Use mojang item ids for alternative item despawn rate (#6997)

patches/server/0723-Make-CallbackExecutor-strict-again.patch

@@ -0,0 +1,48 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <spottedleaf@spottedleaf.dev>
+Date: Fri, 24 Apr 2020 09:06:15 -0700
+Subject: [PATCH] Make CallbackExecutor strict again
+
+The correct fix for double scheduling is to avoid it. The reason
+this class is used is because double scheduling causes issues
+elsewhere, and it acts as an explicit detector of what double
+schedules. Effectively, use the callback executor as a tool of
+finding issues rather than hiding these issues.
+
+diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
+index 104e7d0c18b032ee8198c4de25a57676d0f64745..d53ff732a503eab3aea0384475f8a56d3076828d 100644
+--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
++++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
+@@ -164,17 +164,28 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+     public final CallbackExecutor callbackExecutor = new CallbackExecutor();
+     public static final class CallbackExecutor implements java.util.concurrent.Executor, Runnable {
+ 
+-        private final java.util.Queue<Runnable> queue = new java.util.ArrayDeque<>();
++        private Runnable queued; // Paper - revert CB changes
+ 
+         @Override
+         public void execute(Runnable runnable) {
+-            this.queue.add(runnable);
++            // Paper start - revert CB changes
++            org.spigotmc.AsyncCatcher.catchOp("Callback Executor execute");
++            if (this.queued != null) {
++                LOGGER.error("Failed to schedule runnable", new IllegalStateException("Already queued"));
++                throw new IllegalStateException("Already queued");
++            }
++            this.queued = runnable;
++            // Paper end - revert CB changes
+         }
+ 
+         @Override
+         public void run() {
+-            Runnable task;
+-            while ((task = this.queue.poll()) != null) {
++            // Paper start - revert CB changes
++            org.spigotmc.AsyncCatcher.catchOp("Callback Executor execute");
++            Runnable task = this.queued;
++            if (task != null) {
++                this.queued = null;
++                // Paper end - revert CB changes
+                 task.run();
+             }
+         }