bpo-45209: removes UserWarning: resource_tracker in test_multiprocessing

Author: sobolevn

Lib/test/_test_multiprocessing.py

@@ -4177,6 +4177,13 @@ def test_shared_memory_cleaned_after_process_termination(self):
                 raise AssertionError("A SharedMemory segment was leaked after"
                                      " a process was abruptly terminated.")
 
+            # Without this line it was raising warnings like:
+            #   UserWarning: resource_tracker:
+            #   There appear to be 1 leaked shared_memory
+            #   objects to clean up at shutdown
+            # See: https://bugs.python.org/issue45209
+            resource_tracker.unregister(f"/{name}", "shared_memory")
+
             if os.name == 'posix':
                 # A warning was emitted by the subprocess' own
                 # resource_tracker (on Windows, shared memory segments

Misc/NEWS.d/next/Tests/2021-09-15-23-32-39.bpo-45209.55ntL5.rst

@@ -0,0 +1,2 @@
+Fixes ``UserWarning: resource_tracker`` warning in
+``test_shared_memory_cleaned_after_process_termination``