1 files changed, 25 insertions, 6 deletions

diff --git a/Lib/asyncio/windows_events.py b/Lib/asyncio/windows_events.py
index ec427d5c70..6763f0b7bd 100644
--- a/Lib/asyncio/windows_events.py
+++ b/Lib/asyncio/windows_events.py
@@ -111,10 +111,17 @@ class _WaitHandleFuture(futures.Future):
             return
         try:
             _overlapped.UnregisterWait(self._wait_handle)
-        except OSError as e:
-            if e.winerror != _overlapped.ERROR_IO_PENDING:
-                raise
+        except OSError as exc:
             # ERROR_IO_PENDING is not an error, the wait was unregistered
+            if exc.winerror != _overlapped.ERROR_IO_PENDING:
+                context = {
+                    'message': 'Failed to unregister the wait handle',
+                    'exception': exc,
+                    'future': self,
+                }
+                if self._source_traceback:
+                    context['source_traceback'] = self._source_traceback
+                self._loop.call_exception_handler(context)
         self._wait_handle = None
         self._iocp = None
         self._ov = None
@@ -145,6 +152,11 @@ class PipeServer(object):
     def __init__(self, address):
         self._address = address
         self._free_instances = weakref.WeakSet()
+        # initialize the pipe attribute before calling _server_pipe_handle()
+        # because this function can raise an exception and the destructor calls
+        # the close() method
+        self._pipe = None
+        self._accept_pipe_future = None
         self._pipe = self._server_pipe_handle(True)
 
     def _get_unconnected_pipe(self):
@@ -174,6 +186,9 @@ class PipeServer(object):
         return pipe
 
     def close(self):
+        if self._accept_pipe_future is not None:
+            self._accept_pipe_future.cancel()
+            self._accept_pipe_future = None
         # Close all instances which have not been connected to by a client.
         if self._address is not None:
             for pipe in self._free_instances:
@@ -216,7 +231,7 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
     def start_serving_pipe(self, protocol_factory, address):
         server = PipeServer(address)
 
-        def loop(f=None):
+        def loop_accept_pipe(f=None):
             pipe = None
             try:
                 if f:
@@ -237,13 +252,17 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
                         'pipe': pipe,
                     })
                     pipe.close()
+                elif self._debug:
+                    logger.warning("Accept pipe failed on pipe %r",
+                                   pipe, exc_info=True)
             except futures.CancelledError:
                 if pipe:
                     pipe.close()
             else:
-                f.add_done_callback(loop)
+                server._accept_pipe_future = f
+                f.add_done_callback(loop_accept_pipe)
 
-        self.call_soon(loop)
+        self.call_soon(loop_accept_pipe)
         return [server]
 
     @coroutine