I'm playing around with the locmem cache backend and I set my 'max_entries' to a particularly low value such that the culling algorithm will kick in and prune my cache.
ORG_CACHE = cache.get_cache("locmem:///?max_entries=20&timeout=3600")
When the cull logic actually fires, I experience what appears to be a deadlock condition, on this line of the locmem backend:
def _cull(self):
if self._cull_frequency == 0:
self._cache.clear()
self._expire_info.clear()
else:
doomed = [k for (i, k) in enumerate(self._cache) if i % self._cull_frequency == 0]
for k in doomed:
self.delete(k)
def delete (self, key):
self._lock.writer_enters() # <------ deadlocks here
try:
self._delete(key)
finally:
self._lock.writer_leaves()
Based on the way the surrounding code is written, I think the '_cull' method should actually be calling the '_delete' method instead of 'delete' as the lock has already been acquired earlier in the call stack. Indeed, when I change it to call the '_delete' method, the deadlock condition no longer occurs.
