gh-76785: Improved Subinterpreters Compatibility with 3.12 (1/2) (gh-126704)

These changes makes it easier to backport the _interpreters, _interpqueues, and _interpchannels modules to Python 3.12.

This involves the following:

* rename several structs and typedefs
* add several typedefs
* stop using the PyThreadState.state field directly in parking_lot.c

3 files changed, 25 insertions, 19 deletions

diff --git a/Python/crossinterp.c b/Python/crossinterp.c
index b7aa8da..dfdb5f9 100644
--- a/Python/crossinterp.c
+++ b/Python/crossinterp.c
@@ -126,7 +126,7 @@ void
 _PyXIData_Init(_PyXIData_t *data,
                PyInterpreterState *interp,
                void *shared, PyObject *obj,
-               xid_newobjectfunc new_object)
+               xid_newobjfunc new_object)
 {
     assert(data != NULL);
     assert(new_object != NULL);
@@ -150,7 +150,7 @@ int
 _PyXIData_InitWithSize(_PyXIData_t *data,
                        PyInterpreterState *interp,
                        const size_t size, PyObject *obj,
-                       xid_newobjectfunc new_object)
+                       xid_newobjfunc new_object)
 {
     assert(size > 0);
     // For now we always free the shared data in the same interpreter
@@ -202,11 +202,9 @@ _check_xidata(PyThreadState *tstate, _PyXIData_t *data)
 }
 
 static inline void
-_set_xid_lookup_failure(PyInterpreterState *interp,
-                        PyObject *obj, const char *msg)
+_set_xid_lookup_failure(_PyXI_state_t *state, PyObject *obj, const char *msg)
 {
-    exceptions_t *state = &_PyInterpreterState_GetXIState(interp)->exceptions;
-    PyObject *exctype = state->PyExc_NotShareableError;
+    PyObject *exctype = state->exceptions.PyExc_NotShareableError;
     assert(exctype != NULL);
     if (msg != NULL) {
         assert(obj == NULL);
@@ -226,10 +224,11 @@ int
 _PyObject_CheckXIData(PyObject *obj)
 {
     PyInterpreterState *interp = PyInterpreterState_Get();
+    _PyXI_state_t *state = _PyXI_GET_STATE(interp);
     xidatafunc getdata = lookup_getdata(interp, obj);
     if (getdata == NULL) {
         if (!PyErr_Occurred()) {
-            _set_xid_lookup_failure(interp, obj, NULL);
+            _set_xid_lookup_failure(state, obj, NULL);
         }
         return -1;
     }
@@ -241,6 +240,7 @@ _PyObject_GetXIData(PyObject *obj, _PyXIData_t *data)
 {
     PyThreadState *tstate = PyThreadState_Get();
     PyInterpreterState *interp = tstate->interp;
+    _PyXI_state_t *state = _PyXI_GET_STATE(interp);
 
     // Reset data before re-populating.
     *data = (_PyXIData_t){0};
@@ -252,7 +252,7 @@ _PyObject_GetXIData(PyObject *obj, _PyXIData_t *data)
     if (getdata == NULL) {
         Py_DECREF(obj);
         if (!PyErr_Occurred()) {
-            _set_xid_lookup_failure(interp, obj, NULL);
+            _set_xid_lookup_failure(state, obj, NULL);
         }
         return -1;
     }
@@ -969,6 +969,7 @@ _PyXI_ClearExcInfo(_PyXI_excinfo *info)
 static int
 _PyXI_ApplyErrorCode(_PyXI_errcode code, PyInterpreterState *interp)
 {
+    _PyXI_state_t *state;
     assert(!PyErr_Occurred());
     switch (code) {
     case _PyXI_ERR_NO_ERROR: _Py_FALLTHROUGH;
@@ -999,7 +1000,8 @@ _PyXI_ApplyErrorCode(_PyXI_errcode code, PyInterpreterState *interp)
                         "failed to apply namespace to __main__");
         break;
     case _PyXI_ERR_NOT_SHAREABLE:
-        _set_xid_lookup_failure(interp, NULL, NULL);
+        state = _PyXI_GET_STATE(interp);
+        _set_xid_lookup_failure(state, NULL, NULL);
         break;
     default:
 #ifdef Py_DEBUG
@@ -1061,7 +1063,8 @@ _PyXI_ApplyError(_PyXI_error *error)
     }
     else if (error->code == _PyXI_ERR_NOT_SHAREABLE) {
         // Propagate the exception directly.
-        _set_xid_lookup_failure(error->interp, NULL, error->uncaught.msg);
+        _PyXI_state_t *state = _PyXI_GET_STATE(error->interp);
+        _set_xid_lookup_failure(state, NULL, error->uncaught.msg);
     }
     else {
         // Raise an exception corresponding to the code.
@@ -1606,9 +1609,9 @@ _propagate_not_shareable_error(_PyXI_session *session)
         return;
     }
     PyInterpreterState *interp = PyInterpreterState_Get();
-    exceptions_t *state = &_PyInterpreterState_GetXIState(interp)->exceptions;
-    assert(state->PyExc_NotShareableError != NULL);
-    if (PyErr_ExceptionMatches(state->PyExc_NotShareableError)) {
+    _PyXI_state_t *state = _PyXI_GET_STATE(interp);
+    assert(state->exceptions.PyExc_NotShareableError != NULL);
+    if (PyErr_ExceptionMatches(state->exceptions.PyExc_NotShareableError)) {
         // We want to propagate the exception directly.
         session->_error_override = _PyXI_ERR_NOT_SHAREABLE;
         session->error_override = &session->_error_override;
@@ -1779,11 +1782,13 @@ _PyXI_Exit(_PyXI_session *session)
 PyStatus
 _PyXI_Init(PyInterpreterState *interp)
 {
+    _PyXI_state_t *state = _PyXI_GET_STATE(interp);
+
     // Initialize the XID lookup state (e.g. registry).
     if (_Py_IsMainInterpreter(interp)) {
         xid_lookup_init(&_PyXI_GET_GLOBAL_STATE(interp)->data_lookup);
     }
-    xid_lookup_init(&_PyXI_GET_STATE(interp)->data_lookup);
+    xid_lookup_init(&state->data_lookup);
 
     // Initialize exceptions.(heap types).
     // See _PyXI_InitTypes() for the static types.
@@ -1801,12 +1806,14 @@ _PyXI_Init(PyInterpreterState *interp)
 void
 _PyXI_Fini(PyInterpreterState *interp)
 {
+    _PyXI_state_t *state = _PyXI_GET_STATE(interp);
+
     // Finalize exceptions (heap types).
     // See _PyXI_FiniTypes() for the static types.
     fini_heap_exctypes(&_PyXI_GET_STATE(interp)->exceptions);
 
     // Finalize the XID lookup state (e.g. registry).
-    xid_lookup_fini(&_PyXI_GET_STATE(interp)->data_lookup);
+    xid_lookup_fini(&state->data_lookup);
     if (_Py_IsMainInterpreter(interp)) {
         xid_lookup_fini(&_PyXI_GET_GLOBAL_STATE(interp)->data_lookup);
     }
diff --git a/Python/crossinterp_data_lookup.h b/Python/crossinterp_data_lookup.h
index 88c662a..9048f90 100644
--- a/Python/crossinterp_data_lookup.h
+++ b/Python/crossinterp_data_lookup.h
@@ -1,8 +1,8 @@
 #include "pycore_weakref.h"       // _PyWeakref_GET_REF()
 
 
-typedef struct _xidregistry dlregistry_t;
-typedef struct _xidregitem dlregitem_t;
+typedef _PyXIData_registry_t dlregistry_t;
+typedef _PyXIData_regitem_t dlregitem_t;
 
 
 // forward
diff --git a/Python/parking_lot.c b/Python/parking_lot.c
index bffc959..8edf432 100644
--- a/Python/parking_lot.c
+++ b/Python/parking_lot.c
@@ -221,8 +221,7 @@ _PySemaphore_Wait(_PySemaphore *sema, PyTime_t timeout, int detach)
     PyThreadState *tstate = NULL;
     if (detach) {
         tstate = _PyThreadState_GET();
-        if (tstate && _Py_atomic_load_int_relaxed(&tstate->state) ==
-                          _Py_THREAD_ATTACHED) {
+        if (tstate && _PyThreadState_IsAttached(tstate)) {
             // Only detach if we are attached
             PyEval_ReleaseThread(tstate);
         }