only retry known recoverable errors

Author: graingert

Lib/asyncio/proactor_events.py

@@ -571,13 +571,17 @@ def _loop_reading(self, fut=None):
             else:
                 self._read_fut = self._loop._proactor.recvfrom(self._sock,
                                                                self.max_size)
-        except OSError as exc:
+        except ConnectionResetError as exc:
+            # WSARecvFrom() reports a stale ICMP port unreachable
+            # notification as a synchronous ConnectionResetError when the
+            # same socket was used to send to an address that is not
+            # listening.  This is transient, so reschedule the read loop
+            # instead of leaving it dead.
             self._protocol.error_received(exc)
             if not self._closing:
-                # The error can be transient, e.g. a ConnectionResetError
-                # from a stale ICMP port unreachable notification, so
-                # reschedule the read loop instead of leaving it dead.
                 self._loop.call_soon(self._loop_reading)
+        except OSError as exc:
+            self._protocol.error_received(exc)
         except exceptions.CancelledError:
             if not self._closing:
                 raise