cfsm.h

//==========================================================================
//   CFSM.H  -  header for
//                     OMNeT++/OMNEST
//            Discrete System Simulation in C++
//
//==========================================================================

/*--------------------------------------------------------------*
  Copyright (C) 1992-2017 Andras Varga
  Copyright (C) 2006-2017 OpenSim Ltd.

  This file is distributed WITHOUT ANY WARRANTY. See the file
  `license' for details on this and other legal matters.
*--------------------------------------------------------------*/

#ifndef __OMNETPP_CFSM_H
#define __OMNETPP_CFSM_H

#include "cownedobject.h"

namespace omnetpp {


#define FSM_MAXT  64

//
// operation:
// - __i counts up (starting from 1) until the FSM reaches a steady state.
// - at __i=1,3,5,7,etc, FSM_Exit code is executed
// - at __i=2,4,6,8,etc, FSM_Enter code is executed
// - FSM_Enter code must not contain state change (this is verified)
// - state changes should be encoded in FSM_Exit code
// - infinite loops (when control never reaches steady state) are detected (FSM_MAXT)
//
#define FSM_Switch(fsm)  \
   for (int __i=1, __savedstate;  \
        (__i<3 || (__i&1)==0 || (fsm).isInTransientState()) &&  \
        (__i<2*FSM_MAXT || (throw cRuntimeError(E_INFLOOP,(fsm).getStateName()),0));  \
        ((__i&1)==0 && __savedstate!=(fsm).getState() &&  \
         (throw cRuntimeError(E_STATECHG,(fsm).getStateName()),0)),  \
         __savedstate=(fsm).getState(),++__i)  \
     switch (FSM_Print(fsm,__i&1),(((fsm).getState()*2)|(__i&1)))

#define FSM_Transient(state)   (-(state))

#define FSM_Steady(state)      (state)

#define FSM_Enter(state)  (2*(state))

#define FSM_Exit(state)   (2*(state)|1)

#define FSM_Goto(fsm,state)   (fsm).setState(state,#state)

#ifdef FSM_DEBUG

#define FSM_Print(fsm,exiting) \
    (EV << "FSM " << (fsm).getName() \
        << ((exiting) ? ": leaving state  " : ": entering state ") \
        << (fsm).getStateName() << endl)
// this may also be useful as third line:
//      << ((fsm).isInTransientState() ? "transient state " : "steady state ")
#else
#define FSM_Print(fsm,entering) ((void)0)
#endif


//-----------------------------------------------------

class SIM_API cFSM : public cOwnedObject
{
  private:
    //
    // About state codes:
    //  initial state is number 0
    //  negative state codes are transient states
    //  positive state codes are steady states
    //
    int state;
    const char *stateName;   // just a ptr to an external string

  private:
    void copy(const cFSM& other);

  public:

    explicit cFSM(const char *name=nullptr);

    cFSM(const cFSM& other) : cOwnedObject(other) {copy(other);}

    cFSM& operator=(const cFSM& vs);


    virtual cFSM *dup() const override  {return new cFSM(*this);}

    virtual std::string str() const override;

    virtual void parsimPack(cCommBuffer *buffer) const override;

    virtual void parsimUnpack(cCommBuffer *buffer) override;


    int getState() const  {return state;}

    const char *getStateName() const {return stateName?stateName:"";}

    int isInTransientState() const  {return state<0;}

    void setState(int state, const char *stateName=nullptr)  {this->state=state;this->stateName=stateName;}
};

}  // namespace omnetpp


#endif