Hi Folks,

I got an error that drives me crazy because it only occurs sometimes and I
can`t even reproduce it.

I got a __gc class here is it`s header:

#pragma once

#include "../empLib/empImg.h"

namespace empDll
{
    public __gc struct Image {
        int x;
        int y;
        int z;
        float data __gc[];
    };

   public __gc class Imager {
    private:
        char            __nogc *_cfile;
        empImg<float>   __nogc *_img;
    public:
        Imager (System::String *filename);
        ~Imager(void);

        int getDimX ();
        int getDimY ();
        int getDimZ ();

        Image* load (int startPos, int count );
    };

}

and here the code:

#include "Imager.h"
#include "../empLib/empDiscIO.h"

#using <mscorlib.dll>

using namespace System;

namespace empDll {
    Imager::Imager (System::String *filename)  {
        try {
            _cfile = new char [filename->Length];
            memset (_cfile,0, strlen(_cfile));

            for (int i=0; i < filename->Length; i++) {
                _cfile[i] = (char) filename->get_Chars(i);
            }
            _img = new empImg<float>;
        } catch (empError e) {
            e.msg();
        }
    }

    Imager::~Imager(void) {
        delete _img;
        delete _cfile;
    }
   
    int Imager::getDimX () { return _img->dimx();}
    int Imager::getDimY () { return _img->dimy();}
    int Imager::getDimZ () { return _img->dimz();}

    Image* Imager::load (int startPos, int count) {
        try {
            empDiscIO __nogc* imgIO = new empDiscIO(_cfile);
            *_img = imgIO->load(_cfile, startPos, count).normalize(0,255);

            Image *tmp = new Image;

            tmp->data = new float __gc[_img->size()];
            tmp->x = _img->dimx();
            tmp->y = _img->dimy();
            tmp->z = _img->dimz();

            System::Runtime::InteropServices::Marshal::Copy(_img->data, tmp->data, 0  
,_img->size());
            delete imgIO;
            return tmp;
        } catch (empError e) {
            e.msg();
        } catch (...) {
            cout << "ERROR";
        }

    }

}

I use this managed and __gc class from C# in the following way:

public emData(string filename)
{
     empDll.Imager myIo = new empDll.Imager(filename);
     empDll.Image temp = myIo.load(0,0);                                       
     m_dims = new int[3];
     m_dims[0] = temp.x;
     m_dims[1] = temp.y;
     m_dims[2] = temp.z;
     
     m_emData  = new float[m_dims[0]*m_dims[1]*m_dims[2]];
           
     long bytecount = m_dims[0]*m_dims[1]*m_dims[2];
           
     for (long i = 0; i<bytecount; i++) m_emData[i] = temp.data[i];

     myIo = null;
}

When I use the emData Class in C# sometimes it simply works, sometimes i get
an null reference exception when accessing temp.x, temp.y or something else
and sometimes I get a very strange debugging error message:

DAMAGE: after Normal block (#114) at 0x060C5230

and everything crashes.

I assume that somehow memory allocated in the managed C++ DLL is not freeed
or something similar but I have no idea what I am doing wrong isn`t calling
delete enough in this case? Can someone please help me?  Additionally I am
quite sure that I don`t have to loop through arrays and copy them value by
value I am just doing this to make sure this is not the problem here.

Thanks in Advance

Chucker