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/*

 * Bitmap-based link-listable fixed-size memory cache.

 *

 * Copyright (C) 2007 Bahadir Balban

 */

#ifndef __MEMCACHE_H__

#define __MEMCACHE_H__

#include <l4/config.h>

#include <l4/macros.h>

#include <l4/types.h>

#include <l4/lib/list.h>

#include <l4/lib/mutex.h>

/*

 * Very basic cache structure. All it does is, keep an internal bitmap of

 * items of struct_size. (Note bitmap is fairly efficient and simple for a

 * fixed-size memory cache) Keeps track of free/occupied items within its

 * start/end boundaries. Does not grow/shrink but you can link-list it.

 */

struct mem_cache {

        struct link list;

        struct mutex mutex;

        int total;

        int free;

        unsigned int start;

        unsigned int end;

        unsigned int struct_size;

        unsigned int *bitmap;

};

int mem_cache_bufsize(void *start, int struct_size, int nstructs, int aligned);

void *mem_cache_zalloc(struct mem_cache *cache);

void *mem_cache_alloc(struct mem_cache *cache);

int mem_cache_free(struct mem_cache *cache, void *addr);

struct mem_cache *mem_cache_init(void *start, int cache_size,

                                 int struct_size, unsigned int alignment);

static inline int mem_cache_is_full(struct mem_cache *cache)

{

        return cache->free == 0;

}

static inline int mem_cache_is_empty(struct mem_cache *cache)

{

        return cache->free == cache->total;

}

static inline int mem_cache_is_last_free(struct mem_cache *cache)

{

        return cache->free == 1;

}

static inline int mem_cache_total_empty(struct mem_cache *cache)

{

        return cache->free;

}

#endif /* __MEMCACHE_H__ */