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56 lines
1.5 KiB
C
56 lines
1.5 KiB
C
/*
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* Bitmap-based link-listable fixed-size memory cache.
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*
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* Copyright (C) 2007 Bahadir Balban
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*/
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#ifndef __MEMCACHE_H__
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#define __MEMCACHE_H__
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#include <l4/config.h>
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#include <l4/macros.h>
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#include <l4/types.h>
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#include <l4/lib/list.h>
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#include <l4/lib/mutex.h>
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/*
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* Very basic cache structure. All it does is, keep an internal bitmap of
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* items of struct_size. (Note bitmap is fairly efficient and simple for a
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* fixed-size memory cache) Keeps track of free/occupied items within its
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* start/end boundaries. Does not grow/shrink but you can link-list it.
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*/
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struct mem_cache {
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struct link list;
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struct mutex mutex;
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int total;
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int free;
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unsigned int start;
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unsigned int end;
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unsigned int struct_size;
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unsigned int *bitmap;
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};
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int mem_cache_bufsize(void *start, int struct_size, int nstructs, int aligned);
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void *mem_cache_zalloc(struct mem_cache *cache);
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void *mem_cache_alloc(struct mem_cache *cache);
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int mem_cache_free(struct mem_cache *cache, void *addr);
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struct mem_cache *mem_cache_init(void *start, int cache_size,
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int struct_size, unsigned int alignment);
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static inline int mem_cache_is_full(struct mem_cache *cache)
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{
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return cache->free == 0;
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}
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static inline int mem_cache_is_empty(struct mem_cache *cache)
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{
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return cache->free == cache->total;
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}
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static inline int mem_cache_is_last_free(struct mem_cache *cache)
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{
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return cache->free == 1;
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}
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static inline int mem_cache_total_empty(struct mem_cache *cache)
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{
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return cache->free;
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}
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#endif /* __MEMCACHE_H__ */
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