Paper/Spigot-Server-Patches/0480-Fix-Chunk-Post-Processing-deadlock-risk.patch
Aikar ce270e1412
Updated Upstream (Bukkit/CraftBukkit/Spigot)
Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
b2f1908c SPIGOT-5783: Add helpful info to UnknownDependencyException
e4f46260 SPIGOT-2623: Add EntityEquipment methods to get/set ItemStacks by slot.
529a9a69 SPIGOT-5751: Clarify behaviour of block drop-related API methods

CraftBukkit Changes:
8ea9b138 Remove outdated build delay.
ffc2b251 Revert "#675: Fix redirected CommandNodes sometimes not being properly redirected"
cb701f6b #675: Fix redirected CommandNodes sometimes not being properly redirected
c9d7c16b SPIGOT-2623: Add EntityEquipment methods to get/set ItemStacks by slot.
fad2494a #673: Fix Craftworld#isChunkLoaded
8637ec00 SPIGOT-5751: Made breakNaturally and getDrops returns the correct item if no argument is given

Spigot Changes:
a99063f7 Rebuild patches

Fixes #3602
2020-06-23 04:40:03 -04:00

61 Zeilen
3.3 KiB
Diff

From 0000000000000000000000000000000000000000 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/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index 695d12e1942018be6a9e8c999ba6071b9f778568..665d83042dab467cddf315fade883fd55ffc8bfd 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -1050,6 +1050,7 @@ public class ChunkProviderServer extends IChunkProvider {
return super.executeNext() || execChunkTask; // Paper
}
} finally {
+ playerChunkMap.chunkLoadConversionCallbackExecutor.run(); // Paper - Add chunk load conversion callback executor to prevent deadlock due to recursion in the chunk task queue sorter
playerChunkMap.callbackExecutor.run();
}
// CraftBukkit end
diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index 6bdaaf8daef15cd7c11943254e412e0e2d2898fb..48f858388029e77f710365e73905f8570f1103f5 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -131,6 +131,8 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
};
// CraftBukkit end
+ final CallbackExecutor chunkLoadConversionCallbackExecutor = new CallbackExecutor(); // Paper
+
// Paper start - distance maps
private final com.destroystokyo.paper.util.misc.PooledLinkedHashSets<EntityPlayer> pooledLinkedPlayerHashSets = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets<>();
@@ -987,7 +989,7 @@ 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, () -> PlayerChunkMap.this.chunkLoadConversionCallbackExecutor.execute(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) -> {