gh-102251: Explicitly free state for test modules with state in test_import

Lib/test/test_import/__init__.py

@@ -2320,6 +2320,7 @@ def test_variants(self):
         self.add_module_cleanup(name)
         with self.subTest(name):
             loaded = self.load(name)
+            self.addCleanup(loaded.module._clear_module_state)
 
             self.check_common(loaded)
             self.assertIsNot(loaded.snapshot.state_initialized, None)
@@ -2330,6 +2331,7 @@ def test_variants(self):
             self.assertIs(basic.look_up_self(), basic_lookedup)
             self.assertEqual(basic.initialized_count(), expected_init_count)
 
+
     def test_basic_reloaded(self):
         # m_copy is copied into the existing module object.
         # Global state is not changed.
@@ -2388,6 +2390,10 @@ def test_with_reinit_reloaded(self):
                 loaded = self.load(name)
                 reloaded = self.re_load(name, loaded.module)
 
+                if name == f'{self.NAME}_with_state':
+                    self.addCleanup(loaded.module._clear_module_state)
+                    self.addCleanup(reloaded.module._clear_module_state)
+
                 self.check_common(loaded)
                 self.check_common(reloaded)
 
@@ -2413,6 +2419,7 @@ def test_with_reinit_reloaded(self):
 
                 self.assertIs(reloaded.snapshot.cached, reloaded.module)
 
+
     # Currently, for every single-phrase init module loaded
     # in multiple interpreters, those interpreters share a
     # PyModuleDef for that object, which can be a problem.

Modules/_testsinglephase.c

@@ -248,6 +248,25 @@ basic__clear_globals(PyObject *self, PyObject *Py_UNUSED(ignored))
      basic__clear_globals_doc}
 
 
+PyDoc_STRVAR(basic__clear_module_state_doc, "_clear_module_state()\n\
+\n\
+Free the module state and set it to uninitialized.");
+
+static PyObject *
+basic__clear_module_state(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    module_state *state = get_module_state(self);
+    if (state != NULL) {
+        clear_state(state);
+    }
+    Py_RETURN_NONE;
+}
+
+#define _CLEAR_MODULE_STATE_METHODDEF \
+    {"_clear_module_state", basic__clear_module_state, METH_NOARGS, \
+     basic__clear_module_state_doc}
+
+
 /*********************************************/
 /* the _testsinglephase module (and aliases) */
 /*********************************************/
@@ -408,7 +427,7 @@ PyInit__testsinglephase_with_reinit(void)
 /* the _testsinglephase_with_state module */
 /******************************************/
 
-/* This ia less typical of legacy extensions in the wild:
+/* This is a less typical of legacy extensions in the wild:
    - single-phase init  (same as _testsinglephase above)
    - has some module state
    - supports repeated initialization
@@ -424,6 +443,7 @@ static PyMethodDef TestMethods_WithState[] = {
     LOOK_UP_SELF_METHODDEF,
     SUM_METHODDEF,
     STATE_INITIALIZED_METHODDEF,
+    _CLEAR_MODULE_STATE_METHODDEF,
     {NULL, NULL}           /* sentinel */
 };