sim: realize sim timer tickless

Signed-off-by: ligd <liguiding1@xiaomi.com>

arch/sim/src/sim/posix/sim_hosttime.c

@@ -93,29 +93,40 @@ void host_sleepuntil(uint64_t nsec)
  *   Set up a timer to send periodic signals.
  *
  * Input Parameters:
- *   irq - a pointer where we save the host signal number for SIGALRM
+ *   nsec - timer expire time
  *
  * Returned Value:
  *   On success, (0) zero value is returned, otherwise a negative value.
  *
  ****************************************************************************/
 
-int host_settimer(int *irq)
+int host_settimer(uint64_t nsec)
 {
   struct itimerval it;
 
-  if (irq == NULL)
-    {
-      return -EINVAL;
-    }
-
-  *irq = SIGALRM;
-
   it.it_interval.tv_sec  = 0;
-  it.it_interval.tv_usec = CONFIG_USEC_PER_TICK;
-  it.it_value            = it.it_interval;
-
-  /* Start a host timer at a rate indicated by CONFIG_USEC_PER_TICK */
+  it.it_interval.tv_usec = 0;
+  it.it_value.tv_sec     = nsec / 1000000000;
+  it.it_value.tv_usec    = (nsec + 1000) / 1000;
 
   return setitimer(ITIMER_REAL, &it, NULL);
 }
+
+/****************************************************************************
+ * Name: host_timerirq
+ *
+ * Description:
+ *   Get timer irq
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   On success, irq num returned, otherwise a negative value.
+ *
+ ****************************************************************************/
+
+int host_timerirq(void)
+{
+  return SIGALRM;
+}

arch/sim/src/sim/sim_internal.h

@@ -177,7 +177,8 @@ void host_mallinfo(int *aordblks, int *uordblks);
 uint64_t host_gettime(bool rtc);
 void host_sleep(uint64_t nsec);
 void host_sleepuntil(uint64_t nsec);
-int host_settimer(int *irq);
+int host_timerirq(void);
+int host_settimer(uint64_t nsec);
 
 /* sim_sigdeliver.c *********************************************************/
 

arch/sim/src/sim/sim_oneshot.c

@@ -122,6 +122,52 @@ static inline void sim_timer_current(struct timespec *ts)
   ts->tv_nsec = nsec;
 }
 
+/****************************************************************************
+ * Name: sim_update_hosttimer
+ *
+ * Description:
+ *   Ths function is called periodically to deliver the tick events to the
+ *   NuttX simulation.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SIM_WALLTIME_SIGNAL
+static void sim_update_hosttimer(void)
+{
+  struct timespec *next = NULL;
+  struct timespec current;
+  sq_entry_t *entry;
+  uint64_t nsec;
+
+  for (entry = sq_peek(&g_oneshot_list); entry; entry = sq_next(entry))
+    {
+      struct sim_oneshot_lowerhalf_s *priv =
+        container_of(entry, struct sim_oneshot_lowerhalf_s, link);
+
+      if (next == NULL)
+        {
+          next = &priv->alarm;
+          continue;
+        }
+
+      if (clock_timespec_compare(next, &priv->alarm) > 0)
+        {
+          next = &priv->alarm;
+        }
+    }
+
+  sim_timer_current(&current);
+  clock_timespec_subtract(next, &current, &current);
+
+  nsec  = current.tv_sec * NSEC_PER_SEC;
+  nsec += current.tv_nsec;
+
+  host_settimer(nsec);
+}
+#else
+#  define sim_update_hosttimer()
+#endif
+
 /****************************************************************************
  * Name: sim_timer_update_internal
  *
@@ -134,11 +180,18 @@ static inline void sim_timer_current(struct timespec *ts)
 static void sim_timer_update_internal(void)
 {
   sq_entry_t *entry;
+  irqstate_t flags;
+
+  flags = enter_critical_section();
 
   for (entry = sq_peek(&g_oneshot_list); entry; entry = sq_next(entry))
     {
       sim_process_tick(entry);
     }
+
+  sim_update_hosttimer();
+
+  leave_critical_section(flags);
 }
 
 /****************************************************************************
@@ -244,15 +297,22 @@ static int sim_start(struct oneshot_lowerhalf_s *lower,
   struct sim_oneshot_lowerhalf_s *priv =
     (struct sim_oneshot_lowerhalf_s *)lower;
   struct timespec current;
+  irqstate_t flags;
 
   DEBUGASSERT(priv != NULL && callback != NULL && ts != NULL);
 
+  flags = enter_critical_section();
+
   sim_timer_current(&current);
   clock_timespec_add(&current, ts, &priv->alarm);
 
   priv->callback = callback;
   priv->arg      = arg;
 
+  sim_update_hosttimer();
+
+  leave_critical_section(flags);
+
   return OK;
 }
 
@@ -286,15 +346,25 @@ static int sim_cancel(struct oneshot_lowerhalf_s *lower,
   struct sim_oneshot_lowerhalf_s *priv =
     (struct sim_oneshot_lowerhalf_s *)lower;
   struct timespec current;
+  irqstate_t flags;
 
   DEBUGASSERT(priv != NULL && ts != NULL);
 
+  flags = enter_critical_section();
+
   sim_timer_current(&current);
   clock_timespec_subtract(&priv->alarm, &current, ts);
 
+  priv->alarm.tv_sec  = UINT_MAX;
+  priv->alarm.tv_nsec = NSEC_PER_SEC - 1;
+
+  sim_update_hosttimer();
+
   priv->callback = NULL;
   priv->arg      = NULL;
 
+  leave_critical_section(flags);
+
   return OK;
 }
 
@@ -329,7 +399,7 @@ static int sim_current(struct oneshot_lowerhalf_s *lower,
 
 #ifdef CONFIG_SIM_WALLTIME_SIGNAL
 /****************************************************************************
- * Name: sim_alarm_handler
+ * Name: sim_timer_handler
  *
  * Description:
  *   The signal handler is called periodically and is used to deliver TICK
@@ -342,7 +412,7 @@ static int sim_current(struct oneshot_lowerhalf_s *lower,
  *
  ****************************************************************************/
 
-static int sim_alarm_handler(int irq, void *context, void *arg)
+static int sim_timer_handler(int irq, void *context, void *arg)
 {
   sim_timer_update_internal();
   return OK;
@@ -408,14 +478,12 @@ struct oneshot_lowerhalf_s *oneshot_initialize(int chan,
 void up_timer_initialize(void)
 {
 #ifdef CONFIG_SIM_WALLTIME_SIGNAL
-  int host_alarm_irq;
-
-  host_settimer(&host_alarm_irq);
+  int timer_irq = host_timerirq();
 
   /* Enable the alarm handler and attach the interrupt to the NuttX logic */
 
-  up_enable_irq(host_alarm_irq);
-  irq_attach(host_alarm_irq, sim_alarm_handler, NULL);
+  up_enable_irq(timer_irq);
+  irq_attach(timer_irq, sim_timer_handler, NULL);
 #endif
 
   up_alarm_set_lowerhalf(oneshot_initialize(0, 0));

arch/sim/src/sim/win/sim_hosttime.c

@@ -120,14 +120,33 @@ void host_sleepuntil(uint64_t nsec)
  *   Set up a timer to send periodic signals.
  *
  * Input Parameters:
- *   irq - a pointer where we save the host signal number for SIGALRM
+ *   nsec - timer expire time
  *
  * Returned Value:
  *   On success, (0) zero value is returned, otherwise a negative value.
  *
  ****************************************************************************/
 
-int host_settimer(int *irq)
+int host_settimer(uint64_t nsec)
 {
   return -ENOSYS;
 }
+
+/****************************************************************************
+ * Name: host_timerirq
+ *
+ * Description:
+ *   Get timer irq
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   On success, irq num returned, otherwise a negative value.
+ *
+ ****************************************************************************/
+
+int host_timerirq(void)
+{
+  return 0;
+}