From 6e1910bb8aaa1149bb7ebb7aba3c0c73a5522262 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Mon, 26 Jan 2015 22:13:20 +0100 Subject: Python issue #23095: Fix _WaitHandleFuture.cancel() If UnregisterWaitEx() fais with ERROR_IO_PENDING, it doesn't mean that the wait is unregistered yet. We still have to wait until the wait is cancelled. --- asyncio/windows_events.py | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-) diff --git a/asyncio/windows_events.py b/asyncio/windows_events.py index c9ba785..8f1d9d2 100644 --- a/asyncio/windows_events.py +++ b/asyncio/windows_events.py @@ -126,14 +126,12 @@ class _BaseWaitHandleFuture(futures.Future): return self._registered = False + wait_handle = self._wait_handle + self._wait_handle = None try: - _overlapped.UnregisterWait(self._wait_handle) + _overlapped.UnregisterWait(wait_handle) except OSError as exc: - self._wait_handle = None - if exc.winerror == _overlapped.ERROR_IO_PENDING: - # ERROR_IO_PENDING is not an error, the wait was unregistered - self._unregister_wait_cb(None) - elif exc.winerror != _overlapped.ERROR_IO_PENDING: + if exc.winerror != _overlapped.ERROR_IO_PENDING: context = { 'message': 'Failed to unregister the wait handle', 'exception': exc, @@ -142,9 +140,10 @@ class _BaseWaitHandleFuture(futures.Future): if self._source_traceback: context['source_traceback'] = self._source_traceback self._loop.call_exception_handler(context) - else: - self._wait_handle = None - self._unregister_wait_cb(None) + return + # ERROR_IO_PENDING means that the unregister is pending + + self._unregister_wait_cb(None) def cancel(self): self._unregister_wait() @@ -209,14 +208,12 @@ class _WaitHandleFuture(_BaseWaitHandleFuture): return self._registered = False + wait_handle = self._wait_handle + self._wait_handle = None try: - _overlapped.UnregisterWaitEx(self._wait_handle, self._event) + _overlapped.UnregisterWaitEx(wait_handle, self._event) except OSError as exc: - self._wait_handle = None - if exc.winerror == _overlapped.ERROR_IO_PENDING: - # ERROR_IO_PENDING is not an error, the wait was unregistered - self._unregister_wait_cb(None) - elif exc.winerror != _overlapped.ERROR_IO_PENDING: + if exc.winerror != _overlapped.ERROR_IO_PENDING: context = { 'message': 'Failed to unregister the wait handle', 'exception': exc, @@ -225,11 +222,11 @@ class _WaitHandleFuture(_BaseWaitHandleFuture): if self._source_traceback: context['source_traceback'] = self._source_traceback self._loop.call_exception_handler(context) - else: - self._wait_handle = None - self._event_fut = self._proactor._wait_cancel( - self._event, - self._unregister_wait_cb) + return + # ERROR_IO_PENDING is not an error, the wait was unregistered + + self._event_fut = self._proactor._wait_cancel(self._event, + self._unregister_wait_cb) class PipeServer(object): -- cgit v1.2.1