Ticket #4909: wsgi-thread-safe-init.patch

django/core/handlers/wsgi.py

@@ -6 +6 @@
 from django import http
 from pprint import pformat
 from shutil import copyfileobj
+from threading import Lock
 try:
     from cStringIO import StringIO
 except ImportError:
@@ -176 +177 @@
     raw_post_data = property(_get_raw_post_data)
 
 class WSGIHandler(BaseHandler):
+    initLock = Lock()
     def __call__(self, environ, start_response):
         from django.conf import settings
 
         # Set up middleware if needed. We couldn't do this earlier, because
         # settings weren't available.
         if self._request_middleware is None:
-            self.load_middleware()
+            self.initLock.acquire()
+            # Check that we are the first thread to try loading the middleware.
+            if self._request_middleware is None:
+                self.load_middleware()
+            self.initLock.release()
 
         dispatcher.send(signal=signals.request_started)
         try: