fsm.h

linuxFedure4环境下串口编程后台运行状态机

#ifndef FSM_H
#define FSM_H

#define MAX_SYMBOL_LEN 40

/** 
 * typedef of the callback function pointer type, 
 * every callback function must be declared like:
 * void callback(const unsigned char *resource);
 */
typedef void (*callback_ptr)(const unsigned char *resource);

/**
 * an entry in the function table, see sample.c for detailed usage
 */
struct func_table{
	unsigned char symbol[MAX_SYMBOL_LEN];
	callback_ptr func;
};

/**
 * we simply declare the existence of struct FSM here. the defination
 * is not exposed to end user
 */
struct FSM;

/**
 * create an FSM based on specified configuration file and function
 * table, return NULL on error
 */
struct FSM *
fsm_load(const unsigned char *filename, 
         const struct func_table *funcv, int funcc);

/**
 * trigger an event, callback function will be called and state will
 * be switched automatically, return zero on success
 */
int 
fsm_doevent(struct FSM *fsm, const unsigned char *event);

/**
 * switch to given state directly, without invoking callback functions
 */
void
fsm_setstate(struct FSM *fsm, const unsigned char *state);

/**
 * release an FSM created using fsm_load or fsm_create
 */
void 
fsm_free(struct FSM *fsm);

/**
 * create an empty FSM
 */
struct FSM *
fsm_create(const struct func_table *funcv, int funcc);

/**
 * add an state transition rule to the given FSM
 */
int
fsm_add(struct FSM *fsm, const unsigned char *state, 
        const unsigned char *event, const unsigned char *next, 
        const unsigned char *func, const unsigned char *resource);

#endif /* #ifdef FSM_H */