Improve async packet processing logic (#2503)

* fix: enqueue async packet event after processing delay is zero
* fix: async packet processing

Author: Ingrim4

src/main/java/com/comphenix/protocol/async/AsyncFilterManager.java

@@ -413,6 +413,23 @@ private void signalPacketTransmission(PacketEvent packet, boolean onMainThread)
 
         // Only send if the packet is ready
         if (marker.decrementProcessingDelay() == 0) {
+
+            // Now, get the next non-cancelled listener
+            if (!marker.hasExpired()) {
+                for (; marker.getListenerTraversal().hasNext(); ) {
+                    AsyncListenerHandler handler = marker.getListenerTraversal().next().getListener();
+                    
+                    if (!handler.isCancelled()) {
+                    	marker.incrementProcessingDelay();
+                    	handler.enqueuePacket(packet);
+                        return;
+                    }
+                }
+            }
+            
+            // There are no more listeners - queue the packet for transmission
+            signalFreeProcessingSlot(packet);
+
             PacketSendingQueue queue = getSendingQueue(packet, false);
 
             // No need to create a new queue if the player has logged out

src/main/java/com/comphenix/protocol/async/AsyncListenerHandler.java

@@ -632,21 +632,6 @@ private void processPacket(int workerID, PacketEvent packet, String methodName)
             filterManager.getErrorReporter().reportMinimal(listener.getPlugin(), methodName, e);
         }
 
-        // Now, get the next non-cancelled listener
-        if (!marker.hasExpired()) {
-            for (; marker.getListenerTraversal().hasNext(); ) {
-                AsyncListenerHandler handler = marker.getListenerTraversal().next().getListener();
-                
-                if (!handler.isCancelled()) {
-                    handler.enqueuePacket(packet);
-                    return;
-                }
-            }
-        }
-        
-        // There are no more listeners - queue the packet for transmission
-        filterManager.signalFreeProcessingSlot(packet);
-        
         // Note that listeners can opt to delay the packet transmission
         filterManager.signalPacketTransmission(packet);
     }