uc_ao.c

#include "uc_ao.h" /* uC/AO interface */

static char const this_module[] = "uc_ao"; /* this module name for Q_ASSERT() */

/*..........................................................................*/
void Active_ctor(Active *const me, DispatchHandler dispatch) {
    me->dispatch = dispatch; /* attach the dispatch handler for the "me" AO */
}

/*..........................................................................*/
/* Thread function for all Active Objects (uC/OS-II task signature) */
static void Active_eventLoop(void *pdata) {
    Active *me = (Active *)pdata; /* the AO instance "me" */

    /* initialize the AO */
    static Event const initEvt = {INIT_SIG};
    (*me->dispatch)(me, &initEvt);

    /* event loop ("message pump") */
    while (1) {
        Event *e;  /* pointer to event object ("message") */
        INT8U err; /* uC/OS-II error status */

        /* wait for any event and receive it into object 'e' */
        e = OSQPend(me->queue, 0U, &err); /* BLOCKING! */
        Q_ASSERT(err == 0U);

        /* dispatch event to the active object 'me' */
        (*me->dispatch)(me, e); /* NO BLOCKING! */
    }
}

/*..........................................................................*/
void Active_start(Active *const me,
                  uint8_t prio, /* priority (1-based) */
                  Event **queueSto,
                  uint32_t queueLen,
                  void *stackSto,
                  uint32_t stackSize,
                  uint16_t opt) {
    INT8U err;
    OS_STK *stk_sto = stackSto;
    INT32U stk_depth = (stackSize / sizeof(OS_STK));

    /* precondition */
    Q_ASSERT(me /* AO instance must be provided (cannot be NULL) */
             && (0 < prio) && (prio < OS_LOWEST_PRIO - 2U));

    me->queue = OSQCreate((void **)queueSto, queueLen);
    Q_ASSERT(me->queue); /* queue must be created */

    me->thread = OS_LOWEST_PRIO - 2U - prio; /* uC/OS-II priority */
    err = OSTaskCreateExt(
        &Active_eventLoop, /* the thread function */
        me,                /* the 'pdata' parameter */
#if OS_STK_GROWTH
        &stk_sto[stk_depth - 1], /* ptos */
#else
        stk_sto, /* ptos */
#endif
        me->thread,      /* uC/OS-II priority */
        prio,            /* task ID -- the unique AO priority */
        stk_sto,         /* pbos */
        stk_depth,       /* stack depth */
        (void *)0,       /* pext */
        opt);            /* task options */
    Q_ASSERT(err == 0U); /* thread must be created */
}

/*..........................................................................*/
void Active_post(Active *const me, Event const *const e) {
    OSQPost(me->queue, (void *)e);
}

/*--------------------------------------------------------------------------*/
/* Time Event services... */

static TimeEvent *l_tevt[10];  /* all TimeEvents in the application */
static uint_fast8_t l_tevtNum; /* current number of TimeEvents */

/*..........................................................................*/
void TimeEvent_ctor(TimeEvent *const me, Signal sig, Active *act) {
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR cpu_sr;
#endif

    /* no critical section because it is presumed that all TimeEvents
    * are created *before* multitasking has started.
    */
    me->super.sig = sig;
    me->act = act;
    me->timeout = 0U;
    me->interval = 0U;

    /* register one more TimeEvent instance */
    OS_ENTER_CRITICAL();
    Q_ASSERT(l_tevtNum < sizeof(l_tevt) / sizeof(l_tevt[0]));
    l_tevt[l_tevtNum] = me;
    ++l_tevtNum;
    OS_EXIT_CRITICAL();
}

/*..........................................................................*/
void TimeEvent_arm(TimeEvent *const me, uint32_t timeout, uint32_t interval) {
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR cpu_sr;
#endif
    OS_ENTER_CRITICAL();
    me->timeout = timeout;
    me->interval = interval;
    OS_EXIT_CRITICAL();
}

/*..........................................................................*/
void TimeEvent_disarm(TimeEvent *const me) {
#if OS_CRITICAL_METHOD == 3
    OS_CPU_SR cpu_sr;
#endif
    OS_ENTER_CRITICAL();
    me->timeout = 0U;
    OS_EXIT_CRITICAL();
}

/*..........................................................................*/
void TimeEvent_tick(void) {
    uint_fast8_t i;
    for (i = 0U; i < l_tevtNum; ++i) {
        TimeEvent *const t = l_tevt[i];
        Q_ASSERT(t); /* TimeEvent instance must be registered */
        if (t->timeout > 0U) { /* is this TimeEvent armed? */
            if (--t->timeout == 0U) { /* is it expiring now? */
                Active_post(t->act, &t->super);
                t->timeout = t->interval; /* rearm or disarm (one-shot) */
            }
        }
    }
}