void SWIG_Wrap_callback(int event, tMy_MSG *p_data)
{
      printf("entering perl callback handler...\n");
      dTHX;  /*Not sure this is needed, but doesnt make any difference */
      if ( my_perl != NULL )
         printf ("my_perl == %ul\n", my_perl);
      else
         printf ("my_perl == NULL\n");  /* This line is printed*/

      PERL_SET_CONTEXT(my_perl); /* Not sure this is needed, but tried in vain */

      printf("dTHX done...\n");
      dSP;  /* Crashes here */

      printf("Destruct level : %d...\n", PL_perl_destruct_level);  /* "0" (ZERO) is printed under the scenario where callback invokation works.  Does it mean perl is not built correctly per my needs?? */

      printf("DSP done...\n");
      SV * sv = bsa_perl_disc_callback;
      if (sv == (SV*)NULL)
         croak("Internal error...\n");

      printf("Preparing to call perl callback...\n");
      PUSHMARK(SP);
      XPUSHs(sv_2mortal(newSViv(event)));
      printf("newSViv of %d done...\n", event);
      XPUSHs(SWIG_NewPointerObj(SWIG_as_voidptr(p_data), SWIGTYPE_p_tMy_MSG, SWIG_SHADOW));
      printf("newSVsv...\n");
      PUTBACK;

      printf("calling the Perl sub...\n");
      /* Call the Perl sub */
      call_sv(sv, G_DISCARD);
      printf("Perl sub completed successfully...\n");
}