asyncio: clean up event loop acquisition

We now acquire the event loop through asyncio.get_event_loop, avoiding having
to pass the loop explicity in a bunch of places. This function does not return
the currently running loop from within coroutines in versions of Python prior
to 3.6.

mitmproxy/master.py

@@ -2,7 +2,6 @@ import threading
 import contextlib
 import asyncio
 import signal
-import time
 
 from mitmproxy import addonmanager
 from mitmproxy import options
@@ -37,11 +36,10 @@ class Master:
         The master handles mitmproxy's main event loop.
     """
     def __init__(self, opts):
-        self.loop = asyncio.new_event_loop()
-        asyncio.set_event_loop(self.loop)
+        loop = asyncio.get_event_loop()
         for signame in ('SIGINT', 'SIGTERM'):
-            self.loop.add_signal_handler(getattr(signal, signame), self.shutdown)
-        self.event_queue = asyncio.Queue(loop=self.loop)
+            loop.add_signal_handler(getattr(signal, signame), self.shutdown)
+        self.event_queue = asyncio.Queue()
 
         self.options = opts or options.Options()  # type: options.Options
         self.commands = command.CommandManager(self)
@@ -57,9 +55,7 @@ class Master:
 
     @server.setter
     def server(self, server):
-        server.set_channel(
-            controller.Channel(self.loop, self.event_queue)
-        )
+        server.set_channel(controller.Channel(asyncio.get_event_loop(), self.event_queue))
         self._server = server
 
     @contextlib.contextmanager
@@ -111,18 +107,16 @@ class Master:
             self.addons.trigger("running")
         while True:
             if self.should_exit.is_set():
-                self.loop.stop()
+                asyncio.get_event_loop().stop()
                 return
             self.addons.trigger("tick")
-            await asyncio.sleep(0.1, loop=self.loop)
+            await asyncio.sleep(0.1)
 
-    def run(self, inject=None):
+    def run(self):
         self.start()
-        asyncio.ensure_future(self.main(), loop=self.loop)
-        asyncio.ensure_future(self.tick(), loop=self.loop)
-        if inject:
-            asyncio.ensure_future(inject(), loop=self.loop)
-        self.loop.run_forever()
+        asyncio.ensure_future(self.main())
+        asyncio.ensure_future(self.tick())
+        asyncio.get_event_loop().run_forever()
         self.shutdown()
         self.addons.trigger("done")
 
@@ -214,7 +208,7 @@ class Master:
         rt = http_replay.RequestReplayThread(
             self.options,
             f,
-            self.loop,
+            asyncio.get_event_loop(),
             self.event_queue,
             self.should_exit
         )

test/mitmproxy/test_controller.py

@@ -1,102 +1,31 @@
 import asyncio
-from threading import Thread, Event
-from unittest.mock import Mock
 import queue
 import pytest
-import sys
 
 from mitmproxy.exceptions import Kill, ControlException
 from mitmproxy import controller
-from mitmproxy import master
-from mitmproxy import proxy
 from mitmproxy.test import taddons
 
 
-class TMsg:
-    pass
+@pytest.mark.asyncio
+async def test_master():
+    class TMsg:
+        pass
 
-
-def test_master():
     class tAddon:
         def log(self, _):
             ctx.master.should_exit.set()
 
-    with taddons.context() as ctx:
-        ctx.master.addons.add(tAddon())
+    with taddons.context(tAddon()) as ctx:
         assert not ctx.master.should_exit.is_set()
 
         async def test():
             msg = TMsg()
             msg.reply = controller.DummyReply()
-            await ctx.master.event_queue.put(("log", msg))
+            await ctx.master.channel.tell("log", msg)
 
-        ctx.master.run(inject=test)
-
-
-# class TestMaster:
-#     # def test_simple(self):
-#     #     class tAddon:
-#     #         def log(self, _):
-#     #             ctx.master.should_exit.set()
-
-#     #     with taddons.context() as ctx:
-#     #         ctx.master.addons.add(tAddon())
-#     #         assert not ctx.master.should_exit.is_set()
-#     #         msg = TMsg()
-#     #         msg.reply = controller.DummyReply()
-#     #         ctx.master.event_queue.put(("log", msg))
-#     #         ctx.master.run()
-#     #         assert ctx.master.should_exit.is_set()
-
-#     # def test_server_simple(self):
-#     #     m = master.Master(None)
-#     #     m.server = proxy.DummyServer()
-#     #     m.start()
-#     #     m.shutdown()
-#     #     m.start()
-#     #     m.shutdown()
-#     pass
-
-
-# class TestServerThread:
-#     def test_simple(self):
-#         m = Mock()
-#         t = master.ServerThread(m)
-#         t.run()
-#         assert m.serve_forever.called
-
-
-# class TestChannel:
-#     def test_tell(self):
-#         q = queue.Queue()
-#         channel = controller.Channel(q, Event())
-#         m = Mock(name="test_tell")
-#         channel.tell("test", m)
-#         assert q.get() == ("test", m)
-#         assert m.reply
-
-#     def test_ask_simple(self):
-#         q = queue.Queue()
-
-#         def reply():
-#             m, obj = q.get()
-#             assert m == "test"
-#             obj.reply.send(42)
-#             obj.reply.take()
-#             obj.reply.commit()
-
-#         Thread(target=reply).start()
-
-#         channel = controller.Channel(q, Event())
-#         assert channel.ask("test", Mock(name="test_ask_simple")) == 42
-
-#     def test_ask_shutdown(self):
-#         q = queue.Queue()
-#         done = Event()
-#         done.set()
-#         channel = controller.Channel(q, done)
-#         with pytest.raises(Kill):
-#             channel.ask("test", Mock(name="test_ask_shutdown"))
+        asyncio.ensure_future(test())
+        assert not ctx.master.should_exit.is_set()
 
 
 class TestReply: