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/*

 * Copyright (c) 2007 Jan Hudecek

 * Copyright (c) 2006 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.

 */

/** @addtogroup sync

 * @{

 */

/** @file

 */

#ifndef KERN_RCU_H_

#define KERN_RCU_H_

#include <arch/types.h>

#include <proc/tasklet.h>

#include <arch/barrier.h>

#include <arch.h>

#include <preemption.h>

typedef struct rcu_callback_list {

    struct rcu_callback_list* next;

    void (*func)(void*);

    void* data;

} rcu_callback_list_t;

/** Read lock for RCU protected pointer */

#define rcu_read_lock() preemption_disable()

/** Release of read lock for RCU protected pointer */

#define rcu_read_unlock() preemption_enable()

/** Dereferencing of an RCU protected pointer */

#define rcu_dereference_pointer(p) (*(p))

/** Assigning a value to an RCU protected pointer */

#define rcu_assign_pointer(p, newp) {write_barrier(); (p)=(newp);}

/** RCU sync callback for those who don't need custom allocation */

#define rcu_sync_callback_normal_alloc(func, data) {\

    rcu_callback_list_t* rd = malloc(sizeof(rcu_callback_list_t),0);\

    rcu_sync_callback(func, data, rd);}

/** RCU sync callback without custom allocation, default callback (just frees the argument) */

#define rcu_sync_callback_normal_alloc_free(data) rcu_sync_callback_normal_alloc(&rcu_callback_free, data)

void rcu_init(void);

void rcu_synchronize(void);

void rcu_synchronize_callback_function(void* waitq);

void rcu_sync_callback(void (*func)(void* data), void* data, rcu_callback_list_t* rcu_struct);

void rcu_tasklet(void* data);  

void rcu_passQS(void);

void rcu_run_callbacks(void);

void rcu_callback_free(void* pointer);

#endif