Tornado Coroutines with Locks

tornado_async_locks.py

import tornado.web
from tornado import gen
from tornado.locks import Lock

class Service():

    def __init__(self, service_id, nth=None):
        self._nth = nth
        self._service_id = service_id
        self._count = 0
        self._lock = Lock()
        print('starting class', service_id)

    async def do_work(self):
        async with self._lock:
            self._count += 1
            print('%s starting work %s' % (self._service_id, self._count))
            if self._nth and not self._count % self._nth:
                print('%s sleeping work %s' %
                    (self._service_id, self._count))
                await gen.sleep(3)
            print('%s done with work %s' %
                (self._service_id, self._count))
            return self._count

s1 = Service(1, 2)
s2 = Service(2)

class Handler(tornado.web.RequestHandler):
    async def get(self):

        r1, r2 = await gen.multi([s1.do_work(), s2.do_work()])

        self.write("s1: {:<4} s2: {:<4}".format(r1, r2))

if __name__ == "__main__":
    app = tornado.web.Application(
        [
            (r"/", Handler),
        ],
    )
    app.listen(8888)
    tornado.ioloop.IOLoop.current().start()