TAmPluginTemplate.h

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#ifndef PLUGINTEMPLATE_H_
#define PLUGINTEMPLATE_H_

#include <dlfcn.h>
#include <libgen.h>
#include "CAmDltWrapper.h"

namespace am
{

template<class T> T* getCreateFunction(const std::string& libname, void*& libraryHandle)
{

    logInfo("getCreateFunction : Trying to load library with name: ",libname);

    // cut off directories
    char* fileWithPath = const_cast<char*>(libname.c_str());
    std::string libFileName = basename(fileWithPath);

    // cut off "lib" in front and cut off .so end"
    std::string createFunctionName = libFileName.substr(3, libFileName.length() - 6) + "Factory";
    // open library
    dlerror(); // Clear any existing error
    libraryHandle = dlopen(libname.c_str(), RTLD_LAZY );
    const char* dlopen_error = dlerror();
    if (!libraryHandle || dlopen_error)
    {
        logError("getCreateFunction : dlopen failed",dlopen_error);
        return (0);
    }

    // get entry point from shared lib
    dlerror(); // Clear any existing error

    union
    {
        void* voidPointer;
        T* typedPointer;
    } functionPointer;

    // Note: direct cast is not allowed by ISO C++. e.g.
    // T* createFunction = reinterpret_cast<T*>(dlsym(libraryHandle, createFunctionName.c_str()));
    // compiler warning: "forbids casting between pointer-to-function and pointer-to-object"

    functionPointer.voidPointer = dlsym(libraryHandle, createFunctionName.c_str());
    T* createFunction = functionPointer.typedPointer;

    const char* dlsym_error = dlerror();
    if (!createFunction || dlsym_error)
    {
        logError("getCreateFunction: Failed to load shared lib entry point",dlsym_error);
    }
    else
    {
        logInfo("getCreateFunction : loaded successfully plugin", createFunctionName);
    }
    return (createFunction);
}

template<class T> T* getDestroyFunction(const std::string& libname,void* libraryHandle)
{
    logInfo("destroy : Trying to destroy : ",libname);

    // cut off directories
    char* fileWithPath = const_cast<char*>(libname.c_str());
    std::string libFileName = basename(fileWithPath);

    // cut off "lib" in front and cut off .so end"
    std::string destroyFunctionName = "destroy" + libFileName.substr(3, libFileName.length() - 6);

    // get entry point from shared lib
    dlerror(); // Clear any existing error
    union
    {
        void* voidPointer;
        T* typedPointer;
    } functionPointer;

    functionPointer.voidPointer = dlsym(libraryHandle, destroyFunctionName.c_str());
    T* destroyFunction = functionPointer.typedPointer;

    const char* dlsym_error = dlerror();
    if (!destroyFunction || dlsym_error)
    {
        logError("getDestroyFunction: Failed to load shared lib entry point function name=",
                                            destroyFunctionName, "error=",dlsym_error);
    }
    else
    {
        logInfo("getDestroyFunction: loaded successfully plugin", destroyFunctionName);
    }
    return (destroyFunction);
}

}

#endif /* PLUGINTEMPLATE_H_ */