#include <mango/sched.h>
#include <mango/cpu.h>

void wait_item_init(struct wait_item *item, struct thread *thr)
{
	item->w_thread = thr;
	item->w_entry = QUEUE_ENTRY_INIT;
}

void thread_wait_begin(struct wait_item *waiter, struct waitqueue *q)
{
	unsigned long flags;
	spin_lock_irqsave(&q->wq_lock, &flags);

	queue_push_back(&q->wq_waiters, &waiter->w_entry);
	waiter->w_thread->tr_state = THREAD_SLEEPING;

	spin_unlock_irqrestore(&q->wq_lock, flags);
}

void thread_wait_end(struct wait_item *waiter, struct waitqueue *q)
{
	waiter->w_thread->tr_state = THREAD_READY;

	unsigned long flags;
	spin_lock_irqsave(&q->wq_lock, &flags);

	queue_delete(&q->wq_waiters, &waiter->w_entry);

	spin_unlock_irqrestore(&q->wq_lock, flags);
}

void wakeup_queue(struct waitqueue *q)
{
	unsigned long flags;
	spin_lock_irqsave(&q->wq_lock, &flags);
	struct queue_entry *ent = queue_pop_front(&q->wq_waiters);
	while (ent) {
		struct wait_item *waiter = QUEUE_CONTAINER(struct wait_item, w_entry, ent);
		struct thread *thr = waiter->w_thread;
		struct runqueue *rq = thr->tr_rq;
		if (!rq) {
			rq = cpu_rq(this_cpu());
		}

		thr->tr_state = THREAD_READY;
		rq_enqueue(rq, thr);

		ent = queue_pop_front(&q->wq_waiters);
	}

	spin_unlock_irqrestore(&q->wq_lock, flags);
}

void wakeup_one(struct waitqueue *q)
{
	unsigned long flags;
	spin_lock_irqsave(&q->wq_lock, &flags);
	struct queue_entry *ent = queue_pop_front(&q->wq_waiters);
	if(ent) {
		struct wait_item *waiter = QUEUE_CONTAINER(struct wait_item, w_entry, ent);
		struct thread *thr = waiter->w_thread;
		struct runqueue *rq = thr->tr_rq;
		if (!rq) {
			rq = cpu_rq(this_cpu());
		}

		thr->tr_state = THREAD_READY;
		rq_enqueue(rq, thr);
	}

	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);
	}
}