1 files changed, 8 insertions, 0 deletions
diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py
index 830d8ed..54e4deb 100644
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -766,6 +766,14 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
         try:
             if f is not None:
                 f.result()  # may raise
+            if self._self_reading_future is not f:
+                # When we scheduled this Future, we assigned it to
+                # _self_reading_future. If it's not there now, something has
+                # tried to cancel the loop while this callback was still in the
+                # queue (see windows_events.ProactorEventLoop.run_forever). In
+                # that case stop here instead of continuing to schedule a new
+                # iteration.
+                return
             f = self._proactor.recv(self._ssock, 4096)
         except exceptions.CancelledError:
             # _close_self_pipe() has been called, stop waiting for data