Misc thread dumps (#5200)

Spigot-Server-Patches/0675-misc-debugging-dumps.patch

@@ -0,0 +1,83 @@
+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..d5e5c6153675855bb8798b11d905b5f2d6ea158e
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/util/TraceUtil.java
+@@ -0,0 +1,14 @@
++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);
++        }
++    }
++}
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index ccf2d0b090f0c360dfc7886bb0726e099acec42c..ccac3589820f244f36dac310d08091f218d5935e 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -15,6 +15,7 @@ import io.netty.buffer.ByteBuf;
+ import io.netty.buffer.ByteBufOutputStream;
+ import io.netty.buffer.Unpooled;
+ import io.papermc.paper.event.entity.EntityMoveEvent;
++import io.papermc.paper.util.TraceUtil;
+ import it.unimi.dsi.fastutil.longs.LongIterator;
+ import java.awt.image.BufferedImage;
+ import java.io.BufferedWriter;
+@@ -731,6 +732,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+     // 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 (stopLock) {
+@@ -745,6 +747,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+             if (hasStopped) return;
+             hasStopped = true;
+         }
++        if (!hasLoggedStop && isDebugging()) TraceUtil.dumpTraceForThread(this.getThread(), "Server stopped"); // Paper
+         // Paper start - kill main thread, and kill it hard
+         shutdownThread = Thread.currentThread();
+         org.spigotmc.WatchdogThread.doStop(); // Paper
+@@ -861,6 +864,8 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
+     public void safeShutdown(boolean flag, boolean isRestarting) {
+         this.isRunning = false;
+         this.isRestarting = isRestarting;
++        this.hasLoggedStop = true; // Paper
++        if (isDebugging()) TraceUtil.dumpTraceForThread(this.getThread(), "Server stopped"); // Paper
+         if (flag) {
+             try {
+                 this.serverThread.join();
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+index 85023c68a9c85802383cfcf52ec21392abdf3d85..ea1c47ff81d88e1b8d003b66e992727b943b7186 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+@@ -18,6 +18,7 @@ import com.mojang.serialization.Lifecycle;
+ import io.netty.buffer.ByteBuf;
+ import io.netty.buffer.ByteBufOutputStream;
+ import io.netty.buffer.Unpooled;
++import io.papermc.paper.util.TraceUtil;
+ import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
+ import java.awt.image.BufferedImage;
+ import java.io.File;
+@@ -938,6 +939,7 @@ public final class CraftServer implements Server {
+                 plugin.getDescription().getName(),
+                 "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()) TraceUtil.dumpTraceForThread(worker.getThread(), "still running"); // Paper
+         }
+         loadPlugins();
+         enablePlugins(PluginLoadOrder.STARTUP);