Paper/Spigot-Server-Patches/0456-Allow-multiple-callbacks-to-schedule-for-Callback-Ex.patch
Mariell Hoversholm 0f78e95250 More work
2021-03-18 18:03:22 +01:00

59 lines
2.4 KiB
Diff

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/PlayerChunkMap.java b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
index 94860c06717e8dcf969277562e88687e9a99aaa4..1b309682b58a2ef52b973181aefb0136f1aa3e80 100644
--- a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
@@ -162,24 +162,32 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
public final CallbackExecutor callbackExecutor = new CallbackExecutor();
public static final class CallbackExecutor implements java.util.concurrent.Executor, Runnable {
- private Runnable queued;
+ // 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.ArrayDeque<Runnable> queued = new java.util.ArrayDeque<>();
@Override
public void execute(Runnable runnable) {
- if (queued != null) {
- throw new IllegalStateException("Already queued");
+ if (queued == null) {
+ queued = new java.util.ArrayDeque<>();
}
- queued = runnable;
+ queued.add(runnable);
}
@Override
public void run() {
- Runnable task = queued;
+ if (queued == null) {
+ return;
+ }
+ java.util.ArrayDeque<Runnable> queue = queued;
queued = null;
- if (task != null) {
+ Runnable task;
+ while ((task = queue.pollFirst()) != null) {
task.run();
}
}
+ // Paper end
};
// CraftBukkit end