Fix for updater

cps/helper.py

@@ -341,9 +341,13 @@ class Updater(threading.Thread):
         ub.session.close()
         ub.engine.dispose()
         self.status=6
-        # stop tornado server
-        server = IOLoop.instance()
-        server.add_callback(server.stop)
+
+        if web.gevent_server:
+            web.gevent_server.stop()
+        else:
+            # stop tornado server            
+            server = IOLoop.instance()
+            server.add_callback(server.stop)
         self.status=7
 
     def get_update_status(self):

cps/web.py

@@ -198,6 +198,8 @@ mimetypes.add_type('image/vnd.djvu', '.djvu')
 app = (Flask(__name__))
 app.wsgi_app = ReverseProxied(app.wsgi_app)
 
+gevent_server=None
+
 formatter = logging.Formatter(
     "[%(asctime)s] {%(pathname)s:%(lineno)d} %(levelname)s - %(message)s")
 file_handler = RotatingFileHandler(os.path.join(config.get_main_dir, "calibre-web.log"), maxBytes=50000, backupCount=2)
@@ -2683,3 +2685,9 @@ def upload():
     book_in_shelfs = []
     return render_title_template('detail.html', entry=db_book, cc=cc, title=db_book.title,
                                  books_shelfs=book_in_shelfs, )
+
+def start_gevent():
+    from gevent.wsgi import WSGIServer
+    global gevent_server
+    gevent_server = WSGIServer(('', ub.config.config_port), app)
+    gevent_server.serve_forever()