Implemented proper Async Event Loop

event-loop/src/main/java/mc/core/events/SimpleEventLoop.java

@@ -17,6 +17,8 @@ public class SimpleEventLoop extends BaseEventLoop {
         Class<? extends Event> eventType = event.getClass();
         if (handlers.containsKey(eventType)) {
             for (ExecutorLink link : handlers.get(eventType)) {
+                if (link.isIgnoreCancelled() && event.isCanceled())
+                    continue;
                 try {
                     link.getMethod().invoke(link.object, event);
                 } catch (IllegalAccessException | InvocationTargetException e) {

event-loop/src/main/java/mc/core/events/async/AsyncEventLoop.java

@@ -11,29 +11,47 @@ import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.*;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 @SuppressWarnings("Duplicates")
 @Slf4j
 public class AsyncEventLoop extends BaseEventLoop {
     private Map<Class<? extends Event>, List<ExecutorLink>> handlers = new HashMap<>();
+    private ExecutorService preEventExecutor = Executors.newSingleThreadExecutor();
 
     @Override
     public void callEvent(Event event) {
         Class<? extends Event> eventType = event.getClass();
+
         if (handlers.containsKey(eventType)) {
-            for (ExecutorLink link : handlers.get(eventType)) {
-                Object preprocessResult = null;
-                if (link.getPreprocessMethod() != null) {
-                    try {
-                        preprocessResult = link.getPreprocessMethod().invoke(link.object, event);
-                    } catch (IllegalAccessException | InvocationTargetException e) {
-                        log.error("Exception caught while attempting to run event preprocessing for {}.", eventType.getSimpleName(), e);
+            List<ExecutorLink> handlerList = handlers.get(eventType);
+            EventBatch eventBatch = new EventBatch(handlerList.size());
+            CountDownLatch latch = new CountDownLatch(handlerList.size());
+
+            for (int i = 0; i < handlerList.size(); i++) {
+                if (handlerList.get(i).getPreprocessMethod() == null) {
+                    latch.countDown();
+                    continue;
                 }
+                preEventExecutor.submit(new PreprocessTask(i, eventBatch, latch, handlerList.get(i), event));
             }
 
+            try {
+                latch.await();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            for (int i = 0; i < handlerList.size(); i++) {
+                ExecutorLink link = handlerList.get(i);
+                if (link.isIgnoreCancelled() && event.isCanceled())
+                    continue;
+
                 try {
                     if (link.getResultInjection() != null)
-                        link.getMethod().invoke(link.object, event, preprocessResult);
+                        link.getMethod().invoke(link.object, event, eventBatch.getInjectionObject(i));
                     else
                         link.getMethod().invoke(link.object, event);
                 } catch (IllegalAccessException | InvocationTargetException e) {
@@ -130,7 +148,7 @@ public class AsyncEventLoop extends BaseEventLoop {
      */
     @RequiredArgsConstructor
     @Getter
-    private static class ExecutorLink {
+    static class ExecutorLink {
         private final int priority;
         private final boolean ignoreCancelled;
         private final Method method;

event-loop/src/main/java/mc/core/events/async/EventBatch.java

@@ -0,0 +1,17 @@
+package mc.core.events.async;
+
+public class EventBatch {
+    private Object[] returnInject;
+
+    public EventBatch(int size) {
+        this.returnInject = new Object[size];
+    }
+
+    public Object getInjectionObject(int id) {
+        return returnInject[id];
+    }
+
+    public void setInjectionObject(int id, Object value) {
+        returnInject[id] = value;
+    }
+}

event-loop/src/main/java/mc/core/events/async/PreprocessTask.java

@@ -0,0 +1,32 @@
+package mc.core.events.async;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import mc.core.events.Event;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.concurrent.CountDownLatch;
+
+@RequiredArgsConstructor
+@Slf4j
+public class PreprocessTask implements Runnable {
+    private final int id;
+    private final EventBatch eventBatch;
+    private final CountDownLatch latch;
+    private final AsyncEventLoop.ExecutorLink link;
+    private final Event event;
+
+    @Override
+    public void run() {
+        try {
+            Object result = link.getPreprocessMethod().invoke(link.getObject(), event);
+            if (result != null)
+                eventBatch.setInjectionObject(id, result);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            log.error("Exception caught while attempting to run event preprocessing.", e);
+        } finally {
+            latch.countDown();
+        }
+
+    }
+}