“Private Bytes” doesn't reflect it. How to find exact memory allocated by process?

Question

Here is sample piece of C++ code compiled and run using VS2010 on Windows XP.

It prints \"private bytes\" before and after allocation.

void PrintPri         


        

Answer 1

Your solution of checking the private bytes is correct, only your assumption about _heapmin is wrong.

_heapmin does not work as documented. _heapmin is documented as "Releases unused heap memory to the operating system."

The implementation (see "\Program Files (x86)\Microsoft Visual Studio 10.0\VC\crt\src\heapmin.c") is

int __cdecl _heapmin(void)
{
        if ( HeapCompact( _crtheap, 0 ) == 0 ) {
            return -1;
        }
        else {
            return 0;
        }
}

HeapCompact is documented to normally do quite nothing despite returning the size of the largest free block in the heap. It only does some extra stuff if a special global (debug purpose) flag is used.