Deloy with ansible-playbook async mode cost too much time on 2000+ hosts

I found ansible stuck on this code,and I dont know why.

runner/init.py

1377 TIMEOUT = 100
1378 start_time = time.time()
1379 try:
1380 while not result_queue.empty():
1381 results.append(result_queue.get(block=False))
1382 except socket.error:
1383 raise errors.AnsibleError(“”)
1384 return results

best wishes.