How to evaluate a python module is thread-safe or not?

Well, the initial thing to my mind was how to make sure if pydispatcher or pubsub is thread-safe or 开发者_StackOverflownot. pubsub might be a little tricky or complex to figure out but pydispatcher seems simple to realize. Then I started to wonder how to figure out if a python module thread-safe or not. Any heuristics?

For determining if a library or application is thread safe, without author input, I would look for mechanisms for synchronizing threads: http://effbot.org/zone/thread-synchronization.htm or that it contains threading methods: http://docs.python.org/library/threading.html

However, none of that will tell you how to use the API in a thread safe manner. Practically anything can be stuffed inside a thread object and communicated to using thread synchronization objects.

For something like pubsub one could create a class that wraps the API and communicates over Queues exclusively. If pubsub lived in the same thread as wx for example, then an API could be created to inject messages into the Queue using a threading API for sending messages. Then a pubsub loop or timer could be monitoring the Queue. It would then send out messages. One of the issues with wrapping something like pubsub is that somewhere it will require polling. It could be made transparent if the polling were done by timers. Each thread would have to allocate a timer to receive messages if pubsub did not reside in that thread. There might be more elegant approaches to this, but I am not aware of them.

From a theoretic point of view: There is no algorithm which does this for an arbitrary program. It is like the halting problem.

You can inspect the used modules and check if these are granted to be thread safe. But there is no general way to check the byte code of a module for thread safety.