2 files changed, 21 insertions, 2 deletions
diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 53938e3..e421aa4 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -240,7 +240,6 @@ struct _is {
     struct _is *next;
 
     struct pythreads {
-        int _preallocated_used;
         uint64_t next_unique_id;
         struct _ts *head;
         /* Used in Modules/_threadmodule.c. */
@@ -262,6 +261,11 @@ struct _is {
     int requires_idref;
     PyThread_type_lock id_mutex;
 
+    /* Has been initialized to a safe state.
+
+       In order to be effective, this must be set to 0 during or right
+       after allocation. */
+    int _initialized;
     int finalizing;
 
     struct _ceval_state ceval;
diff --git a/Include/internal/pycore_runtime.h b/Include/internal/pycore_runtime.h
index 9df833c..39e30b7 100644
--- a/Include/internal/pycore_runtime.h
+++ b/Include/internal/pycore_runtime.h
@@ -67,6 +67,12 @@ struct _Py_unicode_runtime_ids {
 /* Full Python runtime state */
 
 typedef struct pyruntimestate {
+    /* Has been initialized to a safe state.
+
+       In order to be effective, this must be set to 0 during or right
+       after allocation. */
+    int _initialized;
+
     /* Is running Py_PreInitialize()? */
     int preinitializing;
 
@@ -136,9 +142,18 @@ typedef struct pyruntimestate {
 } _PyRuntimeState;
 
 #define _PyRuntimeState_INIT \
-    {.preinitialized = 0, .core_initialized = 0, .initialized = 0}
+    { \
+        ._initialized = 0, \
+    }
 /* Note: _PyRuntimeState_INIT sets other fields to 0/NULL */
 
+static inline void
+_PyRuntimeState_reset(_PyRuntimeState *runtime)
+{
+    /* Make it match _PyRuntimeState_INIT. */
+    memset(runtime, 0, sizeof(*runtime));
+}
+
 
 PyAPI_DATA(_PyRuntimeState) _PyRuntime;