source: rtems/cpukit/libfs/src/jffs2/include/linux/list.h @ 78b85286

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 *
 * Created by Jonathan Larmour <jlarmour@redhat.com>
 * 
 *===========================================================================
 * ####ECOSGPLCOPYRIGHTBEGIN####                                            
 * -------------------------------------------                              
 * This file is part of eCos, the Embedded Configurable Operating System.   
 * Copyright (C) 2002, 2003 Free Software Foundation, Inc.                  
 *
 * eCos 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 or (at your option) any later      
 * version.                                                                 
 *
 * eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,    
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
 *
 * As a special exception, if other files instantiate templates or use      
 * macros or inline functions from this file, or you compile this file      
 * and link it with other works to produce a work based on this file,       
 * this file does not by itself cause the resulting work to be covered by   
 * the GNU General Public License. However the source code for this file    
 * must still be made available in accordance with section (3) of the GNU   
 * General Public License v2.                                               
 *
 * This exception does not invalidate any other reasons why a work based    
 * on this file might be covered by the GNU General Public License.         
 * -------------------------------------------                              
 * ####ECOSGPLCOPYRIGHTEND####                                              
 *===========================================================================
 *
 */

#ifndef CYGONCE_FS_JFFS2_LIST_H
#define CYGONCE_FS_JFFS2_LIST_H


/* -----------------------------------------------------------------------*/

/* Doubly linked list implementation to replace the GPL'd one used in
   the Linux kernel. */

#include <stddef.h>
#include <cyg/infra/cyg_type.h>

/* TYPES */

struct list_head {
    struct list_head *next;
    struct list_head *prev;
};

/* MACROS */

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
        struct list_head name = LIST_HEAD_INIT(name)

#define INIT_LIST_HEAD( _list_ )              \
CYG_MACRO_START                               \
(_list_)->next = (_list_)->prev = (_list_);   \
CYG_MACRO_END

/* FUNCTIONS */

/* Insert an entry _after_ the specified entry */
static __inline__ void
list_add( struct list_head *newent, struct list_head *afterthisent )
{
    struct list_head *next = afterthisent->next;
    newent->next = next;
    newent->prev = afterthisent;
    afterthisent->next = newent;
    next->prev = newent;
} /* list_add() */

/* Insert an entry _before_ the specified entry */
static __inline__ void
list_add_tail( struct list_head *newent, struct list_head *beforethisent )
{
    struct list_head *prev = beforethisent->prev;
    newent->prev = prev;
    newent->next = beforethisent;
    beforethisent->prev = newent;
    prev->next = newent;
} /* list_add_tail() */

/* Delete the specified entry */
static __inline__ void
list_del( struct list_head *ent )
{
    ent->prev->next = ent->next;
    ent->next->prev = ent->prev;
} /* list_del() */

static __inline__ void
list_move( struct list_head *list, struct list_head *head )
{
    list_del( list );
    list_add( list, head );
}

static __inline__ void
list_move_tail( struct list_head *list, struct list_head *head )
{
    list_del( list );
    list_add_tail( list, head );
}

/* Is this list empty? */
static __inline__ int
list_empty( struct list_head *list )
{
    return ( list->next == list );
} /* list_empty() */

/* list_entry - Assuming you have a struct of type _type_ that contains a
   list which has the name _member_ in that struct type, then given the
   address of that list in the struct, _list_, this returns the address
   of the container structure */

#define list_entry( _list_, _type_, _member_ ) \
    ((_type_ *)((char *)(_list_)-(char *)(offsetof(_type_,_member_))))

/* list_for_each - using _ent_, iterate through list _list_ */

#define list_for_each( _ent_, _list_ )   \
    for ( (_ent_) = (_list_)->next;      \
    (_ent_) != (_list_);                 \
    (_ent_) = (_ent_)->next )

/*
 * list_for_each_entry - this function can be use to iterate over all
 * items in a list* _list_ with it's head at _head_ and link _item_
 */
#define list_for_each_entry(_list_, _head_, _item_)                     \
for ((_list_) = list_entry((_head_)->next, typeof(*_list_), _item_); \
     &((_list_)->_item_) != (_head_);                                 \
     (_list_) = list_entry((_list_)->_item_.next, typeof(*_list_), _item_))

/* -----------------------------------------------------------------------*/
#endif /* #ifndef CYGONCE_FS_JFFS2_LIST_H */
/* EOF list.h */