[cache_writeback] Coded, needs testing

block-cache/mem_pool.h

@@ -0,0 +1,45 @@
+#ifndef BLOCK_CACHE_MEM_POOL_H
+#define BLOCK_CACHE_MEM_POOL_H
+
+#include <boost/intrusive/list.hpp>
+#include <boost/optional.hpp>
+#include <list>
+
+namespace bi = boost::intrusive;
+
+//----------------------------------------------------------------
+
+namespace bcache {
+	// FIXME: move to base?
+
+	namespace mempool_detail {
+		struct alloc_block : public bi::list_base_hook<> {
+		};
+	};
+
+	class mempool {
+	public:
+		mempool(size_t block_size, size_t total_mem);
+		~mempool();
+
+		boost::optional<void *> alloc();
+		void free(void *data);
+
+	private:
+		static void *alloc_aligned(size_t len, size_t alignment);
+
+		using block_list = bi::list<mempool_detail::alloc_block>;
+
+		void *mem_;
+		block_list free_;
+
+		//----------------
+
+		mempool(mempool const &) = delete;
+		mempool &operator =(mempool const &) = delete;
+	};
+}
+
+//----------------------------------------------------------------
+
+#endif