AsyncSemaphore.queueSize method added

redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java

@@ -49,16 +49,9 @@ public class AsyncSemaphore {
         }
     }
 
-    public boolean tryAcquire() {
+    public int queueSize() {
         synchronized (this) {
-            if (counter == 0) {
-                return false;
-            }
-            if (counter > 0) {
-                counter--;
-                return true;
-            }
-            throw new IllegalStateException();
+            return listeners.size();
         }
     }