Require Tornado >= 3.2

Survey of version available in the oldest distros we care about:

- Debian 8, squeeze: 3.2.2
- Debian 8, squeeze-backports: 4.2.0
- Ubuntu 16.04 LTS: 4.2.1
- Arch Linux: 4.4.2

.travis.yml

@@ -8,8 +8,7 @@ python:
 
 env:
   - TOX_ENV=py27
-  - TOX_ENV=py27-tornado23
-  - TOX_ENV=py27-tornado31
+  - TOX_ENV=py27-tornado32
   - TOX_ENV=docs
   - TOX_ENV=flake8
 

docs/changelog.rst

@@ -10,6 +10,11 @@ v2.1.0 (UNRELEASED)
 
 Feature release.
 
+- Dependencies: Drop support for Tornado < 3.2. Though strictly a breaking
+  change, this shouldn't have any effect on what systems we support, as Tornado
+  3.2 or newer is available from the distros that include GStreamer >= 1.2.3,
+  which we already require.
+
 - Core: Mopidy restores its last state when started. Can be enabled by setting
   the config value :confval:`core/restore_state` to ``true``.
 

mopidy/http/handlers.py

@@ -89,16 +89,12 @@ class WebSocketHandler(tornado.websocket.WebSocketHandler):
 
     @classmethod
     def broadcast(cls, msg):
-        if hasattr(tornado.ioloop.IOLoop, 'current'):
-            loop = tornado.ioloop.IOLoop.current()
-        else:
-            loop = tornado.ioloop.IOLoop.instance()  # Fallback for pre 3.0
+        loop = tornado.ioloop.IOLoop.current()
 
         # This can be called from outside the Tornado ioloop, so we need to
         # safely cross the thread boundary by adding a callback to the loop.
         for client in cls.clients:
             # One callback per client to keep time we hold up the loop short
-            # NOTE: Pre 3.0 does not support *args or **kwargs...
             loop.add_callback(functools.partial(_send_broadcast, client, msg))
 
     def initialize(self, core):
@@ -139,10 +135,7 @@ class WebSocketHandler(tornado.websocket.WebSocketHandler):
         except Exception as e:
             error_msg = encoding.locale_decode(e)
             logger.error('WebSocket request error: %s', error_msg)
-            if self.ws_connection:
-                # Tornado 3.2+ checks if self.ws_connection is None before
-                # using it, but not older versions.
-                self.close()
+            self.close()
 
     def check_origin(self, origin):
         # Allow cross-origin WebSocket connections, like Tornado before 4.0

setup.py

@@ -27,7 +27,7 @@ setup(
         'Pykka >= 1.1',
         'requests >= 2.0',
         'setuptools',
-        'tornado >= 2.3',
+        'tornado >= 3.2',
     ],
     extras_require={'http': []},
     entry_points={

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py27-tornado23, py27-tornado31, docs, flake8
+envlist = py27, py27-tornado32, docs, flake8
 
 [testenv]
 sitepackages = true
@@ -17,17 +17,11 @@ deps =
     pytest-xdist
     responses
 
-[testenv:py27-tornado23]
+[testenv:py27-tornado32]
 commands = py.test tests/http
 deps =
     {[testenv]deps}
-    tornado==2.3
-
-[testenv:py27-tornado31]
-commands = py.test tests/http
-deps =
-    {[testenv]deps}
-    tornado==3.1.1
+    tornado==3.2.2
 
 [testenv:docs]
 deps = -r{toxinidir}/docs/requirements.txt