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 e25451056b6eedde2c5ffc281918ca13967e0a67..af2d703fe3cb74ced502ca89c5bf6ca1f47474bb 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -871,6 +871,7 @@ 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) {
@@ -885,6 +886,7 @@ 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
@@ -1014,6 +1016,8 @@ 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 31a506e78264f354394afc37fb7ebb3d0c7d6ebd..40b27dbdc15e07a6a9d63d41babe5ed0245c0e0b 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -218,6 +218,11 @@ public class ServerLoginPacketListenerImpl implements TickablePacketListener, Se
             } catch (Exception exception) {
                 ServerLoginPacketListenerImpl.LOGGER.error("Couldn't place player in world", exception);
                 MutableComponent ichatmutablecomponent = Component.translatable("multiplayer.disconnect.invalid_player_data");
+                // Paper start
+                if (MinecraftServer.getServer().isDebugging()) {
+                    exception.printStackTrace();
+                }
+                // Paper end
 
                 this.connection.send(new ClientboundDisconnectPacket(ichatmutablecomponent));
                 this.connection.disconnect(ichatmutablecomponent);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index d45d1ec667fba102a20f62df1b207a95b06318b7..96e4ba547472cbb29009574458865090d63464e3 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1000,6 +1000,7 @@ 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);