kilpatds/pluginframework

A simple C++ framework for Plugins (interface + factory) loadable from shared libraries

pluginframework's Issues

Does my code have some problems?

Hi, there.

I'm use your Plugin Framework code to study c++ skill.

Below is my test code: main.cpp

#include <iostream>
#include <string>
#include <map>

class IPrint
{
public:
	virtual ~IPrint(){}

	virtual void print() = 0;
};

template <typename T, typename ...T1>
class TemplateClass:public T
{
public:
	typedef T *(*class_t)(T1...);
	typedef std::map<int, class_t> map_int_t;


	virtual ~TemplateClass(){}

	static int Set(int a, class_t b);

	static T* Get(int a, T1... args);

	static void dump();
private:
	static map_int_t mMapIntContainer;
};

template <typename T, typename ...T1>
typename TemplateClass<T,T1...>::map_int_t TemplateClass<T,T1...>::mMapIntContainer;

template <typename T, typename ...T1>
int TemplateClass<T, T1...>::Set(int a, class_t b)
{
	/*test creation*/
	//T* test = b();
	//delete test;
	std::cout << "create:" << a << std::endl;
	std::cout << "map_size:" << mMapIntContainer.size() << std::endl;
	//mMapIntContainer.insert(std::make_pair(a, b)); // @FixMe: if insert anything will be crashed immediately.
	return 0;
}

template <typename T, typename ... T1>
T* TemplateClass<T, T1...>::Get(int a, T1 ... args)
{
	std::cout << "query:" << a << std::endl;
	std::cout << "map_size:" << mMapIntContainer.size() << std::endl;
	auto it = mMapIntContainer.find(a);
	if(it!=mMapIntContainer.end())
	{
		std::cout << "Find*" << std::endl;
		return (it->second)(args...);
	}
	return nullptr;
}


template <typename T, typename ...T1>
void TemplateClass<T, T1...>::dump()
{
	for(auto s :mMapIntContainer)
	{
		std::cout << s.first << ", " << s.second << std::endl;
	}

}
static int count = 0;
template <typename T, typename T1, typename ...T2>
class StaticReg
{
public:
	static T* factory(T2 ... args)
	{
		std::cout << "sublcass creation" << std::endl;
		return new T1(args...);
	}

	StaticReg(){
		std::cout << "StaticReg::StaticReg" << std::endl;
		std::cout << typeid(T).name() << std::endl;
		TemplateClass<T, T2...>::Set(++count, factory);
		std::cout << "count:" << count << std::endl;
	}
};

template <typename T, typename T1, typename ...T2>
class RealTemplateClass: public TemplateClass<T,T2...>
{
public:
	RealTemplateClass(){}
	static StaticReg<T, T1, T2...> hold_obj;
};

template<typename T, typename T1, typename ...T2>
StaticReg<T, T1, T2...> RealTemplateClass<T, T1, T2...>::hold_obj;

class APrint:public RealTemplateClass<IPrint, APrint>
{
public:
	APrint() { std::cout << "APrint:construct" << std::endl; }
	virtual ~APrint(){}

	void print()
	{
		std::cout << "APrint::print" << std::endl;

	}
};

template class RealTemplateClass<IPrint, APrint>;

class BPrint:public TemplateClass<IPrint, BPrint>
{
public:
	BPrint(){std::cout << "BPrint:construct" << std::endl;}
	virtual ~BPrint(){}
	void print()
	{
		std::cout << "BPrint:print" << std::endl;
	}
};

template class RealTemplateClass<IPrint, BPrint>;

int main()
{
	IPrint* aa_ptr = TemplateClass<IPrint>::Get(1);  // return new APrint();
	if(aa_ptr!=nullptr)
	{
		//APrint* a = dynamic_cast<APrint*>(aa_ptr);
		aa_ptr->print();
		delete aa_ptr;
		aa_ptr = nullptr;
	}
	IPrint* bb_ptr = TemplateClass<IPrint>::Get(2);  // return new BPrint();
	if(bb_ptr!=nullptr)
	{
		//BPrint* b = dynamic_cast<BPrint*>(bb_ptr);
		bb_ptr->print();
		delete bb_ptr;
		bb_ptr = nullptr;
	}
	return 0;
}

When i debug this code in VS 2015 x64.

The debugger tell me :

Line 43:mMapIntContainer.insert(std::make_pair(a, b));

Exception thrown: read access violation.
std::_Tree<std::_Tmap_traits<int,IPrint * __ptr64 (__cdecl*)(void),std::less<int>,std::allocator<std::pair<int const ,IPrint * __ptr64 (__cdecl*)(void)> >,0> >::_Root(...) returned 0x8.

Perhaps it is the std::map container is not initialize?

Can you help me fix this problem? Thanks.

Loading modules.

Hello!
How to load multiple modules?
Thanks!

Can I get this under BSD license?

Crash when requested type wrong, instead of exception

If the plugin declares the wrong types (like to the constructor), the loader crashes in dlopen() as the init object attempts to add an entry to a set that doesn't exist. That shouldn't crash (the set should exist). Weak symbols?