_test_concurrency fails periodically #799
Description
Originally reported by: Anonymous
lakin@zedd:~/Projects/cherrypy/trunk/cherrypy$ python test/test.py --test_session
Python version used to run this test script: 2.5.1
CherryPy version 3.1.0beta3
HTTP server version HTTP/1.1
PID: 25410
Running tests: cherrypy._cpwsgi.CPWSGIServer
test (test_session.MemcachedSessionTest) ... ok
test_0_Session (test_session.SessionTest) ... ok
test_1_Ram_Concurrency (test_session.SessionTest) ... ok
test_2_File_Concurrency (test_session.SessionTest) ... FAIL
test_3_Redirect (test_session.SessionTest) ... ok
test_4_File_deletion (test_session.SessionTest) ... ok
test_5_Error_paths (test_session.SessionTest) ... ok
test_6_regenerate (test_session.SessionTest) ... ok
======================================================================
FAIL: test_2_File_Concurrency (test_session.SessionTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/lakin/Projects/cherrypy/trunk/cherrypy/test/webtest.py", line 278, in __call__
testMethod()
File "/home/lakin/Projects/cherrypy/trunk/cherrypy/test/test_session.py", line 180, in test_2_File_Concurrency
self._test_Concurrency()
File "/home/lakin/Projects/cherrypy/trunk/cherrypy/test/test_session.py", line 230, in _test_Concurrency
self.assertEqual(hitcount, expected)
AssertionError: 148 != 151
FAILED (failures=1)
skipped
hit enter
Surprisingly it typically only happens with the FileSession, although from looking at the tests itself it's obvious that there is a concurrency issue.
is not threadsafe. It would be easy for two threads to overwrite each others increments. For reference this is how the threads are created:
http://cherrypy.org/browser/trunk/cherrypy/test/test_session.py#L182l
So, I'm not sure if the session is supposed guard against these sorts of concurrency issues, but my first impression is that it shouldn't. So I'd say the test is broken, thoughts?
Reported by lakin