pythongh-109370: Fix unexpected traceback output in test_concurrent_f…

…utures

Follow-up of pythongh-107219.

* Only close the connection writer on Windows.
* Also use existing constant _winapi.ERROR_OPERATION_ABORTED instead of
  WSA_OPERATION_ABORTED.

Lib/concurrent/futures/process.py

@@ -521,7 +521,8 @@ def terminate_broken(self, cause):
 
         # gh-107219: Close the connection writer which can unblock
         # Queue._feed() if it was stuck in send_bytes().
-        self.call_queue._writer.close()
+        if sys.platform == 'win32':
+            self.call_queue._writer.close()
 
         # clean up resources
         self.join_executor_internals()

Lib/multiprocessing/connection.py

@@ -42,7 +42,6 @@
 BUFSIZE = 8192
 # A very generous timeout when it comes to local connections...
 CONNECTION_TIMEOUT = 20.
-WSA_OPERATION_ABORTED = 995
 
 _mmap_counter = itertools.count()
 
@@ -300,7 +299,7 @@ def _send_bytes(self, buf):
             finally:
                 self._send_ov = None
                 nwritten, err = ov.GetOverlappedResult(True)
-            if err == WSA_OPERATION_ABORTED:
+            if err == _winapi.ERROR_OPERATION_ABORTED:
                 # close() was called by another thread while
                 # WaitForMultipleObjects() was waiting for the overlapped
                 # operation.