bpo-37224: Improve test__xxsubinterpreters.DestroyTests (GH-18058)

Adds an additional assertion check based on a race condition for `test__xxsubinterpreters.DestroyTests.test_still_running` discovered in the bpo issue.

https://bugs.python.org/issue37224
(cherry picked from commit f03a8f8d5001963ad5b5b28dbd95497e9cc15596)

Co-authored-by: Kyle Stanley <aeros167@gmail.com>

diff --git a/Lib/test/test__xxsubinterpreters.py b/Lib/test/test__xxsubinterpreters.py
index 207b5db5d8fb9be0b5f21568ff72301490b64ad4..30f8f98acc9dd3232d2f314d8a7cb197c1f03c44 100644 (file)
--- a/Lib/test/test__xxsubinterpreters.py
+++ b/Lib/test/test__xxsubinterpreters.py
@@ -759,7 +759,11 @@ class DestroyTests(TestBase):
         main, = interpreters.list_all()
         interp = interpreters.create()
         with _running(interp):
-            with self.assertRaises(RuntimeError):
+            self.assertTrue(interpreters.is_running(interp),
+                            msg=f"Interp {interp} should be running before destruction.")
+
+            with self.assertRaises(RuntimeError,
+                                   msg=f"Should not be able to destroy interp {interp} while it's still running."):
                 interpreters.destroy(interp)
             self.assertTrue(interpreters.is_running(interp))