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gvanrossumgvanrossum
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Add internal routine _PyModule_Clear(), which does approximately what
clear_carefully() used to do in import.c. Differences: leave only __builtins__ alone in the 2nd pass; and don't clear the dictionary (on the theory that as long as there are references left to the dictionary, those might be destructors that might expect __builtins__ to be alive when they run; and __builtins__ can't normally be part of a cycle).
1 parent c83db33 commit f1dc061

2 files changed

Lines changed: 51 additions & 1 deletion

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‎Include/moduleobject.h‎

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Original file line numberDiff line numberDiff line change
@@ -44,6 +44,7 @@ extern DL_IMPORT(PyTypeObject) PyModule_Type;
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extern PyObject *PyModule_New Py_PROTO((char *));
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extern PyObject *PyModule_GetDict Py_PROTO((PyObject *));
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extern char *PyModule_GetName Py_PROTO((PyObject *));
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extern void _PyModule_Clear Py_PROTO((PyObject *));
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#ifdef __cplusplus
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}

‎Objects/moduleobject.c‎

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Original file line numberDiff line numberDiff line change
@@ -93,14 +93,63 @@ PyModule_GetName(m)
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return PyString_AsString(nameobj);
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}
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void
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_PyModule_Clear(m)
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PyObject *m;
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{
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/* To make the execution order of destructors for global
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objects a bit more predictable, we first zap all objects
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whose name starts with a single underscore, before we clear
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the entire dictionary. We zap them by replacing them with
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None, rather than deleting them from the dictionary, to
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avoid rehashing the dictionary (to some extent). */
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int pos;
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PyObject *key, *value;
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PyObject *d;
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d = ((PyModuleObject *)m)->md_dict;
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/* First, clear only names starting with a single underscore */
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pos = 0;
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while (PyDict_Next(d, &pos, &key, &value)) {
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if (value != Py_None && PyString_Check(key)) {
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char *s = PyString_AsString(key);
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if (s[0] == '_' && s[1] != '_') {
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if (Py_VerboseFlag > 1)
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fprintf(stderr, "# clear[1] %s\n", s);
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PyDict_SetItem(d, key, Py_None);
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}
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}
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}
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/* Next, clear all names except for __builtins__ */
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pos = 0;
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while (PyDict_Next(d, &pos, &key, &value)) {
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if (value != Py_None && PyString_Check(key)) {
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char *s = PyString_AsString(key);
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if (s[0] != '_' || strcmp(s, "__builtins__") != 0) {
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if (Py_VerboseFlag > 1)
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fprintf(stderr, "# clear[2] %s\n", s);
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PyDict_SetItem(d, key, Py_None);
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}
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}
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}
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/* Note: we leave __builtins__ in place, so that destructors
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of non-global objects defined in this module can still use
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builtins, in particularly 'None'. */
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}
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/* Methods */
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static void
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module_dealloc(m)
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PyModuleObject *m;
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{
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if (m->md_dict != NULL) {
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PyDict_Clear(m->md_dict);
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_PyModule_Clear((PyObject *)m);
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Py_DECREF(m->md_dict);
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}
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free((char *)m);

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