bpo-40077: Convert zoneinfo type to heap type

Lib/test/test_zoneinfo/test_zoneinfo.py

@@ -1775,12 +1775,9 @@ def test_cache_location(self):
  self.assertTrue(hasattr(py_zoneinfo.ZoneInfo, "_weak_cache"))
 
  def test_gc_tracked(self):
- # The pure Python version is tracked by the GC but (for now) the C
- # version is not.
  import gc
-
  self.assertTrue(gc.is_tracked(py_zoneinfo.ZoneInfo))
- self.assertFalse(gc.is_tracked(c_zoneinfo.ZoneInfo))
+ self.assertTrue(gc.is_tracked(c_zoneinfo.ZoneInfo))
 
 
 @dataclasses.dataclass(frozen=True)

Misc/NEWS.d/next/Library/2021-02-08-09-47-39.bpo-40077.12_jl3.rst

@@ -0,0 +1 @@
+Convert ``zoneinfo.ZoneInfo`` type to heap type. Patch by Erlend E. Aasland.

Modules/_zoneinfo.c

@@ -79,7 +79,7 @@ struct StrongCacheNode{
  PyObject *zone;
 };
 
-static PyTypeObject PyZoneInfo_ZoneInfoType;
+static PyTypeObject *PyZoneInfo_ZoneInfoType;
 
 // Globals
 static PyObject *TIMEDELTA_CACHE = NULL;
@@ -242,7 +242,7 @@ zoneinfo_new_instance(PyTypeObject *type, PyObject *key)
 static PyObject *
 get_weak_cache(PyTypeObject *type)
 {
- if (type == &PyZoneInfo_ZoneInfoType){
+ if (type == PyZoneInfo_ZoneInfoType){
  return ZONEINFO_WEAK_CACHE;
  }
  else{
@@ -296,10 +296,19 @@ zoneinfo_new(PyTypeObject *type, PyObject *args, PyObject *kw)
  return instance;
 }
 
+static int
+zoneinfo_traverse(PyObject *self, visitproc visit, void *arg)
+{
+ Py_VISIT(Py_TYPE(self));
+ return 0;
+}
+
 static void
 zoneinfo_dealloc(PyObject *obj_self)
 {
+ PyObject_GC_UnTrack(obj_self);
  PyZoneInfo_ZoneInfo *self = (PyZoneInfo_ZoneInfo *)obj_self;
+ PyTypeObject *tp = Py_TYPE(obj_self);
 
  if (self->weakreflist != NULL){
  PyObject_ClearWeakRefs(obj_self);
@@ -331,7 +340,8 @@ zoneinfo_dealloc(PyObject *obj_self)
  Py_XDECREF(self->key);
  Py_XDECREF(self->file_repr);
 
- Py_TYPE(self)->tp_free((PyObject *)self);
+ tp->tp_free(self);
+ Py_DECREF(tp);
 }
 
 static PyObject *
@@ -2366,7 +2376,7 @@ find_in_strong_cache(const StrongCacheNode *const root, PyObject *const key)
 static int
 eject_from_strong_cache(const PyTypeObject *const type, PyObject *key)
 {
- if (type != &PyZoneInfo_ZoneInfoType){
+ if (type != PyZoneInfo_ZoneInfoType){
  return 0;
  }
 
@@ -2419,7 +2429,7 @@ move_strong_cache_node_to_front(StrongCacheNode **root, StrongCacheNode *node)
 static PyObject *
 zone_from_strong_cache(const PyTypeObject *const type, PyObject *const key)
 {
- if (type != &PyZoneInfo_ZoneInfoType){
+ if (type != PyZoneInfo_ZoneInfoType){
  return NULL; // Strong cache currently only implemented for base class
  }
 
@@ -2444,7 +2454,7 @@ static void
 update_strong_cache(const PyTypeObject *const type, PyObject *key,
  PyObject *zone)
 {
- if (type != &PyZoneInfo_ZoneInfoType){
+ if (type != PyZoneInfo_ZoneInfoType){
  return;
  }
 
@@ -2477,7 +2487,7 @@ update_strong_cache(const PyTypeObject *const type, PyObject *key,
 void
 clear_strong_cache(const PyTypeObject *const type)
 {
- if (type != &PyZoneInfo_ZoneInfoType){
+ if (type != PyZoneInfo_ZoneInfoType){
  return;
  }
 
@@ -2585,23 +2595,30 @@ static PyMemberDef zoneinfo_members[] ={
  .type = T_OBJECT_EX,
  .flags = READONLY,
  .doc = NULL},
+{.name = "__weaklistoffset__",
+ .offset = offsetof(PyZoneInfo_ZoneInfo, weakreflist),
+ .type = T_PYSSIZET,
+ .flags = READONLY},
 {NULL}, /* Sentinel */
 };
 
-static PyTypeObject PyZoneInfo_ZoneInfoType ={
- PyVarObject_HEAD_INIT(NULL, 0) //
- .tp_name = "zoneinfo.ZoneInfo",
- .tp_basicsize = sizeof(PyZoneInfo_ZoneInfo),
- .tp_weaklistoffset = offsetof(PyZoneInfo_ZoneInfo, weakreflist),
- .tp_repr = (reprfunc)zoneinfo_repr,
- .tp_str = (reprfunc)zoneinfo_str,
- .tp_getattro = PyObject_GenericGetAttr,
- .tp_flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE),
- /* .tp_doc = zoneinfo_doc, */
- .tp_methods = zoneinfo_methods,
- .tp_members = zoneinfo_members,
- .tp_new = zoneinfo_new,
- .tp_dealloc = zoneinfo_dealloc,
+static PyType_Slot zoneinfo_slots[] ={
+{Py_tp_repr, zoneinfo_repr},
+{Py_tp_str, zoneinfo_str},
+{Py_tp_getattro, PyObject_GenericGetAttr},
+{Py_tp_methods, zoneinfo_methods},
+{Py_tp_members, zoneinfo_members},
+{Py_tp_new, zoneinfo_new},
+{Py_tp_dealloc, zoneinfo_dealloc},
+{Py_tp_traverse, zoneinfo_traverse},
+{0, NULL},
+};
+
+static PyType_Spec zoneinfo_spec ={
+ .name = "zoneinfo.ZoneInfo",
+ .basicsize = sizeof(PyZoneInfo_ZoneInfo),
+ .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC),
+ .slots = zoneinfo_slots,
 };
 
 /////
@@ -2633,7 +2650,7 @@ module_free()
  Py_CLEAR(ZONEINFO_WEAK_CACHE);
  }
 
- clear_strong_cache(&PyZoneInfo_ZoneInfoType);
+ clear_strong_cache(PyZoneInfo_ZoneInfoType);
 }
 
 static int
@@ -2643,13 +2660,19 @@ zoneinfomodule_exec(PyObject *m)
  if (PyDateTimeAPI == NULL){
  goto error;
  }
- PyZoneInfo_ZoneInfoType.tp_base = PyDateTimeAPI->TZInfoType;
- if (PyType_Ready(&PyZoneInfo_ZoneInfoType) < 0){
+ PyObject *base = (PyObject *)PyDateTimeAPI->TZInfoType;
+ PyZoneInfo_ZoneInfoType = (PyTypeObject *)PyType_FromModuleAndSpec(m,
+ &zoneinfo_spec,
+ base);
+ if (PyZoneInfo_ZoneInfoType == NULL){
  goto error;
  }
 
- Py_INCREF(&PyZoneInfo_ZoneInfoType);
- PyModule_AddObject(m, "ZoneInfo", (PyObject *)&PyZoneInfo_ZoneInfoType);
+ int rc = PyModule_AddObjectRef(m, "ZoneInfo", (PyObject *)PyZoneInfo_ZoneInfoType);
+ Py_DECREF(PyZoneInfo_ZoneInfoType);
+ if (rc < 0){
+ goto error;
+ }
 
  /* Populate imports */
  PyObject *_tzpath_module = PyImport_ImportModule("zoneinfo._tzpath");