#XS
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "unistd.h"
 
MODULE = TestMemXS              PACKAGE = TestMemXS
 
 
void
_test( yp )
         char * yp
 
   CODE:
{
  double * ya;
 
  ya = (double *) yp;
 
  sleep( 1000 );
}
-------------------
#testMemXS.pm
....
sub testMem{
  my $str = "\000" x 50e6;
  _test( $str );
}
....
-------------------
perl -MTestMemXS -e 'testMem()'