event_loop: enable asyncio on windows, needs Nvim 0.3.0+

Revert "event loop: disable asyncio on nt for now (#308)"

This reverts commit 42b6e18.

neovim/api/nvim.py

@@ -121,7 +121,7 @@ def __init__(self, session, channel_id, metadata, types,
         self._err_cb = err_cb
 
         # only on python3.4+ we expose asyncio
-        if IS_PYTHON3 and os.name != 'nt':
+        if IS_PYTHON3:
             self.loop = self._session.loop._loop
 
     def _from_nvim(self, obj, decode=None):

neovim/msgpack_rpc/event_loop/__init__.py

@@ -3,12 +3,10 @@
 Tries to use pyuv as a backend, falling back to the asyncio implementation.
 """
 
-import os
-
 from ...compat import IS_PYTHON3
 
 # on python3 we only support asyncio, as we expose it to plugins
-if IS_PYTHON3 and os.name != 'nt':
+if IS_PYTHON3:
     from .asyncio import AsyncioEventLoop
     EventLoop = AsyncioEventLoop
 else:

neovim/msgpack_rpc/event_loop/asyncio.py

@@ -10,6 +10,7 @@
 """
 from __future__ import absolute_import
 
+import logging
 import os
 import sys
 from collections import deque
@@ -23,11 +24,17 @@
 
 from .base import BaseEventLoop
 
+logger = logging.getLogger(__name__)
+debug, info, warn = (logger.debug, logger.info, logger.warning,)
 
 loop_cls = asyncio.SelectorEventLoop
 if os.name == 'nt':
+    from asyncio.windows_utils import PipeHandle
+    import msvcrt
+
     # On windows use ProactorEventLoop which support pipes and is backed by the
     # more powerful IOCP facility
+    # NOTE: we override in the stdio case, because it doesn't work.
     loop_cls = asyncio.ProactorEventLoop
 
 
@@ -89,14 +96,26 @@ def _connect_socket(self, path):
         self._loop.run_until_complete(coroutine)
 
     def _connect_stdio(self):
-        coroutine = self._loop.connect_read_pipe(self._fact, sys.stdin)
+        if os.name == 'nt':
+            pipe = PipeHandle(msvcrt.get_osfhandle(sys.stdin.fileno()))
+        else:
+            pipe = sys.stdin
+        coroutine = self._loop.connect_read_pipe(self._fact, pipe)
         self._loop.run_until_complete(coroutine)
-        coroutine = self._loop.connect_write_pipe(self._fact, sys.stdout)
+        debug("native stdin connection successful")
+
+        if os.name == 'nt':
+            pipe = PipeHandle(msvcrt.get_osfhandle(sys.stdout.fileno()))
+        else:
+            pipe = sys.stdout
+        coroutine = self._loop.connect_write_pipe(self._fact, pipe)
         self._loop.run_until_complete(coroutine)
+        debug("native stdout connection successful")
 
     def _connect_child(self, argv):
-        self._child_watcher = asyncio.get_child_watcher()
-        self._child_watcher.attach_loop(self._loop)
+        if os.name != 'nt':
+            self._child_watcher = asyncio.get_child_watcher()
+            self._child_watcher.attach_loop(self._loop)
         coroutine = self._loop.subprocess_exec(self._fact, *argv)
         self._loop.run_until_complete(coroutine)
 

setup.py

@@ -17,11 +17,12 @@
     'test': tests_require,
 }
 
-if os.name == 'nt':
-    install_requires.append('pyuv>=1.0.0')
-elif sys.version_info < (3, 4):
-    # trollius is just a backport of 3.4 asyncio module
-    install_requires.append('trollius')
+if sys.version_info < (3, 4):
+    if os.name == 'nt':
+        install_requires.append('pyuv>=1.0.0')
+    else:
+        # trollius is just a backport of 3.4 asyncio module
+        install_requires.append('trollius')
 
 if platform.python_implementation() != 'PyPy':
     # pypy already includes an implementation of the greenlet module