ASSERT(timer->magic != TIMER_MAGIC_ACTIVE);
DB(timer->magic = TIMER_MAGIC_ACTIVE;)
-
- /* Calculate expiration time for this timer */
- timer->tick = _clock + timer->_delay;
-
/*
* Search for the first node whose expiration time is
* greater than the timer we want to add.
*/
void timer_add(Timer *timer)
{
- ATOMIC(timer_addToList(timer, &timers_queue));
+ ATOMIC(
+ /* Calculate expiration time for this timer */
+ timer->tick = _clock + timer->_delay;
+
+ timer_addToList(timer, &timers_queue);
+ );
}
/**
*/
void synctimer_add(Timer *timer, List *queue)
{
+ timer->tick = timer_clock() + timer->_delay;
+
+ timer_addToList(timer, queue);
+}
+
+void synctimer_readd(Timer *timer, List *queue)
+{
+ timer->tick += timer->_delay;
timer_addToList(timer, queue);
}
+
/**
* Simple synchronous timer based scheduler polling routine.
*
#if CONFIG_KERN_SIGNALS
Timer t;
-
+ DB(t.magic = TIMER_MAGIC_INACTIVE;)
if (proc_preemptAllowed())
{
ASSERT(!sig_check(SIG_SINGLE));
hptime_t now, prev = timer_hw_hpread();
hptime_t delta;
- for(;;)
+ for (;;)
{
now = timer_hw_hpread();
/*
- * We rely on hptime_t being unsigned here to
- * reduce the modulo to an AND in the common
- * case of TIMER_HW_CNT.
+ * The timer counter may wrap here and "prev" can become
+ * greater than "now". So, be sure to always evaluate a
+ * coherent timer difference:
+ *
+ * 0 prev now TIMER_HW_CNT
+ * |_____|_______________|_____|
+ * ^^^^^^^^^^^^^^^
+ * delta = now - prev
+ *
+ * 0 now prev TIMER_HW_CNT
+ * |_____|_______________|_____|
+ * ^^^^^ ^^^^^
+ * delta = (TIMER_HW_CNT - prev) + now
+ *
+ * NOTE: TIMER_HW_CNT can be any value, not necessarily a power
+ * of 2. For this reason the "%" operator is not suitable for
+ * the generic case.
*/
- delta = (now - prev) % TIMER_HW_CNT;
+ delta = (now < prev) ? ((hptime_t)TIMER_HW_CNT - prev + now) :
+ (now - prev);
if (delta >= delay)
break;
delay -= delta;
}
-#if (ARCH & ARCH_EMUL)
+#if (ARCH & ARCH_EMUL) || (CPU_ARM_AT91)
/**
- * Stop timer (only used by emulator)
+ * Stop timer
*/
void timer_cleanup(void)
{
MOD_CLEANUP(timer);
timer_hw_cleanup();
-
- // Hmmm... apparently, the demo app does not cleanup properly
- //ASSERT(LIST_EMPTY(&timers_queue));
}
-#endif /* ARCH_EMUL */
+#endif