[3.14] gh-142752: add more thread safety tests for mock (GH-142791) (#142856)

gh-142752: add more thread safety tests for mock (GH-142791)
(cherry picked from commit 4fd006e712)

Co-authored-by: Kumar Aditya <kumaraditya@python.org>

Lib/test/test_unittest/testmock/testthreadingmock.py

@@ -219,5 +219,81 @@ def test_function():
         self.assertEqual(m.call_count, LOOPS * THREADS)
 
 
+    def test_call_args_thread_safe(self):
+        m = ThreadingMock()
+        LOOPS = 100
+        THREADS = 10
+        def test_function(thread_id):
+            for i in range(LOOPS):
+                m(thread_id, i)
+
+        oldswitchinterval = sys.getswitchinterval()
+        setswitchinterval(1e-6)
+        try:
+            threads = [
+                threading.Thread(target=test_function, args=(thread_id,))
+                for thread_id in range(THREADS)
+            ]
+            with threading_helper.start_threads(threads):
+                pass
+        finally:
+            sys.setswitchinterval(oldswitchinterval)
+        expected_calls = {
+            (thread_id, i)
+            for thread_id in range(THREADS)
+            for i in range(LOOPS)
+        }
+        self.assertSetEqual({call.args for call in m.call_args_list}, expected_calls)
+
+    def test_method_calls_thread_safe(self):
+        m = ThreadingMock()
+        LOOPS = 100
+        THREADS = 10
+        def test_function(thread_id):
+            for i in range(LOOPS):
+                getattr(m, f"method_{thread_id}")(i)
+
+        oldswitchinterval = sys.getswitchinterval()
+        setswitchinterval(1e-6)
+        try:
+            threads = [
+                threading.Thread(target=test_function, args=(thread_id,))
+                for thread_id in range(THREADS)
+            ]
+            with threading_helper.start_threads(threads):
+                pass
+        finally:
+            sys.setswitchinterval(oldswitchinterval)
+        for thread_id in range(THREADS):
+            self.assertEqual(getattr(m, f"method_{thread_id}").call_count, LOOPS)
+            self.assertEqual({call.args for call in getattr(m, f"method_{thread_id}").call_args_list},
+                              {(i,) for i in range(LOOPS)})
+
+    def test_mock_calls_thread_safe(self):
+        m = ThreadingMock()
+        LOOPS = 100
+        THREADS = 10
+        def test_function(thread_id):
+            for i in range(LOOPS):
+                m(thread_id, i)
+
+        oldswitchinterval = sys.getswitchinterval()
+        setswitchinterval(1e-6)
+        try:
+            threads = [
+                threading.Thread(target=test_function, args=(thread_id,))
+                for thread_id in range(THREADS)
+            ]
+            with threading_helper.start_threads(threads):
+                pass
+        finally:
+            sys.setswitchinterval(oldswitchinterval)
+        expected_calls = {
+            (thread_id, i)
+            for thread_id in range(THREADS)
+            for i in range(LOOPS)
+        }
+        self.assertSetEqual({call.args for call in m.mock_calls}, expected_calls)
+
 if __name__ == "__main__":
     unittest.main()