gh-116738: test uuid module thread safety in free-threading (#140068)

Lib/test/test_free_threading/test_uuid.py

@@ -0,0 +1,60 @@
+import os
+import unittest
+
+from test.support import import_helper, threading_helper
+from test.support.threading_helper import run_concurrently
+from uuid import SafeUUID
+
+c_uuid = import_helper.import_module("_uuid")
+
+NTHREADS = 10
+UUID_PER_THREAD = 1000
+
+
+@threading_helper.requires_working_threading()
+class UUIDTests(unittest.TestCase):
+    @unittest.skipUnless(os.name == "posix", "POSIX only")
+    def test_generate_time_safe(self):
+        uuids = []
+
+        def worker():
+            local_uuids = []
+            for _ in range(UUID_PER_THREAD):
+                uuid, is_safe = c_uuid.generate_time_safe()
+                self.assertIs(type(uuid), bytes)
+                self.assertEqual(len(uuid), 16)
+                # Collect the UUID only if it is safe. If not, we cannot ensure
+                # UUID uniqueness. According to uuid_generate_time_safe() man
+                # page, it is theoretically possible for two concurrently
+                # running processes to generate the same UUID(s) if the return
+                # value is not 0.
+                if is_safe == SafeUUID.safe:
+                    local_uuids.append(uuid)
+
+            # Merge all safe uuids
+            uuids.extend(local_uuids)
+
+        run_concurrently(worker_func=worker, nthreads=NTHREADS)
+        self.assertEqual(len(uuids), len(set(uuids)))
+
+    @unittest.skipUnless(os.name == "nt", "Windows only")
+    def test_UuidCreate(self):
+        uuids = []
+
+        def worker():
+            local_uuids = []
+            for _ in range(UUID_PER_THREAD):
+                uuid = c_uuid.UuidCreate()
+                self.assertIs(type(uuid), bytes)
+                self.assertEqual(len(uuid), 16)
+                local_uuids.append(uuid)
+
+            # Merge all uuids
+            uuids.extend(local_uuids)
+
+        run_concurrently(worker_func=worker, nthreads=NTHREADS)
+        self.assertEqual(len(uuids), len(set(uuids)))
+
+
+if __name__ == "__main__":
+    unittest.main()