Fixed synchronization issue when adding/removing scheduled tasks

src/main/java/net/minestom/server/command/builder/CommandDispatcher.java

@@ -267,6 +267,7 @@ public class CommandDispatcher {
                     syntaxValues.setArg(argument.getId(), parsedValue);
                 } else {
                     fullyCorrect = false;
+                    break;
                 }
             }
 

src/main/java/net/minestom/server/command/builder/arguments/ArgumentWord.java

@@ -1,6 +1,7 @@
 package net.minestom.server.command.builder.arguments;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Arrays;
 
@@ -22,7 +23,14 @@ public class ArgumentWord extends Argument<String> {
         super(id, false);
     }
 
-    public ArgumentWord from(String... restrictions) {
+    /**
+     * Used to force the use of a few precise words instead of complete freedom.
+     *
+     * @param restrictions the accepted words
+     * @return 'this'
+     */
+    @NotNull
+    public ArgumentWord from(@Nullable String... restrictions) {
         this.restrictions = restrictions;
         return this;
     }
@@ -44,7 +52,7 @@ public class ArgumentWord extends Argument<String> {
     @Override
     public int getConditionResult(@NotNull String value) {
         // Check restrictions
-        if (restrictions != null && restrictions.length > 0) {
+        if (hasRestrictions()) {
             for (String r : restrictions) {
                 if (value.equalsIgnoreCase(r))
                     return SUCCESS;
@@ -55,10 +63,21 @@ public class ArgumentWord extends Argument<String> {
         return SUCCESS;
     }
 
+    /**
+     * Gets if this argument allow complete freedom in the word choice or if a list has been defined.
+     *
+     * @return true if the word selection is restricted
+     */
     public boolean hasRestrictions() {
         return restrictions != null && restrictions.length > 0;
     }
 
+    /**
+     * Gets all the word restrictions
+     *
+     * @return the word restrictions, can be null
+     */
+    @Nullable
     public String[] getRestrictions() {
         return restrictions;
     }

src/main/java/net/minestom/server/timer/SchedulerManager.java

@@ -68,7 +68,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Initializes a new {@link TaskBuilder} for creating a shutdown {@link Task}
+     * Initializes a new {@link TaskBuilder} for creating a shutdown {@link Task}.
      *
      * @param runnable The shutdown {@link Task} to run when scheduled
      * @return the {@link TaskBuilder}
@@ -78,16 +78,18 @@ public class SchedulerManager {
     }
 
     /**
-     * Removes/Forces the end of a {@link Task}
+     * Removes/Forces the end of a {@link Task}.
      *
      * @param task The {@link Task} to remove
      */
     public void removeTask(Task task) {
-        this.tasks.remove(task.getId());
+        synchronized (tasks) {
+            this.tasks.remove(task.getId());
+        }
     }
 
     /**
-     * Removes/Forces the end of a {@link Task}
+     * Removes/Forces the end of a {@link Task}.
      *
      * @param task The {@link Task} to remove
      */
@@ -96,7 +98,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Shutdowns all normal tasks and call the registered shutdown tasks
+     * Shutdowns all normal tasks and call the registered shutdown tasks.
      */
     public void shutdown() {
         MinecraftServer.getLOGGER().info("Executing all shutdown tasks..");
@@ -122,7 +124,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Increments the current shutdown counter value
+     * Increments the current shutdown counter value.
      *
      * @return the updated shutdown counter value
      */
@@ -131,7 +133,9 @@ public class SchedulerManager {
     }
 
     /**
-     * Gets a {@link Collection} with all the registered {@link Task}
+     * Gets a {@link Collection} with all the registered {@link Task}.
+     * <p>
+     * Be aware that the collection is not thread-safe.
      *
      * @return a {@link Collection} with all the registered {@link Task}
      */
@@ -140,7 +144,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Gets a {@link Collection} with all the registered shutdown {@link Task}
+     * Gets a {@link Collection} with all the registered shutdown {@link Task}.
      *
      * @return a {@link Collection} with all the registered shutdown {@link Task}
      */
@@ -149,7 +153,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Gets the execution service for all the registered {@link Task}
+     * Gets the execution service for all the registered {@link Task}.
      *
      * @return the execution service for all the registered {@link Task}
      */
@@ -158,7 +162,7 @@ public class SchedulerManager {
     }
 
     /**
-     * Gets the scheduled execution service for all the registered {@link Task}
+     * Gets the scheduled execution service for all the registered {@link Task}.
      *
      * @return the scheduled execution service for all the registered {@link Task}
      */

src/main/java/net/minestom/server/timer/TaskBuilder.java

@@ -1,5 +1,6 @@
 package net.minestom.server.timer;
 
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import net.minestom.server.utils.time.TimeUnit;
 
 /**
@@ -22,9 +23,9 @@ public class TaskBuilder {
     private long repeat;
 
     /**
-     * Creates a task builder
+     * Creates a task builder.
      * <br>
-     * <b>Note:</b> The task builder creates a normal task
+     * <b>Note:</b> The task builder creates a normal task.
      *
      * @param schedulerManager The manager for the tasks
      * @param runnable         The task to run when scheduled
@@ -34,7 +35,7 @@ public class TaskBuilder {
     }
 
     /**
-     * Creates task builder
+     * Creates a task builder.
      *
      * @param schedulerManager The manager for the tasks
      * @param runnable         The task to run when scheduled
@@ -71,7 +72,7 @@ public class TaskBuilder {
     }
 
     /**
-     * Clears the delay interval of the {@link Task}
+     * Clears the delay interval of the {@link Task}.
      *
      * @return this builder, for chaining
      */
@@ -81,7 +82,7 @@ public class TaskBuilder {
     }
 
     /**
-     * Clears the repeat interval of the {@link Task}
+     * Clears the repeat interval of the {@link Task}.
      *
      * @return this builder, for chaining
      */
@@ -91,7 +92,7 @@ public class TaskBuilder {
     }
 
     /**
-     * Schedule this {@link Task} for execution
+     * Schedule this {@link Task} for execution.
      *
      * @return the built {@link Task}
      */
@@ -103,9 +104,15 @@ public class TaskBuilder {
                 this.delay,
                 this.repeat);
         if (this.shutdown) {
-            this.schedulerManager.shutdownTasks.put(task.getId(), task);
+            Int2ObjectMap<Task> shutdownTasks = this.schedulerManager.shutdownTasks;
+            synchronized (shutdownTasks) {
+                shutdownTasks.put(task.getId(), task);
+            }
         } else {
-            this.schedulerManager.tasks.put(task.getId(), task);
+            Int2ObjectMap<Task> tasks = this.schedulerManager.tasks;
+            synchronized (tasks) {
+                tasks.put(task.getId(), task);
+            }
             task.schedule();
         }
         return task;