gh-110300: Fix Refleaks in test_interpreters and test__xxinterpchannels (gh-110318)

Author: ericsnowcurrently

Lib/test/support/interpreters.py

@@ -215,4 +215,5 @@ def close(self):
         _channels.close(self._id, send=True)
 
 
-_channels._register_end_types(SendChannel, RecvChannel)
+# XXX This is causing leaks (gh-110318):
+#_channels._register_end_types(SendChannel, RecvChannel)

Lib/test/test_interpreters.py

@@ -68,6 +68,17 @@ def run():
 
 class TestBase(unittest.TestCase):
 
+    def pipe(self):
+        def ensure_closed(fd):
+            try:
+                os.close(fd)
+            except OSError:
+                pass
+        r, w = os.pipe()
+        self.addCleanup(lambda: ensure_closed(r))
+        self.addCleanup(lambda: ensure_closed(w))
+        return r, w
+
     def tearDown(self):
         clean_up_interpreters()
 
@@ -262,7 +273,7 @@ def test_subinterpreter(self):
         self.assertFalse(interp.is_running())
 
     def test_finished(self):
-        r, w = os.pipe()
+        r, w = self.pipe()
         interp = interpreters.create()
         interp.run(f"""if True:
             import os
@@ -299,8 +310,8 @@ def test_bad_id(self):
             interp.is_running()
 
     def test_with_only_background_threads(self):
-        r_interp, w_interp = os.pipe()
-        r_thread, w_thread = os.pipe()
+        r_interp, w_interp = self.pipe()
+        r_thread, w_thread = self.pipe()
 
         DONE = b'D'
         FINISHED = b'F'
@@ -425,8 +436,8 @@ def test_still_running(self):
             self.assertTrue(interp.is_running())
 
     def test_subthreads_still_running(self):
-        r_interp, w_interp = os.pipe()
-        r_thread, w_thread = os.pipe()
+        r_interp, w_interp = self.pipe()
+        r_thread, w_thread = self.pipe()
 
         FINISHED = b'F'
 
@@ -532,8 +543,8 @@ def test_bytes_for_script(self):
             interp.run(b'print("spam")')
 
     def test_with_background_threads_still_running(self):
-        r_interp, w_interp = os.pipe()
-        r_thread, w_thread = os.pipe()
+        r_interp, w_interp = self.pipe()
+        r_thread, w_thread = self.pipe()
 
         RAN = b'R'
         DONE = b'D'
@@ -822,6 +833,7 @@ def test_list_all(self):
         after = set(interpreters.list_all_channels())
         self.assertEqual(after, created)
 
+    @unittest.expectedFailure  # See gh-110318:
     def test_shareable(self):
         rch, sch = interpreters.create_channel()
 

Modules/_xxinterpchannelsmodule.c

@@ -1992,6 +1992,7 @@ _get_current_channel_end_type(int end)
                 return NULL;
             }
         }
+        Py_DECREF(highlevel);
         if (end == CHANNEL_SEND) {
             cls = state->send_channel_type;
         }
@@ -2012,6 +2013,7 @@ _channel_end_from_xid(_PyCrossInterpreterData *data)
     }
     PyTypeObject *cls = _get_current_channel_end_type(cid->end);
     if (cls == NULL) {
+        Py_DECREF(cid);
         return NULL;
     }
     PyObject *obj = PyObject_CallOneArg((PyObject *)cls, (PyObject *)cid);
@@ -2027,7 +2029,9 @@ _channel_end_shared(PyThreadState *tstate, PyObject *obj,
     if (cidobj == NULL) {
         return -1;
     }
-    if (_channelid_shared(tstate, cidobj, data) < 0) {
+    int res = _channelid_shared(tstate, cidobj, data);
+    Py_DECREF(cidobj);
+    if (res < 0) {
         return -1;
     }
     data->new_object = _channel_end_from_xid;
@@ -2464,7 +2468,10 @@ channel__channel_id(PyObject *self, PyObject *args, PyObject *kwds)
         return NULL;
     }
     PyTypeObject *cls = state->ChannelIDType;
-    assert(get_module_from_owned_type(cls) == self);
+
+    PyObject *mod = get_module_from_owned_type(cls);
+    assert(mod == self);
+    Py_DECREF(mod);
 
     return _channelid_new(self, cls, args, kwds);
 }