Data between executables (ANSI C, MFC 4.1)

Question

Hi all,

I have a structure and a member of it is char* * (2d pointer). I allocate space from EXE1 and call EXE2 with the data. I use memcpy to get all data on EXE2. The memory address on both EXE is the same (lets say 0x013740b0), though the data of char** on EXE2 are not present. How can I retrieve the data on EXE2?

Thanks in advance, SunScreen

Answer 1

You can not share pointers like that as each exe is having its own virtual address space and whatever address you are seeing is not a physical address, it is virtual address. This virtual address will be translated into different physical addresses in different exes. You can use shared memory to share the data between different processes.

Answer 2

I think you can not refer to anoher memory address in another executable directly, if you want this behaviour you have to make shared dll and put your structure in a shared place

Answer 3

Naveen is correct.

You can try something like this:

  HGLOBAL hglbBuf = GlobalAlloc(GMEM_MOVEABLE, buffer_size);
  if (  hglbBuf == NULL  ) {
    // ...
    return;
  }

  /* do something with the buffer */
  void* buf = (void*)GlobalLock(hglbBuf);
  // ...
  GlobalUnlock(hglbBuf);