From: Ben Darnell <ben@bendarnell.com>
Date: Thu, 30 Jul 2015 04:11:24 +0000 (-0400)
Subject: Restore IOLoop.current() when AsyncIOLoop exits.
X-Git-Tag: v4.3.0b1~69
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8943ee06df4ad850a9e4fd2aec85c537e31040af;p=thirdparty%2Ftornado.git

Restore IOLoop.current() when AsyncIOLoop exits.

Also make this process repeatable.
---

diff --git a/tornado/platform/asyncio.py b/tornado/platform/asyncio.py
index 8f3dbff64..cfeadc98f 100644
--- a/tornado/platform/asyncio.py
+++ b/tornado/platform/asyncio.py
@@ -35,7 +35,6 @@ class BaseAsyncIOLoop(IOLoop):
         super(BaseAsyncIOLoop, self).initialize(**kwargs)
         self.asyncio_loop = asyncio_loop
         self.close_loop = close_loop
-        self.asyncio_loop.call_soon(self.make_current)
         # Maps fd to (fileobj, handler function) pair (as in IOLoop.add_handler)
         self.handlers = {}
         # Set of fds listening for reads/writes
@@ -105,8 +104,16 @@ class BaseAsyncIOLoop(IOLoop):
         handler_func(fileobj, events)
 
     def start(self):
-        self._setup_logging()
-        self.asyncio_loop.run_forever()
+        old_current = IOLoop.current(instance=False)
+        try:
+            self._setup_logging()
+            self.make_current()
+            self.asyncio_loop.run_forever()
+        finally:
+            if old_current is None:
+                IOLoop.clear_current()
+            else:
+                old_current.make_current()
 
     def stop(self):
         self.asyncio_loop.stop()
@@ -140,8 +147,14 @@ class AsyncIOMainLoop(BaseAsyncIOLoop):
 
 class AsyncIOLoop(BaseAsyncIOLoop):
     def initialize(self, **kwargs):
-        super(AsyncIOLoop, self).initialize(asyncio.new_event_loop(),
-                                            close_loop=True, **kwargs)
+        loop = asyncio.new_event_loop()
+        try:
+            super(AsyncIOLoop, self).initialize(loop, close_loop=True, **kwargs)
+        except Exception:
+            # If initialize() does not succeed (taking ownership of the loop),
+            # we have to close it.
+            loop.close()
+            raise
 
 
 def to_tornado_future(asyncio_future):
diff --git a/tornado/platform/twisted.py b/tornado/platform/twisted.py
index 0bb8d54fe..272955a85 100644
--- a/tornado/platform/twisted.py
+++ b/tornado/platform/twisted.py
@@ -423,7 +423,6 @@ class TwistedIOLoop(tornado.ioloop.IOLoop):
             reactor = twisted.internet.reactor
         self.reactor = reactor
         self.fds = {}
-        self.reactor.callWhenRunning(self.make_current)
 
     def close(self, all_fds=False):
         fds = self.fds
@@ -480,6 +479,7 @@ class TwistedIOLoop(tornado.ioloop.IOLoop):
         old_current = IOLoop.current(instance=False)
         try:
             self._setup_logging()
+            self.make_current()
             self.reactor.run()
         finally:
             if old_current is None:
diff --git a/tornado/test/ioloop_test.py b/tornado/test/ioloop_test.py
index 062d7225b..c914b1c74 100644
--- a/tornado/test/ioloop_test.py
+++ b/tornado/test/ioloop_test.py
@@ -429,15 +429,18 @@ class TestIOLoopCurrent(unittest.TestCase):
         self.io_loop = IOLoop(make_current=False)
         # The new IOLoop is not initially made current.
         self.assertIsNone(IOLoop.current(instance=False))
-        def f():
-            # But it is current after it is started.
-            self.current_io_loop = IOLoop.current()
-            self.io_loop.stop()
-        self.io_loop.add_callback(f)
-        self.io_loop.start()
-        self.assertIs(self.current_io_loop, self.io_loop)
-        # Now that the loop is stopped, it is no longer current.
-        self.assertIsNone(IOLoop.current(instance=False))
+        # Starting the IOLoop makes it current, and stopping the loop
+        # makes it non-current. This process is repeatable.
+        for i in range(3):
+            def f():
+                self.current_io_loop = IOLoop.current()
+                self.io_loop.stop()
+            self.io_loop.add_callback(f)
+            self.io_loop.start()
+            self.assertIs(self.current_io_loop, self.io_loop)
+            # Now that the loop is stopped, it is no longer current.
+            self.assertIsNone(IOLoop.current(instance=False))
+
 
     def test_force_current(self):
         self.io_loop = IOLoop(make_current=True)