From d8748d5c545a428eaeded92708f1e4e5d8cc8249 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=82=B9=E6=99=93=E8=88=AA?= <1210603696@qq.com>
Date: Wed, 17 Sep 2014 09:56:06 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0Alloc=E7=A9=BA=E9=97=B4?=
 =?UTF-8?q?=E9=85=8D=E7=BD=AE=E5=99=A8=E7=9A=84=E7=B1=BB=E5=A3=B0=E6=98=8E?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 TinySTL/Alloc.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 TinySTL/Alloc.h

diff --git a/TinySTL/Alloc.h b/TinySTL/Alloc.h
new file mode 100644
index 0000000..b474787
--- /dev/null
+++ b/TinySTL/Alloc.h
@@ -0,0 +1,49 @@
+#ifndef _ALLOC_H_
+#define _ALLOC_H_
+
+namespace TinySTL{
+
+	/*
+	**空间配置器
+	*/
+	class alloc{
+	private:
+		enum EAlign{ ALIGN = 8};//小型区块的上调边界
+		enum EMaxBytes{ MAXBYTES = 128};//小型区块的上限
+		enum ENFreeLists{ NFREELISTS = (EMaxBytes::MAXBYTES / EAlign::ALIGN)};//free-lists的个数
+	private:
+		//free-lists的节点构造
+		union obj{
+			union obj *next;
+			char client[1];
+		};
+
+		static obj *free_list[ENFreeLists::NFREELISTS];
+	private:
+		static char *start_free;//内存池起始位置
+		static char *end_free;//内存池结束位置
+		static size_t heap_size;//
+	private:
+		//将bytes上调至8的倍数
+		static size_t ROUND_UP(size_t bytes){
+			return ((bytes + EAlign::ALIGN - 1) & ~(EAlign::ALIGN - 1));
+		}
+		//根据区块大小，决定使用第n号free-list，n从0开始计算
+		static size_t FREELIST_INDEX(size_t bytes){
+			return (((bytes)+EAlign::ALIGN - 1) / EAlign::ALIGN - 1);
+		}
+		//返回一个大小为n的对象，并可能加入大小为n的其他区块到free-list
+		static void *refill(size_t n);
+		//配置一大块空间，可容纳nobjs个大小为size的区块
+		//如果配置nobjs个区块有所不便，nobjs可能会降低
+		static char *chunk_alloc(size_t size, size_t& nobjs);
+
+	public:
+		static void *allocate(size_t bytes);
+		static void deallocate(void *ptr, size_t bytes);
+		static void *reallocate(void *ptr, size_t old_sz, size_t new_sz);
+	};
+
+}
+
+#endif
\ No newline at end of file