bpo-36356: Release Unicode interned strings on Valgrind (#12431)
When Python is compiled with Valgrind support, release Unicode
interned strings at exit in _PyUnicode_Fini().
* Rename _Py_ReleaseInternedUnicodeStrings() to
unicode_release_interned() and make it private.
* unicode_release_interned() is now called from _PyUnicode_Fini():
it must be called with a running Python thread state for TRASHCAN,
it cannot be called from pymain_free().
* Don't display statistics on interned strings at exit anymore
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 9d3ed0d..6e83ed6 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -51,6 +51,11 @@
#include <windows.h>
#endif
+/* Uncomment to display statistics on interned strings at exit when
+ using Valgrind or Insecure++. */
+/* #define INTERNED_STATS 1 */
+
+
/*[clinic input]
class str "PyObject *" "&PyUnicode_Type"
[clinic start generated code]*/
@@ -15157,18 +15162,6 @@
return 0;
}
-void
-_PyUnicode_Fini(void)
-{
- int i;
-
- Py_CLEAR(unicode_empty);
-
- for (i = 0; i < 256; i++)
- Py_CLEAR(unicode_latin1[i]);
- _PyUnicode_ClearStaticStrings();
- (void)PyUnicode_ClearFreeList();
-}
void
PyUnicode_InternInPlace(PyObject **p)
@@ -15233,8 +15226,10 @@
return s;
}
-void
-_Py_ReleaseInternedUnicodeStrings(void)
+
+#if defined(WITH_VALGRIND) || defined(__INSURE__)
+static void
+unicode_release_interned(void)
{
PyObject *keys;
PyObject *s;
@@ -15249,14 +15244,16 @@
return;
}
- /* Since _Py_ReleaseInternedUnicodeStrings() is intended to help a leak
+ /* Since unicode_release_interned() is intended to help a leak
detector, interned unicode strings are not forcibly deallocated;
rather, we give them their stolen references back, and then clear
and DECREF the interned dict. */
n = PyList_GET_SIZE(keys);
+#ifdef INTERNED_STATS
fprintf(stderr, "releasing %" PY_FORMAT_SIZE_T "d interned strings\n",
n);
+#endif
for (i = 0; i < n; i++) {
s = PyList_GET_ITEM(keys, i);
if (PyUnicode_READY(s) == -1) {
@@ -15279,13 +15276,16 @@
}
_PyUnicode_STATE(s).interned = SSTATE_NOT_INTERNED;
}
+#ifdef INTERNED_STATS
fprintf(stderr, "total size of all interned strings: "
"%" PY_FORMAT_SIZE_T "d/%" PY_FORMAT_SIZE_T "d "
"mortal/immortal\n", mortal_size, immortal_size);
+#endif
Py_DECREF(keys);
PyDict_Clear(interned);
Py_CLEAR(interned);
}
+#endif
/********************* Unicode Iterator **************************/
@@ -15564,6 +15564,33 @@
return copy;
}
+
+void
+_PyUnicode_Fini(void)
+{
+#if defined(WITH_VALGRIND) || defined(__INSURE__)
+ /* Insure++ is a memory analysis tool that aids in discovering
+ * memory leaks and other memory problems. On Python exit, the
+ * interned string dictionaries are flagged as being in use at exit
+ * (which it is). Under normal circumstances, this is fine because
+ * the memory will be automatically reclaimed by the system. Under
+ * memory debugging, it's a huge source of useless noise, so we
+ * trade off slower shutdown for less distraction in the memory
+ * reports. -baw
+ */
+ unicode_release_interned();
+#endif /* __INSURE__ */
+
+ Py_CLEAR(unicode_empty);
+
+ for (Py_ssize_t i = 0; i < 256; i++) {
+ Py_CLEAR(unicode_latin1[i]);
+ }
+ _PyUnicode_ClearStaticStrings();
+ (void)PyUnicode_ClearFreeList();
+}
+
+
/* A _string module, to export formatter_parser and formatter_field_name_split
to the string.Formatter class implemented in Python. */