From c829c08588842173ed4ce8d43a61f25e2a6a848c Mon Sep 17 00:00:00 2001 From: Shane Freeder 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 97917551..1959bc06 100644 --- a/src/main/java/net/minecraft/server/FileIOThread.java +++ b/src/main/java/net/minecraft/server/FileIOThread.java @@ -9,7 +9,7 @@ import org.apache.logging.log4j.Logger; public class FileIOThread implements Runnable { private static final Logger a = LogManager.getLogger(); private static final FileIOThread b = new FileIOThread(); - private final List c = Collections.synchronizedList(Lists.newArrayList()); + private final List c = Collections.synchronizedList(Lists.newArrayList()); private List getThreadedIOQueue() { return c; } // Paper - OBFHELPER private volatile long d; private volatile long e; private volatile boolean f; @@ -72,7 +72,7 @@ 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); } -- 2.19.0