papermc/patches/server/0420-Allow-multiple-callbacks-to-schedule-for-Callback-Ex.patch
2021-06-15 21:53:50 -07:00

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2.3 KiB
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 21 Apr 2020 03:51:53 -0400
Subject: [PATCH] Allow multiple callbacks to schedule for Callback Executor
ChunkMapDistance polls multiple entries for pendingChunkUpdates
Each of these have the potential to move a chunk in and out of
"Loaded" state, which will result in multiple callbacks being
needed within a single tick of ChunkMapDistance
Use an ArrayDeque to store this Queue
We make sure to also implement a pattern that is recursion safe too.
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index b64a3dd03a22542b070eae34f0eaa9b321dca4ec..218a20e85c9b6d31bcdf5432f4ea9cf0c0d7b952 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -173,17 +173,29 @@ 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<>();
+ // Paper start - replace impl with recursive safe multi entry queue
+ // it's possible to schedule multiple tasks currently, so it's vital we change this impl
+ // If we recurse into the executor again, we will append to another queue, ensuring task order consistency
+ private java.util.Queue<Runnable> queue = new java.util.ArrayDeque<>(); // Paper - remove final
@Override
public void execute(Runnable runnable) {
+ if (this.queue == null) {
+ this.queue = new java.util.ArrayDeque<>();
+ }
this.queue.add(runnable);
}
@Override
public void run() {
+ if (this.queue == null) {
+ return;
+ }
+ java.util.Queue<Runnable> queue = this.queue;
+ this.queue = null;
+ // Paper end
Runnable task;
- while ((task = this.queue.poll()) != null) {
+ while ((task = queue.poll()) != null) { // Paper
task.run();
}
}