Add test for free-threading

python · ambv · Mar 12, 2025 · Jun 24, 2024 · Jun 24, 2024 · Jun 24, 2024
commit 7127a856b5f88e1773e89ee09079f9a4c9091f14
diff --git a/Lib/test/test_reversed.py b/Lib/test/test_reversed.py
@@ -0,0 +1,34 @@
+import unittest
+from threading import Thread
+from test.support import threading_helper
+
+
+@threading_helper.reap_threads
+@threading_helper.requires_working_threading()
+def test_reversed_threading(self):
+    # Test that when reading out with multiple treads no identical elemenents are returned
+    def work(r, output):
+        while True:
+            try:
+                value = next(r)
+            except StopIteration:
+                break
+            else:
+                output.append(value)
+
+    number_of_threads = 10
+    x = tuple(range(4_000))
+    r = reversed(x)
+    worker_threads = []
+    output = []
+    for ii in range(number_of_threads):
+        worker_threads.append(Thread(target=work, args=[r, output]))
+    _ = [t.start() for t in worker_threads]
+    _ = [t.join() for t in worker_threads]
+
+    if sorted(output) != x:
+        raise ValueError('reversed returned value from sequence twice')
+
+
+if __name__ == "__main__":
+    unittest.main()