#include <lunaix/ds/waitq.h>
#include <lunaix/process.h>
#include <lunaix/sched.h>
#include <lunaix/spike.h>

void
pwait(waitq_t* queue)
{
    assert(current_thread);
    // prevent race condition.
    cpu_disable_interrupt();

    waitq_t* current_wq = &current_thread->waitqueue;
    assert(llist_empty(&current_wq->waiters));

    llist_append(&queue->waiters, &current_wq->waiters);

    block_current_thread();
    sched_pass();

    // In case of SIGINT-forced awaken
    llist_delete(&current_wq->waiters);
    cpu_enable_interrupt();
}

void
pwake_one(waitq_t* queue)
{
    if (llist_empty(&queue->waiters)) {
        return;
    }

    waitq_t* wq = list_entry(queue->waiters.next, waitq_t, waiters);
    struct thread* thread = container_of(wq, struct thread, waitqueue);

    assert(thread->state == PS_BLOCKED);
    thread->state = PS_READY;
    llist_delete(&wq->waiters);
}

void
pwake_all(waitq_t* queue)
{
    if (llist_empty(&queue->waiters)) {
        return;
    }

    struct thread* thread;
    waitq_t *pos, *n;
    llist_for_each(pos, n, &queue->waiters, waiters)
    {
        thread = container_of(pos, struct thread, waitqueue);

        assert(thread->state == PS_BLOCKED);
        thread->state = PS_READY;
        llist_delete(&pos->waiters);
    }
}