作者：piaolingtear

來源：http://blog.csdn.net/u011833609/article/details/46834203

本代碼基于無操作系統的個簡管理STM32單片機開發，功能強大，單而的單可申請到地址空間連續的強大器不同大小的內存空間，且用戶接口簡單，片機使用方便。內存直接貼代碼：

memory.h：

#ifndef?__MEMORY_H__
#define?__MEMORY_H__
?
#include?"stdio.h"
#include?"string.h"
#include?"includes.h"
//用戶使用
typedef?struct
{ 
????void????*addr;??????//申請到的個簡管理內存的起始地址
????uint32_t?size;??????//申請到的內存的大小，按照塊大小分配，單而的單大于等于申請大小
????uint16_t??tb;???????//申請表序號，強大器申請內存時分配，片機釋放內存時使用，內存用戶不使用
}DMEM;
?
//若返回空，則申請失敗
DMEM?*DynMemGet(uint32_t?size);
void?DynMemPut(DMEM?*pDmem);
?
#endif?//__MEMORY_H__

memory.c：

#include?"memory.h"
?
#define?DMEM_BLOCK_SIZE?????????256??????//內存塊大小為128字節
#define?DMEM_BLOCK_NUM??????????20???????//內存塊個數為40個
#define?DMEM_TOTAL_SIZE?????????(DMEM_BLOCK_SIZE*DMEM_BLOCK_NUM)????//內存總大小
?
typedef?enum
{ 
????DMEM_FREE???=?0,
????DMEM_USED???=?1,
}DMEM_USED_ITEM;
?
typedef?struct
{ 
????DMEM_USED_ITEM???used;???????//使用狀態
????uint16_t?????????blk_s;??????//起始塊序號
????uint16_t?????????blk_num;????//塊個數
}DMEM_APPLY;
?
typedef?struct
{ 
????DMEM_USED_ITEM??tb_blk[DMEM_BLOCK_NUM];
????DMEM????????????tb_user[DMEM_BLOCK_NUM];????????//用戶申請內存信息
????DMEM_APPLY??????tb_apply[DMEM_BLOCK_NUM];???????//系統分配內存信息
????uint16_t????????apply_num;??????//內存申請表占用數目
????uint16_t????????blk_num;????????//內存塊占用數目
}DMEM_STATE;
?
static?uint8_t?DMEMORY[DMEM_TOTAL_SIZE];
static?DMEM_STATE?DMEMS?=?{ 0};

DMEM?*DynMemGet(uint32_t?size)
{ 
????uint16_t?loop?=?0;
????uint16_t?find?=?0;
????uint16_t?blk_num_want?=?0;
????DMEM?*?user?=?NULL;
????DMEM_APPLY?*apply?=?NULL;
????
????//申請內存大小不能為0
????if(size?==?0)???????????????{ ???return?NULL;????}
????//申請內存不可超過總內存大小
????if(size?>?DMEM_TOTAL_SIZE)??{ ???return?NULL;????}
????//申請內存不可超過剩余內存大小
????if(size?>?(DMEM_BLOCK_NUM?-?DMEMS.blk_num)?*?DMEM_BLOCK_SIZE)???{ ???return?NULL;????}
????//申請表必須有空余
????if(DMEMS.apply_num?>=?DMEM_BLOCK_NUM)???{ ???return?NULL;????}
????
????//計算所需連續塊的個數
????blk_num_want?=?(size?+?DMEM_BLOCK_SIZE?-?1)?/?DMEM_BLOCK_SIZE;
????
????//尋找申請表
????for(loop?=?0;?loop?????{ 
????????if(DMEMS.tb_apply[loop].used?==?DMEM_FREE)
????????{ 
????????????apply?=?&DMEMS.tb_apply[loop];??????????????????//申請表已找到
????????????user?=?&DMEMS.tb_user[loop];????????????????????//用戶表對應找到
????????????user->tb?=?loop;????????????????????????????????//申請表編號記錄
????????????user->size?=?blk_num_want?*?DMEM_BLOCK_SIZE;????//分配大小計算
????????????break;
????????}
????}
????
????//沒有找到可用申請表，理論上是不會出現此現象的，申請表剩余已在上面校驗
????if(loop?==?DMEM_BLOCK_NUM)??{ ???return?NULL;????}
????
????//尋找連續內存塊
????for(loop?=?0;?loop?????{ 
????????if(DMEMS.tb_blk[loop]?==?DMEM_FREE)
????????{ //找到第一個空閑內存塊
????????????for(find?=?1;?(find?????????????{ //找到下一個空閑內存塊
????????????????if(DMEMS.tb_blk[loop?+?find]?!=?DMEM_FREE)
????????????????{ //發現已使用內存塊
????????????????????break;
????????????????}
????????????}
????????????if(find?>=?blk_num_want)
????????????{ //尋找到的空閑內存塊數目已經夠用
????????????????user->addr?=?DMEMORY?+?loop?*?DMEM_BLOCK_SIZE;??//計算申請到的內存的地址
????????????????apply->blk_s?=?loop;????????????????????????????//記錄申請到的內存塊首序號
????????????????apply->blk_num?=?blk_num_want;??????????????????//記錄申請到的內存塊數目
????????????????for(find?=?0?;?find?blk_num;?find++)
????????????????{ 
????????????????????DMEMS.tb_blk[loop?+?find]?=?DMEM_USED;
????????????????}
????????????????apply->used?=?DMEM_USED;????????????????????????//標記申請表已使用
????????????????DMEMS.apply_num?+=?1;
????????????????DMEMS.blk_num?+=?blk_num_want;
????????????????
????????????????return?user;
????????????}
????????????else
????????????{ //尋找到的空閑內存塊不夠用，從下一個開始找
????????????????loop?+=?find;
????????????}
????????}
????}
????
????//搜索整個內存塊，未找到大小適合的空間
????return?NULL;
}
?
void?DynMemPut(DMEM?*user)
{ 
????uint16_t?loop?=?0;
????//若參數為空，直接返回
????if(NULL?==?user)????{ ???return;?}
????
????//釋放內存空間
????for(loop?=?DMEMS.tb_apply[user->tb].blk_s;?loop?tb].blk_s?+?DMEMS.tb_apply[user->tb].blk_num;?loop++)
????{ 
????????DMEMS.tb_blk[loop]?=?DMEM_FREE;
????????DMEMS.blk_num?-=?1;
????}
????//釋放申請表
????DMEMS.tb_apply[user->tb].used?=?DMEM_FREE;
????DMEMS.apply_num?-=?1;
}