From f4507231e3f0cf8827cec5592571ce371c6813e8 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Sat, 26 Dec 2020 20:26:08 +0100
Subject: [PATCH] bpo-42745: finalize_interp_types() calls _PyType_Fini()
 (GH-23953)

Call _PyType_Fini() in subinterpreters.

Fix reference leaks in subinterpreters.
---
 Objects/typeobject.c    | 4 +++-
 Objects/unicodeobject.c | 7 +++----
 Python/pylifecycle.c    | 4 +---
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 43c499a0452..3498f0d484e 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -286,7 +286,9 @@ void
 _PyType_Fini(PyThreadState *tstate)
 {
     _PyType_ClearCache(&tstate->interp->type_cache);
-    clear_slotdefs();
+    if (_Py_IsMainInterpreter(tstate)) {
+        clear_slotdefs();
+    }
 }
 
 
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index a03ca9a10d1..ad32a062d48 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -2359,10 +2359,9 @@ _PyUnicode_FromId(_Py_Identifier *id)
 
 
 static void
-unicode_clear_identifiers(PyThreadState *tstate)
+unicode_clear_identifiers(struct _Py_unicode_state *state)
 {
-    PyInterpreterState *interp = _PyInterpreterState_GET();
-    struct _Py_unicode_ids *ids = &interp->unicode.ids;
+    struct _Py_unicode_ids *ids = &state->ids;
     for (Py_ssize_t i=0; i < ids->size; i++) {
         Py_XDECREF(ids->array[i]);
     }
@@ -16243,7 +16242,7 @@ _PyUnicode_Fini(PyThreadState *tstate)
 
     _PyUnicode_FiniEncodings(&state->fs_codec);
 
-    unicode_clear_identifiers(tstate);
+    unicode_clear_identifiers(state);
 
     for (Py_ssize_t i = 0; i < 256; i++) {
         Py_CLEAR(state->latin1[i]);
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ccbacb48194..9828dffad5c 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1573,6 +1573,7 @@ finalize_interp_types(PyThreadState *tstate)
     _PyFrame_Fini(tstate);
     _PyAsyncGen_Fini(tstate);
     _PyContext_Fini(tstate);
+    _PyType_Fini(tstate);
     // Call _PyUnicode_ClearInterned() before _PyDict_Fini() since it uses
     // a dict internally.
     _PyUnicode_ClearInterned(tstate);
@@ -1751,9 +1752,6 @@ Py_FinalizeEx(void)
     /* Destroy the database used by _PyImport_{Fixup,Find}Extension */
     _PyImport_Fini();
 
-    /* Cleanup typeobject.c's internal caches. */
-    _PyType_Fini(tstate);
-
     /* unload faulthandler module */
     _PyFaulthandler_Fini();