watchdog.diff

diff --git a/src/main/java/net/minecraft/server/CrashReport.java b/src/main/java/net/minecraft/server/CrashReport.java
index 3de19c998..c7dc8787c 100644
--- a/src/main/java/net/minecraft/server/CrashReport.java
+++ b/src/main/java/net/minecraft/server/CrashReport.java
@@ -257,6 +257,7 @@ public class CrashReport {
     }
 
     public static CrashReport a(Throwable throwable, String s) {
+        if (throwable instanceof ThreadDeath) com.destroystokyo.paper.util.SneakyThrow.sneaky(throwable); // Paper
         while (throwable instanceof CompletionException && throwable.getCause() != null) {
             throwable = throwable.getCause();
         }
diff --git a/src/main/java/net/minecraft/server/DedicatedServer.java b/src/main/java/net/minecraft/server/DedicatedServer.java
index 1ef7890da..e62ca0543 100644
--- a/src/main/java/net/minecraft/server/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/DedicatedServer.java
@@ -750,7 +750,7 @@ public class DedicatedServer extends MinecraftServer implements IMinecraftServer
     @Override
     public void stop() {
         super.stop();
-        SystemUtils.f();
+        //SystemUtils.f(); // Paper - moved into super
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 36fff92f3..a386c1ab4 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -144,6 +144,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
     private final ResourcePackRepository<ResourcePackLoader> resourcePackRepository;
     @Nullable
     private ResourcePackSourceFolder resourcePackFolder;
+    public volatile Thread shutdownThread; // Paper
     public CommandDispatcher commandDispatcher;
     private final CraftingManager craftingManager;
     private final TagRegistry tagRegistry;
@@ -737,7 +738,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
         // CraftBukkit start - prevent double stopping on multiple threads
         synchronized(stopLock) {
             if (hasStopped) return;
+            shutdownThread = Thread.currentThread();
             hasStopped = true;
+            org.spigotmc.WatchdogThread.doStop(); // Paper
+            if (!isMainThread()) {
+                this.getThread().stop();
+            }
         }
         // CraftBukkit end
         MinecraftServer.LOGGER.info("Stopping server");
@@ -794,8 +800,18 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
             this.getUserCache().c(false); // Paper
         }
         // Spigot end
+        // Paper start - move final shutdown items here
+        LOGGER.info("Flushing Chunk IO");
         com.destroystokyo.paper.io.PaperFileIOThread.Holder.INSTANCE.close(true, true); // Paper
-        System.exit(0); // Paper
+        LOGGER.info("Closing Thread Pool");
+        SystemUtils.shutdownServerThreadPool(); // Paper
+        LOGGER.info("Closing Server");
+        try {
+            net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+        } catch (Exception e) {
+        }
+        this.exit();
+        // Paper end
     }
 
     public String getServerIp() {
@@ -887,6 +903,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
     // Spigot End
 
     public void run() {
+        boolean isThreadDeath = false; // Paper
         try {
             if (this.init()) {
                 this.nextTick = SystemUtils.getMonotonicMillis();
@@ -951,6 +968,13 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
                 this.a((CrashReport) null);
             }
         } catch (Throwable throwable) {
+            // Paper start
+            if (throwable instanceof ThreadDeath) {
+                MinecraftServer.LOGGER.error("Main thread terminated by WatchDog due to hard crash", throwable);
+                isThreadDeath = true;
+                return;
+            }
+            // Paper end
             MinecraftServer.LOGGER.error("Encountered an unexpected exception", throwable);
             // Spigot Start
             if ( throwable.getCause() != null )
@@ -982,14 +1006,14 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
             } catch (Throwable throwable1) {
                 MinecraftServer.LOGGER.error("Exception stopping the server", throwable1);
             } finally {
-                org.spigotmc.WatchdogThread.doStop(); // Spigot
+                //org.spigotmc.WatchdogThread.doStop(); // Spigot // Paper - move into stop
                 // CraftBukkit start - Restore terminal to original settings
                 try {
-                    net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+                    //net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Move into stop
                 } catch (Exception ignored) {
                 }
                 // CraftBukkit end
-                this.exit();
+                //this.exit(); // Paper - moved into stop
             }
 
         }
@@ -1040,6 +1064,12 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
 
     @Override
     protected TickTask postToMainThread(Runnable runnable) {
+        // Paper start - anything that does try to post to main during watchdog crash, run on watchdog
+        if (this.hasStopped && Thread.currentThread().equals(shutdownThread)) {
+            runnable.run();
+            runnable = () -> {};
+        }
+        // Paper end
         return new TickTask(this.ticks, runnable);
     }
 
diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index 6d6fbf2f5..0e1703c9d 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -411,7 +411,7 @@ public abstract class PlayerList {
         cserver.getPluginManager().callEvent(playerQuitEvent);
         entityplayer.getBukkitEntity().disconnect(playerQuitEvent.getQuitMessage());
 
-        entityplayer.playerTick();// SPIGOT-924
+        if (server.isMainThread()) entityplayer.playerTick();// SPIGOT-924 // Paper - don't tick during emergency shutdowns (Watchdog)
         // CraftBukkit end
 
         // Paper start - Remove from collideRule team if needed
diff --git a/src/main/java/net/minecraft/server/SystemUtils.java b/src/main/java/net/minecraft/server/SystemUtils.java
index dc6d03062..bc8b90466 100644
--- a/src/main/java/net/minecraft/server/SystemUtils.java
+++ b/src/main/java/net/minecraft/server/SystemUtils.java
@@ -109,6 +109,7 @@ public class SystemUtils {
         return SystemUtils.c;
     }
 
+    public static void shutdownServerThreadPool() { f(); } // Paper - OBFHELPER
     public static void f() {
         SystemUtils.c.shutdown();
 
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 5fa045998..09b03afff 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -786,6 +786,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
 
                         gameprofilerfiller.exit();
                     } catch (Throwable throwable) {
+                        if (throwable instanceof ThreadDeath) throw throwable; // Paper
                         // Paper start - Prevent tile entity and entity crashes
                         String msg = "TileEntity threw exception at " + tileentity.world.getWorld().getName() + ":" + tileentity.position.getX() + "," + tileentity.position.getY() + "," + tileentity.position.getZ();
                         System.err.println(msg);
@@ -861,6 +862,7 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
         try {
             consumer.accept(entity);
         } catch (Throwable throwable) {
+            if (throwable instanceof ThreadDeath) throw throwable; // Paper
             // Paper start - Prevent tile entity and entity crashes
             String msg = "Entity threw exception at " + entity.world.getWorld().getName() + ":" + entity.locX() + "," + entity.locY() + "," + entity.locZ();
             System.err.println(msg);
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 8cc0f66ce..dcc44be61 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1705,7 +1705,7 @@ public final class CraftServer implements Server {
 
     @Override
     public boolean isPrimaryThread() {
-        return Thread.currentThread().equals(console.serverThread); // Paper - Fix issues with detecting main thread properly
+        return Thread.currentThread().equals(console.serverThread) || Thread.currentThread().equals(net.minecraft.server.MinecraftServer.getServer().shutdownThread); // Paper - Fix issues with detecting main thread properly, the only time Watchdog will be used is during a crash shutdown which is a "try our best" scenario
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
index f255c448a..899a52520 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
@@ -30,7 +30,7 @@ public class ServerShutdownThread extends Thread {
             // Paper end
         } finally {
             try {
-                net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
+                //net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Move into stop
             } catch (Exception e) {
             }
         }
diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
index 6dda6d168..acc880c7c 100644
--- a/src/main/java/org/spigotmc/WatchdogThread.java
+++ b/src/main/java/org/spigotmc/WatchdogThread.java
@@ -67,10 +67,10 @@ public class WatchdogThread extends Thread
             // Paper start
             Logger log = Bukkit.getServer().getLogger();
             long currentTime = monotonicMillis();
-            if ( lastTick != 0 && currentTime > lastTick + earlyWarningEvery && !Boolean.getBoolean("disable.watchdog") )
+            MinecraftServer server = MinecraftServer.getServer();
+            if ( !server.isRunning() || (lastTick != 0 && currentTime > lastTick + earlyWarningEvery && !Boolean.getBoolean("disable.watchdog")) )
             {
-                MinecraftServer server = MinecraftServer.getServer();
-                boolean isLongTimeout = currentTime > lastTick + timeoutTime || !server.isRunning();
+                boolean isLongTimeout = currentTime > lastTick + timeoutTime || (!server.isRunning() && !server.hasStopped() && currentTime > lastTick + 1000);
                 // Don't spam early warning dumps
                 if ( !isLongTimeout && (earlyWarningEvery <= 0 || !hasStarted || currentTime < lastEarlyWarning + earlyWarningEvery || currentTime < lastTick + earlyWarningDelay)) continue;
                 if ( !isLongTimeout && server.hasStopped()) continue; // Don't spam early watchdog warnings during shutdown, we'll come back to this...