Charles Waldman writes:
"""
Running "test_extcall" repeatedly results in memory leaks.
One of these can't be fixed (at least not easily!), it happens since
this code:
def saboteur(**kw):
kw['x'] = locals()
d = {}
saboteur(a=1, **d)
creates a circular reference - d['x']['d']==d
The others are due to some missing decrefs in ceval.c, fixed by the
patch attached below.
Note: I originally wrote this without the "goto", just adding the
missing decref's where needed. But I think the goto is justified in
keeping the executable code size of ceval as small as possible.
"""
[I think the circular reference is more like kw['x']['kw'] == kw. --GvR]
diff --git a/Python/ceval.c b/Python/ceval.c
index 989e17f..d0958bd 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1623,8 +1623,7 @@
if (!PyDict_Check(kwdict)) {
PyErr_SetString(PyExc_TypeError,
"** argument must be a dictionary");
- x = NULL;
- break;
+ goto extcall_fail;
}
}
if (flags & 1) {
@@ -1632,39 +1631,34 @@
if (!PySequence_Check(stararg)) {
PyErr_SetString(PyExc_TypeError,
"* argument must be a sequence");
- x = NULL;
- break;
+ goto extcall_fail;
}
/* Convert abstract sequence to concrete tuple */
if (!PyTuple_Check(stararg)) {
PyObject *t = NULL;
t = PySequence_Tuple(stararg);
if (t == NULL) {
- x = NULL;
- break;
+ goto extcall_fail;
}
Py_DECREF(stararg);
stararg = t;
}
nstar = PyTuple_GET_SIZE(stararg);
if (nstar < 0) {
- x = NULL;
- break;
+ goto extcall_fail;
}
}
if (nk > 0) {
if (kwdict == NULL) {
kwdict = PyDict_New();
if (kwdict == NULL) {
- x = NULL;
- break;
+ goto extcall_fail;
}
}
else {
PyObject *d = PyDict_Copy(kwdict);
if (d == NULL) {
- x = NULL;
- break;
+ goto extcall_fail;
}
Py_DECREF(kwdict);
kwdict = d;
@@ -1680,7 +1674,7 @@
PyString_AsString(key));
Py_DECREF(key);
Py_DECREF(value);
- break;
+ goto extcall_fail;
}
err = PyDict_SetItem(kwdict, key, value);
Py_DECREF(key);
@@ -1689,7 +1683,11 @@
break;
}
if (err) {
- Py_DECREF(kwdict);
+ extcall_fail:
+ Py_XDECREF(kwdict);
+ Py_XDECREF(stararg);
+ Py_DECREF(func);
+ x=NULL;
break;
}
}
@@ -2382,6 +2380,7 @@
if (kw != NULL && !PyDict_Check(kw)) {
PyErr_SetString(PyExc_TypeError,
"keyword list must be a dictionary");
+ Py_DECREF(arg);
return NULL;
}