fix: introduce SignalUtils and fix ctrl+c operation

server/src/main/java/org/allaymc/server/AllayServer.java

@@ -49,6 +49,7 @@
 import org.allaymc.server.scroreboard.storage.JsonScoreboardStorage;
 import org.allaymc.server.terminal.AllayTerminalConsole;
 import org.allaymc.server.utils.AllayComputeThread;
+import org.allaymc.server.utils.SignalUtils;
 import org.allaymc.server.world.AllayWorldPool;
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
@@ -84,6 +85,7 @@ public final class AllayServer implements Server {
     @Getter
     private final AllayWorldPool worldPool = new AllayWorldPool();
     private final AtomicBoolean isRunning = new AtomicBoolean(true);
+    private boolean isFullyStopped = false;
     private final Object2ObjectMap<UUID, PlayerListPacket.Entry> playerListEntryMap = new Object2ObjectOpenHashMap<>();
     @Getter
     private final PlayerStorage playerStorage = Server.SETTINGS.storageSettings().savePlayerData() ? new AllayNBTFilePlayerStorage(Path.of("players")) : AllayEmptyPlayerStorage.INSTANCE;
@@ -153,11 +155,11 @@ public void start(long initialTime) {
             ctx.updateLoggers();
         }
 
-        Runtime.getRuntime().addShutdownHook(new Thread("ShutDownHookThread") {
-            @Override
-            public void run() {
-                if (isRunning.get()) return;
-                shutdown();
+        SignalUtils.addTask(() -> {
+            if (!isRunning.get()) return;
+            shutdown();
+            while (!isFullyStopped) {
+                Thread.yield();
             }
         });
 
@@ -238,6 +240,8 @@ private void shutdownReally() {
         // Shutdown thread pools
         virtualThreadPool.shutdown();
         computeThreadPool.shutdown();
+
+        isFullyStopped = true;
     }
 
     @Override

server/src/main/java/org/allaymc/server/utils/SignalUtils.java

@@ -0,0 +1,68 @@
+package org.allaymc.server.utils;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+import sun.misc.Signal;
+
+import java.util.Deque;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * @author daoge_cmd
+ */
+@Slf4j
+@UtilityClass
+public class SignalUtils {
+
+    private static final AtomicBoolean TRIGGERED = new AtomicBoolean(false);
+    private static final AtomicBoolean SIGNAL_REGISTERED = new AtomicBoolean(false);
+    private static final String[] SIGNAL_LISTEN_TO = {"TERM", "INT"};
+    private static final Deque<Runnable> TASKS = new ConcurrentLinkedDeque<>();
+
+    public static void addTask(Runnable runnable) {
+        registerSignalIfNeeded();
+        TASKS.addLast(runnable);
+    }
+
+    public static void addTaskToFirst(Runnable runnable) {
+        registerSignalIfNeeded();
+        TASKS.addFirst(runnable);
+    }
+
+    private static void registerSignalIfNeeded() {
+        if (!SIGNAL_REGISTERED.getAndSet(true)) {
+            registerTermSignalIfNeeded();
+        }
+    }
+
+    private static void registerTermSignalIfNeeded() {
+        for (var name : SIGNAL_LISTEN_TO) {
+            Signal.handle(new Signal(name), signal -> {
+                log.info("Signal {} received", name);
+
+                if (TRIGGERED.getAndSet(true)) {
+                    return;
+                }
+
+                try {
+                    doTasks();
+                    System.exit(0);
+                } catch (Throwable t) {
+                    log.error("Error while executing shutdown tasks", t);
+                    System.exit(1);
+                }
+            });
+        }
+    }
+
+    private static void doTasks() {
+        for (Runnable runnable : TASKS) {
+            try {
+                runnable.run();
+            } catch (Throwable t) {
+                log.error("Error while executing shutdown task: {}", runnable, t);
+            }
+        }
+    }
+}