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- apply DOKs cosmetic changes

/*
   (c) Copyright 2004  convergence GmbH

   All rights reserved.

   Written by Michael Hunold <hunold@convergence.de> and
              Denis Oliver Kropp <dok@directfb.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the
   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
*/

#ifndef __SOFTMPEG__LIST_H__
#define __SOFTMPEG__LIST_H__

#include "internal.h"

/* Simple doubly linked list implementation
with additional item count and mutex for locking */

struct list_element {
	struct list_element *next, *prev;
};

struct list {
	struct list_element head;
	unsigned int offset;
	pthread_mutex_t mutex;
	unsigned int items;
};

#define link_to_element(liste, link) \
	(void*) (((char*) link) - (liste)->offset)

#define element_to_link(liste, element) \
        (struct list_element*) (((char*) element) + (liste)->offset)

static __inline__ void list_init(struct list *l, unsigned int offset)
{
	l->head.next = &l->head;
	l->head.prev = &l->head;
	l->items = 0;
	l->offset = offset;
	pthread_mutex_init(&l->mutex, NULL);
}

static __inline__ void list_lock(struct list *l)
{
	pthread_mutex_lock(&l->mutex);
}

static __inline__ void list_unlock(struct list *l)
{
	pthread_mutex_unlock(&l->mutex);
}

static __inline__ void list_add_tail(void *new_element, struct list *l)
{
	struct list_element *to_add = element_to_link(l, new_element);
	struct list_element *prev = l->head.prev;
	struct list_element *next = &l->head;

	next->prev = to_add;
	to_add->next = next;
	to_add->prev = prev;
	prev->next = to_add;

	l->items++;
}

static __inline__ void element_del(struct list_element *entry)
{
	struct list_element *prev = entry->prev;
	struct list_element *next = entry->next;

	next->prev = prev;
	prev->next = next;
}

static __inline__ void *list_del_head(struct list *l)
{
	struct list_element *lh = l->head.next;
	element_del(lh);
	l->items--;
	return link_to_element(l, lh);
}

static __inline__ void *list_get_head(struct list *l)
{
	struct list_element *lh = l->head.next;
	return link_to_element(l, lh);
}

static __inline__ int list_empty(struct list *l)
{
	return l->head.next == &l->head;
}

#endif