c++memorynew-operatordelete-operatorvirtualalloc

New/delete[] and VirtualAlloc

#include <Windows.h>
#include <iostream>

using namespace std;

int main(void)
{
    unsigned char* pFoo = new unsigned char[1000];

    pFoo = (unsigned char*)VirtualAlloc(NULL, 1000, MEM_COMMIT, PAGE_EXECUTE_READWRITE);

    VirtualFree(pFoo, 0, MEM_RELEASE);

    delete[] pFoo;

    cin.ignore();
    cin.get();

    return 0;
}

This crashes for me at

delete[] pFoo;

I know this is crashing because of VirtualAlloc but I'm not sure how to fix this...

Solution

  • You're using the same variable. So your first allocation gets leaked.

    After you free it with VirtualFree, the pointer is invalid. So delete on it is undefined.

    Furthermore:

    You can't mix VirtualAlloc and delete for the same reason you can't mix malloc with delete.