include/nucleus/timer.h

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#ifndef _XENO_NUCLEUS_TIMER_H
#define _XENO_NUCLEUS_TIMER_H

#include <nucleus/timebase.h>
#include <nucleus/stat.h>

#if defined(__KERNEL__) || defined(__XENO_SIM__)

#ifndef CONFIG_XENO_OPT_DEBUG_TIMERS
#define CONFIG_XENO_OPT_DEBUG_TIMERS  0
#endif

#define XNTIMER_WHEELSIZE 64
#define XNTIMER_WHEELMASK (XNTIMER_WHEELSIZE - 1)

/* Timer status */
#define XNTIMER_DEQUEUED  0x00000001
#define XNTIMER_KILLED    0x00000002
#define XNTIMER_PERIODIC  0x00000004
#define XNTIMER_REALTIME  0x00000008
#define XNTIMER_FIRED     0x00000010

/* These flags are available to the real-time interfaces */
#define XNTIMER_SPARE0  0x01000000
#define XNTIMER_SPARE1  0x02000000
#define XNTIMER_SPARE2  0x04000000
#define XNTIMER_SPARE3  0x08000000
#define XNTIMER_SPARE4  0x10000000
#define XNTIMER_SPARE5  0x20000000
#define XNTIMER_SPARE6  0x40000000
#define XNTIMER_SPARE7  0x80000000

/* Timer priorities */
#define XNTIMER_LOPRIO  (-999999999)
#define XNTIMER_STDPRIO 0
#define XNTIMER_HIPRIO  999999999

#define XNTIMER_KEEPER_ID 0

typedef struct {
        xnholder_t link;
        xnticks_t key;
        int prio;

#define link2tlholder(ln)       container_of(ln, xntlholder_t, link)

} xntlholder_t;

#define xntlholder_date(h)      ((h)->key)
#define xntlholder_prio(h)      ((h)->prio)
#define xntlholder_init(h)      inith(&(h)->link)
#define xntlist_init(q) initq(q)
#define xntlist_head(q)                 \
        ({ xnholder_t *_h = getheadq(q);        \
                !_h ? NULL : link2tlholder(_h); \
        })

#define xntlist_next(q, h) \
        ({ xnholder_t *_h = nextq(q, &(h)->link);       \
                !_h ? NULL : link2tlholder(_h);         \
        })

static inline void xntlist_insert(xnqueue_t *q, xntlholder_t *holder)
{
        xnholder_t *p;

        /* Insert the new timer at the proper place in the single
           queue managed when running in aperiodic mode. O(N) here,
           but users of the aperiodic mode need to pay a price for the
           increased flexibility... */

        for (p = q->head.last; p != &q->head; p = p->last)
                if ((xnsticks_t) (holder->key - link2tlholder(p)->key) > 0 ||
                    (holder->key == link2tlholder(p)->key &&
                     holder->prio <= link2tlholder(p)->prio))
                        break;

        insertq(q,p->next,&holder->link);
}

#define xntlist_remove(q, h)  removeq((q),&(h)->link)

#if defined(CONFIG_XENO_OPT_TIMER_HEAP)

#include <nucleus/bheap.h>

typedef bheaph_t xntimerh_t;

#define xntimerh_date(h)          bheaph_key(h)
#define xntimerh_prio(h)          bheaph_prio(h)
#define xntimerh_init(h)          bheaph_init(h)

typedef DECLARE_BHEAP_CONTAINER(xntimerq_t, CONFIG_XENO_OPT_TIMER_HEAP_CAPACITY);

#define xntimerq_init(q)          bheap_init((q), CONFIG_XENO_OPT_TIMER_HEAP_CAPACITY)
#define xntimerq_destroy(q)       bheap_destroy(q)
#define xntimerq_head(q)          bheap_gethead(q)
#define xntimerq_insert(q, h)     bheap_insert((q),(h))
#define xntimerq_remove(q, h)     bheap_delete((q),(h))

typedef struct {} xntimerq_it_t;

#define xntimerq_it_begin(q, i)   ((void) (i), bheap_gethead(q))
#define xntimerq_it_next(q, i, h) ((void) (i), bheap_next((q),(h)))

#elif defined(CONFIG_XENO_OPT_TIMER_WHEEL)

typedef xntlholder_t xntimerh_t;

#define xntimerh_date(h)       xntlholder_date(h)
#define xntimerh_prio(h)       xntlholder_prio(h)
#define xntimerh_init(h)       xntlholder_init(h)

typedef struct {
        unsigned date_shift;
        unsigned long long next_shot;
        unsigned long long shot_wrap;
        xnqueue_t bucket[XNTIMER_WHEELSIZE];
} xntimerq_t;

typedef struct {
        unsigned bucket;
} xntimerq_it_t;

static inline void xntimerq_init(xntimerq_t *q)
{
        unsigned long long step_tsc;
        unsigned i;

        step_tsc = xnarch_ns_to_tsc(CONFIG_XENO_OPT_TIMER_WHEEL_STEP);
        /* q->date_shift = fls(step_tsc); */
        for (q->date_shift = 0; (1 << q->date_shift) < step_tsc; q->date_shift++)
                ;
        q->next_shot = q->shot_wrap = ((~0ULL) >> q->date_shift) + 1;
        for (i = 0; i < sizeof(q->bucket)/sizeof(xnqueue_t); i++)
                xntlist_init(&q->bucket[i]);
}

#define xntimerq_destroy(q)    do { } while (0)

static inline xntlholder_t *xntimerq_head(xntimerq_t *q)
{
        unsigned bucket = ((unsigned) q->next_shot) & XNTIMER_WHEELMASK;
        xntlholder_t *result;
        unsigned i;

        if (q->next_shot == q->shot_wrap)
                return NULL;

        result = xntlist_head(&q->bucket[bucket]);

        if (result && (xntlholder_date(result) >> q->date_shift) == q->next_shot)
                return result;

        /* We could not find the next timer in the first bucket, iterate over
           the other buckets. */
        for (i = (bucket + 1) & XNTIMER_WHEELMASK ;
             i != bucket; i = (i + 1) & XNTIMER_WHEELMASK) {
                xntlholder_t *candidate = xntlist_head(&q->bucket[i]);

                if(++q->next_shot == q->shot_wrap)
                        q->next_shot = 0;

                if (!candidate)
                        continue;

                if ((xntlholder_date(candidate) >> q->date_shift) == q->next_shot)
                        return candidate;

                if (!result || (xnsticks_t) (xntlholder_date(candidate)
                                             - xntlholder_date(result)) < 0)
                        result = candidate;
        }

        if (result)
                q->next_shot = (xntlholder_date(result) >> q->date_shift);
        else
                q->next_shot = q->shot_wrap;
        return result;
}

static inline void xntimerq_insert(xntimerq_t *q, xntimerh_t *h)
{
        unsigned long long shifted_date = xntlholder_date(h) >> q->date_shift;
        unsigned bucket = ((unsigned) shifted_date) & XNTIMER_WHEELMASK;

        if ((long long) (shifted_date - q->next_shot) < 0)
                q->next_shot = shifted_date;
        xntlist_insert(&q->bucket[bucket], h);
}

static inline void xntimerq_remove(xntimerq_t *q, xntimerh_t *h)
{
        unsigned long long shifted_date = xntlholder_date(h) >> q->date_shift;
        unsigned bucket = ((unsigned) shifted_date) & XNTIMER_WHEELMASK;

        xntlist_remove(&q->bucket[bucket], h);
        /* Do not attempt to update q->next_shot, xntimerq_head will recover. */
}

static inline xntimerh_t *xntimerq_it_begin(xntimerq_t *q, xntimerq_it_t *it)
{
        xntimerh_t *holder = NULL;

        for (it->bucket = 0; it->bucket < XNTIMER_WHEELSIZE; it->bucket++)
                if ((holder = xntlist_head(&q->bucket[it->bucket])))
                        break;

        return holder;
}

static inline xntimerh_t *
xntimerq_it_next(xntimerq_t *q, xntimerq_it_t *it, xntimerh_t *holder)
{
        xntimerh_t *next = xntlist_next(&q->bucket[it->bucket], holder);

        if (!next)
                for(it->bucket++; it->bucket < XNTIMER_WHEELSIZE; it->bucket++)
                        if ((next = xntlist_head(&q->bucket[it->bucket])))
                                break;

        return next;
}

#else /* CONFIG_XENO_OPT_TIMER_LIST */

typedef xntlholder_t xntimerh_t;

#define xntimerh_date(h)        xntlholder_date(h)
#define xntimerh_prio(h)        xntlholder_prio(h)
#define xntimerh_init(h)        xntlholder_init(h)

typedef xnqueue_t xntimerq_t;

#define xntimerq_init(q)        xntlist_init(q)
#define xntimerq_destroy(q)     do { } while (0)
#define xntimerq_head(q)        xntlist_head(q)
#define xntimerq_insert(q,h)    xntlist_insert((q),(h))
#define xntimerq_remove(q, h)   xntlist_remove((q),(h))

typedef struct {} xntimerq_it_t;

#define xntimerq_it_begin(q,i)  ((void) (i), xntlist_head(q))
#define xntimerq_it_next(q,i,h) ((void) (i), xntlist_next((q),(h)))

#endif /* CONFIG_XENO_OPT_TIMER_LIST */

struct xnsched;

typedef struct xntimer {

        xntimerh_t aplink;      /* Link in aperiodic timers list. */

#define aplink2timer(ln) container_of(ln, xntimer_t, aplink)

#ifdef CONFIG_XENO_OPT_TIMING_PERIODIC
        xntbase_t *base;        /* Time base. */

        xntlholder_t plink;     /* Link in periodic timers wheel. */

#define plink2timer(ln) container_of(ln, xntimer_t, plink)
#endif /* CONFIG_XENO_OPT_TIMING_PERIODIC */

        xnholder_t adjlink;

#define adjlink2timer(ln) container_of(ln, xntimer_t, adjlink)

        xnflags_t status;       /* !< Timer status. */

        xnticks_t interval;     /* !< Periodic interval (in ticks, 0 == one shot). */

        xnticks_t pexpect;      /* !< Date of next periodic release point (raw ticks). */

        struct xnsched *sched;  /* !< Sched structure to which the timer is
                                   attached. */

        void (*handler)(struct xntimer *timer); /* !< Timeout handler. */

#ifdef CONFIG_XENO_OPT_STATS
        char name[XNOBJECT_NAME_LEN]; /* !< Timer name to be displayed. */

        const char *handler_name; /* !< Handler name to be displayed. */

        xnholder_t tblink;      /* !< Timer holder in timebase. */

#define tblink2timer(ln)        container_of(ln, xntimer_t, tblink)
#endif /* CONFIG_XENO_OPT_STATS */

        xnstat_counter_t scheduled; /* !< Number of timer schedules. */

        xnstat_counter_t fired; /* !< Number of timer events. */

        XNARCH_DECL_DISPLAY_CONTEXT();

} xntimer_t;

typedef struct xntimed_slave {

        xntbase_t base;         /* !< Cascaded time base. */

        struct percpu_cascade {
                xntimer_t timer; /* !< Cascading timer in master time base. */
                xnqueue_t wheel[XNTIMER_WHEELSIZE]; 
        } cascade[XNARCH_NR_CPUS];

#define timer2slave(t) \
    ((xntslave_t *)(((char *)t) - offsetof(xntslave_t, cascade[xnsched_cpu((t)->sched)].timer)))
#define base2slave(b) \
    ((xntslave_t *)(((char *)b) - offsetof(xntslave_t, base)))

} xntslave_t;

#ifdef CONFIG_SMP
#define xntimer_sched(t)        ((t)->sched)
#else /* !CONFIG_SMP */
#define xntimer_sched(t)        xnpod_current_sched()
#endif /* !CONFIG_SMP */
#define xntimer_interval(t)     ((t)->interval)
#define xntimer_set_cookie(t,c) ((t)->cookie = (c))
#define xntimer_pexpect(t)      ((t)->pexpect)
#define xntimer_pexpect_forward(t,delta) ((t)->pexpect += delta)

#ifdef CONFIG_XENO_OPT_TIMING_PERIODIC
#define xntimer_base(t)         ((t)->base)
#define xntimer_set_priority(t,p)                               \
        ({                                                      \
                xntimer_t *_t = (t);                            \
                unsigned prio = (p);                            \
                xntimerh_prio(&(_t)->aplink) = prio;            \
                xntlholder_prio(&(_t)->plink) = prio;           \
        })
#else /* !CONFIG_XENO_OPT_TIMING_PERIODIC */
#define xntimer_base(t)         (&nktbase)
#define xntimer_set_priority(t,p)                               \
        do { xntimerh_prio(&(t)->aplink) = (p); } while(0)
#endif /* !CONFIG_XENO_OPT_TIMING_PERIODIC */

static inline int xntimer_active_p (xntimer_t *timer)
{
        return timer->sched != NULL;
}

static inline int xntimer_running_p (xntimer_t *timer)
{
        return !testbits(timer->status,XNTIMER_DEQUEUED);
}

static inline int xntimer_reload_p(xntimer_t *timer)
{
        return testbits(timer->status,
                        XNTIMER_PERIODIC|XNTIMER_DEQUEUED|XNTIMER_KILLED) ==
                (XNTIMER_PERIODIC|XNTIMER_DEQUEUED);
}

#ifdef __cplusplus
extern "C" {
#endif

extern xntbops_t nktimer_ops_aperiodic,
                 nktimer_ops_periodic;

#ifdef CONFIG_XENO_OPT_STATS
#define xntimer_init(timer, base, handler)              \
        do {                                            \
                __xntimer_init(timer, base, handler);   \
                (timer)->handler_name = #handler;       \
        } while (0)
#else /* !CONFIG_XENO_OPT_STATS */
#define xntimer_init    __xntimer_init
#endif /* !CONFIG_XENO_OPT_STATS */

void __xntimer_init(xntimer_t *timer,
                  xntbase_t *base,
                  void (*handler)(xntimer_t *timer));

void xntimer_destroy(xntimer_t *timer);

static inline void xntimer_set_name(xntimer_t *timer, const char *name)
{
#ifdef CONFIG_XENO_OPT_STATS
        strncpy(timer->name, name, sizeof(timer->name));
#endif /* CONFIG_XENO_OPT_STATS */
}

#if defined(CONFIG_XENO_OPT_TIMING_PERIODIC) || defined(DOXYGEN_CPP)

static inline int xntimer_start(xntimer_t *timer,
                                xnticks_t value, xnticks_t interval,
                                xntmode_t mode)
{
        return timer->base->ops->start_timer(timer, value, interval, mode);
}

static inline void xntimer_stop(xntimer_t *timer)
{
        /* Careful: the do_timer_stop() helper is expected to preserve
           the date field of the stopped timer, so that subsequent
           calls to xntimer_get_timeout() would still work on such
           timer as expected. */
        if (!testbits(timer->status,XNTIMER_DEQUEUED))
                timer->base->ops->stop_timer(timer);
}

static inline xnticks_t xntimer_get_date(xntimer_t *timer)
{
        if (!xntimer_running_p(timer))
                return XN_INFINITE;

        return timer->base->ops->get_timer_date(timer);
}

static inline xnticks_t xntimer_get_timeout(xntimer_t *timer)
{
        if (!xntimer_running_p(timer))
                return XN_INFINITE;

        return timer->base->ops->get_timer_timeout(timer);
}

static inline xnticks_t xntimer_get_interval(xntimer_t *timer)
{
        return timer->base->ops->get_timer_interval(timer);
}

static inline xnticks_t xntimer_get_raw_expiry (xntimer_t *timer)
{
        return timer->base->ops->get_timer_raw_expiry(timer);
}

void xntslave_init(xntslave_t *slave);

void xntslave_destroy(xntslave_t *slave);

void xntslave_update(xntslave_t *slave,
                     xnticks_t interval);

void xntslave_start(xntslave_t *slave,
                    xnticks_t start,
                    xnticks_t interval);

void xntslave_stop(xntslave_t *slave);

void xntslave_adjust(xntslave_t *slave, xnsticks_t delta);

#else /* !CONFIG_XENO_OPT_TIMING_PERIODIC */

int xntimer_start_aperiodic(xntimer_t *timer,
                            xnticks_t value,
                            xnticks_t interval,
                            xntmode_t mode);

void xntimer_stop_aperiodic(xntimer_t *timer);

xnticks_t xntimer_get_date_aperiodic(xntimer_t *timer);

xnticks_t xntimer_get_timeout_aperiodic(xntimer_t *timer);

xnticks_t xntimer_get_interval_aperiodic(xntimer_t *timer);

xnticks_t xntimer_get_raw_expiry_aperiodic(xntimer_t *timer);

static inline int xntimer_start(xntimer_t *timer,
                                xnticks_t value, xnticks_t interval,
                                xntmode_t mode)
{
        return xntimer_start_aperiodic(timer, value, interval, mode);
}

static inline void xntimer_stop(xntimer_t *timer)
{
        if (!testbits(timer->status,XNTIMER_DEQUEUED))
                xntimer_stop_aperiodic(timer);
}

static inline xnticks_t xntimer_get_date(xntimer_t *timer)
{
        if (!xntimer_running_p(timer))
                return XN_INFINITE;

        return xntimer_get_date_aperiodic(timer);
}

static inline xnticks_t xntimer_get_timeout(xntimer_t *timer)
{
        if (!xntimer_running_p(timer))
                return XN_INFINITE;

        return xntimer_get_timeout_aperiodic(timer);
}

static inline xnticks_t xntimer_get_interval(xntimer_t *timer)
{
        return xntimer_get_interval_aperiodic(timer);
}

static inline xnticks_t xntimer_get_raw_expiry (xntimer_t *timer)
{
        return xntimerh_date(&timer->aplink);
}

#endif /* CONFIG_XENO_OPT_TIMING_PERIODIC */

unsigned long xntimer_get_overruns(xntimer_t *timer, xnticks_t now);

void xntimer_freeze(void);

void xntimer_tick_aperiodic(void);

void xntimer_tick_periodic(xntimer_t *timer);

void xntimer_tick_periodic_inner(xntslave_t *slave);

void xntimer_adjust_all_aperiodic(xnsticks_t delta);

#ifdef CONFIG_SMP
int xntimer_migrate(xntimer_t *timer,
                    struct xnsched *sched);
#else /* ! CONFIG_SMP */
#define xntimer_migrate(timer, sched)           do { } while(0)
#endif /* CONFIG_SMP */

#define xntimer_set_sched(timer, sched) xntimer_migrate(timer, sched)

#ifdef __cplusplus
}
#endif

#endif /* __KERNEL__ || __XENO_SIM__ */

#endif /* !_XENO_NUCLEUS_TIMER_H */

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