1 files changed, 43 insertions, 0 deletions
diff --git a/Lib/test/test_free_threading/test_slots.py b/Lib/test/test_free_threading/test_slots.py
new file mode 100644
index 00000000000..758f74f54d0
--- /dev/null
+++ b/Lib/test/test_free_threading/test_slots.py
@@ -0,0 +1,43 @@
+import threading
+from test.support import threading_helper
+from unittest import TestCase
+
+
+def run_in_threads(targets):
+    """Run `targets` in separate threads"""
+    threads = [
+        threading.Thread(target=target)
+        for target in targets
+    ]
+    for thread in threads:
+        thread.start()
+    for thread in threads:
+        thread.join()
+
+
+@threading_helper.requires_working_threading()
+class TestSlots(TestCase):
+
+    def test_object(self):
+        class Spam:
+            __slots__ = [
+                "eggs",
+            ]
+
+            def __init__(self, initial_value):
+                self.eggs = initial_value
+
+        spam = Spam(0)
+        iters = 20_000
+
+        def writer():
+            for _ in range(iters):
+                spam.eggs += 1
+
+        def reader():
+            for _ in range(iters):
+                eggs = spam.eggs
+                assert type(eggs) is int
+                assert 0 <= eggs <= iters
+
+        run_in_threads([writer, reader, reader, reader])