PEP 489: Multi-phase extension module initialization
Known limitations of the current implementation:
- documentation changes are incomplete
- there's a reference leak I haven't tracked down yet
The leak is most visible by running:
./python -m test -R3:3 test_importlib
However, you can also see it by running:
./python -X showrefcount
Importing the array or _testmultiphase modules, and
then deleting them from both sys.modules and the local
namespace shows significant increases in the total
number of active references each cycle. By contrast,
with _testcapi (which continues to use single-phase
initialisation) the global refcounts stabilise after
a couple of cycles.
diff --git a/Python/dynload_dl.c b/Python/dynload_dl.c
index 5836cb3b..d235a84 100644
--- a/Python/dynload_dl.c
+++ b/Python/dynload_dl.c
@@ -12,11 +12,12 @@
const char *_PyImport_DynLoadFiletab[] = {".o", NULL};
-dl_funcptr _PyImport_GetDynLoadFunc(const char *shortname,
- const char *pathname, FILE *fp)
+dl_funcptr _PyImport_FindSharedFuncptr(const char *prefix,
+ const char *shortname,
+ const char *pathname, FILE *fp)
{
char funcname[258];
- PyOS_snprintf(funcname, sizeof(funcname), "PyInit_%.200s", shortname);
+ PyOS_snprintf(funcname, sizeof(funcname), "%20s_%.200s", prefix, shortname);
return dl_loadmod(Py_GetProgramName(), pathname, funcname);
}