Initial commit

include/l4/lib/memcache.h

@@ -0,0 +1,54 @@
+/*
+ * 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 list_head list;
+	struct mutex mutex;
+	int total;
+	int free;
+	unsigned int start;
+	unsigned int end;
+	unsigned int struct_size;
+	unsigned int *bitmap;
+};
+
+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__ */