最近想给64kb rom 以及 4kb ram mcu准备图形系统所以避免不了内存管理，以下为mcu装备的几种内存管理
第一款混合堆栈方案（占用大，被抛弃版本）
外围辅助头文件
#ifndef __GUI_MEMPOOL_CONFIG_H #define __GUI_MEMPOOL_CONFIG_H //内存池配置 #define GUI_MEMPOOL_ENABLE_STATISTICS 0 #define GUI_MEMPOOL_DEBUG 0 #define GUI_MEMPOOL_ALIGN_SIZE 4 //分区 #define GUI_SMALL_POOL_SIZE 1 #define GUI_MEDIUM_POOL_SIZE 1 #define GUI_LARGE_POOL_SIZE 0 #define GUI_SPECIAL_POOL_SIZE 1 typedef enum{ OBJ_TYPE_INVALID = 0, OBJ_TYPE_BASE, OBJ_TYPE_BUTTON, OBJ_TYPE_LABLE, OBJ_TYPE_IMAGE, OBJ_TYPE_CONTAINER, OBJ_TYPE_SCREEN, OBJ_TYPE_CUSTOM, OBJ_TYPE_MAX }obj_type_t; typedef enum{ BLOCK_FREE = 0, BLOCK_USED, BLOCK_COIRRUPTED, }block_state_t; #endif声明（头文件）
#ifndef _GUI_MEM_H_ #define _GUI_MEM_H_ #include "gui_mempool_config.h" #include <stdint.h> #include <stdbool.h> #include <stddef.h> typedef struct memblock_header{ struct memblock_header* next; struct memblock_header* prev; uint16_t size; uint8_t type; uint8_t state; uint32_t magic; }mem_block_header_t; //内存块头指针 typedef struct{ uint8_t* start; uint8_t* end; uint16_t block_size; uint16_t total_blocks; uint16_t free_blocks; uint16_t used_blocks; mem_block_header_t* free_list; uint8_t* bitmap; }mem_zone_t; //内存块描述 typedef struct{ mem_zone_t small_zone; //64字节 mem_zone_t medium_zone; //256字节 mem_zone_t large_zone; //1024字节 mem_zone_t special_zone; //1024字节 uint32_t total_allocs; uint32_t total_frees; uint32_t alloc_fails; uint32_t max_used_memory; uint32_t current_used_memory; bool initialized; bool use_bitmap; }gui_mempool_t; //对齐宏 #define ALIGN_UP(x,align) (((x) + ((align) - 1)) & ~((align) - 1)) #define BLOCK_HEADER_SIZE ALIGN_UP(sizeof(mem_block_header_t), GUI_MEMPOOL_ALIGN_SIZE) #define MAGIC_NUMBER 0xDEADBEEF bool gui_mempool_init(void); void* gui_mempool_alloc(size_t size, obj_type_t type); void gui_mempool_free(void* ptr); void gui_mempool_is_valid(void* ptr); void gui_mempool_dump_stats(void); void gui_mempool_check_integrity(void); size_t gui_mempool_get_alloc_size(void); obj_type_t gui_mempool_get_obj_type(void* ptr); #endif初始化
bool gui_mempool_init(void) { if(mempool.initialized){ // MEMPOOL_DEBUG("[MEMPOOL] Already initialized\n"); return true; } uint8_t* current = memory_pool; mempool.small_zone.start = current; mempool.small_zone.end = current + GUI_SMALL_POOL_SIZE * 1024; mempool.small_zone.block_size = 64; mempool.small_zone.total_blocks = 0; mempool.small_zone.free_blocks = 0; mempool.small_zone.used_blocks = 0; mempool.small_zone.used_blocks = 0; mempool.small_zone.free_list = NULL; mempool.small_zone.bitmap = NULL; current = mempool.small_zone.end; mempool.medium_zone.start = current; mempool.medium_zone.end = current + GUI_SMALL_POOL_SIZE * 1024; mempool.medium_zone.block_size = 64; mempool.medium_zone.total_blocks = 0; mempool.medium_zone.free_blocks = 0; mempool.medium_zone.used_blocks = 0; mempool.medium_zone.used_blocks = 0; mempool.medium_zone.free_list = NULL; mempool.medium_zone.bitmap = NULL; mempool.large_zone.start = current; mempool.large_zone.end = current + GUI_SMALL_POOL_SIZE * 1024; mempool.large_zone.block_size = 64; mempool.large_zone.total_blocks = 0; mempool.large_zone.free_blocks = 0; mempool.large_zone.used_blocks = 0; mempool.large_zone.used_blocks = 0; mempool.large_zone.free_list = NULL; mempool.large_zone.bitmap = NULL; mempool.special_zone.start = current; mempool.special_zone.end = current + GUI_SMALL_POOL_SIZE * 1024; mempool.special_zone.block_size = 64; mempool.special_zone.total_blocks = 0; mempool.special_zone.free_blocks = 0; mempool.special_zone.used_blocks = 0; mempool.special_zone.used_blocks = 0; mempool.special_zone.free_list = NULL; mempool.special_zone.bitmap = NULL; mempool.total_allocs = 0; mempool.total_frees = 0; mempool.alloc_fails = 0; mempool.max_used_memory = 0; mempool.current_used_memory = 0; mempool.initialized = true; mempool.use_bitmap = true; return true; }在区中分配内存
static void *zone_alloc(mem_zone_t* zone,size_t size,obj_type_t type){ if(!zone || size == 0) return NULL; // 计算实际需要的内存大小（包含头部） size_t total_size = BLOCK_HEADER_SIZE + ALIGN_UP(size, GUI_MEMPOOL_ALIGN_SIZE); if(zone->block_size > 0 && total_size > zone->block_size) { return NULL; } // 特殊区域使用首次适配算法 if(zone->block_size == 0) { mem_block_header_t* current = (mem_block_header_t*)zone->start; mem_block_header_t* prev = NULL; // 遍历特殊区域寻找足够大的空闲块 while((uint8_t*)current < zone->end) { if(current->state == BLOCK_FREE && current->size >= total_size) { // 找到合适的块 if(current->size > total_size + BLOCK_HEADER_SIZE + GUI_MEMPOOL_ALIGN_SIZE) { // 分割块 mem_block_header_t* new_block = (mem_block_header_t*) ((uint8_t*)current + BLOCK_HEADER_SIZE + total_size); new_block->size = current->size - total_size - BLOCK_HEADER_SIZE; new_block->state = BLOCK_FREE; new_block->magic = MAGIC_NUMBER; new_block->type = OBJ_TYPE_INVALID; // 插入到空闲链表 new_block->next = current->next; new_block->prev = current; if(current->next) { ((mem_block_header_t*)current->next)->prev = new_block; } current->next = new_block; current->size = total_size; } // 从空闲链表中移除 if(current->prev) { current->prev->next = current->next; } if(current->next) { current->next->prev = current->prev; } if(zone->free_list == current) { zone->free_list = current->next; } // 设置块信息 current->state = BLOCK_USED; current->type = type; current->magic = MAGIC_NUMBER; current->prev = NULL; current->next = NULL; zone->used_blocks++; zone->free_blocks--; return (uint8_t*)current + BLOCK_HEADER_SIZE; } prev = current; current = (mem_block_header_t*)((uint8_t*)current + BLOCK_HEADER_SIZE + current->size); } return NULL; } // 固定大小区域使用空闲链表 if(!zone->free_list) { // 初始化空闲链表 size_t block_count = (zone->end - zone->start) / (BLOCK_HEADER_SIZE + zone->block_size); for(size_t i = 0; i < block_count; i++) { mem_block_header_t* block = (mem_block_header_t*) (zone->start + i * (BLOCK_HEADER_SIZE + zone->block_size)); block->size = zone->block_size; block->state = BLOCK_FREE; block->type = OBJ_TYPE_INVALID; block->magic = MAGIC_NUMBER; block->next = zone->free_list; block->prev = NULL; if(zone->free_list) { zone->free_list->prev = block; } zone->free_list = block; zone->total_blocks++; zone->free_blocks++; } } if(!zone->free_list) { return NULL; } // 从空闲链表头部取出一个块 mem_block_header_t* block = zone->free_list; zone->free_list = block->next; if(zone->free_list) { zone->free_list->prev = NULL; } block->state = BLOCK_USED; block->type = type; block->prev = NULL; block->next = NULL; zone->used_blocks++; zone->free_blocks--; return (uint8_t*)block + BLOCK_HEADER_SIZE; }主分配函数
static mem_zone_t* select_zone(size_t size) { if(size <= 64){ return &mempool.small_zone; }else if(size<= 256){ return &mempool.medium_zone; }else if(size <= 1024){ return &mempool.large_zone; }else{ return &mempool.special_zone; } } void* gui_mempool_alloc(size_t size, obj_type_t type){ if(!mempool.initialized || size == 0){ return NULL; } mem_zone_t* zone = select_zone(size); if(!zone){ mempool.alloc_fails++; return NULL; } void* ptr = zone_alloc(zone,size,type); if(ptr){ mempool.total_allocs++; mempool.current_used_memory += BLOCK_HEADER_SIZE + ALIGN_UP(size,GUI_MEMPOOL_ALIGN_SIZE); if(mempool.current_used_memory > mempool.max_used_memory){ mempool.max_used_memory = mempool.current_used_memory; } }else{ mempool.alloc_fails++; } return ptr; }释放内存函数
void gui_mempool_free(void* ptr){ if(!ptr || !mempool.initialized){ return; } mem_block_header_t* block = (mem_block_header_t*)((uint8_t*)ptr - BLOCK_HEADER_SIZE); if(block->magic != MAGIC_NUMBER){ return; } mem_zone_t* zone = NULL; if((uint8_t*) block >= mempool.small_zone.start && (uint8_t*)block < mempool.small_zone.end){ zone = &mempool.small_zone; }else if((uint8_t*) block >= mempool.medium_zone.start && (uint8_t*)block < mempool.small_zone.end){ zone = &mempool.medium_zone; }else if((uint8_t*)block >= mempool.large_zone.start && (uint8_t*)block < mempool.large_zone.end) { zone = &mempool.large_zone; }else if((uint8_t*)block >= mempool.special_zone.start && (uint8_t*)block < mempool.special_zone.end) { zone = &mempool.special_zone; }else{ return; } if(block->state != BLOCK_USED) { return; } if(zone->block_size == 0){ mem_block_header_t* prev = block->prev; if(prev && prev->state == BLOCK_FREE){ prev->size += BLOCK_HEADER_SIZE + block->size; if(block->next){ block->next->prev = prev; } if(block->prev){ block->prev->next = block->next; } } block = prev; } mem_block_header_t* next = (mem_block_header_t*) ((uint8_t*)block + BLOCK_HEADER_SIZE + block->size); if((uint8_t*)next < zone->end && next->state == BLOCK_FREE){ block->size += BLOCK_HEADER_SIZE + next->size; //从空闲链表中移除下一个块 if(next->next){ next->next->prev = block; } if(next->prev){ next->prev->next = next->prev; } } block->state = BLOCK_FREE; block->type = OBJ_TYPE_INVALID; block->next = zone->free_list; block->prev = NULL; if(zone->free_list){ zone->free_list->prev = block; } zone->free_list = block; zone->used_blocks--; zone->free_blocks++; mempool.total_frees++; mempool.current_used_memory -= BLOCK_HEADER_SIZE + block->size; }
