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/*

 * Copyright (c) 2007 Jan Hudecek

 * Copyright (c) 2005 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - 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.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <synch/rcu.h>

#include <print.h>

#include <test.h>

#include <arch/types.h>

#include <proc/tasklet.h>

#include <arch/barrier.h>

#include <arch.h>

#include <preemption.h>

#include <proc/thread.h>

#define RCU_MAX_I 1000

#define READER_THREADS 10

#define WRITER_THREADS 10

#define THREADS_SLEEP_LENGTH (uint32_t)50

bool gquiet;

volatile bool finished;

typedef struct data_struc {

    int number;

    struct data_struc* next;

} data_t;

data_t* first;

SPINLOCK_INITIALIZE(write_lock);

static void reader(void* a)

{

    a = (a);

    data_t* cur;

    int i = 0;

    while (true)

    {

        i = 0;

        rcu_read_lock();

        for (cur = rcu_dereference_pointer(first).next; cur != first; cur = cur->next) {

            i += rcu_dereference_pointer(cur).number;

        }

        rcu_read_unlock();

        thread_usleep(THREADS_SLEEP_LENGTH);

        if (i>RCU_MAX_I || finished)

        {

            printf("@");

            break;

        }

    }

    finished = true;

}

static void writer(void* a)

{

    a = (a);

    data_t* cur;

    data_t* newdata, *oldata;

    rcu_callback_list_t* rcudata;

    int i = 0;

    printf("a1 ");

    rcudata = malloc(sizeof(rcu_callback_list_t),0);

    while (true)

    {

        i = rcu_dereference_pointer(first).number;

        rcu_read_lock();

        printf("a2 ");

        for (cur = rcu_dereference_pointer(first).next; cur != first; cur = rcu_dereference_pointer(cur).next) {

            i += rcu_dereference_pointer(cur).number;

        }

        rcu_read_unlock();

        if (!gquiet)

            printf("i%d ",i);

        if (i>RCU_MAX_I || finished)

        {

            printf("!");

            break;

        }

        printf("a2b ");

        thread_usleep(THREADS_SLEEP_LENGTH);

        printf("a3 ");

        newdata = malloc(sizeof(data_t),0);

        printf("a4 ");

        rcu_read_lock();

        //prepend a new member

        spinlock_lock(&write_lock);

        printf("a5 ");

        newdata->number = (i/10)+1;

        oldata = first;

        newdata->next = first;

        rcu_assign_pointer(first, newdata);

        printf("a6 ");

        rcu_sync_callback(&rcu_callback_free, oldata, rcudata);

        spinlock_unlock(&write_lock);

        printf("a7 ");

        rcu_read_unlock();

        thread_usleep(THREADS_SLEEP_LENGTH);

        printf("a8 ");

        if (!gquiet)

            printf(".",i);

        rcu_read_lock();

        for (cur = rcu_dereference_pointer(first).next; rcu_dereference_pointer(cur).number % 5 != 4 && cur != first; cur = rcu_dereference_pointer(cur).next) {

        }

        if (cur != first){

            //delete the cur->next

            spinlock_lock(&write_lock);

            oldata = rcu_dereference_pointer(cur).next;

            newdata->next = rcu_dereference_pointer(rcu_dereference_pointer(cur).next).next;

            rcu_assign_pointer(rcu_dereference_pointer(cur).next, newdata);

            rcu_sync_callback(&rcu_callback_free, oldata, rcudata);

            spinlock_unlock(&write_lock);

            if (!gquiet)

                printf(", ",i);

        }

        rcu_read_unlock();

        thread_usleep(THREADS_SLEEP_LENGTH);

    }

    finished = true;

}

char * test_rcu1(bool quiet)

{

    gquiet = quiet;

    data_t* cur, *oldata;

    int i;

    thread_t* t;

    thread_t** threads;

    first = malloc(sizeof(data_t),0);

    first->number = 10;

    first->next = first;

    threads = malloc(sizeof(thread_t*),0);

    finished = false;

    for(i = 0; i< WRITER_THREADS; i++) {

        threads[i]=t=thread_create(writer,NULL, TASK, 0, "writerthread", false );

        if (t != NULL)

            thread_ready(t);

    }

    for(i = 0; i< READER_THREADS; i++) {

        threads[WRITER_THREADS+i]=t=thread_create(reader,NULL, TASK, 0, "readerthread", false );

        if (t != NULL)

            thread_ready(t);

    }

    for (i=0;i<WRITER_THREADS+READER_THREADS;i++)

        thread_join(threads[i]);

    for(cur=first->next;cur->next!=first;) {

        oldata = cur->next;

        free(cur);

        cur = oldata;

    }

    free(first);

    return NULL;

}