From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Thu, 18 Feb 2021 20:23:28 +0000
Subject: [PATCH] misc debugging dumps


diff --git a/src/main/java/io/papermc/paper/util/TraceUtil.java b/src/main/java/io/papermc/paper/util/TraceUtil.java
new file mode 100644
index 0000000000000000000000000000000000000000..2d5494d2813b773e60ddba6790b750a9a08f21f8
--- /dev/null
+++ b/src/main/java/io/papermc/paper/util/TraceUtil.java
@@ -0,0 +1,18 @@
+package io.papermc.paper.util;
+
+import org.bukkit.Bukkit;
+
+public final class TraceUtil {
+
+    public static void dumpTraceForThread(Thread thread, String reason) {
+        Bukkit.getLogger().warning(thread.getName() + ": " + reason);
+        StackTraceElement[] trace = thread.getStackTrace();
+        for (StackTraceElement traceElement : trace) {
+            Bukkit.getLogger().warning("\tat " + traceElement);
+        }
+    }
+
+    public static void dumpTraceForThread(String reason) {
+        new Throwable(reason).printStackTrace();
+    }
+}
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 7049126dabd8bd497b7a63f8b0980e0252638c23..d613d9bbd2096788cd0f7e3a8aa901e44a4e25ff 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -919,6 +919,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
     // CraftBukkit start
     private boolean hasStopped = false;
     public volatile boolean hasFullyShutdown = false; // Paper
+    private boolean hasLoggedStop = false; // Paper
     private final Object stopLock = new Object();
     public final boolean hasStopped() {
         synchronized (this.stopLock) {
@@ -933,6 +934,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
             if (this.hasStopped) return;
             this.hasStopped = true;
         }
+        if (!hasLoggedStop && isDebugging()) io.papermc.paper.util.TraceUtil.dumpTraceForThread("Server stopped"); // Paper
         // Paper start - kill main thread, and kill it hard
         shutdownThread = Thread.currentThread();
         org.spigotmc.WatchdogThread.doStop(); // Paper
@@ -1041,6 +1043,8 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
     }
     public void safeShutdown(boolean flag, boolean isRestarting) {
         this.isRestarting = isRestarting;
+        this.hasLoggedStop = true; // Paper
+        if (isDebugging()) io.papermc.paper.util.TraceUtil.dumpTraceForThread("Server stopped"); // Paper
         // Paper end
         this.running = false;
         if (flag) {
diff --git a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
index 301042e7a0d372a914f27ec0988dd938cf2a8262..1766a22e65af2e08611a9435c7384377120406de 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -208,6 +208,11 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener
             } catch (Exception exception) {
                 ServerLoginPacketListenerImpl.LOGGER.error("Couldn't place player in world", exception);
                 TranslatableComponent chatmessage = new TranslatableComponent("multiplayer.disconnect.invalid_player_data");
+                // Paper start
+                if (MinecraftServer.getServer().isDebugging()) {
+                    exception.printStackTrace();
+                }
+                // Paper end
 
                 this.connection.send(new ClientboundDisconnectPacket(chatmessage));
                 this.connection.disconnect(chatmessage);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index af05f2fe686fbdd52f7e536e7f14e96b157de6ca..134f9efd6267c3baeabc110f75d7182b0f78fa77 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -997,6 +997,7 @@ public final class CraftServer implements Server {
                 plugin.getDescription().getFullName(),
                 "This plugin is not properly shutting down its async tasks when it is being reloaded.  This may cause conflicts with the newly loaded version of the plugin"
             ));
+            if (console.isDebugging()) io.papermc.paper.util.TraceUtil.dumpTraceForThread(worker.getThread(), "still running"); // Paper
         }
         this.loadPlugins();
         this.enablePlugins(PluginLoadOrder.STARTUP);
