sched: Introduce sched_wake_tasks() function to wake up tasks

Add function to indicate when tasks need to be run.  This will allow
the scheduler code to know if there are any tasks that need to be
processed.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/sched.c

@@ -28,6 +28,9 @@ static struct timer sentinel_timer, deleted_timer;
 static uint_fast8_t
 periodic_event(struct timer *t)
 {
+    // Make sure the stats task runs periodically
+    sched_wake_tasks();
+    // Reschedule timer
     periodic_timer.waketime += timer_from_us(100000);
     sentinel_timer.waketime = periodic_timer.waketime + 0x80000000;
     return SF_RESCHEDULE;
@@ -177,10 +180,17 @@ sched_timer_reset(void)
  * Task waking
  ****************************************************************/
 
+// Note that at least one task is ready to run
+void
+sched_wake_tasks(void)
+{
+}
+
 // Note that a task is ready to run
 void
 sched_wake_task(struct task_wake *w)
 {
+    sched_wake_tasks();
     writeb(&w->wake, 1);
 }