How to terminate a running compiled library

I used MATLAB compiler (on 2012a) to generate a C++ shared library, from this I'm able to integrate the process in my application, but I need to be able to terminate the process if the user clicks on the "cancel" buttom.

My library is called MSILIB, simple calling:

  MSILIBTerminate();
  mclTerminateApplication();

Does not seams to work and the application hangs. For being able to have the cancel buttom behaviour I`m launching the MATLAB function call from a second thread.