Address reference leak issue (fixes #1029)
Creating an instance of of a pybind11-bound type caused a reference leak in the
associated Python type object, which could prevent these from being collected
upon interpreter shutdown. This commit fixes that issue for all types that are
defined in a scope (e.g. a module). Unscoped anonymous types (e.g. custom
iterator types) always retain a positive reference count to prevent their
collection.
diff --git a/tests/test_class.py b/tests/test_class.py
index b2cc275..ac2a3c0 100644
--- a/tests/test_class.py
+++ b/tests/test_class.py
@@ -202,3 +202,24 @@
a = m.BraceInitialization(123, "test")
assert a.field1 == 123
assert a.field2 == "test"
+
+
+@pytest.unsupported_on_pypy
+def test_class_refcount():
+ """Instances must correctly increase/decrease the reference count of their types (#1029)"""
+ from sys import getrefcount
+
+ class PyDog(m.Dog):
+ pass
+
+ for cls in m.Dog, PyDog:
+ refcount_1 = getrefcount(cls)
+ molly = [cls("Molly") for _ in range(10)]
+ refcount_2 = getrefcount(cls)
+
+ del molly
+ pytest.gc_collect()
+ refcount_3 = getrefcount(cls)
+
+ assert refcount_1 == refcount_3
+ assert refcount_2 > refcount_1