bpo-38858: Allocate small integers on the heap (GH-17301)
Allocate small Python integers (small_ints of longobject.c) on the
heap, rather than using static objects.
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 2b57ea1..294308e 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -40,7 +40,7 @@
The integers that are preallocated are those in the range
-NSMALLNEGINTS (inclusive) to NSMALLPOSINTS (not inclusive).
*/
-static PyLongObject small_ints[NSMALLNEGINTS + NSMALLPOSINTS];
+static PyLongObject* small_ints[NSMALLNEGINTS + NSMALLPOSINTS] = {0};
#define IS_SMALL_INT(ival) (-NSMALLNEGINTS <= (ival) && (ival) < NSMALLPOSINTS)
#define IS_SMALL_UINT(ival) ((ival) < NSMALLPOSINTS)
@@ -52,9 +52,8 @@
static PyObject *
get_small_int(sdigit ival)
{
- PyObject *v;
assert(IS_SMALL_INT(ival));
- v = (PyObject *)&small_ints[ival + NSMALLNEGINTS];
+ PyObject *v = (PyObject*)small_ints[ival + NSMALLNEGINTS];
Py_INCREF(v);
#ifdef COUNT_ALLOCS
if (ival >= 0)
@@ -5784,40 +5783,30 @@
_PyLong_Init(void)
{
#if NSMALLNEGINTS + NSMALLPOSINTS > 0
- int ival, size;
- PyLongObject *v = small_ints;
+ for (Py_ssize_t i=0; i < NSMALLNEGINTS + NSMALLPOSINTS; i++) {
+ sdigit ival = (sdigit)i - NSMALLNEGINTS;
+ int size = (ival < 0) ? -1 : ((ival == 0) ? 0 : 1);
- for (ival = -NSMALLNEGINTS; ival < NSMALLPOSINTS; ival++, v++) {
- size = (ival < 0) ? -1 : ((ival == 0) ? 0 : 1);
- if (Py_TYPE(v) == &PyLong_Type) {
- /* The element is already initialized, most likely
- * the Python interpreter was initialized before.
- */
- Py_ssize_t refcnt;
- PyObject* op = (PyObject*)v;
+ PyLongObject *v = _PyLong_New(1);
+ if (!v) {
+ return -1;
+ }
- refcnt = Py_REFCNT(op) < 0 ? 0 : Py_REFCNT(op);
- _Py_NewReference(op);
- /* _Py_NewReference sets the ref count to 1 but
- * the ref count might be larger. Set the refcnt
- * to the original refcnt + 1 */
- Py_REFCNT(op) = refcnt + 1;
- assert(Py_SIZE(op) == size);
- assert(v->ob_digit[0] == (digit)abs(ival));
- }
- else {
- (void)PyObject_INIT(v, &PyLong_Type);
- }
Py_SIZE(v) = size;
v->ob_digit[0] = (digit)abs(ival);
+
+ small_ints[i] = v;
}
#endif
_PyLong_Zero = PyLong_FromLong(0);
- if (_PyLong_Zero == NULL)
+ if (_PyLong_Zero == NULL) {
return 0;
+ }
+
_PyLong_One = PyLong_FromLong(1);
- if (_PyLong_One == NULL)
+ if (_PyLong_One == NULL) {
return 0;
+ }
/* initialize int_info */
if (Int_InfoType.tp_name == NULL) {
@@ -5832,17 +5821,11 @@
void
_PyLong_Fini(void)
{
- /* Integers are currently statically allocated. Py_DECREF is not
- needed, but Python must forget about the reference or multiple
- reinitializations will fail. */
Py_CLEAR(_PyLong_One);
Py_CLEAR(_PyLong_Zero);
#if NSMALLNEGINTS + NSMALLPOSINTS > 0
- int i;
- PyLongObject *v = small_ints;
- for (i = 0; i < NSMALLNEGINTS + NSMALLPOSINTS; i++, v++) {
- _Py_DEC_REFTOTAL;
- _Py_ForgetReference((PyObject*)v);
+ for (Py_ssize_t i = 0; i < NSMALLNEGINTS + NSMALLPOSINTS; i++) {
+ Py_CLEAR(small_ints[i]);
}
#endif
}