bpo-46070: Fix asyncio initialisation guard (GH-30423)
If init flag is set, exit successfully immediately.
If not, only set the flag after successful initialization.
diff --git a/Misc/NEWS.d/next/Library/2022-01-07-13-51-22.bpo-46070.-axLUW.rst b/Misc/NEWS.d/next/Library/2022-01-07-13-51-22.bpo-46070.-axLUW.rst
new file mode 100644
index 0000000..0fedc9d
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-01-07-13-51-22.bpo-46070.-axLUW.rst
@@ -0,0 +1,2 @@
+Fix possible segfault when importing the :mod:`asyncio` module from
+different sub-interpreters in parallel. Patch by Erlend E. Aasland.
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index 978a1fd..b08a7d1 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -3318,17 +3318,14 @@ static int
module_init(void)
{
PyObject *module = NULL;
+ if (module_initialized) {
+ return 0;
+ }
asyncio_mod = PyImport_ImportModule("asyncio");
if (asyncio_mod == NULL) {
goto fail;
}
- if (module_initialized != 0) {
- return 0;
- }
- else {
- module_initialized = 1;
- }
current_tasks = PyDict_New();
if (current_tasks == NULL) {
@@ -3389,6 +3386,7 @@ module_init(void)
goto fail;
}
+ module_initialized = 1;
Py_DECREF(module);
return 0;
