/* An extension mechanism to store arbitrary additional per-thread state.

   PyThreadState_GetDict() returns a dictionary that can be used to hold such
   state; the caller should pick a unique key and store its state there.  If
   PyThreadState_GetDict() returns NULL, an exception has been raised (most
   likely MemoryError) and the caller should pass on the exception. */

PyObject *
PyThreadState_GetDict()

Python/pystate.c

@@ -126,6 +126,8 @@ PyThreadState_New(interp)
 		tstate->ticker = 0;
 		tstate->tracing = 0;
 
+		tstate->dict = NULL;
+
 		tstate->curexc_type = NULL;
 		tstate->curexc_value = NULL;
 		tstate->curexc_traceback = NULL;
@@ -155,6 +157,8 @@ PyThreadState_Clear(tstate)
 
 	ZAP(tstate->frame);
 
+	ZAP(tstate->dict);
+
 	ZAP(tstate->curexc_type);
 	ZAP(tstate->curexc_value);
 	ZAP(tstate->curexc_traceback);
@@ -213,3 +217,20 @@ PyThreadState_Swap(new)
 
 	return old;
 }
+
+/* An extension mechanism to store arbitrary additional per-thread state.
+   PyThreadState_GetDict() returns a dictionary that can be used to hold such
+   state; the caller should pick a unique key and store its state there.  If
+   PyThreadState_GetDict() returns NULL, an exception has been raised (most
+   likely MemoryError) and the caller should pass on the exception. */
+
+PyObject *
+PyThreadState_GetDict()
+{
+	if (current_tstate == NULL)
+		Py_FatalError("PyThreadState_GetDict: no current thread");
+
+	if (current_tstate->dict == NULL)
+		current_tstate->dict = PyDict_New();
+	return current_tstate->dict;
+}