mirror of
https://github.com/PaperMC/Paper.git
synced 2024-06-30 16:54:55 +02:00
43 lines
2.0 KiB
Diff
43 lines
2.0 KiB
Diff
|
From 0ad488560e10639c5fb359999c8b16487780fd21 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Aikar <aikar@aikar.co>
|
||
|
|
Date: Sat, 18 Apr 2020 04:36:11 -0400
|
||
|
|
Subject: [PATCH] Fix Chunk Post Processing deadlock risk
|
||
|
|
|
||
|
|
See: https://gist.github.com/aikar/dd22bbd2a3d78a2fd3d92e95e9f28dc6
|
||
|
|
|
||
|
|
as part of post processing a chunk, we can call ChunkConverter.
|
||
|
|
|
||
|
|
ChunkConverter then kicks off major physics updates, and when blocks
|
||
|
|
that have connections across chunk boundries occur, a recursive risk
|
||
|
|
can occur where A updates a block that triggers a physics request.
|
||
|
|
|
||
|
|
That physics request may trigger a chunk request, that then enqueues
|
||
|
|
a task into the Mailbox ChunkTaskQueueSorter.
|
||
|
|
|
||
|
|
If anything requests that same chunk that is in the middle of conversion,
|
||
|
|
it's mailbox queue is going to be held up, so the subsequent chunk request
|
||
|
|
will be unable to proceed.
|
||
|
|
|
||
|
|
We delay post processing of Chunk.A() 1 "pass" by re stuffing it back into
|
||
|
|
the executor so that the mailbox ChunkQueue is now considered empty.
|
||
|
|
|
||
|
|
This successfully fixed a reoccurring and highly reproduceable crash
|
||
|
|
for heightmaps.
|
||
|
|
|
||
|
|
diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
|
||
|
|
index c38d31faf..12639dfb9 100644
|
||
|
|
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
|
||
|
|
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
|
||
|
|
@@ -1002,7 +1002,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
|
||
|
|
return Either.left(chunk);
|
||
|
|
});
|
||
|
|
}, (runnable) -> {
|
||
|
|
- this.mailboxMain.a(ChunkTaskQueueSorter.a(playerchunk, runnable)); // CraftBukkit - decompile error
|
||
|
|
+ this.mailboxMain.a(ChunkTaskQueueSorter.a(playerchunk, () -> this.executor.addTask(runnable))); // CraftBukkit - decompile error // Paper - delay running Chunk post processing until outside of the sorter to prevent a deadlock scenario when post processing causes another chunk request.
|
||
|
|
});
|
||
|
|
|
||
|
|
completablefuture1.thenAcceptAsync((either) -> {
|
||
|
|
--
|
||
|
|
2.25.1
|
||
|
|
|