fixed freezing Dispatcher

al2/experiment.py

@@ -51,11 +51,12 @@ class Dispatcher (threading.Thread):
             worker.start()
         
         def wait_to_continue(workers, stop_called):
-            any_worker_alive = any(map(lambda w: w.is_alive(), workers))
+            any_worker_alive = lambda: any(map(lambda w: w.is_alive(), workers))
 
-            while any_worker_alive and not stop_called.is_set():
+            while any_worker_alive() and not stop_called.is_set():
                 time.sleep(0)
 
+
         waiter = threading.Thread(target=wait_to_continue,
                                   args=(self.__workers,
                                         self.__stop_called))
@@ -67,12 +68,20 @@ class Dispatcher (threading.Thread):
             for worker in self.__workers:
                 worker.terminate()
         
+
         for worker in self.__workers:   
             worker.join()
 
     def stop(self):
         self.__stop_called.set()
 
+    def num_active_workers(self):
+        count = 0
+        for worker in self.__workers:
+            count += 1 if worker.is_alive() else 0
+
+        return count
+
 class Worker (multiprocessing.Process):
     def __init__(self, exp_mod, exp_plan):
         multiprocessing.Process.__init__(self)