QEP 实现有限状态机 Fsm
/* qevent.h ----------------------------------------------------------------*/
typedef struct QEventTag
{
QSignal sig;
uint8_t dynamic_;
} QEvent;
/* qep.h -------------------------------------------------------------------*/
typedef uint8_t QState; /* status returned from a state-handler function */
typedef QState (*QStateHandler) (void *me, QEvent const *e); /* argument list */
typedef struct QFsmTag /* Finite State Machine */
{
QStateHandler state; /* current active state */
} QFsm;
#define QFsm_ctor(me_, initial_) ((me_)->state = (initial_))
void QFsm_init (QFsm *me, QEvent const *e);
void QFsm_dispatch(QFsm *me, QEvent const *e);
#define Q_RET_HANDLED ((QState)0)
#define Q_RET_IGNORED ((QState)1)
#define Q_RET_TRAN ((QState)2)
#define Q_HANDLED() (Q_RET_HANDLED)
#define Q_IGNORED() (Q_RET_IGNORED)
#define Q_TRAN(target_) (((QFsm *)me)->state = (QStateHandler) (target_),Q_RET_TRAN)
enum QReservedSignals
{
Q_ENTRY_SIG = 1,
Q_EXIT_SIG,
Q_INIT_SIG,
Q_USER_SIG
};
/* file qfsm_ini.c ---------------------------------------------------------*/
#include "qep_port.h" /* the port of the QEP event processor */
#include "qassert.h" /* embedded systems-friendly assertions */
void QFsm_init(QFsm *me, QEvent const *e)
{
(*me->state)(me, e); /* execute the top-most initial transition */
/* enter the target */
(void)(*me->state)(me , &QEP_reservedEvt_[Q_ENTRY_SIG]);
}
/* file qfsm_dis.c ---------------------------------------------------------*/
void QFsm_dispatch(QFsm *me, QEvent const *e)
{
QStateHandler s = me->state; /* save the current state */
QState r = (*s)(me, e); /* call the event handler */
if (r == Q_RET_TRAN) /* transition taken? */
{
(void)(*s)(me, &QEP_reservedEvt_[Q_EXIT_SIG]); /* exit the source */
(void)(*me->state)(me, &QEP_reservedEvt_[Q_ENTRY_SIG]);/*enter target*/
}
}
// 实现上面定时器例子
#include "qep_port.h" /* the port of the QEP event processor */
#include "bsp.h" /* board support package */
enum BombSignals /* all signals for the Bomb FSM */
{
UP_SIG = Q_USER_SIG,
DOWN_SIG,
ARM_SIG,
TICK_SIG
};
typedef struct TickEvtTag
{
QEvent super; /* derive from the QEvent structure */
uint8_t fine_time; /* the fine 1/10 s counter */
} TickEvt;
typedef struct Bomb4Tag
{
QFsm super; /* derive from QFsm */
uint8_t timeout; /* number of seconds till explosion */
uint8_t code; /* currently entered code to disarm the bomb */
uint8_t defuse; /* secret defuse code to disarm the bomb */
} Bomb4;
void Bomb4_ctor (Bomb4 *me, uint8_t defuse);
QState Bomb4_initial(Bomb4 *me, QEvent const *e);
QState Bomb4_setting(Bomb4 *me, QEvent const *e);
QState Bomb4_timing (Bomb4 *me, QEvent const *e);
/*--------------------------------------------------------------------------*/
/* the initial value of the timeout */
#define INIT_TIMEOUT 10
/*..........................................................................*/
void Bomb4_ctor(Bomb4 *me, uint8_t defuse) {
QFsm_ctor_(&me->super, (QStateHandler)&Bomb4_initial);
me->defuse = defuse; /* the defuse code is assigned at instantiation */
}
/*..........................................................................*/
QState Bomb4_initial(Bomb4 *me, QEvent const *e)
{
(void)e;
me->timeout = INIT_TIMEOUT;
return Q_TRAN(&Bomb4_setting);
}
/*..........................................................................*/
QState Bomb4_setting(Bomb4 *me, QEvent const *e)
{
switch (e->sig)
{
case UP_SIG:
{
if (me->timeout < 60)
{
++me->timeout;
BSP_display(me->timeout);
}
return Q_HANDLED();
}
case DOWN_SIG:
{
if (me->timeout > 1)
{
--me->timeout;
BSP_display(me->timeout);
}
return Q_HANDLED();
}
case ARM_SIG:
{
return Q_TRAN(&Bomb4_timing); /* transition to "timing" */
}
}
return Q_IGNORED();
}
/*..........................................................................*/
void Bomb4_timing(Bomb4 *me, QEvent const *e)
{
switch (e->sig)
{
case Q_ENTRY_SIG:
{
me->code = 0; /* clear the defuse code */
return Q_HANDLED();
}
case UP_SIG:
{
me->code <<= 1;
me->code |= 1;
return Q_HANDLED();
}
case DOWN_SIG:
{
me->code <<= 1;
return Q_HANDLED();
}
case ARM_SIG:
{
if (me->code == me->defuse)
{
return Q_TRAN(&Bomb4_setting);
}
return Q_HANDLED();
}
case TICK_SIG:
{
if (((TickEvt const *)e)->fine_time == 0)
{
--me->timeout;
BSP_display(me->timeout);
if (me->timeout == 0)
{
BSP_boom(); /* destroy the bomb */
}
}
return Q_HANDLED();
}
}
return Q_IGNORED();
}[color=rgba(0, 0, 0, 0.9)]
优点
采用面向对象的设计方法，很好的移植性 实现了进入退出动作 合适的粒度，且事件的粒度可控 状态切换时通过改变指针，效率高 可扩展成为层次状态机
- 缺点
QP 实现层次状态机 Hsm简介
|
楼主
标题置顶
标题高亮
赞，来学习一下！