From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Sat, 3 Oct 2020 04:15:09 -0400
Subject: [PATCH] Lazily track plugin scoreboards by default

On servers with plugins that constantly churn through scoreboards, there is a risk of
degraded GC performance due to the number of scoreboards held on by weak references.
Most plugins don't even need the (vanilla) functionality that requires all plugin
scoreboards to be tracked by the server. Instead, only track scoreboards when an
objective is added with a non-dummy criteria.

This is a breaking change, however the change is a much more sensible default. In case
this breaks your workflow you can always force all scoreboards to be tracked with
settings.track-plugin-scoreboards in paper.yml.

diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 545948f20efd6c8dd42140b565af94cd6b52b661..7d50aded88f5b7dfebaea1aebc86231f7b5c4e25 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -462,4 +462,9 @@ public class PaperConfig {
     private static void maxJoinsPerTick() {
         maxJoinsPerTick = getInt("settings.max-joins-per-tick", 3);
     }
+
+    public static boolean trackPluginScoreboards;
+    private static void trackPluginScoreboards() {
+        trackPluginScoreboards = getBoolean("settings.track-plugin-scoreboards", false);
+    }
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
index 4c93be31fd95d731327479519ecb34a08785c1ca..57537b8871dd5c54d97f3effe1802a3396644e46 100644
--- a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
+++ b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
@@ -18,6 +18,7 @@ import org.bukkit.scoreboard.Team;
 
 public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
     final Scoreboard board;
+    boolean registeredGlobally = false; // Paper
 
     CraftScoreboard(Scoreboard board) {
         this.board = board;
@@ -44,6 +45,12 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
         Validate.isTrue(name.length() <= 16, "The name '" + name + "' is longer than the limit of 16 characters");
         Validate.isTrue(board.getObjective(name) == null, "An objective of name '" + name + "' already exists");
         CraftCriteria craftCriteria = CraftCriteria.getFromBukkit(criteria);
+        // Paper start - the block comment from the old registerNewObjective didnt cause a conflict when rebasing, so this block wasn't added to the adventure registerNewObjective
+        if (craftCriteria.criteria != net.minecraft.world.scores.criteria.ObjectiveCriteria.DUMMY && !registeredGlobally) {
+            net.minecraft.server.MinecraftServer.getServer().server.getScoreboardManager().registerScoreboardForVanilla(this);
+            registeredGlobally = true;
+        }
+        // Paper end
         net.minecraft.world.scores.Objective objective = board.registerObjective(name, craftCriteria.criteria, io.papermc.paper.adventure.PaperAdventure.asVanilla(displayName), CraftScoreboardTranslations.fromBukkitRender(renderType));
         return new CraftObjective(this, objective);
     }
@@ -65,6 +72,12 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
         Validate.isTrue(board.getObjective(name) == null, "An objective of name '" + name + "' already exists");
 
         CraftCriteria craftCriteria = CraftCriteria.getFromBukkit(criteria);
+        // Paper start
+        if (craftCriteria.criteria != net.minecraft.server.IScoreboardCriteria.DUMMY && !registeredGlobally) {
+            net.minecraft.server.MinecraftServer.getServer().server.getScoreboardManager().registerScoreboardForVanilla(this);
+            registeredGlobally = true;
+        }
+        // Paper end
         ScoreboardObjective objective = board.registerObjective(name, craftCriteria.criteria, CraftChatMessage.fromStringOrNull(displayName), CraftScoreboardTranslations.fromBukkitRender(renderType));
         return new CraftObjective(this, objective);*/ // Paper
         return registerNewObjective(name, criteria, io.papermc.paper.adventure.PaperAdventure.LEGACY_SECTION_UXRC.deserialize(displayName), renderType); // Paper
diff --git a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
index 30b0d4986a7edcf324d94d9304d66d0567098855..8217e35f5a3093e63a165ee8c8b30bf3f28f3bd3 100644
--- a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
+++ b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
@@ -30,6 +30,7 @@ public final class CraftScoreboardManager implements ScoreboardManager {
 
     public CraftScoreboardManager(MinecraftServer minecraftserver, net.minecraft.world.scores.Scoreboard scoreboardServer) {
         mainScoreboard = new CraftScoreboard(scoreboardServer);
+        mainScoreboard.registeredGlobally = true; // Paper
         server = minecraftserver;
         scoreboards.add(mainScoreboard);
     }
@@ -43,10 +44,22 @@ public final class CraftScoreboardManager implements ScoreboardManager {
     public CraftScoreboard getNewScoreboard() {
         org.spigotmc.AsyncCatcher.catchOp("scoreboard creation"); // Spigot
         CraftScoreboard scoreboard = new CraftScoreboard(new ServerScoreboard(server));
+        // Paper start
+        if (com.destroystokyo.paper.PaperConfig.trackPluginScoreboards) {
+            scoreboard.registeredGlobally = true;
         scoreboards.add(scoreboard);
+        }
+        // Paper end
         return scoreboard;
     }
 
+    // Paper start
+    public void registerScoreboardForVanilla(CraftScoreboard scoreboard) {
+        org.spigotmc.AsyncCatcher.catchOp("scoreboard registration");
+        scoreboards.add(scoreboard);
+    }
+    // Paper end
+
     // CraftBukkit method
     public CraftScoreboard getPlayerBoard(CraftPlayer player) {
         CraftScoreboard board = playerBoards.get(player);