[boost] [boost.python] tons of memory leak on VC 8.0

3 Jul 2006

      Hi,

I've been assessing and learning boost.python (1.33.1). But when I add 
memory leak detection to a small test program (cf. attachment), I found 
tons of memory leaks (about 20 leaks).

Even when the core of the program is only:

	try {
		Py_Initialize();
		object main_module = object( 
handle<>(borrowed(PyImport_AddModule("__main__"))) );
	}

	catch (const error_already_set &)
	{
		PyErr_Print();
	}

	Py_Finalize();

it is still finding some memory leaks.

Am I doing something wrong? Or is this a bug in boost.python?

Tanguy

#include <iostream>
#include <stdexcept>
#include <string>

#include <boost/python.hpp>

#if defined WIN32
#include <crtdbg.h>
#endif

using namespace boost::python;

class telemetry
{
public:

	telemetry()
		: m_Size(666), m_Name("telemetry name") { }

	int size() const { return m_Size; }
	std::string name() const { return m_Name; }

	void resize(int s) { m_Size = s; }
	void rename(const std::string & n) { m_Name = n; }

private:
	int				m_Size;
	std::string		m_Name;
};

const char * const Script =
		"def test_function(): \n"
		"	print 'Python - test_function called correctly' \n"

		"TM = telemetry() \n"

		"print 'Python - TM size: ', TM.size() \n"
		"print 'Python - TM name: ', TM.name() \n"

		"print 'Python - changing TM size/name to 256/plop' \n"
		"TM.resize(256) \n"
		"TM.rename('plop') \n"

		"print 'Python - TM size: ', TM.size() \n"
		"print 'Python - TM name: ', TM.name() \n"

		"print 'Python - SystemTM size: ', SystemTM.size() \n"
		"print 'Python - SystemTM name: ', SystemTM.name() \n"

		"print 'Python - changing SystemTM size/name to 256/plop' \n"
		"SystemTM.resize(256) \n"
		"SystemTM.rename('plop') \n"

		"print 'Python - SystemTM size: ', SystemTM.size() \n"
		"print 'Python - SystemTM name: ', SystemTM.name() \n"
;

int main(int argc, char * argv[])
{
	#if defined WIN32 && ! defined NDEBUG
	#pragma message("NOTE: Advanced Memory Leak Checks Enabled!")

		int flag = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);		// Get current flag
		flag |= _CRTDBG_LEAK_CHECK_DF;						// Turn on leak-checking bit
		flag |= _CRTDBG_CHECK_ALWAYS_DF;					// Turn on CrtCheckMemory 
		_CrtSetDbgFlag(flag);								// Set flag to the new value
		//_CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_WNDW);	// Pop-up an alert window (Otherwise alert are done on the debug output)

		//_CrtSetBreakAlloc(1);

	#endif

	telemetry SystemTM;

	try
	{
		std::cout << "C++ - SystemTM size: " << SystemTM.size() << std::endl;
		std::cout << "C++ - SystemTM name: " << SystemTM.name() << std::endl;

		Py_Initialize();

		object main_module = object( handle<>(borrowed(PyImport_AddModule("__main__"))) );
		object main_namespace = main_module.attr("__dict__");
		object local_namespace = object(handle<>(PyDict_New()));

		main_namespace["telemetry"] = class_<telemetry>("telemetry")
				.def("size", &telemetry::size)
				.def("name", &telemetry::name)
				.def("resize", &telemetry::resize)
				.def("rename", &telemetry::rename);

		main_namespace["SystemTM"] = ptr(&SystemTM);

		// compile the python script, but do not execute it
		object compiled_code(
			handle<>(
				Py_CompileString(
						Script,
						"main.cpp.py",
						Py_file_input
				)
			)
		);

		// execute the pre-compiled python script
		{ handle<> ignore(
			PyEval_EvalCode(
					(PyCodeObject *) compiled_code.ptr(),
					main_namespace.ptr(),
					local_namespace.ptr()
			)
		); }

		// execute a specific inline script on the local store of previous script
		{ handle<> ignore(
			PyRun_String(
					"print 'Python - Local Namespace: TM.name() =', TM.name() \n"
					"test_function() \n",
					Py_file_input,
					main_namespace.ptr(),
					local_namespace.ptr()
			)
		); }

		// memory leak test
		//for (;;)
		//	handle<> ignore(PyRun_String("", Py_file_input, main_namespace.ptr(), local_namespace.ptr()));

		std::cout << "C++ - SystemTM size: " << SystemTM.size() << std::endl;
		std::cout << "C++ - SystemTM name: " << SystemTM.name() << std::endl;
	}

	catch (const error_already_set &)
	{
		PyErr_Print();
	}

	catch (const std::exception & Error)
	{
		std::cerr << "ERROR: " << Error.what() << std::endl;
	}

	Py_Finalize();
}

[boost] [boost.python] tons of memory leak on VC 8.0

Tanguy Fautre