1 files changed, 76 insertions, 0 deletions
diff --git a/patches/server/0421-Lazily-track-plugin-scoreboards-by-default.patch b/patches/server/0421-Lazily-track-plugin-scoreboards-by-default.patch
new file mode 100644
index 0000000000..28ae9df043
--- /dev/null
+++ b/patches/server/0421-Lazily-track-plugin-scoreboards-by-default.patch
@@ -0,0 +1,76 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Andrew Steinborn <[email protected]>
+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 5681630159bb52628e6cc391db324bbafe333414..c650fc3712de01184509a03f1d1b388859e163d7 100644
+--- a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
++++ b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboard.java
+@@ -20,6 +20,7 @@ import org.bukkit.scoreboard.Team;
+ 
+ public final class CraftScoreboard implements org.bukkit.scoreboard.Scoreboard {
+     final Scoreboard board;
++    boolean registeredGlobally = false; // Paper - Lazily track plugin scoreboards by default
+ 
+     CraftScoreboard(Scoreboard board) {
+         this.board = board;
+@@ -52,6 +53,12 @@ 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 - lazily track plugin scoreboards
++        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 - lazily track plugin scoreboards
+         net.minecraft.world.scores.Objective objective = this.board.addObjective(name, ((CraftCriteria) criteria).criteria, io.papermc.paper.adventure.PaperAdventure.asVanilla(displayName), CraftScoreboardTranslations.fromBukkitRender(renderType), true, null);
+         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 40e348cae063bc1a814f8fcc3a2688c135f23bb5..c7ca6210d6ae37fe95068c9baa5fb654f95307e0 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(this.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);