Convert the internal ctypes array type cache to a WeakValueDict so
that array types do not live longer than needed.
diff --git a/Lib/ctypes/test/test_arrays.py b/Lib/ctypes/test/test_arrays.py
index e635ae1..7ee16c1 100644
--- a/Lib/ctypes/test/test_arrays.py
+++ b/Lib/ctypes/test/test_arrays.py
@@ -116,5 +116,19 @@
self.failUnlessEqual(sz[1:4:2], "o")
self.failUnlessEqual(sz.value, "foo")
+ def test_cache(self):
+ # Array types are cached internally in the _ctypes extension,
+ # in a WeakValueDictionary. Make sure the array type is
+ # removed from the cache when the itemtype goes away. This
+ # test will not fail, but will show a leak in the testsuite.
+
+ # Create a new type:
+ class my_int(c_int):
+ pass
+ # Create a new array type based on it:
+ t1 = my_int * 1
+ t2 = my_int * 1
+ self.failUnless(t1 is t2)
+
if __name__ == '__main__':
unittest.main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 0be1934..0a7d00c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -364,6 +364,9 @@
Library
-------
+- Convert the internal ctypes array type cache to a WeakValueDict so
+ that array types do not live longer than needed.
+
- Issue #1786: pdb should use its own stdin/stdout around an exec call
and when creating a recursive instance.
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 9d7290f..1ff8e12 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -127,6 +127,7 @@
PyObject *PyExc_ArgError;
static PyTypeObject Simple_Type;
+PyObject *array_types_cache;
char *conversion_mode_encoding = NULL;
char *conversion_mode_errors = NULL;
@@ -4086,16 +4087,10 @@
PyObject *
CreateArrayType(PyObject *itemtype, Py_ssize_t length)
{
- static PyObject *cache;
PyObject *key;
PyObject *result;
char name[256];
- if (cache == NULL) {
- cache = PyDict_New();
- if (cache == NULL)
- return NULL;
- }
#if (PY_VERSION_HEX < 0x02050000)
key = Py_BuildValue("(Oi)", itemtype, length);
#else
@@ -4103,12 +4098,12 @@
#endif
if (!key)
return NULL;
- result = PyDict_GetItem(cache, key);
+ result = PyObject_GetItem(array_types_cache, key);
if (result) {
- Py_INCREF(result);
Py_DECREF(key);
return result;
- }
+ } else
+ PyErr_Clear();
if (!PyType_Check(itemtype)) {
PyErr_SetString(PyExc_TypeError,
@@ -4138,7 +4133,11 @@
);
if (!result)
return NULL;
- PyDict_SetItem(cache, key, result);
+ if (-1 == PyObject_SetItem(array_types_cache, key, result)) {
+ Py_DECREF(key);
+ Py_DECREF(result);
+ return NULL;
+ }
Py_DECREF(key);
return result;
}
@@ -4951,6 +4950,7 @@
init_ctypes(void)
{
PyObject *m;
+ PyObject *weakref;
/* Note:
ob_type is the metatype (the 'type'), defaults to PyType_Type,
@@ -4963,6 +4963,16 @@
if (!m)
return;
+ weakref = PyImport_ImportModule("weakref");
+ if (weakref == NULL)
+ return;
+ array_types_cache = PyObject_CallMethod(weakref,
+ "WeakValueDictionary",
+ NULL);
+ if (array_types_cache == NULL)
+ return;
+ Py_DECREF(weakref);
+
if (PyType_Ready(&PyCArg_Type) < 0)
return;