/*      $NetBSD: workqueue.c,v 1.10 2023/08/10 22:20:20 riastradh Exp $ */

/*-
 * Copyright (c) 2017 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#if !defined(lint)
__RCSID("$NetBSD: workqueue.c,v 1.10 2023/08/10 22:20:20 riastradh Exp $");
#endif /* !lint */

#include <sys/param.h>
#include <sys/condvar.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/kthread.h>
#include <sys/mutex.h>
#include <sys/workqueue.h>

#include "kernspace.h"

struct test_softc {
        kmutex_t mtx;
        kcondvar_t cv;
        struct workqueue *wq;
        struct work wk;
        int counter;
        bool pause;
};

static void
rump_work1(struct work *wk, void *arg)
{
        struct test_softc *sc = arg;

        memset(wk, 0x5a, sizeof(*wk));

        if (sc->pause)
                kpause("tstwk1", /*intr*/false, /*timo*/2, /*lock*/NULL);

        mutex_enter(&sc->mtx);
        ++sc->counter;
        cv_broadcast(&sc->cv);
        mutex_exit(&sc->mtx);
}

static struct test_softc *
create_sc(void)
{
        int rv;
        struct test_softc *sc;

        sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
        mutex_init(&sc->mtx, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&sc->cv, "rumpwqcv");
        rv = workqueue_create(&sc->wq, "rumpwq",
            rump_work1, sc, PRI_SOFTNET, IPL_SOFTNET, 0);
        if (rv)
                panic("workqueue creation failed: %d", rv);

        sc->counter = 0;

        return sc;
}

static void
destroy_sc(struct test_softc *sc)
{

        cv_destroy(&sc->cv);
        mutex_destroy(&sc->mtx);
        workqueue_destroy(sc->wq);
}

void
rumptest_workqueue1()
{
        struct test_softc *sc;

        sc = create_sc();

#define ITERATIONS 12435
        for (int i = 0; i < ITERATIONS; ++i) {
                int e;
                mutex_enter(&sc->mtx);
                workqueue_enqueue(sc->wq, &sc->wk, NULL);
                e = cv_timedwait(&sc->cv, &sc->mtx, hz * 2);
                if (e != 0)
                        panic("cv_timedwait timed out (i=%d)", i);
                mutex_exit(&sc->mtx);
        }

        KASSERT(sc->counter == ITERATIONS);

        destroy_sc(sc);
#undef ITERATIONS
}

void
rumptest_workqueue_wait(void)
{
        struct test_softc *sc;
        struct work dummy;

        sc = create_sc();

#define ITERATIONS 12435
        for (size_t i = 0; i < ITERATIONS; ++i) {
                KASSERT(sc->counter == i);
                workqueue_enqueue(sc->wq, &sc->wk, NULL);
                workqueue_wait(sc->wq, &sc->wk);
                KASSERT(sc->counter == (i + 1));
        }

        KASSERT(sc->counter == ITERATIONS);

        /* Wait for a work that is not enqueued. Just return immediately. */
        workqueue_wait(sc->wq, &dummy);

        destroy_sc(sc);
#undef ITERATIONS
}

void
rumptest_workqueue_wait_pause(void)
{
        struct test_softc *sc;
        struct work dummy;

        sc = create_sc();
        sc->pause = true;

#define ITERATIONS 1
        for (size_t i = 0; i < ITERATIONS; ++i) {
                struct work wk;

                KASSERT(sc->counter == i);
                workqueue_enqueue(sc->wq, &wk, NULL);
                workqueue_enqueue(sc->wq, &sc->wk, NULL);
                kpause("tstwk2", /*intr*/false, /*timo*/1, /*lock*/NULL);
                workqueue_wait(sc->wq, &sc->wk);
                workqueue_wait(sc->wq, &wk);
                KASSERT(sc->counter == (i + 2));
        }

        KASSERT(sc->counter == 2*ITERATIONS);

        /* Wait for a work that is not enqueued. Just return immediately. */
        workqueue_wait(sc->wq, &dummy);

        destroy_sc(sc);
#undef ITERATIONS
}