Fix bug 683658 - PyErr_Warn may cause import deadlock.
diff --git a/Python/errors.c b/Python/errors.c
index e509606..d08c1af 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -600,18 +600,17 @@
Py_XDECREF(tb);
}
+extern PyObject *PyModule_WarningsModule;
/* Function to issue a warning message; may raise an exception. */
int
PyErr_Warn(PyObject *category, char *message)
{
- PyObject *mod, *dict, *func = NULL;
+ PyObject *dict, *func = NULL;
- mod = PyImport_ImportModule("warnings");
- if (mod != NULL) {
- dict = PyModule_GetDict(mod);
+ if (PyModule_WarningsModule != NULL) {
+ dict = PyModule_GetDict(PyModule_WarningsModule);
func = PyDict_GetItemString(dict, "warn");
- Py_DECREF(mod);
}
if (func == NULL) {
PySys_WriteStderr("warning: %s\n", message);
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 1faab50..2845d24 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -60,6 +60,11 @@
true divisions (which they will be in 2.3). */
int _Py_QnewFlag = 0;
+/* Reference to 'warnings' module, to avoid importing it
+ on the fly when the import lock may be held. See 683658
+*/
+PyObject *PyModule_WarningsModule = NULL;
+
static int initialized = 0;
/* API to access the initialized flag -- useful for esoteric use */
@@ -169,6 +174,8 @@
_PyImportHooks_Init();
+ PyModule_WarningsModule = PyImport_ImportModule("warnings");
+
initsigs(); /* Signal handling stuff, including initintr() */
initmain(); /* Module __main__ */
@@ -225,6 +232,10 @@
/* Cleanup Codec registry */
_PyCodecRegistry_Fini();
+ /* drop module references we saved */
+ Py_XDECREF(PyModule_WarningsModule);
+ PyModule_WarningsModule = NULL;
+
/* Destroy all modules */
PyImport_Cleanup();