* Copyright 1999, 2001, 2003 Bernie Innocenti <bernie@codewiz.org>
* -->
*
+ * \defgroup event_handling Event handling module
+ * \ingroup core
+ * \{
+ *
* \brief Events handling
*
* This module implements a common system for executing
* a user defined action calling a hook function.
*
- * NOTE: Generic completion events
*
* Device drivers often need to wait the completion of some event, usually to
* allow the hardware to accomplish some asynchronous task.
* behaviour with or without the kernel.
*
* Example usage (wait for a generic device driver initialization):
- * \verbatim
+ * \code
* static Event e;
*
* static void irq_handler(void)
* // Wait for the completion of the event
* event_wait(&e);
* }
- * \endverbatim
+ * \endcode
*
* \author Bernie Innocenti <bernie@codewiz.org>
*/
struct Process;
#endif
-
/// User defined callback type
typedef void (*Hook)(void *);
#endif
-/**
- * Prevent the compiler from optimizing access to the variable \a x, enforcing
- * a refetch from memory. This also forbid from reordering successing instances
- * of ACCESS_SAFE().
- *
- * TODO: move this to cfg/compiler.h
- */
-#define ACCESS_SAFE(x) (*(volatile typeof(x) *)&(x))
-
#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
/** Initialize the generic sleepable event \a e */
#define event_initGeneric(e) \
/**
* Wait the completion of event \a e.
+ *
+ * This function releases the CPU the application is configured to use
+ * the kernel, otherwise it's just a busy wait.
+ * \note It's forbidden to use this function inside irq handling functions.
*/
INLINE void event_wait(Event *e)
{
/**
* Wait the completion of event \a e or \a timeout elapses.
+ *
+ * \note It's forbidden to use this function inside irq handling functions.
*/
INLINE bool event_waitTimeout(Event *e, ticks_t timeout)
{
+ bool ret;
+
#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
e->Ev.Sig.sig_proc = proc_current();
- return (sig_waitTimeout(e->Ev.Sig.sig_bit, timeout) & SIG_TIMEOUT) ?
+ ret = (sig_waitTimeout(e->Ev.Sig.sig_bit, timeout) & SIG_TIMEOUT) ?
false : true;
#else
ticks_t end = timer_clock() + timeout;
- bool ret;
while ((ACCESS_SAFE(e->Ev.Gen.completed) == false) ||
TIMER_AFTER(timer_clock(), end))
cpu_relax();
ret = e->Ev.Gen.completed;
e->Ev.Gen.completed = false;
+#endif
MEMORY_BARRIER;
-
return ret;
-#endif
}
#endif /* CONFIG_TIMER_EVENTS */
-/** Trigger an event */
+/**
+ * Trigger an event.
+ *
+ * Execute the callback function associated with event \a e.
+ *
+ * This function can be used also in interrupt routines, but only if the
+ * event was created as a signal or generic event.
+ */
INLINE void event_do(struct Event *e)
{
e->action(e);
}
+/** \} */
+
#endif /* KERN_EVENT_H */