From 64d408a45a717c918eaa13eb35dfdd18749b4f3f Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Wed, 3 Oct 2018 19:04:53 +0100
Subject: [PATCH] Fix FileIOThread concurrency issues
FileIOThread was using two volatile counters in order to track if
any pending work was in the queue, this causes potential concurrency
issues when this counter is updated from multiple threads, potentially
causing these counters to desync due to the unsafe volatile update
diff --git a/src/main/java/net/minecraft/server/FileIOThread.java b/src/main/java/net/minecraft/server/FileIOThread.java
index 3c688f54..57062460 100644
--- a/src/main/java/net/minecraft/server/FileIOThread.java
+++ b/src/main/java/net/minecraft/server/FileIOThread.java
@@ -10,7 +10,7 @@ public class FileIOThread implements Runnable {
private static final Logger a = LogManager.getLogger();
private static final FileIOThread b = new FileIOThread();
- private final List<IAsyncChunkSaver> c = Collections.synchronizedList(Lists.newArrayList());
+ private final List<IAsyncChunkSaver> c = Collections.synchronizedList(Lists.newArrayList()); private List<IAsyncChunkSaver> getThreadedIOQueue() { return c; } // Paper - OBFHELPER
private volatile long d;
private volatile long e;
private volatile boolean f;
@@ -75,7 +75,7 @@ public class FileIOThread implements Runnable {
public void b() throws InterruptedException {
this.f = true;
- while (this.d != this.e) {
+ while(!this.getThreadedIOQueue().isEmpty()) { // Paper - check actual list size
Thread.sleep(10L);
}
--
2.20.1
