Wait for thread executors to shut down

src/main/java/emu/grasscutter/Grasscutter.java

@@ -1,14 +1,11 @@
 package emu.grasscutter;
 
-import static emu.grasscutter.config.Configuration.SERVER;
-import static emu.grasscutter.utils.lang.Language.translate;
-
 import ch.qos.logback.classic.*;
 import emu.grasscutter.auth.*;
 import emu.grasscutter.command.*;
 import emu.grasscutter.config.ConfigContainer;
 import emu.grasscutter.data.ResourceLoader;
-import emu.grasscutter.database.DatabaseManager;
+import emu.grasscutter.database.*;
 import emu.grasscutter.plugin.PluginManager;
 import emu.grasscutter.plugin.api.ServerHelper;
 import emu.grasscutter.server.dispatch.DispatchServer;
@@ -21,16 +18,20 @@ import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.*;
 import emu.grasscutter.utils.lang.Language;
 import io.netty.util.concurrent.FastThreadLocalThread;
-import java.io.*;
-import java.util.Calendar;
-import java.util.concurrent.*;
-import javax.annotation.Nullable;
 import lombok.*;
 import org.jline.reader.*;
 import org.jline.terminal.*;
 import org.reflections.Reflections;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nullable;
+import java.io.*;
+import java.util.Calendar;
+import java.util.concurrent.*;
+
+import static emu.grasscutter.config.Configuration.SERVER;
+import static emu.grasscutter.utils.lang.Language.translate;
+
 public final class Grasscutter {
     public static final File configFile = new File("./config.json");
     public static final Reflections reflector = new Reflections("emu.grasscutter");
@@ -183,6 +184,22 @@ public final class Grasscutter {
     private static void onShutdown() {
         // Disable all plugins.
         if (pluginManager != null) pluginManager.disablePlugins();
+
+        try {
+            // Wait for Grasscutter's thread pool to finish.
+            var executor = Grasscutter.getThreadPool();
+            executor.shutdown();
+            if (!executor.awaitTermination(5, TimeUnit.SECONDS)) {
+                executor.shutdownNow();
+            }
+
+            // Wait for database operations to finish.
+            var dbExecutor = DatabaseHelper.getEventExecutor();
+            dbExecutor.shutdown();
+            if (!dbExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
+                dbExecutor.shutdownNow();
+            }
+        } catch (InterruptedException ignored) { }
     }
 
     /*

src/main/java/emu/grasscutter/database/DatabaseHelper.java

@@ -1,12 +1,8 @@
 package emu.grasscutter.database;
 
-import static com.mongodb.client.model.Filters.eq;
+import dev.morphia.query.*;
-
-import dev.morphia.query.FindOptions;
-import dev.morphia.query.Sort;
 import dev.morphia.query.experimental.filters.Filters;
-import emu.grasscutter.GameConstants;
+import emu.grasscutter.*;
-import emu.grasscutter.Grasscutter;
 import emu.grasscutter.game.Account;
 import emu.grasscutter.game.achievement.Achievements;
 import emu.grasscutter.game.activity.PlayerActivityData;
@@ -23,12 +19,16 @@ import emu.grasscutter.game.quest.GameMainQuest;
 import emu.grasscutter.game.world.SceneGroupInstance;
 import emu.grasscutter.utils.objects.Returnable;
 import io.netty.util.concurrent.FastThreadLocalThread;
+import lombok.Getter;
+
 import java.util.List;
 import java.util.concurrent.*;
 import java.util.stream.Stream;
 
+import static com.mongodb.client.model.Filters.eq;
+
 public final class DatabaseHelper {
-    private static final ExecutorService eventExecutor =
+    @Getter private static final ExecutorService eventExecutor =
             new ThreadPoolExecutor(
                     6,
                     6,

src/main/java/emu/grasscutter/server/game/GameServer.java

@@ -1,8 +1,5 @@
 package emu.grasscutter.server.game;
 
-import static emu.grasscutter.config.Configuration.*;
-import static emu.grasscutter.utils.lang.Language.translate;
-
 import emu.grasscutter.*;
 import emu.grasscutter.Grasscutter.ServerRunMode;
 import emu.grasscutter.database.DatabaseHelper;
@@ -32,14 +29,19 @@ import emu.grasscutter.server.event.internal.*;
 import emu.grasscutter.server.event.types.ServerEvent;
 import emu.grasscutter.server.scheduler.ServerTaskScheduler;
 import emu.grasscutter.task.TaskMap;
-import java.net.*;
+import emu.grasscutter.utils.Utils;
-import java.time.*;
-import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
 import kcp.highway.*;
 import lombok.*;
 import org.jetbrains.annotations.NotNull;
 
+import java.net.*;
+import java.time.*;
+import java.util.*;
+import java.util.concurrent.*;
+
+import static emu.grasscutter.config.Configuration.*;
+import static emu.grasscutter.utils.lang.Language.translate;
+
 @Getter
 public final class GameServer extends KcpServer implements Iterable<Player> {
     // Game server base
@@ -326,16 +328,27 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
     }
 
     public void onServerShutdown() {
-        ServerStopEvent event = new ServerStopEvent(ServerEvent.Type.GAME, OffsetDateTime.now());
+        var event = new ServerStopEvent(ServerEvent.Type.GAME, OffsetDateTime.now());
         event.call();
 
         this.getPlayers()
             .forEach(
-                        (uid, player) -> {
+                (uid, player) -> player.getSession().close());
-                            player.getSession().close();
-                        });
 
         this.getWorlds().forEach(World::save);
+
+        Utils.sleep(1000L); // Wait 1 second for operations to finish.
+
+        try {
+            var threadPool = GameSessionManager.getLogicThread();
+
+            // Shutdown network thread.
+            threadPool.shutdownGracefully();
+            // Wait for the network thread to finish.
+            if (!threadPool.awaitTermination(5, TimeUnit.SECONDS)) {
+                Grasscutter.getLogger().error("Logic thread did not terminate!");
+            }
+        } catch (InterruptedException ignored) { }
     }
 
     @NotNull @Override

src/main/java/emu/grasscutter/server/game/GameSessionManager.java

@@ -2,16 +2,16 @@ package emu.grasscutter.server.game;
 
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.utils.Utils;
-import io.netty.buffer.ByteBuf;
+import io.netty.buffer.*;
-import io.netty.buffer.Unpooled;
 import io.netty.channel.DefaultEventLoop;
+import kcp.highway.*;
+import lombok.Getter;
+
 import java.net.InetSocketAddress;
 import java.util.concurrent.ConcurrentHashMap;
-import kcp.highway.KcpListener;
-import kcp.highway.Ukcp;
 
 public class GameSessionManager {
-    private static final DefaultEventLoop logicThread = new DefaultEventLoop();
+    @Getter private static final DefaultEventLoop logicThread = new DefaultEventLoop();
     private static final ConcurrentHashMap<Ukcp, GameSession> sessions = new ConcurrentHashMap<>();
     private static final KcpListener listener =
             new KcpListener() {

src/main/java/emu/grasscutter/utils/Utils.java

@@ -504,9 +504,7 @@ public final class Utils {
      * @return A list of all fields in the class.
      */
     public static List<Field> getAllFields(Class<?> type) {
-        var fields = new LinkedList<>(
+        var fields = new LinkedList<>(Arrays.asList(type.getDeclaredFields()));
-            Arrays.asList(type.getDeclaredFields())
-        );
 
         // Check for superclasses.
         if (type.getSuperclass() != null) {
@@ -515,4 +513,16 @@ public final class Utils {
 
         return fields;
     }
+
+    /**
+     * Sleeps the current thread without an exception.
+     *
+     * @param millis The amount of milliseconds to sleep.
+     */
+    public static void sleep(long millis) {
+        try {
+            Thread.sleep(millis);
+        } catch (InterruptedException ignored) {
+        }
+    }
 }