/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include <assert.h>
#include <string.h>
#include "os/mynewt.h"

SLIST_HEAD(, os_sanity_check) g_os_sanity_check_list =
    SLIST_HEAD_INITIALIZER(os_sanity_check_list);

struct os_mutex g_os_sanity_check_mu;

int
os_sanity_check_init(struct os_sanity_check *sc)
{
    memset(sc, 0, sizeof(*sc));

    return (0);
}

/**
 * Lock the sanity check list
 *
 * @return 0 on success, error code on failure.
 */
static int
os_sanity_check_list_lock(void)
{
    int rc;

    if (!g_os_started) {
        return (0);
    }

    rc = os_mutex_pend(&g_os_sanity_check_mu, OS_WAIT_FOREVER);
    if (rc != OS_OK) {
        goto err;
    }

    return (0);
err:
    return (rc);
}

/**
 * Unlock the sanity check list
 *
 * @return 0 on success, error code on failure
 */
static int
os_sanity_check_list_unlock(void)
{
    int rc;

    if (!g_os_started) {
        return (0);
    }

    rc = os_mutex_release(&g_os_sanity_check_mu);
    if (rc != 0) {
        goto err;
    }

    return (0);
err:
    return (rc);
}

int
os_sanity_task_checkin(struct os_task *t)
{
    int rc;

    if (t == NULL) {
        t = os_sched_get_current_task();
    }

    rc = os_sanity_check_reset(&t->t_sanity_check);
    if (rc != OS_OK) {
        goto err;
    }

    return (0);
err:
    return (rc);
}


int
os_sanity_check_register(struct os_sanity_check *sc)
{
    int rc;

    rc = os_sanity_check_list_lock();
    if (rc != OS_OK) {
        goto err;
    }

    SLIST_INSERT_HEAD(&g_os_sanity_check_list, sc, sc_next);

    rc = os_sanity_check_list_unlock();
    if (rc != OS_OK) {
        goto err;
    }

    return (0);
err:
    return (rc);
}


int
os_sanity_check_reset(struct os_sanity_check *sc)
{
    int rc;

    rc = os_sanity_check_list_lock();
    if (rc != OS_OK) {
        goto err;
    }

    sc->sc_checkin_last = os_time_get();

    rc = os_sanity_check_list_unlock();
    if (rc != OS_OK) {
        goto err;
    }

    return (0);
err:
    return (rc);
}

/*
 * Called from the IDLE task context, every MYNEWT_VAL(SANITY_INTERVAL) msecs.
 *
 * Goes through the sanity check list, and performs sanity checks.  If any of
 * these checks failed, or tasks have not checked in, it resets the processor.
 */
void
os_sanity_run(void)
{
    struct os_sanity_check *sc;
    int rc;

    rc = os_sanity_check_list_lock();
    if (rc != 0) {
        assert(0);
    }

    SLIST_FOREACH(sc, &g_os_sanity_check_list, sc_next) {
        rc = OS_OK;

        if (sc->sc_func) {
            rc = sc->sc_func(sc, sc->sc_arg);
            if (rc == OS_OK) {
                sc->sc_checkin_last = os_time_get();
                continue;
            }
        }

        if (OS_TIME_TICK_GT(os_time_get(),
                    sc->sc_checkin_last + sc->sc_checkin_itvl)) {
            assert(0);
        }
    }

    rc = os_sanity_check_list_unlock();
    if (rc != 0) {
        assert(0);
    }
}

int
os_sanity_init(void)
{
    int rc;

    rc = os_mutex_init(&g_os_sanity_check_mu);
    if (rc != 0) {
        goto err;
    }

    return (0);
err:
    return (rc);
}