asyncio: sync with Tulip

* PipeHandle now uses None instead of -1 for a closed handle
* Sort imports in windows_utils.
* Fix test_events on Python older than 3.5. Skip SSL tests on the
  ProactorEventLoop if ssl.MemoryIO is missing
* Fix BaseEventLoop._create_connection_transport(). Close the transport if the
  creation of the transport (if the waiter) gets an exception.
* _ProactorBasePipeTransport now sets _sock to None when the transport is
  closed.
* Fix BaseSubprocessTransport.close(). Ignore pipes for which the protocol is
  not set yet (still equal to None).
* TestLoop.close() now calls the close() method of the parent class
  (BaseEventLoop).
* Cleanup BaseSelectorEventLoop: create the protocol on a separated line for
  readability and ease debugging.
* Fix BaseSubprocessTransport._kill_wait(). Set the _returncode attribute, so
  close() doesn't try to terminate the process.
* Tests: explicitly close event loops and transports
* UNIX pipe transports: add closed/closing in repr(). Add "closed" or "closing"
  state in the __repr__() method of _UnixReadPipeTransport and
  _UnixWritePipeTransport classes.

1 files changed, 1 insertions, 0 deletions

diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py
index 4716bb5..0ecb44e 100644
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -111,6 +111,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
             if hasattr(self._sock, 'shutdown'):
                 self._sock.shutdown(socket.SHUT_RDWR)
             self._sock.close()
+            self._sock = None
             server = self._server
             if server is not None:
                 server._detach()