asyncio: sync with Tulip

* Fix _WaitHandleFuture.cancel(): return the result of the parent cancel()
  method.
* _OverlappedFuture.cancel() now clears its reference to the overlapped object.
  Make also the _OverlappedFuture.ov attribute private.
* Check if _WaitHandleFuture completed before unregistering it in the callback.
  Add also _WaitHandleFuture._poll() and repr(_WaitHandleFuture).
* _WaitHandleFuture now unregisters its wait handler if WaitForSingleObject()
  raises an exception.
* _OverlappedFuture.set_exception() now cancels the overlapped operation.

1 files changed, 2 insertions, 6 deletions

diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py
index c530687..ab566b3 100644
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -44,13 +44,9 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
     def __repr__(self):
         info = [self.__class__.__name__, 'fd=%s' % self._sock.fileno()]
         if self._read_fut is not None:
-            ov = "pending" if self._read_fut.ov.pending else "completed"
-            info.append('read=%s' % ov)
+            info.append('read=%s' % self._read_fut)
         if self._write_fut is not None:
-            if self._write_fut.ov.pending:
-                info.append("write=pending=%s" % self._pending_write)
-            else:
-                info.append("write=completed")
+            info.append("write=%r" % self._write_fut)
         if self._buffer:
             bufsize = len(self._buffer)
             info.append('write_bufsize=%s' % bufsize)