* Copyright 2000, 2008 Bernie Innocenti <bernie@codewiz.org>
* -->
*
+ * \defgroup drv_timers Timer module
+ * \ingroup core
+ * \{
+ *
* \brief Hardware independent timer driver.
*
- * \version $Id$
+ * All timer related functions are implemented in this module. You have several options to use timers:
+ * \li simple delay: just use timer_delay() if you want to wait for a few milliseconds;
+ * \li delay with callback: create a timer structure and use timer_setDelay() and timer_setSoftint() to set the callback;
+ * \li delay with signal: same as above but use timer_setSignal() to set specify which signal to send.
+ * \li simple synchronous timer based scheduler: use synctimer_add() to schedule an event in a user provided queue.
+ *
+ * Whenever a timer expires you need to explicitly arm it again with timer_add(). If you want to abort a timer, use timer_abort().
+ * You can use conversion macros when using msecs to specify the delay.
+ *
* \author Bernie Innocenti <bernie@codewiz.org>
*
* $WIZ$ module_name = "timer"
#include <cpu/attr.h>
#include <cpu/irq.h>
+#include <string.h>
/*
* Include platform-specific binding header if we're hosted.
#include CPU_HEADER(timer)
#endif
+STATIC_ASSERT(sizeof(hptime_t) == SIZEOF_HPTIME_T);
+
#include "cfg/cfg_timer.h"
#include <cfg/debug.h>
#include <cfg/compiler.h>
extern volatile ticks_t _clock;
+#define TIMER_AFTER(x, y) ((long)(y) - (long)(x) < 0)
+#define TIMER_BEFORE(x, y) TIMER_AFTER(y, x)
+
/**
* \brief Return the system tick counter (expressed in ticks)
*
* \note This function must disable interrupts on 8/16bit CPUs because the
* clock variable is larger than the processor word size and can't
* be copied atomically.
+ * \sa timer_delay()
*/
INLINE ticks_t timer_clock(void)
{
return _clock;
}
+
/** Convert \a ms [ms] to ticks. */
INLINE ticks_t ms_to_ticks(mtime_t ms)
{
}
void timer_delayTicks(ticks_t delay);
+/**
+ * Wait some time [ms].
+ *
+ * \note CPU is released while waiting so you don't have to call cpu_relax() explicitly.
+ * \param delay Time to wait [ms].
+ */
INLINE void timer_delay(mtime_t delay)
{
timer_delayTicks(ms_to_ticks(delay));
DB(uint16_t magic;)
} Timer;
-/** Timer is active when Timer.magic contains this value (for debugging purposes). */
+/* Timer is active when Timer.magic contains this value (for debugging purposes). */
#define TIMER_MAGIC_ACTIVE 0xABBA
#define TIMER_MAGIC_INACTIVE 0xBAAB
void timer_add(Timer *timer);
Timer *timer_abort(Timer *timer);
-/** Set the timer so that it calls an user hook when it expires */
+/**
+ * Set the timer so that it calls an user hook when it expires
+ *
+ * Sometimes you may want to use the same callback for different events, so you must have
+ * different data to operate on. The user_data parameter is such data.
+ *
+ * \param timer Timer struct to set the callback to
+ * \param func Function that will be called when the timer expires
+ * \param user_data Additional data you may want to pass to the callback
+ */
INLINE void timer_setSoftint(Timer *timer, Hook func, iptr_t user_data)
{
event_initSoftint(&timer->expire, func, user_data);
}
-/** Set the timer delay (the time before the event will be triggered) */
+/**
+ * Set the timer delay (the time before the event will be triggered)
+ *
+ * \note It's illegal to change the delay of the timer when it's
+ * still running.
+ */
INLINE void timer_setDelay(Timer *timer, ticks_t delay)
{
timer->_delay = delay;
}
+
+void synctimer_add(Timer *timer, List* q);
+
+/** \sa timer_abort */
+#define synctimer_abort(t) timer_abort(t)
+
+void synctimer_poll(List* q);
+
+/**
+ * Extract the timeout for the next event.
+ *
+ * \return Timeout of the next event (may be 0), or -1 on errors.
+ */
+INLINE ticks_t synctimer_nextTimeout(List *q)
+{
+ ticks_t timeout = -1;
+
+ if (!LIST_EMPTY(q))
+ {
+ Timer *expiring_timer = (Timer *)LIST_HEAD(q);
+ timeout = MAX(expiring_timer->tick - timer_clock(), (ticks_t)0);
+ }
+ return timeout;
+}
+
+/*
+ * Explicitly mark a timer as executed.
+ *
+ * When a timer is marked as executed, it is inactive until the next
+ * call to synctimer_add().
+ * Normally you shouldn't need to call this function explicitly, as all
+ * timers in this module are designed to stop themselves after a while
+ * (eg. retransmission timer will stop after a few retransmissions).
+ * The only exception is at startup, where you should mark all timers
+ * as executed to avoid spurious events.
+ *
+ * \note We can't rely on REMOVE() of synctimer_poll() since in release mode
+ * it is empty.
+ */
+INLINE void synctimer_executed(Timer *t)
+{
+ memset(&t->link, 0, sizeof(Node));
+}
+
+/*
+ * Test if a timer is active.
+ *
+ * In the general case it should be ATOMIC() and timer.link should always
+ * be memset() to 0.
+ */
+INLINE bool synctimer_active(Timer *t)
+{
+ return !(t->link.pred == NULL && t->link.succ == NULL);
+}
+
+
+INLINE void synctimer_stop(Timer *timer)
+{
+ if (synctimer_active(timer))
+ {
+ timer_abort(timer);
+ synctimer_executed(timer);
+ }
+}
+
+INLINE void synctimer_restart(Timer *timer, List *list, mtime_t timeout)
+{
+ synctimer_stop(timer);
+
+ timer_setDelay(timer, ms_to_ticks(timeout));
+ synctimer_add(timer, list);
+}
+
+void synctimer_readd(Timer *timer, List *queue);
+
#endif /* CONFIG_TIMER_EVENTS */
#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
#endif /* CONFIG_KERN_SIGNALS */
+/** \} */ //defgroup drv_timers
+
#endif /* DRV_TIMER_H */
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