Add accessor macros for cross-interpreter data.

python · ericsnowcurrently · Feb 13, 2024 · Dec 19, 2023 · Dec 19, 2023 · Dec 19, 2023
commit ba23dd7be5229627692663013ca608e278100f1b
@@ -87,6 +87,11 @@ struct _xid {
 PyAPI_FUNC(_PyCrossInterpreterData *) _PyCrossInterpreterData_New(void);
 PyAPI_FUNC(void) _PyCrossInterpreterData_Free(_PyCrossInterpreterData *data);
 
+#define _PyCrossInterpreterData_DATA(DATA) ((DATA)->data)
+#define _PyCrossInterpreterData_OBJ(DATA) ((DATA)->obj)
+#define _PyCrossInterpreterData_INTERPID(DATA) ((DATA)->interpid)
+// Users should not need getters for "new_object" or "free".
+
 
 /* defining cross-interpreter data */
 
@@ -101,6 +106,25 @@ PyAPI_FUNC(int) _PyCrossInterpreterData_InitWithSize(
 PyAPI_FUNC(void) _PyCrossInterpreterData_Clear(
         PyInterpreterState *, _PyCrossInterpreterData *);
 
+// Normally the Init* functions are sufficient.  The only time
+// additional initialization might be needed is to set the "free" func,
+// though that should be infrequent.
+#define _PyCrossInterpreterData_SET_FREE(DATA, FUNC) \
+    do { \
+        (DATA)->free = (FUNC); \
+    } while (0)
+// Additionally, some shareable types are essentially light wrappers
+// around other shareable types.  The crossinterpdatafunc of the wrapper
+// can often be implemented by calling the wrapped object's
+// crossinterpdatafunc and then changing the "new_object" function.
+// We have _PyCrossInterpreterData_SET_NEW_OBJECT() here for that,
+// but might be better to have a function like
+// _PyCrossInterpreterData_AdaptToWrapper() instead.
+#define _PyCrossInterpreterData_SET_NEW_OBJECT(DATA, FUNC) \
+    do { \
+        (DATA)->new_object = (FUNC); \
+    } while (0)
+
 
 /* using cross-interpreter data */
 

diff --git a/Modules/_xxinterpchannelsmodule.c b/Modules/_xxinterpchannelsmodule.c
@@ -784,7 +784,7 @@ _channelqueue_clear_interpreter(_channelqueue *queue, int64_t interpid)
     while (next != NULL) {
         _channelitem *item = next;
         next = item->next;
-        if (item->data->interpid == interpid) {
+        if (_PyCrossInterpreterData_INTERPID(item->data) == interpid) {
             if (prev == NULL) {
                 queue->first = item->next;
             }
@@ -2474,7 +2474,8 @@ struct _channelid_xid {
 static PyObject *
 _channelid_from_xid(_PyCrossInterpreterData *data)
 {
-    struct _channelid_xid *xid = (struct _channelid_xid *)data->data;
+    struct _channelid_xid *xid = \
+                (struct _channelid_xid *)_PyCrossInterpreterData_DATA(data);
 
     // It might not be imported yet, so we can't use _get_current_module().
     PyObject *mod = PyImport_ImportModule(MODULE_NAME);
@@ -2530,7 +2531,8 @@ _channelid_shared(PyThreadState *tstate, PyObject *obj,
     {
         return -1;
     }
-    struct _channelid_xid *xid = (struct _channelid_xid *)data->data;
+    struct _channelid_xid *xid = \
+                (struct _channelid_xid *)_PyCrossInterpreterData_DATA(data);
     xid->cid = ((channelid *)obj)->cid;
     xid->end = ((channelid *)obj)->end;
     xid->resolve = ((channelid *)obj)->resolve;
@@ -2680,7 +2682,7 @@ _channelend_shared(PyThreadState *tstate, PyObject *obj,
     if (res < 0) {
         return -1;
     }
-    data->new_object = _channelend_from_xid;
+    _PyCrossInterpreterData_SET_NEW_OBJECT(data, _channelend_from_xid);
     return 0;
 }
 

diff --git a/Modules/_xxinterpqueuesmodule.c b/Modules/_xxinterpqueuesmodule.c
@@ -602,7 +602,7 @@ _queue_clear_interpreter(_queue *queue, int64_t interpid)
     while (next != NULL) {
         _queueitem *item = next;
         next = item->next;
-        if (item->data->interpid == interpid) {
+        if (_PyCrossInterpreterData_INTERPID(item->data) == interpid) {
             if (prev == NULL) {
                 queue->items.first = item->next;
             }
@@ -1130,7 +1130,7 @@ _queueid_xid_free(void *data)
 static PyObject *
 _queueobj_from_xid(_PyCrossInterpreterData *data)
 {
-    int64_t qid = *(int64_t *)data->data;
+    int64_t qid = *(int64_t *)_PyCrossInterpreterData_DATA(data);
     PyObject *qidobj = PyLong_FromLongLong(qid);
     if (qidobj == NULL) {
         return NULL;
@@ -1181,7 +1181,7 @@ _queueobj_shared(PyThreadState *tstate, PyObject *queueobj,
     _PyCrossInterpreterData_Init(data, tstate->interp, raw, NULL,
                                  _queueobj_from_xid);
     Py_DECREF(qidobj);
-    data->free = _queueid_xid_free;
+    _PyCrossInterpreterData_SET_FREE(data, _queueid_xid_free);
     return 0;
 }
 

diff --git a/Modules/_xxsubinterpretersmodule.c b/Modules/_xxsubinterpretersmodule.c
@@ -152,16 +152,16 @@ typedef struct {
 static PyObject *
 xibufferview_from_xid(PyTypeObject *cls, _PyCrossInterpreterData *data)
 {
-    assert(data->data != NULL);
-    assert(data->obj == NULL);
-    assert(data->interpid >= 0);
+    assert(_PyCrossInterpreterData_DATA(data) != NULL);
+    assert(_PyCrossInterpreterData_OBJ(data) == NULL);
+    assert(_PyCrossInterpreterData_INTERPID(data) >= 0);
     XIBufferViewObject *self = PyObject_Malloc(sizeof(XIBufferViewObject));
     if (self == NULL) {
         return NULL;
     }
     PyObject_Init((PyObject *)self, cls);
-    self->view = (Py_buffer *)data->data;
-    self->interpid = data->interpid;
+    self->view = (Py_buffer *)_PyCrossInterpreterData_DATA(data);
+    self->interpid = _PyCrossInterpreterData_INTERPID(data);
     return (PyObject *)self;
 }