Tests did not stop a Timer thread at teardown

celery/tests/test_worker/test_worker.py

@@ -350,6 +350,7 @@ class test_Consumer(unittest.TestCase):
         l.connection_errors = (KeyError, )
         self.assertRaises(SyntaxError, l.start)
         l.heart.stop()
+        l.priority_timer.stop()
 
     def test_consume_messages(self):
 

celery/utils/timer2.py

@@ -262,7 +262,7 @@ class Timer(Thread):
     def queue(self):
         return self.schedule.queue
 
-_default_timer = Timer()
+default_timer = _default_timer = Timer()
 apply_after = _default_timer.apply_after
 apply_at = _default_timer.apply_at
 apply_interval = _default_timer.apply_interval

celery/worker/consumer.py

@@ -246,7 +246,7 @@ class Consumer(object):
         self.event_dispatcher = None
         self.heart = None
         self.pool = pool
-        self.priority_timer = priority_timer or timer2.Timer()
+        self.priority_timer = priority_timer or timer2.default_timer
         pidbox_state = AttributeDict(app=self.app,
                                      logger=logger,
                                      hostname=self.hostname,