TLS callback implementation in C

tls.c

#include <stdio.h>
#include <windows.h>
 
void NTAPI tls_callback(void* DllHandle, DWORD Reason, void* Reserved)
{
        if (Reason == DLL_PROCESS_ATTACH)
        {
                //MessageBox(0, L"Cheguei primeiro! ^^", L"Exemplo de TLS callback", MB_ICONEXCLAMATION);
                HWND hnd;
                ShellExecute(hnd, NULL, L"calc.exe", NULL, NULL, SW_SHOWNORMAL);
                Sleep(1000);
        }
}
 
#pragma comment (linker, "/INCLUDE:__tls_used")
#pragma comment (linker, "/INCLUDE:__xl_b")
 
#pragma data_seg(".CRT$XLB")
EXTERN_C
PIMAGE_TLS_CALLBACK _xl_b = tls_callback;
#pragma data_seg()
 
int main(void)
{
        printf("Eu sou a main! O.o\nwww.mentebinaria.com.br\nPressione ENTER para continuar...");
        (void) getchar();
        return 0;
}