Qsharedmemory problem

stima_ua

I wont to write some bridg dll. My Code is:
@
/*************
bridg.dll
************/
//sharedobject.h

#ifndef SHAREDOBJECT
#define SHAREDOBJECT

class ISharedObject {
public:
virtual void set(int data) = 0;
virtual int get() const = 0;
virtual ~ISharedObject() {}
};

class SharedObject : public ISharedObject {

public:
SharedObject() : data(-1) {}

void set(int data) { this->data = data; }
int get() const { return data; }

private:
int data;
};

#endif //SHAREDOBJECT

//main

#include <QSharedMemory>
#include "sharedobject.h"
#include "SLogger.h"

static QSharedMemory* sharedMemory = NULL;

const char* slogger::fileName = "bridg.log";

extern "C" __declspec(dllexport) bool createSharedMemory(const char* key)
{
DEBUG() << "Key is: " << key;
sharedMemory = new QSharedMemory(key);

if ( !sharedMemory->create(sizeof(SharedObject)) ) return false;

SharedObject *obj = new SharedObject();
SharedObject sharedObj = (SharedObject) sharedMemory->data();
DEBUG() << "Shared instance pointer: " << std::hex << obj;
DEBUG() << "Data pointer: " << std::hex << sharedObj;

memcpy(sharedObj, obj, sizeof(SharedObject));

return true; //all is normal
}

extern "C" __declspec(dllexport) bool destroySharedMemory()
{
if ( sharedMemory->detach() )
{
delete sharedMemory;
return true;
}

return false;
}

extern "C" __declspec(dllexport) ISharedObject* getSharedObject(const char* key)
{
DEBUG() << "Key is: " << key; //key is valid

QSharedMemory sm(key);

if ( !sm.attach() ) return NULL; //attach is ok

ISharedObject obj = (ISharedObject)sm.data(); //<--- this local sm return invalid(another) pointer
//ISharedObject obj = (ISharedObject)sharedMemory->data(); //<--- but global shared memory return valid pointer
DEBUG() << "Shared instance " << std::hex << obj;

return obj;
}

/*************
wincons.exe //my test
*************/
#include <windows.h>
#include <iostream>

class ISharedObject {
public:
virtual void set(int data) = 0;
virtual int get() const = 0;
virtual ~ISharedObject() {}
};

typedef bool (FCreate)(const char);
typedef bool (FDestroy)();
typedef ISharedObject (FGet)(const char);

static const char* key = "test";

int main()
{
HINSTANCE dll = LoadLibrary(L"bridg.dll");

if ( dll )
{
FCreate _create = (FCreate)GetProcAddress(dll, "createSharedMemory");
FDestroy _destroy = (FDestroy)GetProcAddress(dll, "destroySharedMemory");
FGet _get = (FGet) GetProcAddress(dll, "getSharedObject");

if ( _create )
{
bool ret = _create(key);

if ( ret )
{
ISharedObject* obj = _get(key);

if ( obj ) // <---object is invalid (!!but not NULL)
{
 //obj->set(42);
 //std::cout << "Data: " << obj->get() << std::endl;
} else std::cout << "Can not get shared instance." << std::endl;

}
else std::cout << "Can not get create shared memory. Error: " << GetLastError() << std::endl;
}
else std::cout << "Can not get create function pointer. Error: " << GetLastError() << std::endl;

FreeLibrary(dll);
}
else std::cout << "Can not load lybrary. Error: " << GetLastError() << std::endl;

std::getchar();
return 0;
}
@

What i doing wrong?

andre

Sorry, we're not here to debug your code. You're not even describing your symptoms...