Fix: implement trivial destructors for static PyObject unique pointers to avoid invalid memory access on exit

src/clp_ffi_py/PyObjectUtils.hpp

@@ -18,12 +18,37 @@ class PyObjectDeleter {
     void operator()(PyObjectType* ptr) { Py_XDECREF(reinterpret_cast<PyObject*>(ptr)); }
 };
 
+/**
+ * An empty deleter that has an empty implementation to ensure object trivial
+ * destruction.
+ * @tparam PyObjectType
+ */
+template <typename PyObjectType>
+class PyObjectTrivialDeleter {
+public:
+    void operator()(PyObjectType* ptr) {}
+};
+
 /**
  * A type of smart pointer that maintains a reference to a Python object for the
  * duration of its lifetime.
  * @tparam PyObjectType
  */
 template <typename PyObjectType>
 using PyObjectPtr = std::unique_ptr<PyObjectType, PyObjectDeleter<PyObjectType>>;
+
+/**
+ * A smart pointer to be used for raw Python object pointers that have static
+ * storage duration. It holds a reference of the underlying Python object.
+ * Compared to PyObjectPtr, when destructed, this smart pointer does not
+ * decrease the reference count of the contained Python object. Since this
+ * pointer has static storage duration, it's possible that the Python
+ * interpreter exits before this pointer's destructor is called; attempting to
+ * decrement the reference count (maintained by the interpreter) in this
+ * situation would lead to undefined behaviour.
+ * @tparam PyObjectType
+ */
+template <typename PyObjectType>
+using PyObjectStaticPtr = std::unique_ptr<PyObjectType, PyObjectTrivialDeleter<PyObjectType>>;
 }  // namespace clp_ffi_py
 #endif  // CLP_FFI_PY_PY_OBJECT_PTR_HPP

src/clp_ffi_py/Py_utils.cpp

@@ -7,10 +7,10 @@
 namespace clp_ffi_py {
 namespace {
 constexpr char const* const cPyFuncNameGetFormattedTimestamp{"get_formatted_timestamp"};
-PyObjectPtr<PyObject> Py_func_get_formatted_timestamp;
+PyObjectStaticPtr<PyObject> Py_func_get_formatted_timestamp{nullptr};
 
 constexpr char const* const cPyFuncNameGetTimezoneFromTimezoneId{"get_timezone_from_timezone_id"};
-PyObjectPtr<PyObject> Py_func_get_timezone_from_timezone_id;
+PyObjectStaticPtr<PyObject> Py_func_get_timezone_from_timezone_id{nullptr};
 
 /**
  * Wrapper of PyObject_CallObject.

src/clp_ffi_py/ir/native/PyDecoder.cpp

@@ -86,7 +86,7 @@ PyType_Spec PyDecoder_type_spec{
 };
 }  // namespace
 
-PyObjectPtr<PyTypeObject> PyDecoder::m_py_type{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyDecoder::m_py_type{nullptr};
 
 auto PyDecoder::module_level_init(PyObject* py_module) -> bool {
     static_assert(std::is_trivially_destructible<PyDecoder>());

src/clp_ffi_py/ir/native/PyDecoder.hpp

@@ -25,7 +25,7 @@ class PyDecoder {
 private:
     PyObject_HEAD;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
 };
 }  // namespace clp_ffi_py::ir::native
 

src/clp_ffi_py/ir/native/PyDecoderBuffer.cpp

@@ -350,8 +350,8 @@ auto PyDecoderBuffer::test_streaming(uint32_t seed) -> PyObject* {
     );
 }
 
-PyObjectPtr<PyTypeObject> PyDecoderBuffer::m_py_type{nullptr};
-PyObjectPtr<PyObject> PyDecoderBuffer::m_py_incomplete_stream_error{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyDecoderBuffer::m_py_type{nullptr};
+PyObjectStaticPtr<PyObject> PyDecoderBuffer::m_py_incomplete_stream_error{nullptr};
 
 auto PyDecoderBuffer::get_py_type() -> PyTypeObject* {
     return m_py_type.get();

src/clp_ffi_py/ir/native/PyDecoderBuffer.hpp

@@ -221,8 +221,8 @@ class PyDecoderBuffer {
     size_t m_num_decoded_message;
     bool m_py_buffer_protocol_enabled;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
-    static PyObjectPtr<PyObject> m_py_incomplete_stream_error;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyObject> m_py_incomplete_stream_error;
 };
 }  // namespace clp_ffi_py::ir::native
 #endif

src/clp_ffi_py/ir/native/PyFourByteEncoder.cpp

@@ -129,7 +129,7 @@ PyType_Spec PyFourByteEncoder_type_spec{
 };
 }  // namespace
 
-PyObjectPtr<PyTypeObject> PyFourByteEncoder::m_py_type{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyFourByteEncoder::m_py_type{nullptr};
 
 auto PyFourByteEncoder::module_level_init(PyObject* py_module) -> bool {
     static_assert(std::is_trivially_destructible<PyFourByteEncoder>());

src/clp_ffi_py/ir/native/PyFourByteEncoder.hpp

@@ -26,7 +26,7 @@ class PyFourByteEncoder {
 private:
     PyObject_HEAD;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
 };
 }  // namespace clp_ffi_py::ir::native
 #endif

src/clp_ffi_py/ir/native/PyLogEvent.cpp

@@ -486,7 +486,7 @@ auto PyLogEvent::init(
     return true;
 }
 
-PyObjectPtr<PyTypeObject> PyLogEvent::m_py_type{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyLogEvent::m_py_type{nullptr};
 
 auto PyLogEvent::get_py_type() -> PyTypeObject* {
     return m_py_type.get();

src/clp_ffi_py/ir/native/PyLogEvent.hpp

@@ -144,7 +144,7 @@ class PyLogEvent {
     LogEvent* m_log_event;
     PyMetadata* m_py_metadata;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
 };
 }  // namespace clp_ffi_py::ir::native
 #endif  // CLP_FFI_PY_PY_LOG_EVENT_HPP

src/clp_ffi_py/ir/native/PyMetadata.cpp

@@ -263,7 +263,7 @@ auto PyMetadata::init_py_timezone() -> bool {
     return true;
 }
 
-PyObjectPtr<PyTypeObject> PyMetadata::m_py_type{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyMetadata::m_py_type{nullptr};
 
 auto PyMetadata::get_py_type() -> PyTypeObject* {
     return m_py_type.get();

src/clp_ffi_py/ir/native/PyMetadata.hpp

@@ -117,7 +117,7 @@ class PyMetadata {
     Metadata* m_metadata;
     PyObject* m_py_timezone;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
 };
 }  // namespace clp_ffi_py::ir::native
 #endif  // CLP_FFI_PY_PY_METADATA_HPP

src/clp_ffi_py/ir/native/PyQuery.cpp

@@ -636,8 +636,8 @@ auto PyQuery::init(
     return true;
 }
 
-PyObjectPtr<PyTypeObject> PyQuery::m_py_type{nullptr};
-PyObjectPtr<PyObject> PyQuery::m_py_wildcard_query_type{nullptr};
+PyObjectStaticPtr<PyTypeObject> PyQuery::m_py_type{nullptr};
+PyObjectStaticPtr<PyObject> PyQuery::m_py_wildcard_query_type{nullptr};
 
 auto PyQuery::get_py_type() -> PyTypeObject* {
     return m_py_type.get();

src/clp_ffi_py/ir/native/PyQuery.hpp

@@ -80,8 +80,8 @@ class PyQuery {
     PyObject_HEAD;
     Query* m_query;
 
-    static PyObjectPtr<PyTypeObject> m_py_type;
-    static PyObjectPtr<PyObject> m_py_wildcard_query_type;
+    static PyObjectStaticPtr<PyTypeObject> m_py_type;
+    static PyObjectStaticPtr<PyObject> m_py_wildcard_query_type;
 };
 }  // namespace clp_ffi_py::ir::native
 #endif