Performance: Added transient builtBuildingObjects list in cittyConstructions, so we won't have to get the list every time we want to calculate, well, loads of stuff

core/src/com/unciv/logic/battle/Battle.kt

@@ -143,14 +143,14 @@ class Battle(val gameInfo:GameInfo) {
         }
 
         if(city.cityConstructions.isBuilt("Palace")){
-            city.cityConstructions.builtBuildings.remove("Palace")
+            city.cityConstructions.removeBuilding("Palace")
             if(enemyCiv.isDefeated()) {
                 gameInfo.getPlayerCivilization()
                         .addNotification("The civilization of [${enemyCiv.civName}] has been destroyed!", null, Color.RED)
                 enemyCiv.getCivUnits().forEach { it.destroy() }
             }
             else if(enemyCiv.cities.isNotEmpty()){
-                enemyCiv.cities.first().cityConstructions.builtBuildings.add("Palace") // relocate palace
+                enemyCiv.cities.first().cityConstructions.addBuilding("Palace") // relocate palace
             }
         }
 

core/src/com/unciv/logic/city/CityConstructions.kt

@@ -6,12 +6,15 @@ import com.unciv.models.gamebasics.Building
 import com.unciv.models.gamebasics.GameBasics
 import com.unciv.models.stats.Stats
 import com.unciv.ui.utils.tr
+import com.unciv.ui.utils.withItem
+import com.unciv.ui.utils.withoutItem
 import java.util.*
+import kotlin.collections.ArrayList
 
 
 class CityConstructions {
-    @Transient
+    @Transient lateinit var cityInfo: CityInfo
-    lateinit var cityInfo: CityInfo
+    @Transient private var builtBuildingObjects=ArrayList<Building>()
 
     var builtBuildings = ArrayList<String>()
     private val inProgressConstructions = HashMap<String, Int>()
@@ -89,7 +92,7 @@ class CityConstructions {
         throw NotBuildingOrUnitException("$constructionName is not a building or a unit!")
     }
 
-    internal fun getBuiltBuildings(): List<Building> = builtBuildings.toList().map { GameBasics.Buildings[it]!! } // toList os to avoid concurrency problems
+    internal fun getBuiltBuildings(): List<Building> = builtBuildingObjects // toList os to avoid concurrency problems
 
     fun containsBuildingOrEquivalent(building: String): Boolean =
             isBuilt(building) || getBuiltBuildings().any{it.replaces==building}
@@ -113,9 +116,13 @@ class CityConstructions {
     //endregion
 
     //region state changing functions
-    fun addConstruction(constructionToAdd: Int) {
+    fun setTransients(){
+        builtBuildingObjects = ArrayList(builtBuildings.map { GameBasics.Buildings[it]!! })
+    }
+
+    fun addProduction(productionToAdd: Int) {
         if (!inProgressConstructions.containsKey(currentConstruction)) inProgressConstructions[currentConstruction] = 0
-        inProgressConstructions[currentConstruction] = inProgressConstructions[currentConstruction]!! + constructionToAdd
+        inProgressConstructions[currentConstruction] = inProgressConstructions[currentConstruction]!! + productionToAdd
     }
 
     fun nextTurn(cityStats: Stats) {
@@ -136,26 +143,41 @@ class CityConstructions {
         var productionToAdd = cityStats.production
         if(!cityInfo.civInfo.isPlayerCivilization())
             productionToAdd *= cityInfo.civInfo.gameInfo.getPlayerCivilization().getDifficulty().aiConstructionModifier
-        addConstruction(Math.round(cityStats.production))
+        addProduction(Math.round(cityStats.production))
         val productionCost = construction.getProductionCost(cityInfo.civInfo.policies.adoptedPolicies)
         if (inProgressConstructions[currentConstruction]!! >= productionCost) {
-            construction.postBuildEvent(this)
+            constructionComplete(construction)
-            inProgressConstructions.remove(currentConstruction)
-
-            if(construction is Building && construction.isWonder && construction.requiredBuildingInAllCities==null) {
-                val playerCiv = cityInfo.civInfo.gameInfo.getPlayerCivilization() 
-                val builtLocation = if(playerCiv.exploredTiles.contains(cityInfo.location)) cityInfo.name else "a faraway land"
-                playerCiv.addNotification("[$currentConstruction] has been built in [$builtLocation]", cityInfo.location, Color.BROWN)
-            }
-            else
-                cityInfo.civInfo.addNotification("[$currentConstruction] has been built in [" + cityInfo.name+"]", cityInfo.location, Color.BROWN)
-
-            currentConstruction=""
-            Automation().chooseNextConstruction(this)
         }
 
     }
 
+    fun constructionComplete(construction: IConstruction) {
+        construction.postBuildEvent(this)
+        inProgressConstructions.remove(currentConstruction)
+
+        if (construction is Building && construction.isWonder && construction.requiredBuildingInAllCities == null) {
+            val playerCiv = cityInfo.civInfo.gameInfo.getPlayerCivilization()
+            val builtLocation = if (playerCiv.exploredTiles.contains(cityInfo.location)) cityInfo.name else "a faraway land"
+            playerCiv.addNotification("[$currentConstruction] has been built in [$builtLocation]", cityInfo.location, Color.BROWN)
+        } else
+            cityInfo.civInfo.addNotification("[$currentConstruction] has been built in [" + cityInfo.name + "]", cityInfo.location, Color.BROWN)
+
+        currentConstruction = ""
+        Automation().chooseNextConstruction(this)
+    }
+
+    fun addBuilding(buildingName:String){
+        val buildingObject = GameBasics.Buildings[buildingName]!!
+        builtBuildingObjects = builtBuildingObjects.withItem(buildingObject)
+        builtBuildings.add(buildingName)
+    }
+
+    fun removeBuilding(buildingName:String){
+        val buildingObject = GameBasics.Buildings[buildingName]!!
+        builtBuildingObjects = builtBuildingObjects.withoutItem(buildingObject)
+        builtBuildings.remove(buildingName)
+    }
+
     fun purchaseBuilding(buildingName: String) {
         cityInfo.civInfo.gold -= getConstruction(buildingName).getGoldCost(cityInfo.civInfo.policies.adoptedPolicies)
         getConstruction(buildingName).postBuildEvent(this)

core/src/com/unciv/logic/city/CityInfo.kt

@@ -54,7 +54,7 @@ class CityInfo {
             civInfo.addNotification("[$name] has been founded!", cityLocation, Color.PURPLE)
         if (civInfo.policies.isAdopted("Legalism") && civInfo.cities.size <= 4) cityConstructions.addCultureBuilding()
         if (civInfo.cities.size == 1) {
-            cityConstructions.builtBuildings.add("Palace")
+            cityConstructions.addBuilding("Palace")
             cityConstructions.currentConstruction = "Worker" // Default for first city only!
         }
 
@@ -159,7 +159,7 @@ class CityInfo {
         expansion.setTransients()
         cityStats.cityInfo = this
         cityConstructions.cityInfo = this
-
+        cityConstructions.setTransients()
     }
 
     fun endTurn() {
@@ -178,7 +178,7 @@ class CityInfo {
                 civInfo.addNotification("[$name] has been razed to the ground!",location, Color.RED)
                 destroyCity()
                 if(isCapital() && civInfo.cities.isNotEmpty()) // Yes, we actually razed the capital. Some people do this.
-                    civInfo.cities.first().cityConstructions.builtBuildings.add("Palace")
+                    civInfo.cities.first().cityConstructions.addBuilding("Palace")
             }
         }
         else population.nextTurn(stats.food)
@@ -206,7 +206,7 @@ class CityInfo {
 
         // Remove all national wonders
         for(building in cityConstructions.getBuiltBuildings().filter { it.requiredBuildingInAllCities!=null })
-            cityConstructions.builtBuildings.remove(building.name)
+            cityConstructions.removeBuilding(building.name)
         isBeingRazed=false
     }
     //endregion

core/src/com/unciv/logic/city/CityStats.kt

@@ -210,7 +210,7 @@ class CityStats {
             stats.production += 5f
         if(policies.contains("Warrior Code") && currentConstruction is BaseUnit && currentConstruction.unitType.isMelee())
             stats.production += 20
-        if (policies.contains("Reformation") && cityConstructions.builtBuildings.any { GameBasics.Buildings[it]!!.isWonder })
+        if (policies.contains("Reformation") && cityConstructions.getBuiltBuildings().any { it.isWonder })
             stats.culture += 33f
         if (policies.contains("Commerce") && cityInfo.isCapital())
             stats.gold += 25f

core/src/com/unciv/logic/civilization/TechManager.kt

@@ -6,6 +6,7 @@ import com.unciv.models.gamebasics.GameBasics
 import com.unciv.models.gamebasics.tech.Technology
 import com.unciv.models.gamebasics.unit.BaseUnit
 import com.unciv.ui.utils.tr
+import com.unciv.ui.utils.withItem
 import java.util.*
 
 class TechManager {
@@ -77,9 +78,7 @@ class TechManager {
         techsResearched.add(currentTechnology)
 
         // this is to avoid concurrent modification problems
-        val newResearchedTechnologies = ArrayList(researchedTechnologies)
+        researchedTechnologies = researchedTechnologies.withItem(GameBasics.Technologies[currentTechnology]!!)
-        newResearchedTechnologies.add(GameBasics.Technologies[currentTechnology]!!)
-        researchedTechnologies = newResearchedTechnologies
 
         civInfo.addNotification("Research of [$currentTechnology] has completed!", null, Color.BLUE)
 

core/src/com/unciv/models/gamebasics/Building.kt

@@ -214,10 +214,10 @@ class Building : NamedStats(), IConstruction{
             civInfo.scienceVictory.currentParts.add(name, 1)
             return
         }
-        construction.builtBuildings.add(name)
+        construction.addBuilding(name)
 
         if (providesFreeBuilding != null && !construction.builtBuildings.contains(providesFreeBuilding!!))
-            construction.builtBuildings.add(providesFreeBuilding!!)
+            construction.addBuilding(providesFreeBuilding!!)
         when {
             "Empire enters golden age" in uniques-> civInfo.goldenAges.enterGoldenAge()
             "Free Great Artist Appears" in uniques-> civInfo.addGreatPerson("Great Artist")

core/src/com/unciv/ui/utils/CameraStageBaseScreen.kt

@@ -203,4 +203,22 @@ fun Table.addSeparator(): Cell<Image> {
     val cell = add(image).colspan(columns).fill()
     row()
     return cell
+}
+
+/**
+ * Solves concurrent modification problems - everyone who had a reference to the previous arrayList can keep using it because it hasn't changed
+ */
+fun <T> ArrayList<T>.withItem(item:T): ArrayList<T> {
+    val newArrayList = ArrayList(this)
+    newArrayList.add(item)
+    return newArrayList
+}
+
+/**
+ * Solves concurrent modification problems - everyone who had a reference to the previous arrayList can keep using it because it hasn't changed
+ */
+fun <T> ArrayList<T>.withoutItem(item:T): ArrayList<T> {
+    val newArrayList = ArrayList(this)
+    newArrayList.remove(item)
+    return newArrayList
 }

core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt

@@ -168,7 +168,7 @@ class UnitActions {
         if (unit.name == "Great Engineer" && !unit.isEmbarked()) {
             actionList += UnitAction( "Hurry Wonder",
                     {
-                        tile.getCity()!!.cityConstructions.addConstruction(300 + 30 * tile.getCity()!!.population.population) //http://civilization.wikia.com/wiki/Great_engineer_(Civ5)
+                        tile.getCity()!!.cityConstructions.addProduction(300 + 30 * tile.getCity()!!.population.population) //http://civilization.wikia.com/wiki/Great_engineer_(Civ5)
                         unit.destroy()
                     },
                     unit.currentMovement != 0f &&