Update window slots w/o holding lock

Author: NichtStudioCode

invui/src/main/java/xyz/xenondevs/invui/window/AbstractWindow.java

@@ -206,14 +206,17 @@ public void handleTick() {
 
     @Override
     public void updateSlots() {
+        BitSet toUpdate;
         synchronized (dirtySlots) {
-            int slot = 0;
-            while ((slot = dirtySlots.nextSetBit(slot)) != -1) {
-                update(slot);
-                slot++;
-            }
+            toUpdate = (BitSet) dirtySlots.clone();
             dirtySlots.clear();
         }
+        
+        int slot = 0;
+        while ((slot = toUpdate.nextSetBit(slot)) != -1) {
+            update(slot);
+            slot++;
+        }
     }
 
     @Override