gh-81057: Move contextvars-related Globals to _PyRuntimeState (gh-99400)

This is part of the effort to consolidate global variables, to make them easier to manage (and make it easier to later move some of them to PyInterpreterState).

https://github.com/python/cpython/issues/81057

Include/internal/pycore_context.h

@@ -18,6 +18,10 @@ void _PyContext_Fini(PyInterpreterState *);
 
 /* other API */
 
+typedef struct {
+    PyObject_HEAD
+} _PyContextTokenMissing;
+
 #ifndef WITH_FREELISTS
 // without freelists
 #  define PyContext_MAXFREELIST 0

Include/internal/pycore_global_objects.h

@@ -10,6 +10,8 @@ extern "C" {
 
 #include "pycore_gc.h"              // PyGC_Head
 #include "pycore_global_strings.h"  // struct _Py_global_strings
+#include "pycore_hamt.h"            // PyHamtNode_Bitmap
+#include "pycore_context.h"         // _PyContextTokenMissing
 #include "pycore_typeobject.h"      // pytype_slotdef
 
 
@@ -52,6 +54,10 @@ struct _Py_global_objects {
 
         _PyGC_Head_UNUSED _tuple_empty_gc_not_used;
         PyTupleObject tuple_empty;
+
+        _PyGC_Head_UNUSED _hamt_bitmap_node_empty_gc_not_used;
+        PyHamtNode_Bitmap hamt_bitmap_node_empty;
+        _PyContextTokenMissing context_token_missing;
     } singletons;
 
     PyObject *interned;
@@ -76,6 +82,9 @@ struct _Py_interp_cached_objects {
 struct _Py_interp_static_objects {
     struct {
         int _not_used;
+        // hamt_empty is here instead of global because of its weakreflist.
+        _PyGC_Head_UNUSED _hamt_empty_gc_not_used;
+        PyHamtObject hamt_empty;
     } singletons;
 };
 

Include/internal/pycore_global_objects_fini_generated.h

@@ -1475,6 +1475,9 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) {
     /* non-generated */
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_SINGLETON(bytes_empty));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_SINGLETON(tuple_empty));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_SINGLETON(hamt_bitmap_node_empty));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_INTERP_SINGLETON(interp, hamt_empty));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_SINGLETON(context_token_missing));
 }
 #endif  // Py_DEBUG
 /* End auto-generated code */

Include/internal/pycore_hamt.h

@@ -28,10 +28,6 @@ extern PyTypeObject _PyHamtKeys_Type;
 extern PyTypeObject _PyHamtValues_Type;
 extern PyTypeObject _PyHamtItems_Type;
 
-/* runtime lifecycle */
-
-void _PyHamt_Fini(PyInterpreterState *);
-
 
 /* other API */
 
@@ -53,6 +49,13 @@ typedef struct {
 } PyHamtObject;
 
 
+typedef struct {
+    PyObject_VAR_HEAD
+    uint32_t b_bitmap;
+    PyObject *b_array[1];
+} PyHamtNode_Bitmap;
+
+
 /* A struct to hold the state of depth-first traverse of the tree.
 
    HAMT is an immutable collection.  Iterators will hold a strong reference

Include/internal/pycore_runtime_init.h

@@ -75,6 +75,12 @@ extern "C" {
                 .tuple_empty = { \
                     .ob_base = _PyVarObject_IMMORTAL_INIT(&PyTuple_Type, 0) \
                 }, \
+                .hamt_bitmap_node_empty = { \
+                    .ob_base = _PyVarObject_IMMORTAL_INIT(&_PyHamt_BitmapNode_Type, 0) \
+                }, \
+                .context_token_missing = { \
+                    .ob_base = _PyObject_IMMORTAL_INIT(&_PyContextTokenMissing_Type), \
+                }, \
             }, \
         }, \
         ._main_interpreter = _PyInterpreterState_INIT, \
@@ -112,6 +118,10 @@ extern "C" {
         .static_objects = { \
             .singletons = { \
                 ._not_used = 1, \
+                .hamt_empty = { \
+                    .ob_base = _PyObject_IMMORTAL_INIT(&_PyHamt_Type), \
+                    .h_root = (PyHamtNode*)&_Py_SINGLETON(hamt_bitmap_node_empty), \
+                }, \
             }, \
         }, \
         ._initial_thread = _PyThreadState_INIT, \