Hi,
I'm currently seeing an intermittent issue in the JBossWS-CXF testsuite
(stacktrace at https://paste.fedoraproject.org/428145/14738847/raw/ ),
with the EHCacheTokenStore creation failing due to the CacheManager
having been shutdown. The testsuite includes multiple tests, almost all
of them create jaxws clients and in most of them the current thread bus
is used (few of them do create a new bus, set it as default thread bus,
run and eventually shutdown the bus). What I suspect is some kind of
concurrency issue in the CacheManager lifecycle management.
I've looked a bit at the code and noticed that there's basically a 1-1
relationship between Bus instances and CacheManager instances. Given I
have some tests that do not explicitly shutdown the bus (or the client)
after execution, it can happen that a client is closed because the JDK
eventually finalize ClientProxy, which in the end causes the
CacheCleanupListener to close the token store and hence to
release/shutdown the cache manager (see the invocation flow at
https://paste.fedoraproject.org/428150/47388530/raw/ ). Unfortunately
that exact cache manager could possibly be in use to serve another
client running in the same bus. AFAICS, there's an attempt to avoid
problems like this in WSS4J's EHCacheManagerHolder (which deals with CXF
requests of creating/releasing cache managers), as it has a
ConcurrentHashMap<String, AtomicInteger> attribute to keep track of how
many consumers of a given cache manager are there and avoid shutting
down a manager if it's still in use. Looking at its getCacheManager and
releaseCacheManager methods I can see a possible concurrency flaw which
could be the root of my failure. The releaseCacheManager method could be
called with cacheManager X as parameter while a different thread is
running getCacheManager and is just before line 106 (that is just before
the AtomicInteger is got from the map) with local cacheManager variable
already resolved to X. That should later deal to an attempt to use an
already shutdown cache manager. I would be tempted to suggest making
those two methods syncronized (the map could then probably be a plain
hash map).
WDYT? I might be missing something, so posting here before opening up a
jira. Any idea?
Cheers
Alessio
--
Alessio Soldano
Web Service Lead, JBoss
