#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <limits.h>

typedef struct FSM_WRAPPER
{
  struct FSM_WRAPPER *(*NextState)(struct FSM_WRAPPER *);
} FSM_WRAPPER;


FSM_WRAPPER *foo(FSM_WRAPPER *);
FSM_WRAPPER *bar(FSM_WRAPPER *);
FSM_WRAPPER *baz(FSM_WRAPPER *);

FSM_WRAPPER *foo(FSM_WRAPPER *f)
{
  printf("I'm foo().\n");
  if(rand() % 4 == 0)
  {
    f->NextState = bar;
  }
  else
  {
    f->NextState = baz;
  }
  return f;
}

FSM_WRAPPER *bar(FSM_WRAPPER *f)
{
  printf("I'm bar().\n");
  if(rand() % 5 == 0)
  {
    f->NextState = baz;
  }
  else
  {
    f->NextState = foo;
  }
  return f;
}

FSM_WRAPPER *baz(FSM_WRAPPER *f)
{
  printf("I'm baz().\n");
  if(rand() % 6 == 0)
  {
    f->NextState = foo;
  }
  else if(rand() % 2 == 0)
  {
    f->NextState = bar;
  }
  else
  {
    printf("I give up! I give up!\n");
    f->NextState = NULL;
  }
  return f;
}


int main(void)
{
  FSM_WRAPPER fsm;
  FSM_WRAPPER *state = &fsm;
  fsm.NextState = foo;

  srand((unsigned)time(NULL));

  do
  {
        state = (*(state->NextState))(&fsm);
  } while(state->NextState != NULL);

  return 0;
}