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-rw-r--r--patches/server/0998-Improved-Watchdog-Support.patch544
1 files changed, 544 insertions, 0 deletions
diff --git a/patches/server/0998-Improved-Watchdog-Support.patch b/patches/server/0998-Improved-Watchdog-Support.patch
new file mode 100644
index 0000000000..2f40b2b0ec
--- /dev/null
+++ b/patches/server/0998-Improved-Watchdog-Support.patch
@@ -0,0 +1,544 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <[email protected]>
+Date: Sun, 12 Apr 2020 15:50:48 -0400
+Subject: [PATCH] Improved Watchdog Support
+
+Forced Watchdog Crash support and Improve Async Shutdown
+
+If the request to shut down the server is received while we are in
+a watchdog hang, immediately treat it as a crash and begin the shutdown
+process. Shutdown process is now improved to also shutdown cleanly when
+not using restart scripts either.
+
+If a server is deadlocked, a server owner can send SIGUP (or any other signal
+the JVM understands to shut down as it currently does) and the watchdog
+will no longer need to wait until the full timeout, allowing you to trigger
+a close process and try to shut the server down gracefully, saving player and
+world data.
+
+Previously there was no way to trigger this outside of waiting for a full watchdog
+timeout, which may be set to a really long time...
+
+Additionally, fix everything to do with shutting the server down asynchronously.
+
+Previously, nearly everything about the process was fragile and unsafe. Main might
+not have actually been frozen, and might still be manipulating state.
+
+Or, some reuest might ask main to do something in the shutdown but main is dead.
+
+Or worse, other things might start closing down items such as the Console or Thread Pool
+before we are fully shutdown.
+
+This change tries to resolve all of these issues by moving everything into the stop
+method and guaranteeing only one thread is stopping the server.
+
+We then issue Thread Death to the main thread of another thread initiates the stop process.
+We have to ensure Thread Death propagates correctly though to stop main completely.
+
+This is to ensure that if main isn't truely stuck, it's not manipulating state we are trying to save.
+
+This also moves all plugins who register "delayed init" tasks to occur just before "Done" so they
+are properly accounted for and wont trip watchdog on init.
+
+diff --git a/src/main/java/com/destroystokyo/paper/Metrics.java b/src/main/java/com/destroystokyo/paper/Metrics.java
+index 6aaed8e8bf8c721fc834da5c76ac72a4c3e92458..4b002e8b75d117b726b0de274a76d3596fce015b 100644
+--- a/src/main/java/com/destroystokyo/paper/Metrics.java
++++ b/src/main/java/com/destroystokyo/paper/Metrics.java
+@@ -92,7 +92,12 @@ public class Metrics {
+ * Starts the Scheduler which submits our data every 30 minutes.
+ */
+ private void startSubmitting() {
+- final Runnable submitTask = this::submitData;
++ final Runnable submitTask = () -> {
++ if (MinecraftServer.getServer().hasStopped()) {
++ return;
++ }
++ submitData();
++ };
+
+ // Many servers tend to restart at a fixed time at xx:00 which causes an uneven distribution of requests on the
+ // bStats backend. To circumvent this problem, we introduce some randomness into the initial and second delay.
+diff --git a/src/main/java/net/minecraft/CrashReport.java b/src/main/java/net/minecraft/CrashReport.java
+index bcb6a3b3cd17ce5db9aaf6bd3ec7a0ec1b44b979..4f3cc14d48690bb183d09bb7a5ba1e23e8a0c08a 100644
+--- a/src/main/java/net/minecraft/CrashReport.java
++++ b/src/main/java/net/minecraft/CrashReport.java
+@@ -234,6 +234,7 @@ public class CrashReport {
+ }
+
+ public static CrashReport forThrowable(Throwable cause, String title) {
++ if (cause instanceof ThreadDeath) com.destroystokyo.paper.util.SneakyThrow.sneaky(cause); // Paper
+ while (cause instanceof CompletionException && cause.getCause() != null) {
+ cause = cause.getCause();
+ }
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index 8607652b274fb8f6eca5f3fb7183925da3c710cf..f31fcf3054b201e52ee84b9523820dc619762eef 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -303,7 +303,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ public java.util.Queue<Runnable> processQueue = new java.util.concurrent.ConcurrentLinkedQueue<Runnable>();
+ public int autosavePeriod;
+ public Commands vanillaCommandDispatcher;
+- private boolean forceTicks;
++ public boolean forceTicks; // Paper
+ // CraftBukkit end
+ // Spigot start
+ public static final int TPS = 20;
+@@ -316,6 +316,9 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ public static long currentTickLong = 0L; // Paper - track current tick as a long
+ public boolean isIteratingOverLevels = false; // Paper - Throw exception on world create while being ticked
+
++ public volatile Thread shutdownThread; // Paper
++ public volatile boolean abnormalExit = false; // Paper
++
+ public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
+ AtomicReference<S> atomicreference = new AtomicReference();
+ Thread thread = new io.papermc.paper.util.TickThread(() -> { // Paper - rewrite chunk system
+@@ -933,6 +936,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ // CraftBukkit start
+ private boolean hasStopped = false;
+ private boolean hasLoggedStop = false; // Paper - Debugging
++ public volatile boolean hasFullyShutdown = false; // Paper
+ private final Object stopLock = new Object();
+ public final boolean hasStopped() {
+ synchronized (this.stopLock) {
+@@ -948,6 +952,19 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ this.hasStopped = true;
+ }
+ if (!hasLoggedStop && isDebugging()) io.papermc.paper.util.TraceUtil.dumpTraceForThread("Server stopped"); // Paper - Debugging
++ // Paper start - kill main thread, and kill it hard
++ shutdownThread = Thread.currentThread();
++ org.spigotmc.WatchdogThread.doStop(); // Paper
++ if (!isSameThread()) {
++ MinecraftServer.LOGGER.info("Stopping main thread (Ignore any thread death message you see! - DO NOT REPORT THREAD DEATH TO PAPER)");
++ while (this.getRunningThread().isAlive()) {
++ this.getRunningThread().stop();
++ try {
++ Thread.sleep(1);
++ } catch (InterruptedException e) {}
++ }
++ }
++ // Paper end
+ // CraftBukkit end
+ if (this.metricsRecorder.isRecording()) {
+ this.cancelRecordingMetrics();
+@@ -1004,7 +1021,21 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ }
+ // Spigot end
+
++ // Paper start - move final shutdown items here
++ LOGGER.info("Flushing Chunk IO");
++ // Paper end - move final shutdown items here
+ io.papermc.paper.chunk.system.io.RegionFileIOThread.close(true); // Paper - rewrite chunk system
++ // Paper start - move final shutdown items here
++ LOGGER.info("Closing Thread Pool");
++ Util.shutdownExecutors(); // Paper
++ LOGGER.info("Closing Server");
++ try {
++ net.minecrell.terminalconsole.TerminalConsoleAppender.close(); // Paper - Use TerminalConsoleAppender
++ } catch (Exception e) {
++ }
++ io.papermc.paper.log.CustomLogManager.forceReset(); // Paper - Reset loggers after shutdown
++ this.onServerExit();
++ // Paper end - move final shutdown items here
+ }
+
+ public String getLocalIp() {
+@@ -1101,6 +1132,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+
+ protected void runServer() {
+ try {
++ long serverStartTime = Util.getNanos(); // Paper
+ if (!this.initServer()) {
+ throw new IllegalStateException("Failed to initialize server");
+ }
+@@ -1110,6 +1142,18 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ this.status = this.buildServerStatus();
+
+ // Spigot start
++ // Paper start - move done tracking
++ LOGGER.info("Running delayed init tasks");
++ this.server.getScheduler().mainThreadHeartbeat(this.tickCount); // run all 1 tick delay tasks during init,
++ // this is going to be the first thing the tick process does anyways, so move done and run it after
++ // everything is init before watchdog tick.
++ // anything at 3+ won't be caught here but also will trip watchdog....
++ // tasks are default scheduled at -1 + delay, and first tick will tick at 1
++ String doneTime = String.format(java.util.Locale.ROOT, "%.3fs", (double) (Util.getNanos() - serverStartTime) / 1.0E9D);
++ LOGGER.info("Done ({})! For help, type \"help\"", doneTime);
++ // Paper end
++
++ org.spigotmc.WatchdogThread.tick(); // Paper
+ org.spigotmc.WatchdogThread.hasStarted = true; // Paper
+ Arrays.fill( this.recentTps, 20 );
+ // Paper start - further improve server tick loop
+@@ -1204,6 +1248,12 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ JvmProfiler.INSTANCE.onServerTick(this.smoothedTickTimeMillis);
+ }
+ } catch (Throwable throwable) {
++ // Paper start
++ if (throwable instanceof ThreadDeath) {
++ MinecraftServer.LOGGER.error("Main thread terminated by WatchDog due to hard crash", throwable);
++ return;
++ }
++ // Paper end
+ MinecraftServer.LOGGER.error("Encountered an unexpected exception", throwable);
+ CrashReport crashreport = MinecraftServer.constructOrExtractCrashReport(throwable);
+
+@@ -1228,15 +1278,15 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ this.services.profileCache().clearExecutor();
+ }
+
+- 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
+- io.papermc.paper.log.CustomLogManager.forceReset(); // Paper - Reset loggers after shutdown
+- this.onServerExit();
++ //io.papermc.paper.log.CustomLogManager.forceReset(); // Paper - Reset loggers after shutdown
++ //this.onServerExit(); // Paper - moved into stop
+ }
+
+ }
+@@ -1343,6 +1393,12 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+
+ @Override
+ public TickTask wrapRunnable(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.tickCount, runnable);
+ }
+
+@@ -2178,7 +2234,15 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ this.worldData.setDataConfiguration(worlddataconfiguration);
+ this.resources.managers.updateRegistryTags();
+ this.potionBrewing = this.potionBrewing.reload(this.worldData.enabledFeatures()); // Paper - Custom Potion Mixes
+- this.getPlayerList().saveAll();
++ // Paper start
++ if (Thread.currentThread() != this.serverThread) {
++ return;
++ }
++ // this.getPlayerList().saveAll(); // Paper - we don't need to save everything, just advancements // TODO Move this to a different patch
++ for (ServerPlayer player : this.getPlayerList().getPlayers()) {
++ player.getAdvancements().save();
++ }
++ // Paper end
+ this.getPlayerList().reloadResources();
+ this.functionManager.replaceLibrary(this.resources.managers.getFunctionLibrary());
+ this.structureTemplateManager.onResourceManagerReload(this.resources.resourceManager);
+diff --git a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+index 89c2c26afc5f06c4f57716cadbebabb8854f3635..eb4fc900164d1fb3a78653ae8bc42ea30323f5b7 100644
+--- a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
++++ b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+@@ -325,7 +325,7 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
+ long j = Util.getNanos() - i;
+ String s = String.format(Locale.ROOT, "%.3fs", (double) j / 1.0E9D);
+
+- DedicatedServer.LOGGER.info("Done ({})! For help, type \"help\"", s);
++ //DedicatedServer.LOGGER.info("Done ({})! For help, type \"help\"", s); // Paper moved to after init
+ if (dedicatedserverproperties.announcePlayerAchievements != null) {
+ ((GameRules.BooleanValue) this.getGameRules().getRule(GameRules.RULE_ANNOUNCE_ADVANCEMENTS)).set(dedicatedserverproperties.announcePlayerAchievements, this.overworld()); // CraftBukkit - per-world
+ }
+@@ -459,7 +459,8 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
+ // this.remoteStatusListener.stop(); // Paper - don't wait for remote connections
+ }
+
+- System.exit(0); // CraftBukkit
++ hasFullyShutdown = true; // Paper
++ System.exit(this.abnormalExit ? 70 : 0); // CraftBukkit // Paper
+ }
+
+ @Override
+@@ -840,7 +841,7 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
+ @Override
+ public void stopServer() {
+ super.stopServer();
+- Util.shutdownExecutors();
++ //Util.shutdownExecutors(); // Paper - moved into super
+ SkullBlockEntity.clear();
+ }
+
+diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
+index 29b35b8c0a6001d626e327a82eaff26d068660db..60ba289e724463129dfb27aa5e3b6daf3dd7386e 100644
+--- a/src/main/java/net/minecraft/server/players/PlayerList.java
++++ b/src/main/java/net/minecraft/server/players/PlayerList.java
+@@ -611,7 +611,7 @@ public abstract class PlayerList {
+ this.cserver.getPluginManager().callEvent(playerQuitEvent);
+ entityplayer.getBukkitEntity().disconnect(playerQuitEvent.getQuitMessage());
+
+- entityplayer.doTick(); // SPIGOT-924
++ if (server.isSameThread()) entityplayer.doTick(); // SPIGOT-924 // Paper - don't tick during emergency shutdowns (Watchdog)
+ // CraftBukkit end
+
+ // Paper start - Configurable player collision; Remove from collideRule team if needed
+diff --git a/src/main/java/net/minecraft/util/thread/BlockableEventLoop.java b/src/main/java/net/minecraft/util/thread/BlockableEventLoop.java
+index 2510589400b3012b827efcab477c6483d9d55901..43487a9ee202c5b0e5a416519939111f77b3059c 100644
+--- a/src/main/java/net/minecraft/util/thread/BlockableEventLoop.java
++++ b/src/main/java/net/minecraft/util/thread/BlockableEventLoop.java
+@@ -150,6 +150,7 @@ public abstract class BlockableEventLoop<R extends Runnable> implements Profiler
+ try {
+ task.run();
+ } catch (Exception var3) {
++ if (var3.getCause() instanceof ThreadDeath) throw var3; // Paper
+ LOGGER.error(LogUtils.FATAL_MARKER, "Error executing task on {}", this.name(), var3);
+ }
+ }
+diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
+index ff8d947c5a498e097a4c480a5dc9af71b0be5ee9..ee49f59ba8ce5708fc5e244eba7b1f910cf69263 100644
+--- a/src/main/java/net/minecraft/world/level/Level.java
++++ b/src/main/java/net/minecraft/world/level/Level.java
+@@ -926,6 +926,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
+ try {
+ tickConsumer.accept(entity);
+ } catch (Throwable throwable) {
++ if (throwable instanceof ThreadDeath) throw throwable; // Paper
+ // Paper start - Prevent block entity and entity crashes
+ final String msg = String.format("Entity threw exception at %s:%s,%s,%s", entity.level().getWorld().getName(), entity.getX(), entity.getY(), entity.getZ());
+ MinecraftServer.LOGGER.error(msg, throwable);
+diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+index 424c4613e202c6ba50fa0de65d2526d400a8e299..2a8609e33716949ff1877b6d10f64a9d7a7c81e9 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
++++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+@@ -1179,6 +1179,7 @@ public class LevelChunk extends ChunkAccess {
+
+ gameprofilerfiller.pop();
+ } catch (Throwable throwable) {
++ if (throwable instanceof ThreadDeath) throw throwable; // Paper
+ // Paper start - Prevent block entity and entity crashes
+ final String msg = String.format("BlockEntity threw exception at %s:%s,%s,%s", LevelChunk.this.getLevel().getWorld().getName(), this.getPos().getX(), this.getPos().getY(), this.getPos().getZ());
+ net.minecraft.server.MinecraftServer.LOGGER.error(msg, throwable);
+diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java
+index 3b8a2de79c79302626f43f320b15bae52416cc37..c097f5d5fbd51cbbc01bbd54101905c59b3f3a4c 100644
+--- a/src/main/java/org/bukkit/craftbukkit/Main.java
++++ b/src/main/java/org/bukkit/craftbukkit/Main.java
+@@ -187,6 +187,36 @@ public class Main {
+
+ OptionSet options = null;
+
++ // Paper start - preload logger classes to avoid plugins mixing versions
++ tryPreloadClass("org.apache.logging.log4j.core.Core");
++ tryPreloadClass("org.apache.logging.log4j.core.appender.AsyncAppender");
++ tryPreloadClass("org.apache.logging.log4j.core.Appender");
++ tryPreloadClass("org.apache.logging.log4j.core.ContextDataInjector");
++ tryPreloadClass("org.apache.logging.log4j.core.Filter");
++ tryPreloadClass("org.apache.logging.log4j.core.ErrorHandler");
++ tryPreloadClass("org.apache.logging.log4j.core.LogEvent");
++ tryPreloadClass("org.apache.logging.log4j.core.Logger");
++ tryPreloadClass("org.apache.logging.log4j.core.LoggerContext");
++ tryPreloadClass("org.apache.logging.log4j.core.LogEventListener");
++ tryPreloadClass("org.apache.logging.log4j.core.AbstractLogEvent");
++ tryPreloadClass("org.apache.logging.log4j.message.AsynchronouslyFormattable");
++ tryPreloadClass("org.apache.logging.log4j.message.FormattedMessage");
++ tryPreloadClass("org.apache.logging.log4j.message.ParameterizedMessage");
++ tryPreloadClass("org.apache.logging.log4j.message.Message");
++ tryPreloadClass("org.apache.logging.log4j.message.MessageFactory");
++ tryPreloadClass("org.apache.logging.log4j.message.TimestampMessage");
++ tryPreloadClass("org.apache.logging.log4j.message.SimpleMessage");
++ tryPreloadClass("org.apache.logging.log4j.core.async.AsyncLogger");
++ tryPreloadClass("org.apache.logging.log4j.core.async.AsyncLoggerContext");
++ tryPreloadClass("org.apache.logging.log4j.core.async.AsyncQueueFullPolicy");
++ tryPreloadClass("org.apache.logging.log4j.core.async.AsyncLoggerDisruptor");
++ tryPreloadClass("org.apache.logging.log4j.core.async.RingBufferLogEvent");
++ tryPreloadClass("org.apache.logging.log4j.core.async.DisruptorUtil");
++ tryPreloadClass("org.apache.logging.log4j.core.async.RingBufferLogEventHandler");
++ tryPreloadClass("org.apache.logging.log4j.core.impl.ThrowableProxy");
++ tryPreloadClass("org.apache.logging.log4j.core.impl.ExtendedClassInfo");
++ tryPreloadClass("org.apache.logging.log4j.core.impl.ExtendedStackTraceElement");
++ // Paper end
+ try {
+ options = parser.parse(args);
+ } catch (joptsimple.OptionException ex) {
+@@ -298,8 +328,65 @@ public class Main {
+ } catch (Throwable t) {
+ t.printStackTrace();
+ }
++ // Paper start
++ // load some required classes to avoid errors during shutdown if jar is replaced
++ // also to guarantee our version loads over plugins
++ tryPreloadClass("com.destroystokyo.paper.util.SneakyThrow");
++ tryPreloadClass("com.google.common.collect.Iterators$PeekingImpl");
++ tryPreloadClass("com.google.common.collect.MapMakerInternalMap$Values");
++ tryPreloadClass("com.google.common.collect.MapMakerInternalMap$ValueIterator");
++ tryPreloadClass("com.google.common.collect.MapMakerInternalMap$WriteThroughEntry");
++ tryPreloadClass("com.google.common.collect.Iterables");
++ for (int i = 1; i <= 15; i++) {
++ tryPreloadClass("com.google.common.collect.Iterables$" + i, false);
++ }
++ tryPreloadClass("org.apache.commons.lang3.mutable.MutableBoolean");
++ tryPreloadClass("org.apache.commons.lang3.mutable.MutableInt");
++ tryPreloadClass("org.jline.terminal.impl.MouseSupport");
++ tryPreloadClass("org.jline.terminal.impl.MouseSupport$1");
++ tryPreloadClass("org.jline.terminal.Terminal$MouseTracking");
++ tryPreloadClass("co.aikar.timings.TimingHistory");
++ tryPreloadClass("co.aikar.timings.TimingHistory$MinuteReport");
++ tryPreloadClass("io.netty.channel.AbstractChannelHandlerContext");
++ tryPreloadClass("io.netty.channel.AbstractChannelHandlerContext$11");
++ tryPreloadClass("io.netty.channel.AbstractChannelHandlerContext$12");
++ tryPreloadClass("io.netty.channel.AbstractChannel$AbstractUnsafe$8");
++ tryPreloadClass("io.netty.util.concurrent.DefaultPromise");
++ tryPreloadClass("io.netty.util.concurrent.DefaultPromise$1");
++ tryPreloadClass("io.netty.util.internal.PromiseNotificationUtil");
++ tryPreloadClass("io.netty.util.internal.SystemPropertyUtil");
++ tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler");
++ tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$1");
++ tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$2");
++ tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$3");
++ tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$4");
++ tryPreloadClass("org.slf4j.helpers.MessageFormatter");
++ tryPreloadClass("org.slf4j.helpers.FormattingTuple");
++ tryPreloadClass("org.slf4j.helpers.BasicMarker");
++ tryPreloadClass("org.slf4j.helpers.Util");
++ tryPreloadClass("com.destroystokyo.paper.event.player.PlayerConnectionCloseEvent");
++ tryPreloadClass("com.destroystokyo.paper.event.entity.EntityRemoveFromWorldEvent");
++ // Minecraft, seen during saving
++ tryPreloadClass(net.minecraft.world.level.lighting.LayerLightEventListener.DummyLightLayerEventListener.class.getName());
++ tryPreloadClass(net.minecraft.world.level.lighting.LayerLightEventListener.class.getName());
++ tryPreloadClass(net.minecraft.util.ExceptionCollector.class.getName());
++ tryPreloadClass(io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.PlayerChunkLoaderData.class.getName());
++ // Paper end
++ }
++ }
++
++ // Paper start
++ private static void tryPreloadClass(String className) {
++ tryPreloadClass(className, true);
++ }
++ private static void tryPreloadClass(String className, boolean printError) {
++ try {
++ Class.forName(className);
++ } catch (ClassNotFoundException e) {
++ if (printError) System.err.println("An expected class " + className + " was not found for preloading: " + e.getMessage());
+ }
+ }
++ // Paper end
+
+ private static List<String> asList(String... params) {
+ return Arrays.asList(params);
+diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+index c6e8441e299f477ddb22c1ce2618710763978f1a..e8e93538dfd71de86515d9405f728db1631e949a 100644
+--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
++++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+@@ -12,11 +12,27 @@ public class ServerShutdownThread extends Thread {
+ @Override
+ public void run() {
+ try {
++ // Paper start - try to shutdown on main
++ server.safeShutdown(false, false);
++ for (int i = 1000; i > 0 && !server.hasStopped(); i -= 100) {
++ Thread.sleep(100);
++ }
++ if (server.hasStopped()) {
++ while (!server.hasFullyShutdown) Thread.sleep(1000);
++ return;
++ }
++ // Looks stalled, close async
+ org.spigotmc.AsyncCatcher.enabled = false; // Spigot
++ server.forceTicks = true;
+ this.server.close();
++ while (!server.hasFullyShutdown) Thread.sleep(1000);
++ } catch (InterruptedException e) {
++ e.printStackTrace();
++ // Paper end
+ } finally {
++ org.apache.logging.log4j.LogManager.shutdown(); // Paper
+ 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/RestartCommand.java b/src/main/java/org/spigotmc/RestartCommand.java
+index e3b262add194a126e731c68e68f3139a00cacacb..da7d5efd76c9ef92e9ce22860fec791890a687be 100644
+--- a/src/main/java/org/spigotmc/RestartCommand.java
++++ b/src/main/java/org/spigotmc/RestartCommand.java
+@@ -138,7 +138,7 @@ public class RestartCommand extends Command
+ // Paper end
+
+ // Paper start - copied from above and modified to return if the hook registered
+- private static boolean addShutdownHook(String restartScript)
++ public static boolean addShutdownHook(String restartScript)
+ {
+ String[] split = restartScript.split( " " );
+ if ( split.length > 0 && new File( split[0] ).isFile() )
+diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
+index 9e5d08f57aa448552d100ca892c211d44441ef68..577f29519156f33b49ee319a64a52249630e28d8 100644
+--- a/src/main/java/org/spigotmc/WatchdogThread.java
++++ b/src/main/java/org/spigotmc/WatchdogThread.java
+@@ -11,6 +11,7 @@ import org.bukkit.Bukkit;
+ public final class WatchdogThread extends io.papermc.paper.util.TickThread // Paper - rewrite chunk system
+ {
+
++ public static final boolean DISABLE_WATCHDOG = Boolean.getBoolean("disable.watchdog"); // Paper
+ private static WatchdogThread instance;
+ private long timeoutTime;
+ private boolean restart;
+@@ -39,6 +40,7 @@ public final class WatchdogThread extends io.papermc.paper.util.TickThread // Pa
+ {
+ if ( WatchdogThread.instance == null )
+ {
++ if (timeoutTime <= 0) timeoutTime = 300; // Paper
+ WatchdogThread.instance = new WatchdogThread( timeoutTime * 1000L, restart );
+ WatchdogThread.instance.start();
+ } else
+@@ -70,12 +72,13 @@ public final class WatchdogThread extends io.papermc.paper.util.TickThread // Pa
+ // Paper start
+ Logger log = Bukkit.getServer().getLogger();
+ long currentTime = WatchdogThread.monotonicMillis();
+- if ( this.lastTick != 0 && this.timeoutTime > 0 && currentTime > this.lastTick + this.earlyWarningEvery && !Boolean.getBoolean("disable.watchdog")) // Paper - Add property to disable
++ MinecraftServer server = MinecraftServer.getServer();
++ if ( this.lastTick != 0 && this.timeoutTime > 0 && WatchdogThread.hasStarted && (!server.isRunning() || (currentTime > this.lastTick + this.earlyWarningEvery && !DISABLE_WATCHDOG) )) // Paper - add property to disable
+ {
+- boolean isLongTimeout = currentTime > lastTick + timeoutTime;
++ 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 && MinecraftServer.getServer().hasStopped()) continue; // Don't spam early watchdog warnings during shutdown, we'll come back to this...
++ if ( !isLongTimeout && server.hasStopped()) continue; // Don't spam early watchdog warnings during shutdown, we'll come back to this...
+ lastEarlyWarning = currentTime;
+ if (isLongTimeout) {
+ // Paper end
+@@ -136,9 +139,24 @@ public final class WatchdogThread extends io.papermc.paper.util.TickThread // Pa
+
+ if ( isLongTimeout )
+ {
+- if ( this.restart && !MinecraftServer.getServer().hasStopped() )
++ if ( !server.hasStopped() )
+ {
+- RestartCommand.restart();
++ AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us
++ server.forceTicks = true;
++ if (restart) {
++ RestartCommand.addShutdownHook( SpigotConfig.restartScript );
++ }
++ // try one last chance to safe shutdown on main incase it 'comes back'
++ server.abnormalExit = true;
++ server.safeShutdown(false, restart);
++ try {
++ Thread.sleep(1000);
++ } catch (InterruptedException e) {
++ e.printStackTrace();
++ }
++ if (!server.hasStopped()) {
++ server.close();
++ }
+ }
+ break;
+ } // Paper end
+diff --git a/src/main/resources/log4j2.xml b/src/main/resources/log4j2.xml
+index 637d64da9938e51a97338b9253b43889585c67bb..d2a75850af9c6ad2aca66a5f994f1b587d73eac4 100644
+--- a/src/main/resources/log4j2.xml
++++ b/src/main/resources/log4j2.xml
+@@ -1,5 +1,5 @@
+ <?xml version="1.0" encoding="UTF-8"?>
+-<Configuration status="WARN">
++<Configuration status="WARN" shutdownHook="disable">
+ <Appenders>
+ <Queue name="ServerGuiConsole">
+ <PatternLayout pattern="[%d{HH:mm:ss} %level]: %msg{nolookups}%n" />