[3.12] gh-130957: Use `sleeping_retry` in `test_free_reference` (GH-130958) (#131092)

The weak reference may not be immediately dead.
(cherry picked from commit 19081158713526a3042c2ad3c6d5a589579b420f)

Co-authored-by: Sam Gross <colesbury@gmail.com>

diff --git a/Lib/test/test_concurrent_futures/executor.py b/Lib/test/test_concurrent_futures/executor.py
index 1e7d4344740943d54285fb455d1ca345d3880ad0..b3574c7c58af422f7981ca4fb7154f6bddcd47f4 100644 (file)
--- a/Lib/test/test_concurrent_futures/executor.py
+++ b/Lib/test/test_concurrent_futures/executor.py
@@ -105,4 +105,7 @@ class ExecutorTest:
             wr = weakref.ref(obj)
             del obj
             support.gc_collect()  # For PyPy or other GCs.
-            self.assertIsNone(wr())
+
+            for _ in support.sleeping_retry(support.SHORT_TIMEOUT):
+                if wr() is None:
+                    break