Is Django middleware thread safe?

Question

Are Django middleware thread safe? Can I do something like this,

class ThreadsafeTestMiddleware(object):

    def process_request(self, request):
        self.thread_safe_variable = some_dynamic_value_from_request

    def process_response(self, request, response):
        # will self.thread_safe_variable always equal to some_dynamic_value_from_request?

Answer 1

Why not bind your variable to the request object, like so:

class ThreadsafeTestMiddleware(object):

    def process_request(self, request):
        request.thread_safe_variable = some_dynamic_value_from_request

    def process_response(self, request, response):
        #... do something with request.thread_safe_variable here ...

Answer 2

No, very definitely not. I write about this issue here - the upshot is that storing state in a middleware class is a very bad idea.

As Steve points out, the solution is to add it to the request instead.