GH-94382: port multiprocessing static types to heap types

Misc/NEWS.d/next/Library/2022-07-03-16-41-03.gh-issue-94382.zuVZeM.rst

@@ -0,0 +1 @@
+Port static types of ``_multiprocessing`` module to heap types. Patch by Kumar Aditya.

Modules/_multiprocessing/multiprocessing.c

@@ -196,33 +196,39 @@ multiprocessing_exec(PyObject *module)
 {
 #ifdef HAVE_MP_SEMAPHORE
 
- /* Add _PyMp_SemLock type to module */
- if (PyModule_AddType(module, &_PyMp_SemLockType) < 0){
+ PyTypeObject *semlock_type = (PyTypeObject *)PyType_FromModuleAndSpec(
+ module, &_PyMp_SemLockType_spec, NULL);
+
+ if (semlock_type == NULL){
+ return -1;
+ }
+ int rc = PyModule_AddType(module, semlock_type);
+ Py_DECREF(semlock_type);
+ if (rc < 0){
  return -1;
  }
 
-{
- PyObject *py_sem_value_max;
- /* Some systems define SEM_VALUE_MAX as an unsigned value that
- * causes it to be negative when used as an int (NetBSD).
- *
- * Issue #28152: Use (0) instead of 0 to fix a warning on dead code
- * when using clang -Wunreachable-code. */
- if ((int)(SEM_VALUE_MAX) < (0))
- py_sem_value_max = PyLong_FromLong(INT_MAX);
- else
- py_sem_value_max = PyLong_FromLong(SEM_VALUE_MAX);
-
- if (py_sem_value_max == NULL){
- return -1;
- }
- if (PyDict_SetItemString(_PyMp_SemLockType.tp_dict, "SEM_VALUE_MAX",
- py_sem_value_max) < 0){
- Py_DECREF(py_sem_value_max);
- return -1;
- }
+ PyObject *py_sem_value_max;
+ /* Some systems define SEM_VALUE_MAX as an unsigned value that
+ * causes it to be negative when used as an int (NetBSD).
+ *
+ * Issue #28152: Use (0) instead of 0 to fix a warning on dead code
+ * when using clang -Wunreachable-code. */
+ if ((int)(SEM_VALUE_MAX) < (0)){
+ py_sem_value_max = PyLong_FromLong(INT_MAX);
+ }
+ else{
+ py_sem_value_max = PyLong_FromLong(SEM_VALUE_MAX);
+ }
+ if (py_sem_value_max == NULL){
+ return -1;
+ }
+ if (PyDict_SetItemString(semlock_type->tp_dict, "SEM_VALUE_MAX",
+ py_sem_value_max) < 0){
  Py_DECREF(py_sem_value_max);
+ return -1;
  }
+ Py_DECREF(py_sem_value_max);
 
 #endif
 
@@ -276,6 +282,7 @@ static PyModuleDef_Slot multiprocessing_slots[] ={
 static struct PyModuleDef multiprocessing_module ={
  PyModuleDef_HEAD_INIT,
  .m_name = "_multiprocessing",
+ .m_size = 0,
  .m_methods = module_methods,
  .m_slots = multiprocessing_slots,
 };

Modules/_multiprocessing/multiprocessing.h

@@ -89,7 +89,7 @@ PyObject *_PyMp_SetError(PyObject *Type, int num);
  * Externs - not all will really exist on all platforms
  */
 
-extern PyTypeObject _PyMp_SemLockType;
+extern PyType_Spec _PyMp_SemLockType_spec;
 extern PyObject *_PyMp_sem_unlink(const char *name);
 
 #endif /* MULTIPROCESSING_H */

Modules/_multiprocessing/semaphore.c

@@ -568,10 +568,13 @@ _multiprocessing_SemLock__rebuild_impl(PyTypeObject *type, SEM_HANDLE handle,
 static void
 semlock_dealloc(SemLockObject* self)
 {
+ PyTypeObject *tp = Py_TYPE(self);
+ PyObject_GC_UnTrack(self);
  if (self->handle != SEM_FAILED)
  SEM_CLOSE(self->handle);
  PyMem_Free(self->name);
- Py_TYPE(self)->tp_free((PyObject*)self);
+ tp->tp_free(self);
+ Py_DECREF(tp);
 }
 
 /*[clinic input]
@@ -701,6 +704,13 @@ _multiprocessing_SemLock___exit___impl(SemLockObject *self,
  return _multiprocessing_SemLock_release_impl(self);
 }
 
+static int
+semlock_traverse(SemLockObject *s, visitproc visit, void *arg)
+{
+ Py_VISIT(Py_TYPE(s));
+ return 0;
+}
+
 /*
  * Semaphore methods
  */
@@ -739,45 +749,26 @@ static PyMemberDef semlock_members[] ={
  * Semaphore type
  */
 
-PyTypeObject _PyMp_SemLockType ={
- PyVarObject_HEAD_INIT(NULL, 0)
- /* tp_name */ "_multiprocessing.SemLock",
- /* tp_basicsize */ sizeof(SemLockObject),
- /* tp_itemsize */ 0,
- /* tp_dealloc */ (destructor)semlock_dealloc,
- /* tp_vectorcall_offset */ 0,
- /* tp_getattr */ 0,
- /* tp_setattr */ 0,
- /* tp_as_async */ 0,
- /* tp_repr */ 0,
- /* tp_as_number */ 0,
- /* tp_as_sequence */ 0,
- /* tp_as_mapping */ 0,
- /* tp_hash */ 0,
- /* tp_call */ 0,
- /* tp_str */ 0,
- /* tp_getattro */ 0,
- /* tp_setattro */ 0,
- /* tp_as_buffer */ 0,
- /* tp_flags */ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
- /* tp_doc */ "Semaphore/Mutex type",
- /* tp_traverse */ 0,
- /* tp_clear */ 0,
- /* tp_richcompare */ 0,
- /* tp_weaklistoffset */ 0,
- /* tp_iter */ 0,
- /* tp_iternext */ 0,
- /* tp_methods */ semlock_methods,
- /* tp_members */ semlock_members,
- /* tp_getset */ 0,
- /* tp_base */ 0,
- /* tp_dict */ 0,
- /* tp_descr_get */ 0,
- /* tp_descr_set */ 0,
- /* tp_dictoffset */ 0,
- /* tp_init */ 0,
- /* tp_alloc */ 0,
- /* tp_new */ _multiprocessing_SemLock,
+static PyType_Slot _PyMp_SemLockType_slots[] ={
+{Py_tp_dealloc, semlock_dealloc},
+{Py_tp_getattro, PyObject_GenericGetAttr},
+{Py_tp_setattro, PyObject_GenericSetAttr},
+{Py_tp_methods, semlock_methods},
+{Py_tp_members, semlock_members},
+{Py_tp_alloc, PyType_GenericAlloc},
+{Py_tp_new, _multiprocessing_SemLock},
+{Py_tp_traverse, semlock_traverse},
+{Py_tp_free, PyObject_GC_Del},
+{Py_tp_doc, (void *)PyDoc_STR("Semaphore/Mutex type")},
+{0, 0},
+};
+
+PyType_Spec _PyMp_SemLockType_spec ={
+ .name = "_multiprocessing.SemLock",
+ .basicsize = sizeof(SemLockObject),
+ .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
+ Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE),
+ .slots = _PyMp_SemLockType_slots,
 };
 
 /*