gh-76785: Consolidate Some Interpreter-related Testing Helpers (gh-117485)

This eliminates the duplication of functionally identical helpers in the _testinternalcapi and _xxsubinterpreters modules.

Author: ericsnowcurrently

Lib/test/support/interpreters/__init__.py

@@ -73,7 +73,7 @@ def __str__(self):
 
 def create():
     """Return a new (idle) Python interpreter."""
-    id = _interpreters.create(isolated=True)
+    id = _interpreters.create(reqrefs=True)
     return Interpreter(id)
 
 
@@ -109,13 +109,13 @@ def __new__(cls, id, /):
             assert hasattr(self, '_ownsref')
         except KeyError:
             # This may raise InterpreterNotFoundError:
-            _interpreters._incref(id)
+            _interpreters.incref(id)
             try:
                 self = super().__new__(cls)
                 self._id = id
                 self._ownsref = True
             except BaseException:
-                _interpreters._deccref(id)
+                _interpreters.decref(id)
                 raise
             _known[id] = self
         return self
@@ -142,7 +142,7 @@ def _decref(self):
             return
         self._ownsref = False
         try:
-            _interpreters._decref(self.id)
+            _interpreters.decref(self.id)
         except InterpreterNotFoundError:
             pass
 

Lib/test/test__xxsubinterpreters.py

@@ -584,7 +584,7 @@ def f():
     def test_create_daemon_thread(self):
         with self.subTest('isolated'):
             expected = 'spam spam spam spam spam'
-            subinterp = interpreters.create(isolated=True)
+            subinterp = interpreters.create('isolated')
             script, file = _captured_script(f"""
                 import threading
                 def f():
@@ -604,7 +604,7 @@ def f():
             self.assertEqual(out, expected)
 
         with self.subTest('not isolated'):
-            subinterp = interpreters.create(isolated=False)
+            subinterp = interpreters.create('legacy')
             script, file = _captured_script("""
                 import threading
                 def f():

Lib/test/test_capi/test_misc.py

@@ -2204,6 +2204,7 @@ def test_module_state_shared_in_global(self):
         self.assertEqual(main_attr_id, subinterp_attr_id)
 
 
+@requires_subinterpreters
 class InterpreterConfigTests(unittest.TestCase):
 
     supported = {
@@ -2277,11 +2278,11 @@ def check(name, expected):
             expected = self.supported[expected]
             args = (name,) if name else ()
 
-            config1 = _testinternalcapi.new_interp_config(*args)
+            config1 = _interpreters.new_config(*args)
             self.assert_ns_equal(config1, expected)
             self.assertIsNot(config1, expected)
 
-            config2 = _testinternalcapi.new_interp_config(*args)
+            config2 = _interpreters.new_config(*args)
             self.assert_ns_equal(config2, expected)
             self.assertIsNot(config2, expected)
             self.assertIsNot(config2, config1)
@@ -2298,7 +2299,7 @@ def test_update_from_dict(self):
             with self.subTest(f'noop ({name})'):
                 expected = vanilla
                 overrides = vars(vanilla)
-                config = _testinternalcapi.new_interp_config(name, **overrides)
+                config = _interpreters.new_config(name, **overrides)
                 self.assert_ns_equal(config, expected)
 
             with self.subTest(f'change all ({name})'):
@@ -2308,7 +2309,7 @@ def test_update_from_dict(self):
                         continue
                     overrides['gil'] = gil
                     expected = types.SimpleNamespace(**overrides)
-                    config = _testinternalcapi.new_interp_config(
+                    config = _interpreters.new_config(
                                                             name, **overrides)
                     self.assert_ns_equal(config, expected)
 
@@ -2324,14 +2325,14 @@ def test_update_from_dict(self):
                         expected = types.SimpleNamespace(
                             **dict(vars(vanilla), **overrides),
                         )
-                        config = _testinternalcapi.new_interp_config(
+                        config = _interpreters.new_config(
                                                             name, **overrides)
                         self.assert_ns_equal(config, expected)
 
         with self.subTest('unsupported field'):
             for name in self.supported:
                 with self.assertRaises(ValueError):
-                    _testinternalcapi.new_interp_config(name, spam=True)
+                    _interpreters.new_config(name, spam=True)
 
         # Bad values for bool fields.
         for field, value in vars(self.supported['empty']).items():
@@ -2341,19 +2342,18 @@ def test_update_from_dict(self):
             for value in [1, '', 'spam', 1.0, None, object()]:
                 with self.subTest(f'unsupported value ({field}={value!r})'):
                     with self.assertRaises(TypeError):
-                        _testinternalcapi.new_interp_config(**{field: value})
+                        _interpreters.new_config(**{field: value})
 
         # Bad values for .gil.
         for value in [True, 1, 1.0, None, object()]:
             with self.subTest(f'unsupported value(gil={value!r})'):
                 with self.assertRaises(TypeError):
-                    _testinternalcapi.new_interp_config(gil=value)
+                    _interpreters.new_config(gil=value)
         for value in ['', 'spam']:
             with self.subTest(f'unsupported value (gil={value!r})'):
                 with self.assertRaises(ValueError):
-                    _testinternalcapi.new_interp_config(gil=value)
+                    _interpreters.new_config(gil=value)
 
-    @requires_subinterpreters
     def test_interp_init(self):
         questionable = [
             # strange
@@ -2412,11 +2412,10 @@ def check(config):
                 with self.subTest(f'valid: {config}'):
                     check(config)
 
-    @requires_subinterpreters
     def test_get_config(self):
         @contextlib.contextmanager
         def new_interp(config):
-            interpid = _testinternalcapi.new_interpreter(config)
+            interpid = _interpreters.create(config, reqrefs=False)
             try:
                 yield interpid
             finally:
@@ -2426,32 +2425,32 @@ def new_interp(config):
                     pass
 
         with self.subTest('main'):
-            expected = _testinternalcapi.new_interp_config('legacy')
+            expected = _interpreters.new_config('legacy')
             expected.gil = 'own'
             interpid = _interpreters.get_main()
-            config = _testinternalcapi.get_interp_config(interpid)
+            config = _interpreters.get_config(interpid)
             self.assert_ns_equal(config, expected)
 
         with self.subTest('isolated'):
-            expected = _testinternalcapi.new_interp_config('isolated')
+            expected = _interpreters.new_config('isolated')
             with new_interp('isolated') as interpid:
-                config = _testinternalcapi.get_interp_config(interpid)
+                config = _interpreters.get_config(interpid)
             self.assert_ns_equal(config, expected)
 
         with self.subTest('legacy'):
-            expected = _testinternalcapi.new_interp_config('legacy')
+            expected = _interpreters.new_config('legacy')
             with new_interp('legacy') as interpid:
-                config = _testinternalcapi.get_interp_config(interpid)
+                config = _interpreters.get_config(interpid)
             self.assert_ns_equal(config, expected)
 
         with self.subTest('custom'):
-            orig = _testinternalcapi.new_interp_config(
+            orig = _interpreters.new_config(
                 'empty',
                 use_main_obmalloc=True,
                 gil='shared',
             )
             with new_interp(orig) as interpid:
-                config = _testinternalcapi.get_interp_config(interpid)
+                config = _interpreters.get_config(interpid)
             self.assert_ns_equal(config, orig)
 
 
@@ -2529,14 +2528,19 @@ def test_lookup_destroyed(self):
         self.assertFalse(
             _testinternalcapi.interpreter_exists(interpid))
 
+    def get_refcount_helpers(self):
+        return (
+            _testinternalcapi.get_interpreter_refcount,
+            (lambda id: _interpreters.incref(id, implieslink=False)),
+            _interpreters.decref,
+        )
+
     def test_linked_lifecycle_does_not_exist(self):
         exists = _testinternalcapi.interpreter_exists
         is_linked = _testinternalcapi.interpreter_refcount_linked
         link = _testinternalcapi.link_interpreter_refcount
         unlink = _testinternalcapi.unlink_interpreter_refcount
-        get_refcount = _testinternalcapi.get_interpreter_refcount
-        incref = _testinternalcapi.interpreter_incref
-        decref = _testinternalcapi.interpreter_decref
+        get_refcount, incref, decref = self.get_refcount_helpers()
 
         with self.subTest('never existed'):
             interpid = _testinternalcapi.unused_interpreter_id()
@@ -2578,8 +2582,7 @@ def test_linked_lifecycle_initial(self):
         get_refcount = _testinternalcapi.get_interpreter_refcount
 
         # A new interpreter will start out not linked, with a refcount of 0.
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
         linked = is_linked(interpid)
         refcount = get_refcount(interpid)
 
@@ -2589,12 +2592,9 @@ def test_linked_lifecycle_initial(self):
     def test_linked_lifecycle_never_linked(self):
         exists = _testinternalcapi.interpreter_exists
         is_linked = _testinternalcapi.interpreter_refcount_linked
-        get_refcount = _testinternalcapi.get_interpreter_refcount
-        incref = _testinternalcapi.interpreter_incref
-        decref = _testinternalcapi.interpreter_decref
+        get_refcount, incref, decref = self.get_refcount_helpers()
 
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
 
         # Incref will not automatically link it.
         incref(interpid)
@@ -2618,8 +2618,7 @@ def test_linked_lifecycle_link_unlink(self):
         link = _testinternalcapi.link_interpreter_refcount
         unlink = _testinternalcapi.unlink_interpreter_refcount
 
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
 
         # Linking at refcount 0 does not destroy the interpreter.
         link(interpid)
@@ -2639,12 +2638,9 @@ def test_linked_lifecycle_link_incref_decref(self):
         exists = _testinternalcapi.interpreter_exists
         is_linked = _testinternalcapi.interpreter_refcount_linked
         link = _testinternalcapi.link_interpreter_refcount
-        get_refcount = _testinternalcapi.get_interpreter_refcount
-        incref = _testinternalcapi.interpreter_incref
-        decref = _testinternalcapi.interpreter_decref
+        get_refcount, incref, decref = self.get_refcount_helpers()
 
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
 
         # Linking it will not change the refcount.
         link(interpid)
@@ -2666,11 +2662,9 @@ def test_linked_lifecycle_link_incref_decref(self):
     def test_linked_lifecycle_incref_link(self):
         is_linked = _testinternalcapi.interpreter_refcount_linked
         link = _testinternalcapi.link_interpreter_refcount
-        get_refcount = _testinternalcapi.get_interpreter_refcount
-        incref = _testinternalcapi.interpreter_incref
+        get_refcount, incref, _ = self.get_refcount_helpers()
 
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
 
         incref(interpid)
         self.assertEqual(
@@ -2688,12 +2682,9 @@ def test_linked_lifecycle_link_incref_unlink_decref(self):
         is_linked = _testinternalcapi.interpreter_refcount_linked
         link = _testinternalcapi.link_interpreter_refcount
         unlink = _testinternalcapi.unlink_interpreter_refcount
-        get_refcount = _testinternalcapi.get_interpreter_refcount
-        incref = _testinternalcapi.interpreter_incref
-        decref = _testinternalcapi.interpreter_decref
+        get_refcount, incref, decref = self.get_refcount_helpers()
 
-        interpid = _testinternalcapi.new_interpreter()
-        self.add_interp_cleanup(interpid)
+        interpid = self.new_interpreter()
 
         link(interpid)
         self.assertTrue(

Lib/test/test_import/__init__.py

@@ -2163,7 +2163,7 @@ def re_load(self, name, mod):
     # subinterpreters
 
     def add_subinterpreter(self):
-        interpid = _interpreters.create(isolated=False)
+        interpid = _interpreters.create('legacy')
         def ensure_destroyed():
             try:
                 _interpreters.destroy(interpid)

Lib/test/test_importlib/test_util.py

@@ -656,7 +656,7 @@ def test_magic_number(self):
 class IncompatibleExtensionModuleRestrictionsTests(unittest.TestCase):
 
     def run_with_own_gil(self, script):
-        interpid = _interpreters.create(isolated=True)
+        interpid = _interpreters.create('isolated')
         def ensure_destroyed():
             try:
                 _interpreters.destroy(interpid)
@@ -669,7 +669,7 @@ def ensure_destroyed():
                 raise ImportError(excsnap.msg)
 
     def run_with_shared_gil(self, script):
-        interpid = _interpreters.create(isolated=False)
+        interpid = _interpreters.create('legacy')
         def ensure_destroyed():
             try:
                 _interpreters.destroy(interpid)