MDK5 keil 下动态内存分配以及使用事例

1.打开mdk的Operation选项，在target栏目里选中Use MicroLIB选项以便支持malloc-free函数原型

                    

2.打开stm32工程源码，找到start_stm32f10x_md.s文件修改：Heap_Size       EQU     0x00001000

/*************************************************************************
	> File Name: /mnt/hgfs/I/PROJECT/Charger/RegrahcOOP/USER/xlist.h
	> Author: XXDK
	> Email: [email protected] 
	> Created Time: 2016年12月26日 星期一 19时04分35秒
 ************************************************************************/

#ifndef _XLIST_H
#define _XLIST_H

#include "string.h"
#include "stdlib.h"
#include "usart.h"

/*
 * Simple doubly linked list implementation.
 *
 */
struct list_head {
	struct list_head *next, *prev; 
};

struct hlist_head {
	struct hlist_node *first;
};

struct hlist_node {
	struct hlist_node *next, **pprev;	
};
/*
 * 自定义数据结构示例：
 */
struct message 
{
	int id;
	int data;
	struct list_head list;
};

#define LIST_HEAD_INIT(name) { &(name), &(name) }

/*
 * 定义链表类型变量name, 并且初始化其prev 和next 
 * 成员变量指向自身
 * */
#define LIST_HEAD(name) \
	struct list_head name = LIST_HEAD_INIT(name)

/*
 * 遍历由head所领导的所有数据结构节点
 * */		
#define list_for_each(pos, head) \
	for (pos = (head)->next; pos != (head); pos = pos->next)

/*
 * 获取链表所在的数据结构的地址
 * @ptr: 指向数据结构的某成员的指针
 * @type: 该数据结构的类型
 * @member: 数据结构的某数据成员变量
 */	
#define list_entry(ptr, type, member) \
	((type*)((char*)(ptr) - (unsigned long)(&((type*)0)->member)))

// 示例函数	
struct message* create_node(void);
void dynamic_memory_allocate_example(void);

/*
 * 初始化一个空链表
 * */
static inline void INIT_LIST_HEAD(struct list_head* list)
{
	list->next = list;
	list->prev = list;
}

/*
 * Insert a new entry between two know consecutive entries.
 * This is only for internal list manipulation where we 
 * know the prev/next entries already. 
 * */
static inline void __list_add(struct list_head *new, 
		struct list_head *prev, struct list_head *next)
{
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
}
/**
 * Add a new entry 
 * Insert a new entry after the specified head.
 * This is good for implementing stacks.
 * */
static inline void list_add(struct list_head *new,
		struct list_head *head)
{
	__list_add(new, head, head->next);
}

/**
 * Add a new entry
 * Insert a new entry before the specified head.
 * This is useful for implementing queue.
 * **/

static inline void list_add_tail(struct list_head *new,
		struct list_head *head)
{
	__list_add(new, head->prev, head);
}

/**
 * Delete a list entry by making the prev/next entries 
 * point to each other.
 * This is only for internal list manipulation where we
 * know the prev/next entries already.
 * */

static inline void __list_del(struct list_head *prev, 
		struct list_head *next)
{
	next->prev = prev;
	prev->next = next;
}

/**
 * deletes entry from list.
 * */
static inline void __list_del_entry(struct list_head* entry)
{
	__list_del(entry->prev, entry->next);
}

static inline void list_del(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
	entry->next = 0;
	entry->prev = 0;
}

/*
 * Replace old entry by new one
 *
 * */
static inline void list_replace(struct list_head *old,
		struct list_head *new)
{
	new->next = old->next;
	new->next->prev = new;
	new->prev = old->prev;
	new->prev->next = new;
}

static inline void list_replace_init(struct list_head* old, 
		struct list_head *new)
{
	list_replace(old, new);
	INIT_LIST_HEAD(old);
}

static inline void list_del_init(struct list_head* entry)
{
	__list_del_entry(entry);
	INIT_LIST_HEAD(entry);
}

/*
 *	Delete from one list and add as another's head.
 * */
static inline void list_move(struct list_head *list,
		struct list_head* head)
{
	__list_del_entry(list);
	list_add(list, head);
}

static inline void list_move_tail(struct list_head *list, struct list_head *head)
{
	__list_del_entry(list);
	list_add_tail(list, head);
}

static inline int list_is_last(const struct list_head *list, 
		struct list_head *head)
{
	return list->next == head;
}

static inline int list_empty(const struct list_head *head)
{
	
	return head->next == head;
}

#endif // _XLIST_H

#include "xlist.h"

struct message* create_node(void)
{

	struct message *pmsg = (struct message*)malloc(sizeof(struct message));
	if (0 == pmsg) {
		printk(KERN_ALERT"allocate memory error.\r\n");
		return 0;
	}
	memset(pmsg, 0, sizeof(struct message));
	
	return pmsg;
}

void dynamic_memory_allocate_example(void)
{	
	struct message *tmp;
	struct list_head *pos;
	LIST_HEAD(msg_head);
	
	for (int i = 0; i < 10; i++) {
		struct message *pmsg =  create_node();
		if(pmsg == 0)
			printk(KERN_ALERT"create node error\r\n");
		pmsg->id = i;
		pmsg->data = i*10;
		list_add(&pmsg->list, &msg_head);
	}
	
	//for (pos = (head)->next; pos != (head); pos = pos->next)
	list_for_each(pos, &msg_head) {
		tmp = list_entry(pos, struct message, list);
		printk(KERN_ALERT"message id: %d, data: %d\r\n", tmp->id, tmp->data);
	}
}