在ARM嵌入式系統實現malloc內存分配機制。

在ARM cpu上驗證通過。

ps：也可在pc ubuntu linux進行驗證

#include "include/lib_replace.h"#include "usb.h"//#define TEST_MALLOC y #ifdef TEST_MALLOC #include <stdio.h> #define PRINT printf #else #define PRINT print #endif#define MEM_SIZE 0x1500 //5kchar __attribute((aligned (16))) mem[MEM_SIZE]; //16 byte aligned #define MEM_START &mem[0] #define MEM_END &mem[MEM_SIZE]// #define MEM_START 0x400012fb0 // #define MEM_END 0x400012fb0 + MEM_SIZE // #define mem ((void *) MEM_START)#define UNUSED 0 #define USED 1#define PACKED_SIZE 16#pragma pack(8) typedef struct mem_block{ /*定義內存管理塊的數據結構*/void *mem_ptr; /*當前內存塊的內存地址*/struct mem_block *nxt_ptr; /*下一個內存管理塊的地址*/u64 mem_size; /*當前內存塊的大小*/u64 mem_sta; /*當前內存塊的狀態*/ }mem_block; #pragma pack()#define BLK_SIZE sizeof(mem_block) /*內存管理塊的大小*/ #define HEAD_NODE (MEM_END - BLK_SIZE)/*頭內存管理塊的地址*/static signed char mem_init_flag = -1; /*內存分配系統初始化的標志(-1 未初始化),(1 已初始化)*/ static int total_size = 0;int get_total_size(void) {return total_size; }void *memset_pro(void *addr, char c, unsigned int size) {int i;unsigned long long *p = (unsigned long long *)addr;unsigned int cnt = size / sizeof(unsigned long long);//unsigned int cnt2 = size % sizeof(unsigned long long);if(p == NULL)return NULL;for(i = 0; i < cnt; i ++){*(p + i) = c;}return addr; }void mem_init_ex(void) {PRINT("mem_init_ex: MEM_START:%p, MEM_END:%p, HEAD_NODE:%p, BLK_SIZE:%d\r\n", mem, (void *)MEM_END, (void *)HEAD_NODE, BLK_SIZE);mem_block *node;memset_pro(mem, 0, sizeof(mem));node = (mem_block *)HEAD_NODE;node->mem_ptr = MEM_START;node->nxt_ptr = (mem_block *)HEAD_NODE;node->mem_size = MEM_SIZE - BLK_SIZE;node->mem_sta = UNUSED;mem_init_flag = 1; }void *malloc_ex(unsigned int nbytes) {u64 suit_size = 0xFFFFFFFFFFFFUL;mem_block *head_node=NULL, *tmp_node=NULL, *suit_node=NULL;if(nbytes % PACKED_SIZE)nbytes = (nbytes/PACKED_SIZE + 1) * PACKED_SIZE;//PRINT("malloc_ex size:%d\r\n", nbytes);if(nbytes == 0){return NULL;}if(mem_init_flag < 0){mem_init_ex();}head_node = tmp_node = (mem_block *)HEAD_NODE;while(1){if(tmp_node->mem_sta == UNUSED){if(nbytes <= tmp_node->mem_size && tmp_node->mem_size < suit_size){suit_node = tmp_node;suit_size = suit_node->mem_size;}}tmp_node = tmp_node->nxt_ptr;if(tmp_node == head_node){if(suit_node == NULL){PRINT("NULL\r\n");return NULL;}break;}}if(nbytes <= suit_node->mem_size && (nbytes + BLK_SIZE) >= suit_node->mem_size){suit_node->mem_sta = USED;total_size += nbytes;PRINT("malloc_ex: addr:%p, size:%d\r\n", suit_node->mem_ptr, nbytes);return suit_node->mem_ptr;}else if(suit_node->mem_size > (nbytes + BLK_SIZE)){tmp_node = suit_node->mem_ptr; tmp_node = (mem_block *)((unsigned char *)tmp_node + nbytes);tmp_node->mem_ptr = suit_node->mem_ptr;tmp_node->nxt_ptr = suit_node->nxt_ptr;tmp_node->mem_size = nbytes;tmp_node->mem_sta = USED;//PRINT("tmp_node->mem_ptr:%p\r\n", tmp_node->mem_ptr);suit_node->mem_ptr = (mem_block *)((unsigned char *)tmp_node + BLK_SIZE);//PRINT("suit_node->mem_ptr:%p\r\n", suit_node->mem_ptr);suit_node->nxt_ptr = tmp_node;suit_node->mem_size -= (nbytes + BLK_SIZE);suit_node->mem_sta = UNUSED;total_size += nbytes;PRINT("malloc_ex: addr:%p, size:%d\r\n", tmp_node->mem_ptr, nbytes);return tmp_node->mem_ptr;}else{PRINT("%s,size err!\r\n",__FUNCTION__);}return NULL; }void free_ex(void *ap) {mem_block *head_node, *tmp_node, *nxt_node;if(ap == NULL)return;if(mem_init_flag < 0){return;}head_node = tmp_node = (mem_block *)HEAD_NODE;while(1){//PRINT("head_node:%p, tmp_node->mem_ptr:%p\r\n", head_node, tmp_node->mem_ptr);if(tmp_node->mem_ptr == ap){if(tmp_node->mem_sta != UNUSED){PRINT("free_ex: p=%p, size:%ld\r\n", ap, tmp_node->mem_size);total_size = total_size - tmp_node->mem_size;tmp_node->mem_sta = UNUSED;break;}else{return;}}tmp_node = tmp_node->nxt_ptr;if(tmp_node == head_node){PRINT("%s,can not found ap!\r\n",__FUNCTION__);return ;}}AGAIN: head_node = tmp_node = (mem_block *)HEAD_NODE;while(1){nxt_node = tmp_node->nxt_ptr;if(nxt_node == head_node){break;}if(tmp_node->mem_sta == UNUSED && nxt_node->mem_sta == UNUSED){tmp_node->mem_ptr = nxt_node->mem_ptr;tmp_node->nxt_ptr = nxt_node->nxt_ptr;tmp_node->mem_size += nxt_node->mem_size + BLK_SIZE;tmp_node->mem_sta = UNUSED;goto AGAIN;}tmp_node = nxt_node;} }#ifdef TEST_MALLOC int main(void) {char *p, *p1, *p3, *p4;PRINT("start:%p\r\n", mem);p = malloc_ex(8);memset_ex(p, 'a', 9);PRINT("p:%p, p=%s\r\n", p, p);free_ex(p);p1 = malloc_ex(10000);memset_ex(p1, 'b', 9);PRINT("p1:%p, p1=%s\r\n", p1, p1); free_ex(p1);p3 = malloc_ex(16);memset_ex(p3, 'c', 9);PRINT("p3:%p, p3=%s\r\n", p3, p3); //free_ex(p3);p4 = malloc_ex(5);memset_ex(p4, 'd', 9);PRINT("p4:%p, p4=%s\r\n", p4, p4); free_ex(p4);while(1); } #endif

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