WIP: _PyThreadState_GetDict(tstate) API gets removed in Python 3.13

Author: Xmader

include/PyEventLoop.hh

@@ -331,8 +331,4 @@ private:
   static inline std::vector<AsyncHandle> _timeoutIdMap;
 };
 
-// See https://github.com/python/cpython/blob/v3.13.0rc1/Python/pystate.c#L1940-L1951
-// Python 3.13 removed it from the public API. Re-exporting here.
-extern PyObject *_PyThreadState_GetDict(PyThreadState *tstate);
-
 #endif

src/PyEventLoop.cc

@@ -140,7 +140,13 @@ PyEventLoop PyEventLoop::_loopNotFound() {
 /* static */
 PyEventLoop PyEventLoop::_getLoopOnThread(PyThreadState *tstate) {
   // Modified from Python 3.9 `get_running_loop` https://github.com/python/cpython/blob/7cb3a44/Modules/_asynciomodule.c#L241-L278
-  #if PY_VERSION_HEX >= 0x03090000 // Python version is greater than 3.9
+
+  #if PY_VERSION_HEX >= 0x030d0000 // Python version is greater than 3.13
+  // The private `_PyThreadState_GetDict(tstate)` API gets removed in Python 3.13.
+  // However, the fix below cannot be a perfect replacement since the public `PyThreadState_GetDict()` API can only get from the current thread.
+  // We need to somehow get the thread dictionary on the main thread instead of the current thread.
+  PyObject *ts_dict = PyThreadState_GetDict();
+  #elif PY_VERSION_HEX >= 0x03090000 // Python version is greater than 3.9
   PyObject *ts_dict = _PyThreadState_GetDict(tstate);  // borrowed reference
   #else // Python 3.8
   PyObject *ts_dict = tstate->dict; // see https://github.com/python/cpython/blob/v3.8.17/Modules/_asynciomodule.c#L244-L245