bpo-37421: test_concurrent_futures stops ForkServer (GH-14643)

test_concurrent_futures now explicitly stops the ForkServer instance
if it's running.

Lib/test/test_concurrent_futures.py

@@ -1309,6 +1309,9 @@ def tearDownModule():
 
     # cleanup multiprocessing
     multiprocessing.process._cleanup()
+    # Stop the ForkServer process if it's running
+    from multiprocessing import forkserver
+    forkserver._forkserver._stop()
     # bpo-37421: Explicitly call _run_finalizers() to remove immediately
     # temporary directories created by multiprocessing.util.get_temp_dir().
     multiprocessing.util._run_finalizers()

Misc/NEWS.d/next/Tests/2019-07-08-10-11-36.bpo-37421.OY77go.rst

+test_concurrent_futures now explicitly stops the ForkServer instance if it's
+running.