#include "synchro.h"
#include "alloc.h"
#include "assert.h"
#include "irq.h"
#include "klibc.h"
#include "list.h"
#include "time.h"

struct wait_queue *waitQueues = NULL;

int mutexInit(struct mutex *m)
{
    uint32_t flags;

    m->owner = NULL;
    m->wait  = (struct wait_queue *)malloc(sizeof(struct wait_queue));
    if (!m->wait)
        return ENOMEM;
    list_init(m->wait->thread);

    disable_IRQs(flags);
    list_add_tail(waitQueues, m->wait);
    restore_IRQs(flags);

    return 0;
}

int mutexFree(struct mutex *m)
{
    int ret = 0;

    if (m) {
        uint32_t flags;

        disable_IRQs(flags);
        if (list_is_empty(m->wait)) {
#ifdef DEBUG
            if (m->owner) {
                printf("Warning: freeing a owned mutex 0x%. owned by 0x%p 0x%p\n", m, m->owner,
                       getCurrentThread());
            }
#endif
            list_delete(waitQueues, m->wait);
            free(m->wait);
        } else {
            ret = EBUSY;
        }
        restore_IRQs(flags);
    }

    return ret;
}

int mutexLock(struct mutex *m)
{
    uint32_t flags;
    struct kthread *current;

    disable_IRQs(flags);
    current = getCurrentThread();
    assert(m->owner != current);
    wait_event(m->wait, m->owner == NULL);
    m->owner = current;

    restore_IRQs(flags);

    return 0;
}

int mutexUnlock(struct mutex *m)
{
    uint32_t flags;

    disable_IRQs(flags);
    assert(m->owner == getCurrentThread());

    m->owner = NULL;

    wake_up(m->wait);

    restore_IRQs(flags);

    return 0;
}