gh-124218: Use per-thread reference counting for globals and builtins (#125713)

Use per-thread refcounting for the reference from function objects to
the globals and builtins dictionaries.

1 files changed, 32 insertions, 6 deletions

diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 3cb2476..44fb4ac 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -3,6 +3,7 @@
 
 #include "Python.h"
 #include "pycore_ceval.h"         // _PyEval_BuiltinsFromGlobals()
+#include "pycore_dict.h"          // _Py_INCREF_DICT()
 #include "pycore_long.h"          // _PyLong_GetOne()
 #include "pycore_modsupport.h"    // _PyArg_NoKeywords()
 #include "pycore_object.h"        // _PyObject_GC_UNTRACK()
@@ -112,8 +113,15 @@ _PyFunction_FromConstructor(PyFrameConstructor *constr)
         Py_XDECREF(module);
         return NULL;
     }
-    op->func_globals = Py_NewRef(constr->fc_globals);
-    op->func_builtins = Py_NewRef(constr->fc_builtins);
+    _Py_INCREF_DICT(constr->fc_globals);
+    op->func_globals = constr->fc_globals;
+    if (PyDict_Check(constr->fc_builtins)) {
+        _Py_INCREF_DICT(constr->fc_builtins);
+    }
+    else {
+        Py_INCREF(constr->fc_builtins);
+    }
+    op->func_builtins = constr->fc_builtins;
     op->func_name = Py_NewRef(constr->fc_name);
     op->func_qualname = Py_NewRef(constr->fc_qualname);
     _Py_INCREF_CODE((PyCodeObject *)constr->fc_code);
@@ -143,7 +151,7 @@ PyFunction_NewWithQualName(PyObject *code, PyObject *globals, PyObject *qualname
 {
     assert(globals != NULL);
     assert(PyDict_Check(globals));
-    Py_INCREF(globals);
+    _Py_INCREF_DICT(globals);
 
     PyThreadState *tstate = _PyThreadState_GET();
 
@@ -184,7 +192,12 @@ PyFunction_NewWithQualName(PyObject *code, PyObject *globals, PyObject *qualname
     if (builtins == NULL) {
         goto error;
     }
-    Py_INCREF(builtins);
+    if (PyDict_Check(builtins)) {
+        _Py_INCREF_DICT(builtins);
+    }
+    else {
+        Py_INCREF(builtins);
+    }
 
     PyFunctionObject *op = PyObject_GC_New(PyFunctionObject, &PyFunction_Type);
     if (op == NULL) {
@@ -1057,8 +1070,21 @@ func_clear(PyObject *self)
 {
     PyFunctionObject *op = _PyFunction_CAST(self);
     func_clear_version(_PyInterpreterState_GET(), op);
-    Py_CLEAR(op->func_globals);
-    Py_CLEAR(op->func_builtins);
+    PyObject *globals = op->func_globals;
+    op->func_globals = NULL;
+    if (globals != NULL) {
+        _Py_DECREF_DICT(globals);
+    }
+    PyObject *builtins = op->func_builtins;
+    op->func_builtins = NULL;
+    if (builtins != NULL) {
+        if (PyDict_Check(builtins)) {
+            _Py_DECREF_DICT(builtins);
+        }
+        else {
+            Py_DECREF(builtins);
+        }
+    }
     Py_CLEAR(op->func_module);
     Py_CLEAR(op->func_defaults);
     Py_CLEAR(op->func_kwdefaults);