/* lock functions  */

void lock_init(lock_t * l)
{
	spinlock_init(&l->spinlock);
	l->waiting = NULL;
	l->status = UNLOCKED;
}

void lock_acquire(lock_t * l)
{
	spinlock_acquire(&l->spinlock);
	if (l->status == LOCKED) {
		block(&l->waiting, &l->spinlock);
	} else {
		l->status = LOCKED;
		spinlock_release(&l->spinlock);
	}
}

void lock_release(lock_t * l)
{
	spinlock_acquire(&l->spinlock);
	if (l->waiting)
		unblock(&l->waiting);
	else
		l->status = UNLOCKED;
	spinlock_release(&l->spinlock);
}

/* condition functions */
void condition_init(condition_t * c)
{
	spinlock_init(&c->spinlock);
	c->waiting = NULL;
}

/*
 * unlock m and block the thread (enqued on c), when unblocked acquire
 * lock m
 */
void condition_wait(lock_t * m, condition_t * c)
{
	spinlock_acquire(&c->spinlock);
	lock_release(m); //TODO revise it all
	block(&c->waiting, &c->spinlock);
	lock_acquire(m);
}

/* unblock first thread enqued on c */
void condition_signal(condition_t * c)
{
	spinlock_acquire(&c->spinlock);
	if (c->waiting)
		unblock(&c->waiting);
	spinlock_release(&c->spinlock);
}

/* unblock all threads enqued on c */
void condition_broadcast(condition_t * c)
{
	spinlock_acquire(&c->spinlock);
	while (c->waiting)
		unblock(&c->waiting);
	spinlock_release(&c->spinlock);
}