dynamicloader.hpp

#ifndef DYNAMICLOADER_H
#define DYNAMICLOADER_H
 
#include <dlfcn.h>
 
#include <string>
 
#include "debugprint.hpp"
 
 
class DynamicLoader
{
public:
    DynamicLoader( const std::string& dynamic_object_path ) {
        int FLAGS = RTLD_NOW | RTLD_GLOBAL;
        //    int FLAGS = RTLD_LAZY | RTLD_GLOBAL;
        _lib_handle = dlopen( dynamic_object_path.c_str(), FLAGS );
 
        if ( _lib_handle != nullptr )
        {   // Clear loader errors:
            dlerror();
        }
        else
            DebugPrint() << "Unable to load dynamic object: " << dynamic_object_path << " - '" << dlerror() << "'";
    }
 
    virtual ~DynamicLoader() {
        if ( _lib_handle != nullptr )
        {
            if ( _lib_handle != nullptr )
                dlclose( _lib_handle );
            _lib_handle = nullptr;
        }
    }
 
    template<typename T>
    T getSymbol( const std::string& symbol_name ) {
        return T( _getSymbol( symbol_name ) );
    }

    bool isLoaded() const {
        return _lib_handle != nullptr;
    }
 
private:
    void* _getSymbol( const std::string& symbol_name ) const {
        if ( _lib_handle == nullptr )
        {
            DebugPrint() << "Cannot to load symbol'" << symbol_name << "' if the dynamic object is not open.";
            return nullptr;
        }
 
        // clear errors...
        dlerror();
        void* ret = dlsym( _lib_handle, symbol_name.c_str());
        if ( ret == NULL )
            DebugPrint() << "Unable to load symbol'" << symbol_name << "'.";
        return ret;
    }
 
    void* _lib_handle;
 
};
 
#endif // DYNAMICLOADER_H