sched: add support for scheduling functions to be executed later

sched/wait.c

@@ -71,3 +71,21 @@ void wakeup_one(struct waitqueue *q)
 
 	spin_unlock_irqrestore(&q->wq_lock, flags);
 }
+
+void sleep_forever(void)
+{
+	struct thread *thr = current_thread();
+	struct runqueue *rq = thr->tr_rq;
+
+	unsigned long flags;
+	rq_lock(rq, &flags);
+
+	rq_remove_thread(rq, thr);
+	thr->tr_state = THREAD_SLEEPING;
+
+	rq_unlock(rq, flags);
+
+	while (thr->tr_state == THREAD_SLEEPING) {
+		schedule(SCHED_NORMAL);
+	}
+}