use warnings;

use Inline C => Config =>
     NAME => 'expt',
     BOOT => 
"
  {
  MY_CXT_INIT;
  MY_CXT.count = 5;
  }
",
    BUILD_NOISY => 1,
;

use Inline C => <<'EOC';

#define MY_CXT_KEY "expt::_guts" XS_VERSION

typedef struct {
  int count;
} my_cxt_t;

START_MY_CXT


void set_x(int z) {
   dMY_CXT;
   MY_CXT.count = z;
}

void get_x(char * id) {
   dMY_CXT;
   printf("%s %d\n", id, MY_CXT.count);
}

void CLONE(SV * x, ...) {
   MY_CXT_CLONE;
}

EOC

get_x('1st call:');

if($pid = fork()) {
  waitpid($pid,0);
} else {
  set_x(10);
  get_x('2nd call:');
  exit(0);
}
 
get_x('3rd call:');