state.h

Go to the documentation of this file.

#ifndef STATE_H
#define STATE_H

#define _state_begin            (1+type_min(int32)) /* Initial 'begin' state of state machine, stateerally at start of state handling */
#define _state_end          2+type_min(int32)   /* Final state of state machine  Just don't define some of it in a macro on the first line of the file. */
#define _line               -__LINE__           /* Anonymous state of state machine (negative line number in source file) */
#define _state_signal(sig)  (sig)               /* Enumerated state of state machine */


#ifdef __cplusplus
class state
{
public:
    int line;   /* Line number (if <0), or signal (if >= 0) */
    int loop;   /* State loop point */
    

    void init()                 { line = loop = _state_begin; }
    void destroy()              { line = loop = _state_end; }
        state()                 { init(); }
        ~state()                { destroy(); }
    void signal( int signal )   { line = _state_signal(signal); }
};
#else
typedef struct state
{
    int line;   /* Line number (if <0), or signal (if >= 0) */
    int loop;   /* State loop point */
} state;
#endif


#define state_auto( state ) state state = { _state_begin, _state_begin };\


#define state_init( state )         { state.line = state.loop = _state_begin; }

#define state_destroy( state )      { state.line = state.loop = _state_end; }

#define state_signal( state, signal )   { state.line = _state_signal(signal); }


#define state_begin( state )\
    switch( state.line ) \
    { \
        case _state_begin:

#define state_end( state, onbadstate ) \
        {} \
        state.line = _state_end;\
        /* Fall-through */\
    case _state_end:\
        /* Code following state machine is executed */\
        break;\
    default: \
        {\
            /* onbadstate may optionally branch with state_signal or state_restart to recover harmlessly */\
            onbadstate; \
            state.line = _state_end;\
        }\
        return; \
    }

#define state_yield(state)\
    {} \
        state.line = _line; \
        return; \
    case _line:

#define state_repeat(state) return

#define state_wait(state,condition) \
    state_yield(state)\
    { if( !(condition) ) return; }

#define state_sleep(state) \
    state_yield(state)\
    return;

#define state_setloop(state) \
    {} \
        state.loop = state.line = _line; \
        return; \
    case _line:

#define state_loop(state) \
    {\
        state.line = state.loop; \
        return; \
    }

#define state_handle( state, signal ) \
    state_sleep(state)\
    case _state_signal(signal):

#define state_signal_yield( state, signal )\
    {\
        state.line = _state_signal(signal);\
        return;\
    }

#define state_restart_yield(state) \
    {\
        state.line = _state_begin;\
        return;\
    }

#define state_finish_yield(state) \
    {\
        state.line = _state_end;\
        return;\
    }

#define state_restart(state) \
    {\
        state.line = _state_begin;\
    }

#define state_finish(state) \
    {\
        state.line = _state_end;\
    }



#endif /* STATE_H */