/*
 *   Lock free FIFO
 *    
 *   Copyright (C) Robert Ham 2002, 2003 (node_AT_users.sourceforge.net)
 *    
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __LOCK_FREE_FIFO_H__
#define __LOCK_FREE_FIFO_H__

#include <asm/atomic.h>

typedef struct _lff lff_t;

/** lock free fifo ring buffer structure */
struct _lff {

  /** Size of the ringbuffer (in elements) */
  unsigned int size;

  /** the memory containing the ringbuffer */
  void * data;

  /** the size of an element */
  size_t object_size;

  /** the current position of the reader */
  atomic_t read_index;

  /** the current position of the writer */
  atomic_t write_index;
};

void lff_init (lff_t * lff, unsigned int size, size_t object_size);
void lff_free (lff_t * lff);

lff_t * lff_new     (unsigned int size, size_t object_size);
void    lff_destroy (lff_t * lock_free_fifo);
               
int lff_read (lff_t * lock_free_fifo, void * data);
int lff_write (lff_t * lock_free_fifo, const void * data);

#endif /* __LOCK_FREE_FIFO_H__ */