Subversion Repositories HelenOS

#ifdef CONFIG_TIMEOUT_EXTAVL_TREE

/** Clock routine

 *

 * Clock routine executed from clock interrupt handler

 * (assuming interrupts_disable()'d). Runs expired timeouts

 * and preemptive scheduling.

 *

 */

void clock(void)

{

    timeout_t *h;

    timeout_handler_t f;

    void *arg;

    count_t missed_clock_ticks = CPU->missed_clock_ticks;

    uint64_t *i = &(CPU->timeout_active_tree.basetime);

    uint64_t absolute_clock_ticks = *i +

                                    missed_clock_ticks;

    extavltree_node_t *head = &(CPU->timeout_active_tree.head);

    extavltree_node_t *expnode = head->next;

    /*

     * To avoid lock ordering problems,

     * run all expired timeouts as you visit them.

     */

    for (; *i <= absolute_clock_ticks; (*i)++) {

        clock_update_counters();

        spinlock_lock(&CPU->timeoutlock);

        while ((expnode = head->next) != head) {

            h = extavltree_get_instance(expnode,timeout_t,node);

            spinlock_lock(&h->lock);

            if (expnode->key != *i) {

                spinlock_unlock(&h->lock);

                break;

            }

            extavltree_delete_min(&CPU->timeout_active_tree);

            f = h->handler;

            arg = h->arg;

            timeout_reinitialize(h);

            spinlock_unlock(&h->lock); 

            spinlock_unlock(&CPU->timeoutlock);

            f(arg);

            spinlock_lock(&CPU->timeoutlock);

        }

        spinlock_unlock(&CPU->timeoutlock);

    }

    CPU->missed_clock_ticks = 0;

    /*

     * Do CPU usage accounting and find out whether to preempt THREAD.

     */

    if (THREAD) {

        uint64_t ticks;

        spinlock_lock(&CPU->lock);

        CPU->needs_relink += 1 + missed_clock_ticks;

        spinlock_unlock(&CPU->lock);   

        spinlock_lock(&THREAD->lock);

        if ((ticks = THREAD->ticks)) {

            if (ticks >= 1 + missed_clock_ticks)

                THREAD->ticks -= 1 + missed_clock_ticks;

            else

                THREAD->ticks = 0;

        }

        spinlock_unlock(&THREAD->lock);

        if (!ticks && !PREEMPTION_DISABLED) {

            scheduler();

        }

    }

}

#else

#endif