Use a Queue for Queueing Commands

Lists are bad as Queues mmmkay.

paper-server/patches/sources/net/minecraft/server/dedicated/DedicatedServer.java.patch

@@ -1,6 +1,6 @@
 --- a/net/minecraft/server/dedicated/DedicatedServer.java
 +++ b/net/minecraft/server/dedicated/DedicatedServer.java
-@@ -54,11 +54,22 @@
+@@ -54,20 +54,31 @@
  import net.minecraft.world.entity.player.Player;
  import net.minecraft.world.level.GameRules;
  import net.minecraft.world.level.GameType;
@@ -24,8 +24,10 @@
  public class DedicatedServer extends MinecraftServer implements ServerInterface {
  
      static final Logger LOGGER = LogUtils.getLogger();
-@@ -67,7 +78,7 @@
-     private final List<ConsoleInput> consoleInput = Collections.synchronizedList(Lists.newArrayList());
+     private static final int CONVERSION_RETRY_DELAY_MS = 5000;
+     private static final int CONVERSION_RETRIES = 2;
+-    private final List<ConsoleInput> consoleInput = Collections.synchronizedList(Lists.newArrayList());
++    private final java.util.Queue<ConsoleInput> serverCommandQueue = new java.util.concurrent.ConcurrentLinkedQueue<>(); // Paper - Perf: use a proper queue
      @Nullable
      private QueryThreadGs4 queryThreadGs4;
 -    private final RconConsoleSource rconConsoleSource;
@@ -171,16 +173,17 @@
          DedicatedServer.LOGGER.info("Default game type: {}", dedicatedserverproperties.gamemode);
          InetAddress inetaddress = null;
  
-@@ -156,21 +247,34 @@
+@@ -155,22 +246,35 @@
+             DedicatedServer.LOGGER.warn("Perhaps a server is already running on that port?");
              return false;
          }
- 
++
 +        // CraftBukkit start
 +        // this.setPlayerList(new DedicatedPlayerList(this, this.registries(), this.playerDataStorage)); // Spigot - moved up
 +        this.server.loadPlugins();
 +        this.server.enablePlugins(org.bukkit.plugin.PluginLoadOrder.STARTUP);
 +        // CraftBukkit end
-+
+ 
          if (!this.usesAuthentication()) {
              DedicatedServer.LOGGER.warn("**** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!");
              DedicatedServer.LOGGER.warn("The server will make no attempt to authenticate usernames. Beware.");
@@ -234,20 +237,19 @@
                  Thread thread1 = new Thread(new ServerWatchdog(this));
  
                  thread1.setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandlerWithName(DedicatedServer.LOGGER));
-@@ -213,7 +317,13 @@
- 
-             return true;
+@@ -215,6 +319,12 @@
          }
-+    }
-+
+     }
+ 
 +    // Paper start
 +    public java.io.File getPluginsFolder() {
 +        return (java.io.File) this.options.valueOf("plugins");
-     }
++    }
 +    // Paper end
- 
++
      @Override
      public boolean isSpawningMonsters() {
+         return this.settings.getProperties().spawnMonsters && super.isSpawningMonsters();
 @@ -293,6 +403,7 @@
              this.queryThreadGs4.stop();
          }
@@ -256,7 +258,7 @@
      }
  
      @Override
-@@ -302,8 +413,8 @@
+@@ -302,19 +413,29 @@
      }
  
      @Override
@@ -267,9 +269,17 @@
      }
  
      public void handleConsoleInput(String command, CommandSourceStack commandSource) {
-@@ -314,7 +425,15 @@
-         while (!this.consoleInput.isEmpty()) {
-             ConsoleInput servercommand = (ConsoleInput) this.consoleInput.remove(0);
+-        this.consoleInput.add(new ConsoleInput(command, commandSource));
++        this.serverCommandQueue.add(new ConsoleInput(command, commandSource)); // Paper - Perf: use proper queue
+     }
+ 
+     public void handleConsoleInputs() {
+-        while (!this.consoleInput.isEmpty()) {
+-            ConsoleInput servercommand = (ConsoleInput) this.consoleInput.remove(0);
++        // Paper start - Perf: use proper queue
++        ConsoleInput servercommand;
++        while ((servercommand = this.serverCommandQueue.poll()) != null) {
++            // Paper end - Perf: use proper queue
  
 -            this.getCommands().performPrefixedCommand(servercommand.source, servercommand.msg);
 +            // CraftBukkit start - ServerCommand for preprocessing
@@ -284,7 +294,7 @@
          }
  
      }
-@@ -383,7 +502,7 @@
+@@ -383,7 +504,7 @@
  
      @Override
      public boolean isUnderSpawnProtection(ServerLevel world, BlockPos pos, Player player) {
@@ -293,7 +303,7 @@
              return false;
          } else if (this.getPlayerList().getOps().isEmpty()) {
              return false;
-@@ -453,7 +572,11 @@
+@@ -453,7 +574,11 @@
      public boolean enforceSecureProfile() {
          DedicatedServerProperties dedicatedserverproperties = this.getProperties();
  
@@ -306,7 +316,7 @@
      }
  
      @Override
-@@ -541,16 +664,52 @@
+@@ -541,16 +666,52 @@
  
      @Override
      public String getPluginNames() {
@@ -363,7 +373,7 @@
      }
  
      public void storeUsingWhiteList(boolean useWhitelist) {
-@@ -660,4 +819,15 @@
+@@ -660,4 +821,15 @@
              }
          }
      }