Fix a concurrency issue with chunk scheduler

It's possible we won't hit this on the servers current state since nothing is async,
but we are working towards that.

I experienced a crash due to this code during my work.
This commit is contained in:
Aikar 2018-07-23 19:41:41 -04:00
parent 433c56c2d3
commit 2c2b45ddb9
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@ -0,0 +1,47 @@
From bdd76dbf6c7b71856f5edb1ea7cf572b76706cad Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 23 Jul 2018 19:13:06 -0400
Subject: [PATCH] Thread Safe Iteration of Chunk Scheduler
diff --git a/src/main/java/net/minecraft/server/ChunkTaskScheduler.java b/src/main/java/net/minecraft/server/ChunkTaskScheduler.java
index 7b3068753..45f9ad372 100644
--- a/src/main/java/net/minecraft/server/ChunkTaskScheduler.java
+++ b/src/main/java/net/minecraft/server/ChunkTaskScheduler.java
@@ -1,8 +1,10 @@
package net.minecraft.server;
+import com.google.common.collect.Lists;
import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
import it.unimi.dsi.fastutil.longs.Long2ObjectMaps;
import java.io.IOException;
+import java.util.ArrayList;
import java.util.EnumMap;
import java.util.Map;
import java.util.function.Consumer;
@@ -79,7 +81,13 @@ public class ChunkTaskScheduler extends Scheduler<ChunkCoordIntPair, ChunkStatus
}
public void a() {
- this.g.values().forEach((scheduler_a) -> {
+ // Paper start
+ ArrayList<Scheduler.a> list;
+ synchronized (this.g) {
+ list = Lists.newArrayList(this.g.values());
+ }
+ list.forEach((scheduler_a) -> {
+ // Paper end
ProtoChunk protochunk = (ProtoChunk) scheduler_a.a();
if (protochunk.h() && protochunk.i().d() == ChunkStatus.Type.PROTOCHUNK) {
@@ -87,6 +95,7 @@ public class ChunkTaskScheduler extends Scheduler<ChunkCoordIntPair, ChunkStatus
protochunk.setLastSaved(this.c.getTime());
this.e.saveChunk(this.c, protochunk);
protochunk.a(false);
+
} catch (IOException ioexception) {
ChunkTaskScheduler.b.error("Couldn\'t save chunk", ioexception);
} catch (ExceptionWorldConflict exceptionworldconflict) {
--
2.18.0