Fix NPEs caused by RepeatingTask initialisation race condition

common/src/main/java/me/lucko/luckperms/common/plugin/AbstractLuckPermsPlugin.java

@@ -206,8 +206,8 @@ public abstract class AbstractLuckPermsPlugin implements LuckPermsPlugin {
 
     public final void disable() {
         // shutdown permission vault and verbose handler tasks
-        this.permissionRegistry.stop();
-        this.verboseHandler.stop();
+        this.permissionRegistry.close();
+        this.verboseHandler.close();
 
         // unload extensions
         this.extensionManager.close();

common/src/main/java/me/lucko/luckperms/common/treeview/PermissionRegistry.java

@@ -28,8 +28,8 @@ package me.lucko.luckperms.common.treeview;
 import com.google.common.base.Splitter;
 
 import me.lucko.luckperms.common.plugin.scheduler.SchedulerAdapter;
+import me.lucko.luckperms.common.plugin.scheduler.SchedulerTask;
 import me.lucko.luckperms.common.util.ImmutableCollectors;
-import me.lucko.luckperms.common.util.RepeatingTask;
 
 import java.util.List;
 import java.util.Map;
@@ -40,19 +40,20 @@ import java.util.concurrent.TimeUnit;
 /**
  * Stores a collection of all permissions known to the platform.
  */
-public class PermissionRegistry extends RepeatingTask {
+public class PermissionRegistry implements AutoCloseable {
     private static final Splitter DOT_SPLIT = Splitter.on('.').omitEmptyStrings();
 
-    // the root node in the tree
+    /** The root node in the tree */
     private final TreeNode rootNode;
-
-    // a queue of permission strings to be processed by the tree
+    /** A queue of permission strings to be added to the tree */
     private final Queue<String> queue;
+    /** The tick task */
+    private final SchedulerTask task;
 
     public PermissionRegistry(SchedulerAdapter scheduler) {
-        super(scheduler, 1, TimeUnit.SECONDS);
         this.rootNode = new TreeNode();
         this.queue = new ConcurrentLinkedQueue<>();
+        this.task = scheduler.asyncRepeating(this::tick, 1, TimeUnit.SECONDS);
     }
 
     public TreeNode getRootNode() {
@@ -70,13 +71,17 @@ public class PermissionRegistry extends RepeatingTask {
         this.queue.offer(permission);
     }
 
-    @Override
-    protected void tick() {
+    private void tick() {
         for (String e; (e = this.queue.poll()) != null; ) {
             insert(e);
         }
     }
 
+    @Override
+    public void close() {
+        this.task.cancel();
+    }
+
     public void insert(String permission) {
         try {
             doInsert(permission);

common/src/main/java/me/lucko/luckperms/common/util/RepeatingTask.java

@@ -1,53 +0,0 @@
-/*
- * This file is part of LuckPerms, licensed under the MIT License.
- *
- *  Copyright (c) lucko (Luck) <luck@lucko.me>
- *  Copyright (c) contributors
- *
- *  Permission is hereby granted, free of charge, to any person obtaining a copy
- *  of this software and associated documentation files (the "Software"), to deal
- *  in the Software without restriction, including without limitation the rights
- *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- *  copies of the Software, and to permit persons to whom the Software is
- *  furnished to do so, subject to the following conditions:
- *
- *  The above copyright notice and this permission notice shall be included in all
- *  copies or substantial portions of the Software.
- *
- *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- *  SOFTWARE.
- */
-
-package me.lucko.luckperms.common.util;
-
-import me.lucko.luckperms.common.plugin.scheduler.SchedulerAdapter;
-import me.lucko.luckperms.common.plugin.scheduler.SchedulerTask;
-
-import java.util.concurrent.TimeUnit;
-
-public abstract class RepeatingTask {
-    private final SchedulerTask task;
-
-    protected RepeatingTask(SchedulerAdapter scheduler, long time, TimeUnit unit) {
-        this.task = scheduler.asyncRepeating(this::run, time, unit);
-    }
-
-    private void run() {
-        try {
-            tick();
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-    protected abstract void tick();
-
-    public void stop() {
-        this.task.cancel();
-    }
-}

common/src/main/java/me/lucko/luckperms/common/verbose/VerboseHandler.java

@@ -27,8 +27,8 @@ package me.lucko.luckperms.common.verbose;
 
 import me.lucko.luckperms.common.calculator.result.TristateResult;
 import me.lucko.luckperms.common.plugin.scheduler.SchedulerAdapter;
+import me.lucko.luckperms.common.plugin.scheduler.SchedulerTask;
 import me.lucko.luckperms.common.sender.Sender;
-import me.lucko.luckperms.common.util.RepeatingTask;
 import me.lucko.luckperms.common.verbose.event.MetaCheckEvent;
 import me.lucko.luckperms.common.verbose.event.PermissionCheckEvent;
 import me.lucko.luckperms.common.verbose.event.VerboseEvent;
@@ -45,21 +45,21 @@ import java.util.concurrent.TimeUnit;
 /**
  * Accepts {@link VerboseEvent}s and passes them onto registered {@link VerboseListener}s.
  */
-public class VerboseHandler extends RepeatingTask {
+public class VerboseHandler implements AutoCloseable {
 
-    // the listeners currently registered
+    /** A map of currently registered listeners */
     private final Map<UUID, VerboseListener> listeners;
-
-    // a queue of events
+    /** A queue of verbose events to be handled */
     private final Queue<VerboseEvent> queue;
-
-    // if there are any listeners currently registered
+    /** If there are any listeners registered */
     private boolean listening = false;
+    /** The tick task */
+    private final SchedulerTask task;
 
     public VerboseHandler(SchedulerAdapter scheduler) {
-        super(scheduler, 100, TimeUnit.MILLISECONDS);
         this.listeners = new ConcurrentHashMap<>();
         this.queue = new ConcurrentLinkedQueue<>();
+        this.task = scheduler.asyncRepeating(this::tick, 100, TimeUnit.MILLISECONDS);
     }
 
     /**
@@ -137,8 +137,7 @@ public class VerboseHandler extends RepeatingTask {
         return this.listeners.remove(uuid);
     }
 
-    @Override
-    protected void tick() {
+    private void tick() {
         // remove listeners where the sender is no longer valid
         this.listeners.values().removeIf(l -> !l.getNotifiedSender().isValid());
 
@@ -159,4 +158,10 @@ public class VerboseHandler extends RepeatingTask {
             }
         }
     }
+
+    @Override
+    public void close() {
+        this.task.cancel();
+    }
+
 }