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/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
index 2471a6d0b7a8086cf4c0a41b10c05ed50d790d11..e233eef291f64622947b0b6c4559639e510c087f 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;
@@ -50,6 +51,12 @@ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
         Preconditions.checkArgument(renderType != null, "RenderType cannot be null");
         Preconditions.checkArgument(name.length() <= Short.MAX_VALUE, "The name '%s' is longer than the limit of 32767 characters (%s)", name, name.length());
         Preconditions.checkArgument(this.board.getObjective(name) == null, "An objective of name '%s' already exists", name);
+        // 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).criteria != net.minecraft.world.scores.criteria.ObjectiveCriteria.DUMMY && !this.registeredGlobally) {
+            net.minecraft.server.MinecraftServer.getServer().server.getScoreboardManager().registerScoreboardForVanilla(this);
+            this.registeredGlobally = true;
+        }
+        // Paper end
         net.minecraft.world.scores.Objective objective = board.addObjective(name, ((CraftCriteria) criteria).criteria, io.papermc.paper.adventure.PaperAdventure.asVanilla(displayName), CraftScoreboardTranslations.fromBukkitRender(renderType));
         return new CraftObjective(this, objective);
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
index d3855731f9b63357ebe4f8f4d5941b5353dff935..6fcb2356b471c5a61faa0813a891c3898683d01f 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) {
         this.mainScoreboard = new CraftScoreboard(scoreboardServer);
+        mainScoreboard.registeredGlobally = true; // Paper
         this.server = minecraftserver;
         this.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(this.server));
-        this.scoreboards.add(scoreboard);
+        // Paper start
+        if (io.papermc.paper.configuration.GlobalConfiguration.get().scoreboards.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 = this.playerBoards.get(player);