From 538fc4cb63c6281c1424dbb1c161e5a8f9f9e0b6 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Fri, 21 Jun 2019 14:42:48 -0700
Subject: [PATCH] Log other thread in DataPaletteBlock lock failure


diff --git a/src/main/java/com/destroystokyo/paper/util/ReentrantLockWithGetOwner.java b/src/main/java/com/destroystokyo/paper/util/ReentrantLockWithGetOwner.java
new file mode 100644
index 000000000..a3b174618
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/util/ReentrantLockWithGetOwner.java
@@ -0,0 +1,11 @@
+package com.destroystokyo.paper.util;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+public class ReentrantLockWithGetOwner extends ReentrantLock {
+
+    @Override
+    public Thread getOwner() {
+        return super.getOwner();
+    }
+}
diff --git a/src/main/java/net/minecraft/server/DataPaletteBlock.java b/src/main/java/net/minecraft/server/DataPaletteBlock.java
index d5f5a5187..2c1d1b1a5 100644
--- a/src/main/java/net/minecraft/server/DataPaletteBlock.java
+++ b/src/main/java/net/minecraft/server/DataPaletteBlock.java
@@ -22,14 +22,17 @@ public class DataPaletteBlock<T> implements DataPaletteExpandable<T> {
     protected DataBits a; protected DataBits getDataBits() { return this.a; } // Paper - OBFHELPER
     private DataPalette<T> h; private DataPalette<T> getDataPalette() { return this.h; } // Paper - OBFHELPER
     private int i; private int getBitsPerObject() { return this.i; } // Paper - OBFHELPER
-    private final ReentrantLock j = new ReentrantLock();
+    private final com.destroystokyo.paper.util.ReentrantLockWithGetOwner j = new com.destroystokyo.paper.util.ReentrantLockWithGetOwner(); private com.destroystokyo.paper.util.ReentrantLockWithGetOwner getLock() { return this.j; } // Paper - change type to ReentrantLockWithGetOwner // Paper - OBFHELPER
 
     public void a() {
-        if (this.j.isLocked() && !this.j.isHeldByCurrentThread()) {
+        // Paper start - log other thread
+        Thread owningThread;
+        if (this.j.isLocked() && (owningThread = this.getLock().getOwner()) != null && owningThread != Thread.currentThread()) {
+            // Paper end
             String s = (String) Thread.getAllStackTraces().keySet().stream().filter(Objects::nonNull).map((thread) -> {
                 return thread.getName() + ": \n\tat " + (String) Arrays.stream(thread.getStackTrace()).map(Object::toString).collect(Collectors.joining("\n\tat "));
             }).collect(Collectors.joining("\n"));
-            CrashReport crashreport = new CrashReport("Writing into PalettedContainer from multiple threads", new IllegalStateException());
+            CrashReport crashreport = new CrashReport("Writing into PalettedContainer from multiple threads (other thread: name: " + owningThread.getName() + ", class: " + owningThread.getClass().toString() + ")", new IllegalStateException()); // Paper - log other thread
             CrashReportSystemDetails crashreportsystemdetails = crashreport.a("Thread dumps");
 
             crashreportsystemdetails.a("Thread dumps", (Object) s);
-- 
2.24.1