python
diff --git a/‎Lib/test/_test_multiprocessing.py
Lines changed: 31 additions & 27 deletions b/‎Lib/test/_test_multiprocessing.py
Lines changed: 31 additions & 27 deletions
@@ -3935,36 +3935,37 @@ def test_shared_memory_pickle_unpickle(self):
 
                 # Test pickling
                 pickled_sms = pickle.dumps(sms, protocol=proto)
-                self.assertNotIn(b'pickle', pickled_sms)
 
                 # Test unpickling
                 sms2 = pickle.loads(pickled_sms)
-                self.assertIsInstance(sms2, sms.__class__)
+                self.assertIsInstance(sms2, shared_memory.SharedMemory)
                 self.assertEqual(sms.name, sms2.name)
-                self.assertEqual(
-                    bytes(sms.buf[0:6]), bytes(sms2.buf[0:6]), b'pickle')
+                self.assertEqual(bytes(sms.buf[0:6]), b'pickle')
+                self.assertEqual(bytes(sms2.buf[0:6]), b'pickle')
 
                 # Test that unpickled version is still the same SharedMemory
                 sms.buf[0:6] = b'newval'
-                self.assertEqual(
-                    bytes(sms.buf[0:6]), bytes(sms2.buf[0:6]), b'newval')
+                self.assertEqual(bytes(sms.buf[0:6]), b'newval')
+                self.assertEqual(bytes(sms2.buf[0:6]), b'newval')
 
                 sms2.buf[0:6] = b'oldval'
-                self.assertEqual(
-                    bytes(sms.buf[0:6]), bytes(sms2.buf[0:6]), b'oldval')
+                self.assertEqual(bytes(sms.buf[0:6]), b'oldval')
+                self.assertEqual(bytes(sms2.buf[0:6]), b'oldval')
 
     def test_shared_memory_pickle_unpickle_dead_object(self):
-        sms = shared_memory.SharedMemory(create=True, size=512)
-        sms.buf[0:6] = b'pickle'
-        pickled_sms = pickle.dumps(sms)
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(proto=proto):
+                sms = shared_memory.SharedMemory(create=True, size=512)
+                sms.buf[0:6] = b'pickle'
+                pickled_sms = pickle.dumps(sms)
 
-        # Now, we are going to kill the original object.
-        # So, unpickled one won't be able to attach to it.
-        sms.close()
-        sms.unlink()
+                # Now, we are going to kill the original object.
+                # So, unpickled one won't be able to attach to it.
+                sms.close()
+                sms.unlink()
 
-        with self.assertRaises(FileNotFoundError):
-            pickle.loads(pickled_sms)
+                with self.assertRaises(FileNotFoundError):
+                    pickle.loads(pickled_sms)
 
     def test_shared_memory_across_processes(self):
         # bpo-40135: don't define shared memory block's name in case of
@@ -4194,11 +4195,12 @@ def test_shared_memory_ShareableList_pickling(self):
                     deserialized_sl, shared_memory.ShareableList)
                 self.assertEqual(deserialized_sl[-1], 9)
                 self.assertIsNot(sl, deserialized_sl)
+
                 deserialized_sl[4] = "changed"
                 self.assertEqual(sl[4], "changed")
+                sl[3] = "newvalue"
+                self.assertEqual(deserialized_sl[3], "newvalue")
 
-                # Verify data is not being put into the pickled representation.
-                name = 'a' * len(sl.shm.name)
                 larger_sl = shared_memory.ShareableList(range(400))
                 self.addCleanup(larger_sl.shm.unlink)
                 serialized_larger_sl = pickle.dumps(larger_sl, protocol=proto)
@@ -4209,16 +4211,18 @@ def test_shared_memory_ShareableList_pickling(self):
                 sl.shm.close()
 
     def test_shared_memory_ShareableList_pickling_dead_object(self):
-        sl = shared_memory.ShareableList(range(10))
-        serialized_sl = pickle.dumps(sl)
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(proto=proto):
+                sl = shared_memory.ShareableList(range(10))
+                serialized_sl = pickle.dumps(sl)
 
-        # Now, we are going to kill the original object.
-        # So, unpickled one won't be able to attach to it.
-        sl.shm.close()
-        sl.shm.unlink()
+                # Now, we are going to kill the original object.
+                # So, unpickled one won't be able to attach to it.
+                sl.shm.close()
+                sl.shm.unlink()
 
-        with self.assertRaises(FileNotFoundError):
-            pickle.loads(serialized_sl)
+                with self.assertRaises(FileNotFoundError):
+                    pickle.loads(serialized_sl)
 
     def test_shared_memory_cleaned_after_process_termination(self):
         cmd = '''if 1: