[3.9] bpo-40514: Remove --with-experimental-isolated-subinterpreters in 3.9 (GH-20228)

Remove --with-experimental-isolated-subinterpreters configure option
in Python 3.9: the experiment continues in the master branch, but
it's no longer needed in 3.9.

6 files changed, 4 insertions, 40 deletions

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 809a5ed..faee6bc 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -251,12 +251,6 @@ static uint64_t pydict_global_version = 0;
 #define PyDict_MAXFREELIST 80
 #endif
 
-/* bpo-40521: dict free lists are shared by all interpreters. */
-#ifdef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  undef PyDict_MAXFREELIST
-#  define PyDict_MAXFREELIST 0
-#endif
-
 #if PyDict_MAXFREELIST > 0
 static PyDictObject *free_list[PyDict_MAXFREELIST];
 static int numfree = 0;
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index af32276..a2fc0a4 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -559,12 +559,6 @@ static PyGetSetDef frame_getsetlist[] = {
 /* max value for numfree */
 #define PyFrame_MAXFREELIST 200
 
-/* bpo-40521: frame free lists are shared by all interpreters. */
-#ifdef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  undef PyFrame_MAXFREELIST
-#  define PyFrame_MAXFREELIST 0
-#endif
-
 #if PyFrame_MAXFREELIST > 0
 static PyFrameObject *free_list = NULL;
 static int numfree = 0;         /* number of frames currently in free_list */
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 37fadca..f9eb370 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -101,12 +101,6 @@ list_preallocate_exact(PyListObject *self, Py_ssize_t size)
 #  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;
 
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index c0b59c0..9092c9f 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -22,12 +22,6 @@ class tuple "PyTupleObject *" "&PyTuple_Type"
 #define PyTuple_MAXFREELIST  2000  /* Maximum number of tuples of each size to save */
 #endif
 
-/* bpo-40521: tuple free lists are shared by all interpreters. */
-#ifdef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  undef PyTuple_MAXSAVESIZE
-#  define PyTuple_MAXSAVESIZE 0
-#endif
-
 #if PyTuple_MAXSAVESIZE > 0
 /* Entries 1 up to PyTuple_MAXSAVESIZE are free lists, entry 0 is the empty
    tuple () of which at most one instance will be allocated.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 243f881..353423b 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -19,10 +19,7 @@ class object "PyObject *" "&PyBaseObject_Type"
 
 #include "clinic/typeobject.c.h"
 
-/* bpo-40521: Type method cache is shared by all subinterpreters */
-#ifndef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  define MCACHE
-#endif
+#define MCACHE
 
 #ifdef MCACHE
 /* Support type attribute cache */
@@ -63,10 +60,7 @@ static size_t method_cache_misses = 0;
 static size_t method_cache_collisions = 0;
 #endif
 
-/* bpo-40521: Interned strings are shared by all subinterpreters */
-#ifndef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  define INTERN_NAME_STRINGS
-#endif
+#define INTERN_NAME_STRINGS
 
 /* alphabetical order */
 _Py_IDENTIFIER(__abstractmethods__);
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index ea46a44..1082eb4 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -198,10 +198,7 @@ extern "C" {
 #  define OVERALLOCATE_FACTOR 4
 #endif
 
-/* bpo-40521: Interned strings are shared by all interpreters. */
-#ifndef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  define INTERNED_STRINGS
-#endif
+#define INTERNED_STRINGS
 
 /* This dictionary holds all interned unicode strings.  Note that references
    to strings in this dictionary are *not* counted in the string's ob_refcnt.
@@ -288,10 +285,7 @@ unicode_decode_utf8(const char *s, Py_ssize_t size,
 /* List of static strings. */
 static _Py_Identifier *static_strings = NULL;
 
-/* bpo-40521: Latin1 singletons are shared by all interpreters. */
-#ifndef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
-#  define LATIN1_SINGLETONS
-#endif
+#define LATIN1_SINGLETONS
 
 #ifdef LATIN1_SINGLETONS
 /* Single character Unicode strings in the Latin-1 range are being