{
}
-#if CONFIG_KERN_SIGNALS
+void event_hook_softint(Event *e)
+{
+ e->Ev.Int.func(e->Ev.Int.user_data);
+}
+
+void event_hook_generic(Event *e)
+{
+ e->Ev.Gen.completed = true;
+ MEMORY_BARRIER;
+}
+
+#if CONFIG_KERN && CONFIG_KERN_SIGNALS
void event_hook_signal(Event *e)
{
sig_post((e)->Ev.Sig.sig_proc, (e)->Ev.Sig.sig_bit);
void event_hook_generic_signal(Event *e)
{
- sig_postSignal(&e->Ev.SigGen.sig,
- e->Ev.SigGen.sig_proc,
- EVENT_GENERIC_SIGNAL);
+ sig_postSignal(&e->Ev.Sig.sig, e->Ev.Sig.sig_proc, e->Ev.Sig.sig_bit);
}
-#endif
-void event_hook_softint(Event *e)
+/*
+ * Custom event hook to notify the completion of a event monitored via
+ * event_select().
+ */
+static void event_hook_generic_multiple_signal(Event *e)
{
- e->Ev.Int.func(e->Ev.Int.user_data);
+ sig_post(e->Ev.Sig.sig_proc, e->Ev.Sig.sig_bit);
}
-void event_hook_generic(Event *e)
+/*
+ * Custom timer hook to notify the timeout of a event_waitTimeout().
+ */
+static void event_hook_generic_timeout_signal(void *arg)
{
- e->Ev.Gen.completed = true;
- MEMORY_BARRIER;
+ Event *e = (Event *)arg;
+
+ sig_postSignal(&e->Ev.Sig.sig, e->Ev.Sig.sig_proc, SIG_TIMEOUT);
}
-/**
- * Wait for multiple events
- *
- * On success return the offset in the \a evs vector of the Event that
- * happened, -1 if the timeout expires.
+/*
+ * event_waitTimeout() slow path: this function put the current process to
+ * sleep until the event is notified. The timeout is managed using the custom
+ * timer hook event_hook_generic_timeout_signal(): if the timeout expires the
+ * signal SIG_TIMEOUT is notified via sig_post() to the sigmask embedded in the
+ * event.
*
- * NOTE: timeout == 0 means no timeout.
+ * The custom timer hook is required because the default timer's behaviour is
+ * to use the process's sigmask to notify the completion of an event, that is
+ * not suitable for this case, because we're sleeping on the event's sigmask
+ * instead.
*/
-#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
-int event_select(Event **evs, int n, ticks_t timeout)
+static NOINLINE bool event_waitTimeoutSlowPath(Event *e, ticks_t timeout)
+{
+ bool ret;
+
+ e->Ev.Sig.sig_proc = proc_current();
+ ret = (sig_waitTimeoutSignal(&e->Ev.Sig.sig,
+ EVENT_GENERIC_SIGNAL, timeout,
+ event_hook_generic_timeout_signal, e) & SIG_TIMEOUT) ?
+ false : true;
+ return ret;
+}
+
+bool event_waitTimeout(Event *e, ticks_t timeout)
+{
+ /*
+ * Fast path: check if the event already happened and return
+ * immediately in this case.
+ */
+ if (sig_checkSignal(&e->Ev.Sig.sig,
+ EVENT_GENERIC_SIGNAL) == EVENT_GENERIC_SIGNAL)
+ return true;
+ return event_waitTimeoutSlowPath(e, timeout);
+}
+
+/*
+ * event_select() slow path: this function handles the case when any event was
+ * not yet notified, so it takes care of making the current process to sleep on
+ * the list of events, mapping them to a different signal bit and issuing a
+ * call to sig_waitTimeout() using the process's sigmask.
+ */
+static NOINLINE int event_selectSlowPath(Event **evs, int n, ticks_t timeout)
{
sigmask_t mask = (1 << n) - 1;
int i;
- ASSERT(n <= SIG_USER_MAX);
for (i = 0; i < n; i++)
{
Event *e = evs[i];
+
/* Map each event to a distinct signal bit */
- event_initSignal(e, proc_current(), 1 << i);
+ e->Ev.Sig.sig_proc = proc_current();
+ e->Ev.Sig.sig_bit = 1 << i;
+ e->action = event_hook_generic_multiple_signal;
}
+ IRQ_ENABLE;
+
mask = timeout ? sig_waitTimeout(mask, timeout) : sig_wait(mask);
- i = UINT8_LOG2(mask);
+ if (mask & SIG_TIMEOUT)
+ return -1;
+ return UINT8_LOG2(mask);
+}
+
+int event_select(Event **evs, int n, ticks_t timeout)
+{
+ int i;
- return i < n ? i : -1;
+ ASSERT(n <= SIG_USER_MAX);
+
+ IRQ_DISABLE;
+ /* Fast path: check if one of the event already happened */
+ for (i = 0; i < n; i++)
+ {
+ Event *e = evs[i];
+
+ if (__sig_checkSignal(&e->Ev.Sig.sig,
+ EVENT_GENERIC_SIGNAL) == EVENT_GENERIC_SIGNAL)
+ {
+ IRQ_ENABLE;
+ return i;
+ }
+ }
+ /* Otherwise, fallback to the slow path */
+ return event_selectSlowPath(evs, n, timeout);
}
-#else
+#else /* !(CONFIG_KERN && CONFIG_KERN_SIGNALS) */
+bool event_waitTimeout(Event *e, ticks_t timeout)
+{
+ 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;
+ MEMORY_BARRIER;
+
+ return ret;
+}
+
int event_select(Event **evs, int n, ticks_t timeout)
{
ticks_t end = timer_clock() + timeout;
}
return -1;
}
-#endif
+#endif /* CONFIG_KERN && CONFIG_KERN_SIGNALS */
#include <cpu/power.h> /* cpu_relax() */
-#if CONFIG_KERN
- #if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
- #include <kern/signal.h>
- #endif
-
- /* Forward decl */
- struct Process;
+#if CONFIG_KERN && CONFIG_KERN_SIGNALS
+#include <kern/signal.h>
+/* Forward decl */
+struct Process;
#endif
typedef struct Event
void (*action)(struct Event *);
union
{
-#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
+#if CONFIG_KERN && CONFIG_KERN_SIGNALS
struct
{
struct Process *sig_proc; /* Process to be signalled */
sigbit_t sig_bit; /* Signal to send */
+ Signal sig; /* Local signal structure (used by generic event) */
} Sig;
-
- struct
- {
- struct Process *sig_proc; /* Process to be signalled */
- Signal sig; /* Signal structure */
- } SigGen;
#endif
struct
{
((e)->action = event_hook_ignore)
/** Same as event_initNone(), but returns the initialized event */
-INLINE Event event_createNone(void);
INLINE Event event_createNone(void)
{
Event e;
return e;
}
-#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
-
+#if CONFIG_KERN && CONFIG_KERN_SIGNALS
/** Initialize the event \a e with a signal (send signal \a s to process \a p) */
#define event_initSignal(e,p,s) \
((e)->action = event_hook_signal,(e)->Ev.Sig.sig_proc = (p), (e)->Ev.Sig.sig_bit = (s))
return e;
}
-#endif
+/**
+ * Signal used to implement generic events.
+ */
+#define EVENT_GENERIC_SIGNAL SIG_SYSTEM6
-#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
/** Initialize the generic sleepable event \a e */
#define event_initGeneric(e) \
((e)->action = event_hook_generic_signal, \
- (e)->Ev.SigGen.sig_proc = proc_current(), \
- (e)->Ev.SigGen.sig.wait = 0, (e)->Ev.SigGen.sig.recv = 0)
+ (e)->Ev.Sig.sig_proc = proc_current(), \
+ (e)->Ev.Sig.sig_bit = EVENT_GENERIC_SIGNAL, \
+ (e)->Ev.Sig.sig.wait = 0, (e)->Ev.Sig.sig.recv = 0)
#else
#define event_initGeneric(e) \
((e)->action = event_hook_generic, (e)->Ev.Gen.completed = false)
#endif
-/**
- * Signal used to implement generic events.
- */
-#define EVENT_GENERIC_SIGNAL SIG_SYSTEM5
-
/**
* Create a generic sleepable event.
*
*/
INLINE void event_wait(Event *e)
{
-#if defined(CONFIG_KERN_SIGNALS) && CONFIG_KERN_SIGNALS
+#if CONFIG_KERN_SIGNALS
e->Ev.Sig.sig_proc = proc_current();
- sig_waitSignal(&e->Ev.SigGen.sig, EVENT_GENERIC_SIGNAL);
+ sig_waitSignal(&e->Ev.Sig.sig, EVENT_GENERIC_SIGNAL);
#else
while (ACCESS_SAFE(e->Ev.Gen.completed) == false)
cpu_relax();
#endif
}
+/**
+ * Wait for multiple events
+ *
+ * On success return the offset in the \a evs vector of the Event that
+ * happened, -1 if the timeout expires.
+ *
+ * NOTE: timeout == 0 means no timeout.
+ *
+ * \attention The API is work in progress and may change in future versions.
+ */
int event_select(Event **evs, int n, ticks_t timeout);
-#if CONFIG_TIMER_EVENTS
-#include <drv/timer.h> /* timer_clock() */
-
/**
* 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();
- ret = (sig_waitTimeoutSignal(&e->Ev.SigGen.sig,
- EVENT_GENERIC_SIGNAL, timeout) & SIG_TIMEOUT) ?
- false : true;
-#else
- ticks_t end = timer_clock() + timeout;
-
- 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 /* CONFIG_TIMER_EVENTS */
+bool event_waitTimeout(Event *e, ticks_t timeout);
/**
* Trigger an event.
projects / bertos.git / commitdiff