *activeSlowUpdateUnit) {
 		++activeSlowUpdateUnit;
-		++activeSlowUpdateWeapon;
 	}
 
 	for (auto usi = activeUnits.begin(); usi != activeUnits.end(); ++usi) {
@@ -273,30 +269,13 @@ void CUnitHandler::Update()
 
 			UNIT_SANITY_CHECK(unit);
 			unit->SlowUpdate();
+			unit->SlowUpdateWeapons();
 			UNIT_SANITY_CHECK(unit);
 
 			n--;
 		}
 	}
 
-	{
-		SCOPED_TIMER("Unit::Weapon::SlowUpdate");
-
-		// reset the iterator every <UNIT_SLOWUPDATE_RATE> frames
-		if ((gs->frameNum % UNIT_SLOWUPDATE_RATE) == 0) {
-			activeSlowUpdateWeapon = activeUnits.begin();
-		}
-
-		// stagger the SlowUpdate's
-		unsigned int n = (activeUnits.size() / UNIT_SLOWUPDATE_RATE) + 1;
-
-		for (; activeSlowUpdateWeapon != activeUnits.end() && n != 0; ++activeSlowUpdateWeapon) {
-			CUnit* unit = *activeSlowUpdateWeapon;
-			unit->SlowUpdateWeapons();
-			n--;
-		}
-	}
-
 	{
 		SCOPED_TIMER("Unit::Update");
 

rts/Sim/Units/UnitHandler.h

@@ -66,7 +66,6 @@ class CUnitHandler
 
 	std::vector<CUnit*> unitsToBeRemoved;              ///< units that will be removed at start of next update
 	std::list<CUnit*>::iterator activeSlowUpdateUnit;  ///< first unit of batch that will be SlowUpdate'd this frame
-	std::list<CUnit*>::iterator activeSlowUpdateWeapon;
 
 	///< global unit-limit (derived from the per-team limit)
 	///< units.size() is equal to this and constant at runtime