gh-106320: Remove private _PyCrossInterpreterData API

Include/cpython/pystate.h

@@ -273,79 +273,3 @@ PyAPI_FUNC(_PyFrameEvalFunction) _PyInterpreterState_GetEvalFrameFunc(
 PyAPI_FUNC(void) _PyInterpreterState_SetEvalFrameFunc(
     PyInterpreterState *interp,
     _PyFrameEvalFunction eval_frame);
-
-
-/* cross-interpreter data */
-
-// _PyCrossInterpreterData is similar to Py_buffer as an effectively
-// opaque struct that holds data outside the object machinery.  This
-// is necessary to pass safely between interpreters in the same process.
-typedef struct _xid _PyCrossInterpreterData;
-
-typedef PyObject *(*xid_newobjectfunc)(_PyCrossInterpreterData *);
-typedef void (*xid_freefunc)(void *);
-
-struct _xid {
-    // data is the cross-interpreter-safe derivation of a Python object
-    // (see _PyObject_GetCrossInterpreterData).  It will be NULL if the
-    // new_object func (below) encodes the data.
-    void *data;
-    // obj is the Python object from which the data was derived.  This
-    // is non-NULL only if the data remains bound to the object in some
-    // way, such that the object must be "released" (via a decref) when
-    // the data is released.  In that case the code that sets the field,
-    // likely a registered "crossinterpdatafunc", is responsible for
-    // ensuring it owns the reference (i.e. incref).
-    PyObject *obj;
-    // interp is the ID of the owning interpreter of the original
-    // object.  It corresponds to the active interpreter when
-    // _PyObject_GetCrossInterpreterData() was called.  This should only
-    // be set by the cross-interpreter machinery.
-    //
-    // We use the ID rather than the PyInterpreterState to avoid issues
-    // with deleted interpreters.  Note that IDs are never re-used, so
-    // each one will always correspond to a specific interpreter
-    // (whether still alive or not).
-    int64_t interp;
-    // new_object is a function that returns a new object in the current
-    // interpreter given the data.  The resulting object (a new
-    // reference) will be equivalent to the original object.  This field
-    // is required.
-    xid_newobjectfunc new_object;
-    // free is called when the data is released.  If it is NULL then
-    // nothing will be done to free the data.  For some types this is
-    // okay (e.g. bytes) and for those types this field should be set
-    // to NULL.  However, for most the data was allocated just for
-    // cross-interpreter use, so it must be freed when
-    // _PyCrossInterpreterData_Release is called or the memory will
-    // leak.  In that case, at the very least this field should be set
-    // to PyMem_RawFree (the default if not explicitly set to NULL).
-    // The call will happen with the original interpreter activated.
-    xid_freefunc free;
-};
-
-PyAPI_FUNC(void) _PyCrossInterpreterData_Init(
-        _PyCrossInterpreterData *data,
-        PyInterpreterState *interp, void *shared, PyObject *obj,
-        xid_newobjectfunc new_object);
-PyAPI_FUNC(int) _PyCrossInterpreterData_InitWithSize(
-        _PyCrossInterpreterData *,
-        PyInterpreterState *interp, const size_t, PyObject *,
-        xid_newobjectfunc);
-PyAPI_FUNC(void) _PyCrossInterpreterData_Clear(
-        PyInterpreterState *, _PyCrossInterpreterData *);
-
-PyAPI_FUNC(int) _PyObject_GetCrossInterpreterData(PyObject *, _PyCrossInterpreterData *);
-PyAPI_FUNC(PyObject *) _PyCrossInterpreterData_NewObject(_PyCrossInterpreterData *);
-PyAPI_FUNC(int) _PyCrossInterpreterData_Release(_PyCrossInterpreterData *);
-
-PyAPI_FUNC(int) _PyObject_CheckCrossInterpreterData(PyObject *);
-
-/* cross-interpreter data registry */
-
-typedef int (*crossinterpdatafunc)(PyThreadState *tstate, PyObject *,
-                                   _PyCrossInterpreterData *);
-
-PyAPI_FUNC(int) _PyCrossInterpreterData_RegisterClass(PyTypeObject *, crossinterpdatafunc);
-PyAPI_FUNC(int) _PyCrossInterpreterData_UnregisterClass(PyTypeObject *);
-PyAPI_FUNC(crossinterpdatafunc) _PyCrossInterpreterData_Lookup(PyObject *);

Include/internal/pycore_cross_interp.h

@@ -0,0 +1,85 @@
+/* Cross-interpreter data */
+
+#ifndef Py_INTERNAL_CROSS_INTERPRETER_DATA_H
+#define Py_INTERNAL_CROSS_INTERPRETER_DATA_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+// _PyCrossInterpreterData is similar to Py_buffer as an effectively
+// opaque struct that holds data outside the object machinery.  This
+// is necessary to pass safely between interpreters in the same process.
+typedef struct _xid _PyCrossInterpreterData;
+
+typedef PyObject *(*xid_newobjectfunc)(_PyCrossInterpreterData *);
+typedef void (*xid_freefunc)(void *);
+
+struct _xid {
+    // data is the cross-interpreter-safe derivation of a Python object
+    // (see _PyObject_GetCrossInterpreterData).  It will be NULL if the
+    // new_object func (below) encodes the data.
+    void *data;
+    // obj is the Python object from which the data was derived.  This
+    // is non-NULL only if the data remains bound to the object in some
+    // way, such that the object must be "released" (via a decref) when
+    // the data is released.  In that case the code that sets the field,
+    // likely a registered "crossinterpdatafunc", is responsible for
+    // ensuring it owns the reference (i.e. incref).
+    PyObject *obj;
+    // interp is the ID of the owning interpreter of the original
+    // object.  It corresponds to the active interpreter when
+    // _PyObject_GetCrossInterpreterData() was called.  This should only
+    // be set by the cross-interpreter machinery.
+    //
+    // We use the ID rather than the PyInterpreterState to avoid issues
+    // with deleted interpreters.  Note that IDs are never re-used, so
+    // each one will always correspond to a specific interpreter
+    // (whether still alive or not).
+    int64_t interp;
+    // new_object is a function that returns a new object in the current
+    // interpreter given the data.  The resulting object (a new
+    // reference) will be equivalent to the original object.  This field
+    // is required.
+    xid_newobjectfunc new_object;
+    // free is called when the data is released.  If it is NULL then
+    // nothing will be done to free the data.  For some types this is
+    // okay (e.g. bytes) and for those types this field should be set
+    // to NULL.  However, for most the data was allocated just for
+    // cross-interpreter use, so it must be freed when
+    // _PyCrossInterpreterData_Release is called or the memory will
+    // leak.  In that case, at the very least this field should be set
+    // to PyMem_RawFree (the default if not explicitly set to NULL).
+    // The call will happen with the original interpreter activated.
+    xid_freefunc free;
+};
+
+PyAPI_FUNC(int) _PyCrossInterpreterData_InitWithSize(
+        _PyCrossInterpreterData *,
+        PyInterpreterState *interp, const size_t, PyObject *,
+        xid_newobjectfunc);
+PyAPI_FUNC(void) _PyCrossInterpreterData_Clear(
+        PyInterpreterState *, _PyCrossInterpreterData *);
+
+PyAPI_FUNC(int) _PyObject_GetCrossInterpreterData(PyObject *, _PyCrossInterpreterData *);
+PyAPI_FUNC(PyObject*) _PyCrossInterpreterData_NewObject(_PyCrossInterpreterData *);
+PyAPI_FUNC(int) _PyCrossInterpreterData_Release(_PyCrossInterpreterData *);
+
+PyAPI_FUNC(int) _PyObject_CheckCrossInterpreterData(PyObject *);
+
+/* cross-interpreter data registry */
+
+typedef int (*crossinterpdatafunc)(PyThreadState *tstate, PyObject *,
+                                   _PyCrossInterpreterData *);
+
+// Export for shared _xxinterpchannels extension
+PyAPI_FUNC(int) _PyCrossInterpreterData_RegisterClass(PyTypeObject *, crossinterpdatafunc);
+PyAPI_FUNC(int) _PyCrossInterpreterData_UnregisterClass(PyTypeObject *);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  // !Py_INTERNAL_CROSS_INTERPRETER_DATA_H

Include/internal/pycore_interp.h

@@ -16,6 +16,7 @@ extern "C" {
 #include "pycore_ceval_state.h"   // struct _ceval_state
 #include "pycore_code.h"          // struct callable_cache
 #include "pycore_context.h"       // struct _Py_context_state
+#include "pycore_cross_interp.h"  // crossinterpdatafunc
 #include "pycore_dict_state.h"    // struct _Py_dict_state
 #include "pycore_dtoa.h"          // struct _dtoa_state
 #include "pycore_exceptions.h"    // struct _Py_exc_state

Lib/test/test__xxsubinterpreters.py

@@ -7,13 +7,13 @@
 import threading
 import unittest
 
-import _testcapi
 from test import support
 from test.support import import_helper
 from test.support import script_helper
 
 
 interpreters = import_helper.import_module('_xxsubinterpreters')
+_testinternalcapi = import_helper.import_module('_testinternalcapi')
 
 
 ##################################
@@ -146,17 +146,17 @@ class ShareableTypeTests(unittest.TestCase):
     def _assert_values(self, values):
         for obj in values:
             with self.subTest(obj):
-                xid = _testcapi.get_crossinterp_data(obj)
-                got = _testcapi.restore_crossinterp_data(xid)
+                xid = _testinternalcapi.get_crossinterp_data(obj)
+                got = _testinternalcapi.restore_crossinterp_data(xid)
 
                 self.assertEqual(got, obj)
                 self.assertIs(type(got), type(obj))
 
     def test_singletons(self):
         for obj in [None]:
             with self.subTest(obj):
-                xid = _testcapi.get_crossinterp_data(obj)
-                got = _testcapi.restore_crossinterp_data(xid)
+                xid = _testinternalcapi.get_crossinterp_data(obj)
+                got = _testinternalcapi.restore_crossinterp_data(xid)
 
                 # XXX What about between interpreters?
                 self.assertIs(got, obj)
@@ -187,7 +187,7 @@ def test_non_shareable_int(self):
         for i in ints:
             with self.subTest(i):
                 with self.assertRaises(OverflowError):
-                    _testcapi.get_crossinterp_data(i)
+                    _testinternalcapi.get_crossinterp_data(i)
 
 
 class ModuleTests(TestBase):

Makefile.pre.in

@@ -1750,9 +1750,10 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_complexobject.h \
 		$(srcdir)/Include/internal/pycore_condvar.h \
 		$(srcdir)/Include/internal/pycore_context.h \
+		$(srcdir)/Include/internal/pycore_cross_interp.h \
+		$(srcdir)/Include/internal/pycore_descrobject.h \
 		$(srcdir)/Include/internal/pycore_dict.h \
 		$(srcdir)/Include/internal/pycore_dict_state.h \
-		$(srcdir)/Include/internal/pycore_descrobject.h \
 		$(srcdir)/Include/internal/pycore_dtoa.h \
 		$(srcdir)/Include/internal/pycore_exceptions.h \
 		$(srcdir)/Include/internal/pycore_faulthandler.h \

Modules/_testcapimodule.c

@@ -1541,58 +1541,6 @@ run_in_subinterp_with_config(PyObject *self, PyObject *args, PyObject *kwargs)
     return PyLong_FromLong(r);
 }
 
-static void
-_xid_capsule_destructor(PyObject *capsule)
-{
-    _PyCrossInterpreterData *data = \
-            (_PyCrossInterpreterData *)PyCapsule_GetPointer(capsule, NULL);
-    if (data != NULL) {
-        assert(_PyCrossInterpreterData_Release(data) == 0);
-        PyMem_Free(data);
-    }
-}
-
-static PyObject *
-get_crossinterp_data(PyObject *self, PyObject *args)
-{
-    PyObject *obj = NULL;
-    if (!PyArg_ParseTuple(args, "O:get_crossinterp_data", &obj)) {
-        return NULL;
-    }
-
-    _PyCrossInterpreterData *data = PyMem_NEW(_PyCrossInterpreterData, 1);
-    if (data == NULL) {
-        PyErr_NoMemory();
-        return NULL;
-    }
-    if (_PyObject_GetCrossInterpreterData(obj, data) != 0) {
-        PyMem_Free(data);
-        return NULL;
-    }
-    PyObject *capsule = PyCapsule_New(data, NULL, _xid_capsule_destructor);
-    if (capsule == NULL) {
-        assert(_PyCrossInterpreterData_Release(data) == 0);
-        PyMem_Free(data);
-    }
-    return capsule;
-}
-
-static PyObject *
-restore_crossinterp_data(PyObject *self, PyObject *args)
-{
-    PyObject *capsule = NULL;
-    if (!PyArg_ParseTuple(args, "O:restore_crossinterp_data", &capsule)) {
-        return NULL;
-    }
-
-    _PyCrossInterpreterData *data = \
-            (_PyCrossInterpreterData *)PyCapsule_GetPointer(capsule, NULL);
-    if (data == NULL) {
-        return NULL;
-    }
-    return _PyCrossInterpreterData_NewObject(data);
-}
-
 static PyMethodDef ml;
 
 static PyObject *
@@ -3707,8 +3655,6 @@ static PyMethodDef TestMethods[] = {
     {"run_in_subinterp_with_config",
      _PyCFunction_CAST(run_in_subinterp_with_config),
      METH_VARARGS | METH_KEYWORDS},
-    {"get_crossinterp_data",    get_crossinterp_data,            METH_VARARGS},
-    {"restore_crossinterp_data", restore_crossinterp_data,       METH_VARARGS},
     {"create_cfunction",        create_cfunction,                METH_NOARGS},
     {"call_in_temporary_c_thread", call_in_temporary_c_thread, METH_VARARGS,
      PyDoc_STR("set_error_class(error_class) -> None")},

Modules/_testinternalcapi.c

@@ -16,6 +16,7 @@
 #include "pycore_bytesobject.h"  // _PyBytes_Find()
 #include "pycore_ceval.h"        // _PyEval_AddPendingCall
 #include "pycore_compile.h"      // _PyCompile_CodeGen, _PyCompile_OptimizeCfg, _PyCompile_Assemble, _PyCompile_CleanDoc
+#include "pycore_cross_interp.h"  // _PyCrossInterpreterData
 #include "pycore_fileutils.h"    // _Py_normpath
 #include "pycore_frame.h"        // _PyInterpreterFrame
 #include "pycore_gc.h"           // PyGC_Head
@@ -1446,6 +1447,61 @@ test_atexit(PyObject *self, PyObject *Py_UNUSED(args))
 }
 
 
+/* Cross-interpreter data (xid) */
+
+static void
+_xid_capsule_destructor(PyObject *capsule)
+{
+    _PyCrossInterpreterData *data = \
+            (_PyCrossInterpreterData *)PyCapsule_GetPointer(capsule, NULL);
+    if (data != NULL) {
+        assert(_PyCrossInterpreterData_Release(data) == 0);
+        PyMem_Free(data);
+    }
+}
+
+static PyObject *
+get_crossinterp_data(PyObject *self, PyObject *args)
+{
+    PyObject *obj = NULL;
+    if (!PyArg_ParseTuple(args, "O:get_crossinterp_data", &obj)) {
+        return NULL;
+    }
+
+    _PyCrossInterpreterData *data = PyMem_NEW(_PyCrossInterpreterData, 1);
+    if (data == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    if (_PyObject_GetCrossInterpreterData(obj, data) != 0) {
+        PyMem_Free(data);
+        return NULL;
+    }
+    PyObject *capsule = PyCapsule_New(data, NULL, _xid_capsule_destructor);
+    if (capsule == NULL) {
+        assert(_PyCrossInterpreterData_Release(data) == 0);
+        PyMem_Free(data);
+    }
+    return capsule;
+}
+
+static PyObject *
+restore_crossinterp_data(PyObject *self, PyObject *args)
+{
+    PyObject *capsule = NULL;
+    if (!PyArg_ParseTuple(args, "O:restore_crossinterp_data", &capsule)) {
+        return NULL;
+    }
+
+    _PyCrossInterpreterData *data = \
+            (_PyCrossInterpreterData *)PyCapsule_GetPointer(capsule, NULL);
+    if (data == NULL) {
+        return NULL;
+    }
+    return _PyCrossInterpreterData_NewObject(data);
+}
+
+
 static PyMethodDef module_functions[] = {
     {"get_configs", get_configs, METH_NOARGS},
     {"get_recursion_depth", get_recursion_depth, METH_NOARGS},
@@ -1502,6 +1558,8 @@ static PyMethodDef module_functions[] = {
     {"test_tstate_capi", test_tstate_capi, METH_NOARGS, NULL},
     {"_PyUnicode_TransformDecimalAndSpaceToASCII", unicode_transformdecimalandspacetoascii, METH_O},
     {"test_atexit", test_atexit, METH_NOARGS},
+    {"get_crossinterp_data", get_crossinterp_data, METH_VARARGS},
+    {"restore_crossinterp_data", restore_crossinterp_data, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };
 

Modules/_xxinterpchannelsmodule.c

@@ -7,6 +7,7 @@
 
 #include "Python.h"
 #include "pycore_atexit.h"        // _Py_AtExit()
+#include "pycore_cross_interp.h"  // crossinterpdatafunc
 #include "pycore_interp_id.h"     // _PyInterpreterState_GetIDObject()
 
 

PCbuild/pythoncore.vcxproj

@@ -214,6 +214,7 @@
     <ClInclude Include="..\Include\internal\pycore_complexobject.h" />
     <ClInclude Include="..\Include\internal\pycore_condvar.h" />
     <ClInclude Include="..\Include\internal\pycore_context.h" />
+    <ClInclude Include="..\Include\internal\pycore_cross_interp.h" />
     <ClInclude Include="..\Include\internal\pycore_descrobject.h" />
     <ClInclude Include="..\Include\internal\pycore_dict.h" />
     <ClInclude Include="..\Include\internal\pycore_dict_state.h" />