gh-127085: fix some data races in memoryview in free-threading (#127412)

1 files changed, 25 insertions, 1 deletions

diff --git a/Lib/test/test_memoryview.py b/Lib/test/test_memoryview.py
index 96320eb..856e179 100644
--- a/Lib/test/test_memoryview.py
+++ b/Lib/test/test_memoryview.py
@@ -16,7 +16,8 @@ import pickle
 import struct
 
 from itertools import product
-from test.support import import_helper
+from test import support
+from test.support import import_helper, threading_helper
 
 
 class MyObject:
@@ -733,5 +734,28 @@ class OtherTest(unittest.TestCase):
         self.assertIsNone(wr())
 
 
+@threading_helper.requires_working_threading()
+@support.requires_resource("cpu")
+class RacingTest(unittest.TestCase):
+    def test_racing_getbuf_and_releasebuf(self):
+        """Repeatly access the memoryview for racing."""
+        from multiprocessing.managers import SharedMemoryManager
+        from threading import Thread
+
+        n = 100
+        with SharedMemoryManager() as smm:
+            obj = smm.ShareableList(range(100))
+            threads = []
+            for _ in range(n):
+                # Issue gh-127085, the `ShareableList.count` is just a convenient way to mess the `exports`
+                # counter of `memoryview`, this issue has no direct relation with `ShareableList`.
+                threads.append(Thread(target=obj.count, args=(1,)))
+
+            with threading_helper.start_threads(threads):
+                pass
+
+            del obj
+
+
 if __name__ == "__main__":
     unittest.main()