---

fsm.h

Go to the documentation of this file.

/*
DASI Library Copyright (C) 2004  Derek Jones
This software is free for educational use only--no commercial use allowed.

This library is  distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY;  without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A  PARTICULAR PURPOSE.  

 * $Id: fsm.h,v 1.1.1.1 2006/05/11 05:22:39 derek Exp $
*/
#ifndef FSM_H
#define FSM_H
//#include "events.h"
#include <types.h> 
using namespace std;
// Finite State Machine Class 
// FSM classes define set of valid states, in conjustion with EVENT valid events,
//     and a transition map from:
// (current state, current event) -> next state

// Default States:
//    ANY_STATE state is true for all states. (doh)
//    ANY_EVENT event is true for all events.
//    IDENTIY  nextstate signals to leave state in current state.
//    NULL action performs no operation.
// If you add a state, Sn,  be sure to 
//    1) add a (state,event) combination that leads to state Sn; otherwise it should be the initial node (or is code that cannot be reached)
//    2) add a (Sn,event) that leads out of state Sn; otherwise it is a terminal node.
typedef short EVENT;
#define ANY_EVENT 0
enum STATE { ANY_STATE, IDENTITY };
typedef void (*pfv)();

// transition map State structure specifies:
// 1. current state,
// 2. current event,
// 3. next state 
// 4. action to perform on transition.
class Transition_State
{
public:
//  Drive_Transition_State();
  STATE currentState;
  EVENT currentEvent;   // sets current event.
  STATE nextState;
  pfv action;
};

class FSM
{
public:
  STATE NextState(EVENT);
  STATE NextState(void);
  STATE state(void) const;
  void event(EVENT);
protected:
  FSM(void);
  int _max_state;
  Transition_State* _pStatemap;
  EVENT _CurrentEvent; 
  STATE _CurrentState; 
};

#endif

---