diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sqlalchemy/orm/attributes.py | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py index 6cf2b74e9..27f4b017c 100644 --- a/lib/sqlalchemy/orm/attributes.py +++ b/lib/sqlalchemy/orm/attributes.py @@ -557,19 +557,25 @@ class InstanceState(object): self.instance_dict = None def __cleanup(self, ref): - if self.instance_dict is None or self.instance_dict() is None: + # tiptoe around Python GC unpredictableness + instance_dict = self.instance_dict + if instance_dict is None: return - instance_dict = self.instance_dict() - + instance_dict = instance_dict() + if instance_dict is None: + return + # the mutexing here is based on the assumption that gc.collect() # may be firing off cleanup handlers in a different thread than that # which is normally operating upon the instance dict. instance_dict._mutex.acquire() try: # if instance_dict de-refed us, or it called our - # _resurrect, return - if self.instance_dict is None or self.instance_dict() is None or self.obj() is not None: + # _resurrect, return. again setting local copy + # to avoid the rug being pulled in between + id2 = self.instance_dict + if id2 is None or id2() is None or self.obj() is not None: return self.__resurrect(instance_dict) |