Dynamic-linked DLL needs to share a global variable with its caller

I have a static library libStatic that defines a global variable like this

Header file libS开发者_运维技巧tatic/globals.h:

extern int globvar;

Code file libStatic/globals.cpp:

int globvar = 42;

The DLL libDynamic and the executable runner are using this global variable. Furtheron, libDynamic is linked at run-time into runner (via LoadLibrary(), GetProcAddress(), and the works...)

I understand this will lead to globvar being created twice, once in the heap of runner and once in the heap of libDynamic, which is of course very undesirable.

Is there a good away around this? How can I ensure that libDynamic and runner are using the same globvar?

An easy way would be to let the .DLL point to the global variable of the executable. Right after loading you would call a special function inside that library (something like SetGlobVar(int*)). That way the library will always point to the same global variable as the .EXE.