Tornado Multiple Ioloop In Multithreads

I am trying to run multiple IOLoop in multiple threads and I am wondering how the IOLoop actually works. class WebThread(threading.Thread): def __init__(self): threadi

Solution 1:

In general you should use IOLoop.current as the default when constructing an asynchronous object, and use IOLoop.instance when you mean to communicate to the main thread from a different one.

IOLoop.current without params returns already created ioloop of thread or it calls IOLoop.instance(). And HTTPServer (actually in TCPServer) use IOLoop.current to interact with ioloop, so the only thing you should change is to create ioloop before HTTPServer e.g.

class WebThread(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self, name='WebThread')

    def run(self):
        curdir = os.path.dirname(os.path.realpath(__file__))

        ioloop = tornado.ioloop.IOLoop()

        application = Application() #Very simple tornado.web.Application
        http_server_api = tornado.httpserver.HTTPServer(application)
        http_server_api.listen(8888)

        logging.info('Starting application')

        ioloop.start()

Also I've removed IOLoop.make_current, since it's redundant - IOLoop() sets self as a current.

---

Code above will work, but only with one thread, because reuse_port is not enabled by default. You will end up with:

OSError: [Errno 98] Address already in use

You can enable this with

    http_server_api.bind(port=8888, reuse_port=True)
    http_server_api.start()

instead of http_server_api.listen(8888)