Use native async

Also remove a test that isn't that useful

README.rst

@@ -26,7 +26,7 @@ call to the ``get`` method as well as a separate metric for the database query.
 
    from sprockets.mixins import mediatype
    from sprockets.mixins.metrics import statsd
-   from tornado import gen, web
+   from tornado import web
    import queries
 
    def make_application():
@@ -47,10 +47,9 @@ call to the ``get`` method as well as a separate metric for the database query.
            super(MyHandler, self).initialize()
            self.db = queries.TornadoSession(os.environ['MY_PGSQL_DSN'])
 
-       @gen.coroutine
-       def get(self, obj_id):
+       async def get(self, obj_id):
            with self.execution_timer('dbquery', 'get'):
-              result = yield self.db.query('SELECT * FROM foo WHERE id=%s',
+              result = await self.db.query('SELECT * FROM foo WHERE id=%s',
                                            obj_id)
            self.send_response(result)
 

examples/statsd.py

@@ -1,7 +1,8 @@
+import asyncio
 import signal
 
 from sprockets.mixins.metrics import statsd
-from tornado import concurrent, gen, ioloop, web
+from tornado import ioloop, web
 
 
 class SimpleHandler(statsd.StatsdMixin, web.RequestHandler):
@@ -14,9 +15,8 @@ class SimpleHandler(statsd.StatsdMixin, web.RequestHandler):
 
     """
 
-    @gen.coroutine
-    def get(self):
-        yield gen.sleep(0.25)
+    async def get(self):
+        await asyncio.sleep(0.25)
         self.set_status(204)
         self.finish()
 

sprockets/mixins/metrics/statsd.py

@@ -1,10 +1,11 @@
+import asyncio
 import contextlib
 import logging
 import os
 import socket
 import time
 
-from tornado import gen, iostream
+from tornado import iostream
 
 LOGGER = logging.getLogger(__name__)
 
@@ -134,12 +135,11 @@ class StatsDCollector:
         sock.set_close_callback(self._tcp_on_closed)
         return sock
 
-    @gen.engine
-    def _tcp_on_closed(self):
+    async def _tcp_on_closed(self):
         """Invoked when the socket is closed."""
         LOGGER.warning('Not connected to statsd, connecting in %s seconds',
                        self._tcp_reconnect_sleep)
-        yield gen.sleep(self._tcp_reconnect_sleep)
+        await asyncio.sleep(self._tcp_reconnect_sleep)
         self._sock = self._tcp_socket()
 
     def _tcp_on_connected(self):

sprockets/mixins/metrics/testing.py

@@ -2,7 +2,7 @@ import logging
 import re
 import socket
 
-from tornado import gen, iostream, locks, tcpserver, testing
+from tornado import iostream, locks, tcpserver, testing
 
 LOGGER = logging.getLogger(__name__)
 
@@ -67,11 +67,10 @@ class FakeStatsdServer(tcpserver.TCPServer):
             self.socket.close()
             self.socket = None
 
-    @gen.coroutine
-    def handle_stream(self, stream, address):
+    async def handle_stream(self, stream, address):
         while True:
             try:
-                result = yield stream.read_until_regex(self.TCP_PATTERN)
+                result = await stream.read_until_regex(self.TCP_PATTERN)
             except iostream.StreamClosedError:
                 break
             else:

tests.py

@@ -1,9 +1,10 @@
+import asyncio
 import itertools
 import socket
 import unittest
 from unittest import mock
 
-from tornado import gen, iostream, testing, web
+from tornado import iostream, testing, web
 
 from sprockets.mixins.metrics import statsd
 from sprockets.mixins.metrics.testing import FakeStatsdServer
@@ -12,10 +13,9 @@ import examples.statsd
 
 class CounterBumper(statsd.StatsdMixin, web.RequestHandler):
 
-    @gen.coroutine
-    def get(self, counter, value):
+    async def get(self, counter, value):
         with self.execution_timer(*counter.split('.')):
-            yield gen.sleep(float(value))
+            await asyncio.sleep(float(value))
         self.set_status(204)
         self.finish()
 
@@ -75,18 +75,6 @@ class TCPStatsdMetricCollectionTests(testing.AsyncHTTPTestCase):
                                             'protocol': 'tcp',
                                             'prepend_metric_type': True})
 
-    def test_tcp_reconnect_on_stream_close(self):
-        path_sleep = 'tornado.gen.sleep'
-        path_statsd = self.application.statsd
-        with mock.patch(path_sleep) as gen_sleep, \
-             mock.patch.object(path_statsd, '_tcp_socket') as mock_tcp_socket:
-                f = web.Future()
-                f.set_result(None)
-                gen_sleep.return_value = f
-
-                self.application.statsd._tcp_on_closed()
-                mock_tcp_socket.assert_called_once_with()
-
     @mock.patch.object(iostream.IOStream, 'write')
     def test_write_not_executed_when_connection_is_closed(self, mock_write):
         self.application.statsd._sock.close()