memory allocation class

Hi.
I made this class, to emulate segment/offset based memory.
it isn't allowed to allocate less then full segment.

Anyway, it seems to be working fine, but somethimes it crashes, i don't know why.......

Please look at my code, and give any comments you can...

Code:

---

#include <stdio.h>
#include <iostream.h>
#include <mem.h>
#include <alloc.h>

#define MAX_SEGMENTS 10

class cMem
{
    private:
        int *mem[MAX_SEGMENTS];
        int IsAllocated[MAX_SEGMENTS];
        int size;  // segment size
    public:
    cMem(int Size);
    ~cMem();
    int* Save(int Seg, int Offset, const int* Data, size_t n);
    int* Load(int Seg, int Offset);
};

cMem::cMem(int Size)
        { int i;
        size=Size;
        for(i=0;i<MAX_SEGMENTS;i++) IsAllocated[i]=0;
        }

cMem::~cMem()
        {
        int i;
        for(i=0;i<MAX_SEGMENTS;i++)
                if(IsAllocated[i])
                        free(mem[i]);
        }

int* cMem::Load(int Seg, int Offset)
{
return mem[Seg]+Offset;
}


int* cMem::Save(int Seg, int Offset, const int* Data, size_t n)
{
if(!IsAllocated[Seg])
        {
        mem[Seg]=(int*)malloc(size);
        IsAllocated[Seg]=1;
        }
return (int*)memcpy(mem[Seg]+Offset, Data, n*sizeof(int));
}

//This is just a main to check the class.
int main(int argc, char* argv[])
{
class cMem Mem(32);
int x[10]={9,8,7,6,5,4,3,2,1,0};
const int *ptr;
int i;
cout << "\n----------\n";
Mem.Save(1, 12, x, 10);
ptr=Mem.Load(1, 12);
for(i=0;i<10;i++) cout << ptr[i] << " ";
return 0;
}

---

this is the code - i compile it with Borland C++ 3.11 in dos enviroment.

Thanks in advance.

I'm not sure what you're doing, but then I'm not sure what I'm doing either, but I did find a problem. It was having problems freeing memory in the destructor because of below.

Code:

---

int* cMem::Save(int Seg, int Offset, const int* Data, size_t n)
{
      if(!IsAllocated[Seg])
      {
          mem[Seg]=(int*)malloc(size); // allocates 32 bytes   
          IsAllocated[Seg]=1;
      }
     
      return (int*)memcpy(mem[Seg]+Offset, Data, n*sizeof(int));  //copies 10 * 4 (n*sizeof(int) = 40 bytes
        and it copies starting  12 past the allocation location
}

mem[Seg]=(int*)malloc(size);
to
mem[Seg]=(int*)malloc(size * sizeof(int)); 32 * 4 = 128
Don't know why I used that size but its big enough to cover the copy

---

also changed the constructor declaration so you can instaniate the object as follows cMem t; This will create a cMem object size = 32, the default which is established in the constructor declaration.

cMem(int Size);

to

cMem(int Size = 32);

i dont want to use a default segment size, but you are right about the allocation size - how could i miss that...

thanks.