From: Victor Stinner <vstinner@python.org>
Date: Wed, 6 May 2020 17:05:27 +0000 (+0200)
Subject: bpo-40521: Disable list free list in subinterpreters (GH-19959)
X-Git-Tag: v3.9.0b1~152
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b7aa23d29fa48238dab3692d02e1f0a7e8a5af9c;p=thirdparty%2FPython%2Fcpython.git

bpo-40521: Disable list free list in subinterpreters (GH-19959)

When Python is built with experimental isolated interpreters, disable
the list free list.

Temporary workaround until this cache is made per-interpreter.
---

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 904bea317c9d..37fadca129ac 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -98,8 +98,15 @@ list_preallocate_exact(PyListObject *self, Py_ssize_t size)
 
 /* Empty list reuse scheme to save calls to malloc and free */
 #ifndef PyList_MAXFREELIST
-#define PyList_MAXFREELIST 80
+#  define PyList_MAXFREELIST 80
 #endif
+
+/* bpo-40521: list free lists are shared by all interpreters. */
+#ifdef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
+#  undef PyList_MAXFREELIST
+#  define PyList_MAXFREELIST 0
+#endif
+
 static PyListObject *free_list[PyList_MAXFREELIST];
 static int numfree = 0;