Fix fabric server hanging on shutdown

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
     id("fabric-loom") version "1.7.4" apply false
 }
 
-val fullVersion = "1.3.2"
+val fullVersion = "1.3.4"
 val snapshot = true
 
 allprojects {

bukkit/src/main/java/me/caseload/knockbacksync/KnockbackSyncPlugin.java

@@ -32,7 +32,7 @@ public final class KnockbackSyncPlugin extends JavaPlugin {
         {
             statsManager = new BukkitStatsManager();
             platformServer = new BukkitServer();
-            pluginJarHashProvider = new PluginJarHashProvider(Bukkit.getPluginManager().getPlugin("KnockbackSync").getClass().getProtectionDomain().getCodeSource().getLocation());
+            pluginJarHashProvider = new PluginJarHashProvider(this.getClass().getProtectionDomain().getCodeSource().getLocation());
         }
 
         private final PluginPermissionChecker permissionChecker = new PluginPermissionChecker();

bukkit/src/main/java/me/caseload/knockbacksync/scheduler/BukkitSchedulerAdapter.java

@@ -42,4 +42,10 @@ public AbstractTaskHandle runTaskLaterAsynchronously(Runnable task, long delay)
     public AbstractTaskHandle runTaskTimerAsynchronously(Runnable task, long delay, long period) {
         return new BukkitTaskHandle(scheduler.runTaskTimerAsynchronously(plugin, task, delay, period));
     }
+
+    // Bukkit should take care of this for us automatically
+    @Override
+    public void shutdown() {
+
+    }
 }

bukkit/src/main/java/me/caseload/knockbacksync/scheduler/FoliaSchedulerAdapter.java

@@ -53,4 +53,10 @@ public AbstractTaskHandle runTaskLaterAsynchronously(Runnable task, long delay)
     public AbstractTaskHandle runTaskTimerAsynchronously(Runnable task, long delay, long period) {
         return new FoliaTaskHandle(scheduler.runAtFixedRate(plugin, scheduledTask -> task.run(), delay, period));
     }
+
+    // Folia takes care of this
+    @Override
+    public void shutdown() {
+
+    }
 }

bukkit/src/main/java/me/caseload/knockbacksync/stats/custom/BukkitStatsManager.java

@@ -3,13 +3,15 @@
 import me.caseload.knockbacksync.KnockbackSyncBase;
 
 public class BukkitStatsManager extends StatsManager {
+
     @Override
     public void init() {
         KnockbackSyncBase.INSTANCE.getScheduler().runTaskAsynchronously(() -> {
             BuildTypePie.determineBuildType(); // Function to calculate hash
             MetricsBukkit metrics = new MetricsBukkit(23568);
             metrics.addCustomChart(new PlayerVersionsPie());
             metrics.addCustomChart(new BuildTypePie());
+            super.metrics = metrics;
         });
     }
 }

bukkit/src/main/java/me/caseload/knockbacksync/stats/custom/MetricsBukkit.java

@@ -107,6 +107,7 @@ public MetricsBukkit(int serviceId) {
     /**
      * Shuts down the underlying scheduler service.
      */
+    @Override
     public void shutdown() {
         metricsBase.shutdown();
     }

common/src/main/java/me/caseload/knockbacksync/scheduler/SchedulerAdapter.java

@@ -7,4 +7,5 @@ public interface SchedulerAdapter {
     AbstractTaskHandle runTaskTimer(Runnable task, long delayTicks, long periodTicks);
     AbstractTaskHandle runTaskLaterAsynchronously(Runnable task, long delay);
     AbstractTaskHandle runTaskTimerAsynchronously(Runnable task, long delay, long period);
+    void shutdown();
 }

common/src/main/java/me/caseload/knockbacksync/stats/custom/Metrics.java

@@ -1,4 +1,5 @@
 package me.caseload.knockbacksync.stats.custom;
 
 public interface Metrics {
+    public void shutdown();
 }

common/src/main/java/me/caseload/knockbacksync/stats/custom/StatsManager.java

@@ -4,6 +4,12 @@
 
 public abstract class StatsManager {
 
+    Metrics metrics;
+
+    public Metrics getMetrics() {
+        return metrics;
+    }
+
     public void init() {
         throw new IllegalStateException("Empty stats class!");
     }

fabric/build.gradle.kts

@@ -28,7 +28,7 @@ dependencies {
     modImplementation("net.fabricmc.fabric-api:fabric-api:${rootProject.property("fabric_version")}")
 
     include(modImplementation("me.lucko:fabric-permissions-api:0.3.1")!!)
-    include(modImplementation("com.github.retrooper:packetevents-fabric:2.5.7-SNAPSHOT")!!)
+    include(modImplementation("com.github.retrooper:packetevents-fabric:2.5.8-SNAPSHOT")!!)
 
     shadeThisThing(implementation("com.fasterxml.jackson.core:jackson-databind:2.17.2")!!)
     shadeThisThing(implementation("com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:2.17.2")!!)
@@ -61,7 +61,6 @@ tasks.remapJar {
     inputFile = tasks.shadowJar.get().archiveFile
 }
 
-
 tasks.processResources {
     inputs.property("version", project.version)
     inputs.property("minecraft_version", rootProject.property("minecraft_version"))

fabric/src/main/java/me/caseload/knockbacksync/KnockbackSyncFabric.java

@@ -159,6 +159,10 @@ public void onInitialize() {
     core.configManager.loadConfig(false);
     core.statsManager.init();
     core.checkForUpdates();
+    ServerLifecycleEvents.SERVER_STOPPING.register((server) -> {
+      core.scheduler.shutdown();
+      core.statsManager.getMetrics().shutdown();
+    });
   }
 
   public static MinecraftServer getServer() {

fabric/src/main/java/me/caseload/knockbacksync/scheduler/FabricSchedulerAdapter.java

@@ -5,22 +5,19 @@
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents;
 import net.minecraft.server.MinecraftServer;
 
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
+import java.util.*;
 
 public class FabricSchedulerAdapter implements SchedulerAdapter {
 //    private final MinecraftServer server;
-    private final List<ScheduledTask> taskList;
+    private final Map<ScheduledTask, Runnable> taskMap = new HashMap<>();
+    private final Map<Thread, Runnable> asyncTasks = new HashMap<>();
 
     public FabricSchedulerAdapter() {
-//        this.server = KnockbackSyncFabric.SERVER;
-        this.taskList = new ArrayList<>();
         ServerTickEvents.END_SERVER_TICK.register(this::handleTasks);
     }
 
     private void handleTasks(MinecraftServer server) {
-        Iterator<ScheduledTask> iterator = taskList.iterator();
+        Iterator<ScheduledTask> iterator = taskMap.keySet().iterator();
         while (iterator.hasNext()) {
             ScheduledTask task = iterator.next();
             if (server.getTickCount() >= task.nextRunTick) {
@@ -37,29 +34,37 @@ private void handleTasks(MinecraftServer server) {
     @Override
     public AbstractTaskHandle runTask(Runnable task) {
         ScheduledTask scheduledTask = new ScheduledTask(task, KnockbackSyncFabric.getServer().getTickCount(), 0, false);
-        taskList.add(scheduledTask);
-        return new FabricTaskHandle(() -> taskList.remove(scheduledTask));
+        Runnable cancellationTask = () -> taskMap.remove(scheduledTask);
+        taskMap.put(scheduledTask, cancellationTask);
+        return new FabricTaskHandle(cancellationTask);
     }
 
     @Override
     public AbstractTaskHandle runTaskAsynchronously(Runnable task) {
         Thread thread = new Thread(task);
+        Runnable cancellationTask = () -> {
+            thread.interrupt();
+            asyncTasks.remove(thread);
+        };
+        asyncTasks.put(thread, cancellationTask);
         thread.start();
-        return new FabricTaskHandle(() -> thread.interrupt());
+        return new FabricTaskHandle(cancellationTask);
     }
 
     @Override
     public AbstractTaskHandle runTaskLater(Runnable task, long delayTicks) {
         ScheduledTask scheduledTask = new ScheduledTask(task, KnockbackSyncFabric.getServer().getTickCount() + delayTicks, 0, false);
-        taskList.add(scheduledTask);
-        return new FabricTaskHandle(() -> taskList.remove(scheduledTask));
+        Runnable cancellationTask = () -> taskMap.remove(scheduledTask);
+        taskMap.put(scheduledTask, cancellationTask);
+        return new FabricTaskHandle(cancellationTask);
     }
 
     @Override
     public AbstractTaskHandle runTaskTimer(Runnable task, long delayTicks, long periodTicks) {
         ScheduledTask scheduledTask = new ScheduledTask(task, KnockbackSyncFabric.getServer().getTickCount() + delayTicks, periodTicks, true);
-        taskList.add(scheduledTask);
-        return new FabricTaskHandle(() -> taskList.remove(scheduledTask));
+        Runnable cancellationTask = () -> taskMap.remove(scheduledTask);
+        taskMap.put(scheduledTask, cancellationTask);
+        return new FabricTaskHandle(cancellationTask);
     }
 
     @Override
@@ -72,8 +77,13 @@ public AbstractTaskHandle runTaskLaterAsynchronously(Runnable task, long delay)
                 // Handle interruption
             }
         });
+        Runnable cancellationTask = () -> {
+            thread.interrupt();
+            asyncTasks.remove(thread);
+        };
+        asyncTasks.put(thread, cancellationTask);
         thread.start();
-        return new FabricTaskHandle(() -> thread.interrupt());
+        return new FabricTaskHandle(cancellationTask);
     }
 
     @Override
@@ -89,8 +99,34 @@ public AbstractTaskHandle runTaskTimerAsynchronously(Runnable task, long delay,
                 // Handle interruption
             }
         });
+        Runnable cancellationTask = () -> {
+            thread.interrupt();
+            asyncTasks.remove(thread);
+        };
+        asyncTasks.put(thread, cancellationTask);
         thread.start();
-        return new FabricTaskHandle(() -> thread.interrupt());
+        return new FabricTaskHandle(cancellationTask);
+    }
+
+    @Override
+    public void shutdown() {
+        // Create a new list to store the tasks that need to be executed
+        List<Runnable> tasksToExecute = new ArrayList<>();
+
+        // Add the tasks from the taskMap to the tasksToExecute list
+        tasksToExecute.addAll(taskMap.values());
+
+        // Add the tasks from the asyncTasks to the tasksToExecute list
+        tasksToExecute.addAll(asyncTasks.values());
+
+        // Clear the taskMap and asyncTasks to avoid further modifications
+        taskMap.clear();
+        asyncTasks.clear();
+
+        // Execute the tasks in the tasksToExecute list
+        for (Runnable task : tasksToExecute) {
+            task.run();
+        }
     }
 
     private static class ScheduledTask {

fabric/src/main/java/me/caseload/knockbacksync/stats/custom/FabricStatsManager.java

@@ -10,6 +10,7 @@ public void init() {
             MetricsFabric metrics = new MetricsFabric(23568);
             metrics.addCustomChart(new PlayerVersionsPie());
             metrics.addCustomChart(new BuildTypePie());
+            super.metrics = metrics;
         });
     }
 }