Add handy functions for handling non recurrent timeouts.

[bertos.git] / bertos / drv / timer.h

diff --git a/bertos/drv/timer.h b/bertos/drv/timer.h
index 50d118a9f8845824f9483ab81ceef7cc0640dd54..f20212e7e1e01ec4fe7706703e8a955e68cff5d8 100644 (file)
--- a/bertos/drv/timer.h
+++ b/bertos/drv/timer.h
@@ -30,6 +30,10 @@
  * Copyright 2000, 2008 Bernie Innocenti <bernie@codewiz.org>
  * -->
  *
+ * \defgroup drv_timers Timer module
+ * \ingroup core
+ * \{
+ *
  * \brief Hardware independent timer driver.
  *
  * All timer related functions are implemented in this module. You have several options to use timers:
@@ -58,6 +62,7 @@
 #include <cpu/attr.h>
 #include <cpu/irq.h>
 
+#include <string.h>
 
 /*
  * Include platform-specific binding header if we're hosted.
@@ -96,6 +101,9 @@ STATIC_ASSERT(sizeof(hptime_t) == SIZEOF_HPTIME_T);
 
 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)
  *
@@ -284,7 +292,12 @@ 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;
@@ -298,6 +311,72 @@ void synctimer_add(Timer *timer, List* q);
 
 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 */
 
@@ -313,4 +392,6 @@ INLINE void timer_setSignal(Timer *timer, struct Process *proc, sigmask_t sigs)
 
 #endif /* CONFIG_KERN_SIGNALS */
 
+/** \} */ //defgroup drv_timers
+
 #endif /* DRV_TIMER_H */