/*
 * Copyright 2022, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef _OBSD_COMPAT_SYS_REFCNT_H_
#define _OBSD_COMPAT_SYS_REFCNT_H_


#include <sys/systm.h>


struct refcnt {
        int32   r_refs;
};


#define REFCNT_INITIALIZER()            { .r_refs = 1 }


static void
refcnt_init(struct refcnt* r)
{
        atomic_set(&r->r_refs, 1);
}

static void
refcnt_take(struct refcnt* r)
{
        int32 refs;

        refs = atomic_add(&r->r_refs, 1);
        KASSERT(refs != 0);
        (void)refs;
}

static int
refcnt_rele(struct refcnt* r)
{
        int32 refs;

        refs = atomic_add(&r->r_refs, -1) - 1;
        KASSERT(refs >= 0);
        if (refs == 0)
                return 1;
        return 0;
}

static void
refcnt_rele_wake(struct refcnt* r)
{
        if (refcnt_rele(r))
                wakeup_one(r);
}

static void
refcnt_finalize(struct refcnt* r, const char* wmesg)
{
        refcnt_rele(r);
        while (r->r_refs > 0)
                tsleep(r, PWAIT, wmesg, 0);
}


#endif  /* _OBSD_COMPAT_SYS_REFCNT_H_ */