|  | @@ -0,0 +1,412 @@
 | 
	
		
			
				|  |  | +// Copyright (C) DragonOS Community  longjin
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// This program is free software; you can redistribute it and/or
 | 
	
		
			
				|  |  | +// modify it under the terms of the GNU General Public License
 | 
	
		
			
				|  |  | +// as published by the Free Software Foundation; either version 2
 | 
	
		
			
				|  |  | +// of the License, or (at your option) any later version.
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// This program is distributed in the hope that it will be useful,
 | 
	
		
			
				|  |  | +// but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
	
		
			
				|  |  | +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 | 
	
		
			
				|  |  | +// GNU General Public License for more details.
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// You should have received a copy of the GNU General Public License
 | 
	
		
			
				|  |  | +// along with this program; if not, write to the Free Software
 | 
	
		
			
				|  |  | +// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 | 
	
		
			
				|  |  | +// Or you can visit https://www.gnu.org/licenses/gpl-2.0.html
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +#include <unistd.h>
 | 
	
		
			
				|  |  | +#include <errno.h>
 | 
	
		
			
				|  |  | +#include <stdio.h>
 | 
	
		
			
				|  |  | +#include <stdint.h>
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +#define PAGE_4K_SHIFT 12
 | 
	
		
			
				|  |  | +#define PAGE_2M_SHIFT 21
 | 
	
		
			
				|  |  | +#define PAGE_1G_SHIFT 30
 | 
	
		
			
				|  |  | +#define PAGE_GDT_SHIFT 39
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/***************************/
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// 不同大小的页的容量
 | 
	
		
			
				|  |  | +#define PAGE_4K_SIZE (1UL << PAGE_4K_SHIFT)
 | 
	
		
			
				|  |  | +#define PAGE_2M_SIZE (1UL << PAGE_2M_SHIFT)
 | 
	
		
			
				|  |  | +#define PAGE_1G_SIZE (1UL << PAGE_1G_SHIFT)
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// 屏蔽低于x的数值
 | 
	
		
			
				|  |  | +#define PAGE_4K_MASK (~(PAGE_4K_SIZE - 1))
 | 
	
		
			
				|  |  | +#define PAGE_2M_MASK (~(PAGE_2M_SIZE - 1))
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// 将addr按照x的上边界对齐
 | 
	
		
			
				|  |  | +//#define PAGE_4K_ALIGN(addr) (((unsigned long)(addr) + PAGE_4K_SIZE - 1) & PAGE_4K_MASK)
 | 
	
		
			
				|  |  | +//#define PAGE_2M_ALIGN(addr) (((unsigned long)(addr) + PAGE_2M_SIZE - 1) & PAGE_2M_MASK)
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 显式链表的结点
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +typedef struct malloc_mem_chunk_t
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    uint64_t length;                 // 整个块所占用的内存区域的大小
 | 
	
		
			
				|  |  | +    uint64_t padding;
 | 
	
		
			
				|  |  | +    struct malloc_mem_chunk_t *prev; // 上一个结点的指针
 | 
	
		
			
				|  |  | +    struct malloc_mem_chunk_t *next; // 下一个结点的指针
 | 
	
		
			
				|  |  | +} malloc_mem_chunk_t;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +static uint64_t brk_base_addr = 0;    // 堆区域的内存基地址
 | 
	
		
			
				|  |  | +static uint64_t brk_max_addr = 0;     // 堆区域的内存最大地址
 | 
	
		
			
				|  |  | +static uint64_t brk_managed_addr = 0; // 堆区域已经被管理的地址
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +// 空闲链表
 | 
	
		
			
				|  |  | +//  按start_addr升序排序
 | 
	
		
			
				|  |  | +static malloc_mem_chunk_t *malloc_free_list = NULL;
 | 
	
		
			
				|  |  | +static malloc_mem_chunk_t *malloc_free_list_end = NULL; // 空闲链表的末尾结点
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +static uint64_t count_last_free_size = 0; // 统计距离上一次回收内存,已经free了多少内存
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 将块插入空闲链表
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param ck 待插入的块
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static void malloc_insert_free_list(malloc_mem_chunk_t *ck);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 当堆顶空闲空间大于2个页的空间的时候,释放1个页
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static void release_brk();
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 在链表中检索符合要求的空闲块(best fit)
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param size 块的大小
 | 
	
		
			
				|  |  | + * @return malloc_mem_chunk_t*
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static malloc_mem_chunk_t *malloc_query_free_chunk_bf(uint64_t size)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    // 在满足best fit的前提下,尽可能的使分配的内存在低地址
 | 
	
		
			
				|  |  | +    //  使得总的堆内存可以更快被释放
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    if (malloc_free_list == NULL)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        return NULL;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *ptr = malloc_free_list;
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *best = NULL;
 | 
	
		
			
				|  |  | +    // printf("query size=%d", size);
 | 
	
		
			
				|  |  | +    while (ptr != NULL)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        // printf("ptr->length=%#010lx\n", ptr->length);
 | 
	
		
			
				|  |  | +        if (ptr->length == size)
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            best = ptr;
 | 
	
		
			
				|  |  | +            break;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        if (ptr->length > size)
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            if (best == NULL)
 | 
	
		
			
				|  |  | +                best = ptr;
 | 
	
		
			
				|  |  | +            else if (best->length > ptr->length)
 | 
	
		
			
				|  |  | +                best = ptr;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +        ptr = ptr->next;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    return best;
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 在链表中检索符合要求的空闲块(first fit)
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param size
 | 
	
		
			
				|  |  | + * @return malloc_mem_chunk_t*
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static malloc_mem_chunk_t *malloc_query_free_chunk_ff(uint64_t size)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    if (malloc_free_list == NULL)
 | 
	
		
			
				|  |  | +        return NULL;
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *ptr = malloc_free_list;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    while (ptr)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        if (ptr->length >= size)
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            return ptr;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +        ptr = ptr->next;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    return NULL;
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 扩容malloc管理的内存区域
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param size 扩大的内存大小
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static int malloc_enlarge(int64_t size)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    if (brk_base_addr == 0) // 第一次调用,需要初始化
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        brk_base_addr = sbrk(0);
 | 
	
		
			
				|  |  | +        // printf("brk_base_addr=%#018lx\n", brk_base_addr);
 | 
	
		
			
				|  |  | +        brk_managed_addr = brk_base_addr;
 | 
	
		
			
				|  |  | +        brk_max_addr = sbrk(0);
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    int64_t free_space = brk_max_addr - brk_managed_addr;
 | 
	
		
			
				|  |  | +    // printf("size=%ld\tfree_space=%ld\n", size, free_space);
 | 
	
		
			
				|  |  | +    if (free_space < size) // 现有堆空间不足
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        if (sbrk(size - free_space) != (void *)(-1))
 | 
	
		
			
				|  |  | +            brk_max_addr = sbrk((0));
 | 
	
		
			
				|  |  | +        else
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            //put_string("malloc_enlarge(): no_mem\n", COLOR_YELLOW, COLOR_BLACK);
 | 
	
		
			
				|  |  | +            return -ENOMEM;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        // printf("brk max addr = %#018lx\n", brk_max_addr);
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    // 扩展管理的堆空间
 | 
	
		
			
				|  |  | +    // 在新分配的内存的底部放置header
 | 
	
		
			
				|  |  | +    // printf("managed addr = %#018lx\n", brk_managed_addr);
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *new_ck = (malloc_mem_chunk_t *)brk_managed_addr;
 | 
	
		
			
				|  |  | +    new_ck->length = brk_max_addr - brk_managed_addr;
 | 
	
		
			
				|  |  | +    // printf("new_ck->start_addr=%#018lx\tbrk_max_addr=%#018lx\tbrk_managed_addr=%#018lx\n", (uint64_t)new_ck, brk_max_addr, brk_managed_addr);
 | 
	
		
			
				|  |  | +    new_ck->prev = NULL;
 | 
	
		
			
				|  |  | +    new_ck->next = NULL;
 | 
	
		
			
				|  |  | +    brk_managed_addr = brk_max_addr;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    malloc_insert_free_list(new_ck);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    return 0;
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 合并空闲块
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static void malloc_merge_free_chunk()
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    if (malloc_free_list == NULL)
 | 
	
		
			
				|  |  | +        return;
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *ptr = malloc_free_list->next;
 | 
	
		
			
				|  |  | +    while (ptr != NULL)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        // 内存块连续
 | 
	
		
			
				|  |  | +        if (((uint64_t)(ptr->prev) + ptr->prev->length == (uint64_t)ptr))
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            // printf("merged %#018lx  and %#018lx\n", (uint64_t)ptr, (uint64_t)(ptr->prev));
 | 
	
		
			
				|  |  | +            // 将ptr与前面的空闲块合并
 | 
	
		
			
				|  |  | +            ptr->prev->length += ptr->length;
 | 
	
		
			
				|  |  | +            ptr->prev->next = ptr->next;
 | 
	
		
			
				|  |  | +            if (ptr->next == NULL)
 | 
	
		
			
				|  |  | +                malloc_free_list_end = ptr->prev;
 | 
	
		
			
				|  |  | +            else
 | 
	
		
			
				|  |  | +                ptr->next->prev = ptr->prev;
 | 
	
		
			
				|  |  | +            // 由于内存组成结构的原因,不需要free掉header
 | 
	
		
			
				|  |  | +            ptr = ptr->prev;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +        ptr = ptr->next;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 将块插入空闲链表
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param ck 待插入的块
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static void malloc_insert_free_list(malloc_mem_chunk_t *ck)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    if (malloc_free_list == NULL) // 空闲链表为空
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        malloc_free_list = ck;
 | 
	
		
			
				|  |  | +        malloc_free_list_end = ck;
 | 
	
		
			
				|  |  | +        ck->prev = ck->next = NULL;
 | 
	
		
			
				|  |  | +        return;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +    else
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        malloc_mem_chunk_t *ptr = malloc_free_list;
 | 
	
		
			
				|  |  | +        while (ptr != NULL)
 | 
	
		
			
				|  |  | +        {
 | 
	
		
			
				|  |  | +            if ((uint64_t)ptr < (uint64_t)ck)
 | 
	
		
			
				|  |  | +            {
 | 
	
		
			
				|  |  | +                if (ptr->next == NULL) // 当前是最后一个项
 | 
	
		
			
				|  |  | +                {
 | 
	
		
			
				|  |  | +                    ptr->next = ck;
 | 
	
		
			
				|  |  | +                    ck->next = NULL;
 | 
	
		
			
				|  |  | +                    ck->prev = ptr;
 | 
	
		
			
				|  |  | +                    malloc_free_list_end = ck;
 | 
	
		
			
				|  |  | +                    break;
 | 
	
		
			
				|  |  | +                }
 | 
	
		
			
				|  |  | +                else if ((uint64_t)(ptr->next) > (uint64_t)ck)
 | 
	
		
			
				|  |  | +                {
 | 
	
		
			
				|  |  | +                    ck->prev = ptr;
 | 
	
		
			
				|  |  | +                    ck->next = ptr->next;
 | 
	
		
			
				|  |  | +                    ptr->next = ck;
 | 
	
		
			
				|  |  | +                    ck->next->prev = ck;
 | 
	
		
			
				|  |  | +                    break;
 | 
	
		
			
				|  |  | +                }
 | 
	
		
			
				|  |  | +            }
 | 
	
		
			
				|  |  | +            else // 在ptr之前插入
 | 
	
		
			
				|  |  | +            {
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +                if (ptr->prev == NULL) // 是第一个项
 | 
	
		
			
				|  |  | +                {
 | 
	
		
			
				|  |  | +                    malloc_free_list = ck;
 | 
	
		
			
				|  |  | +                    ck->prev = NULL;
 | 
	
		
			
				|  |  | +                    ck->next = ptr;
 | 
	
		
			
				|  |  | +                    ptr->prev = ck;
 | 
	
		
			
				|  |  | +                    break;
 | 
	
		
			
				|  |  | +                }
 | 
	
		
			
				|  |  | +                else
 | 
	
		
			
				|  |  | +                {
 | 
	
		
			
				|  |  | +                    ck->prev = ptr->prev;
 | 
	
		
			
				|  |  | +                    ck->next = ptr;
 | 
	
		
			
				|  |  | +                    ck->prev->next = ck;
 | 
	
		
			
				|  |  | +                    ptr->prev = ck;
 | 
	
		
			
				|  |  | +                    break;
 | 
	
		
			
				|  |  | +                }
 | 
	
		
			
				|  |  | +            }
 | 
	
		
			
				|  |  | +            ptr = ptr->next;
 | 
	
		
			
				|  |  | +        }
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 获取一块堆内存
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param size 内存大小
 | 
	
		
			
				|  |  | + * @return void* 内存空间的指针
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * 分配内存的时候,结点的prev next指针所占用的空间被当做空闲空间分配出去
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +void *_dragonos_malloc(ssize_t size)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    
 | 
	
		
			
				|  |  | +    // 计算需要分配的块的大小
 | 
	
		
			
				|  |  | +    // reserve for len
 | 
	
		
			
				|  |  | +    if (size + 2*sizeof(uint64_t) <= sizeof(malloc_mem_chunk_t))
 | 
	
		
			
				|  |  | +        size = sizeof(malloc_mem_chunk_t);
 | 
	
		
			
				|  |  | +    else
 | 
	
		
			
				|  |  | +        size += 2*sizeof(uint64_t);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    // 采用best fit
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *ck = malloc_query_free_chunk_bf(size);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    if (ck == NULL) // 没有空闲块
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        
 | 
	
		
			
				|  |  | +        // printf("no free blocks\n");
 | 
	
		
			
				|  |  | +        // 尝试合并空闲块
 | 
	
		
			
				|  |  | +        malloc_merge_free_chunk();
 | 
	
		
			
				|  |  | +        ck = malloc_query_free_chunk_bf(size);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        // 找到了合适的块
 | 
	
		
			
				|  |  | +        if (ck)
 | 
	
		
			
				|  |  | +            goto found;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        // printf("before enlarge\n");
 | 
	
		
			
				|  |  | +        // 找不到合适的块,扩容堆区域
 | 
	
		
			
				|  |  | +        if (malloc_enlarge(size) == -ENOMEM)
 | 
	
		
			
				|  |  | +            return (void *)-ENOMEM; // 内存不足
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        malloc_merge_free_chunk(); // 扩容后运行合并,否则会导致碎片
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        // 扩容后再次尝试获取
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        ck = malloc_query_free_chunk_bf(size);
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +found:;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    // printf("ck = %#018lx\n", (uint64_t)ck);
 | 
	
		
			
				|  |  | +    if (ck == NULL)
 | 
	
		
			
				|  |  | +        return (void *)-ENOMEM;
 | 
	
		
			
				|  |  | +    // printf("ck->prev=%#018lx ck->next=%#018lx\n", ck->prev, ck->next);
 | 
	
		
			
				|  |  | +    // 分配空闲块
 | 
	
		
			
				|  |  | +    // 从空闲链表取出
 | 
	
		
			
				|  |  | +    if (ck->prev == NULL) // 当前是链表的第一个块
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        malloc_free_list = ck->next;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +    else
 | 
	
		
			
				|  |  | +        ck->prev->next = ck->next;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    if (ck->next != NULL) // 当前不是最后一个块
 | 
	
		
			
				|  |  | +        ck->next->prev = ck->prev;
 | 
	
		
			
				|  |  | +    else
 | 
	
		
			
				|  |  | +        malloc_free_list_end = ck->prev;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    // 当前块剩余的空间还能容纳多一个结点的空间,则分裂当前块
 | 
	
		
			
				|  |  | +    if ((int64_t)(ck->length) - size > sizeof(malloc_mem_chunk_t))
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        // printf("seperate\n");
 | 
	
		
			
				|  |  | +        malloc_mem_chunk_t *new_ck = (malloc_mem_chunk_t *)(((uint64_t)ck) + size);
 | 
	
		
			
				|  |  | +        new_ck->length = ck->length - size;
 | 
	
		
			
				|  |  | +        new_ck->prev = new_ck->next = NULL;
 | 
	
		
			
				|  |  | +        // printf("new_ck=%#018lx, new_ck->length=%#010lx\n", (uint64_t)new_ck, new_ck->length);
 | 
	
		
			
				|  |  | +        ck->length = size;
 | 
	
		
			
				|  |  | +        malloc_insert_free_list(new_ck);
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +    // printf("malloc done: %#018lx, length=%#018lx\n", ((uint64_t)ck + sizeof(uint64_t)), ck->length);
 | 
	
		
			
				|  |  | +    // 此时链表结点的指针的空间被分配出去
 | 
	
		
			
				|  |  | +    return (void *)((uint64_t)ck + sizeof(uint64_t));
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 当堆顶空闲空间大于2个页的空间的时候,释放1个页
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +static void release_brk()
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    // 先检测最顶上的块
 | 
	
		
			
				|  |  | +    // 由于块按照开始地址排列,因此找最后一个块
 | 
	
		
			
				|  |  | +    if (malloc_free_list_end == NULL)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        printf("release(): free list end is null. \n");
 | 
	
		
			
				|  |  | +        return;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +    if ((uint64_t)malloc_free_list_end + malloc_free_list_end->length == brk_max_addr && (uint64_t)malloc_free_list_end <= brk_max_addr - (PAGE_2M_SIZE << 1))
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        int64_t delta = ((brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK) - PAGE_2M_SIZE;
 | 
	
		
			
				|  |  | +        // printf("(brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK=%#018lx\n ", (brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK);
 | 
	
		
			
				|  |  | +        // printf("PAGE_2M_SIZE=%#018lx\n", PAGE_2M_SIZE);
 | 
	
		
			
				|  |  | +        // printf("tdfghgbdfggkmfn=%#018lx\n ", (brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK - PAGE_2M_SIZE);
 | 
	
		
			
				|  |  | +        // printf("delta=%#018lx\n ", delta);
 | 
	
		
			
				|  |  | +        if (delta <= 0) // 不用释放内存
 | 
	
		
			
				|  |  | +            return;
 | 
	
		
			
				|  |  | +        sbrk(-delta);
 | 
	
		
			
				|  |  | +        brk_max_addr = sbrk(0);
 | 
	
		
			
				|  |  | +        brk_managed_addr = brk_max_addr;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +        malloc_free_list_end->length = brk_max_addr - (uint64_t)malloc_free_list_end;
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +}
 | 
	
		
			
				|  |  | +/**
 | 
	
		
			
				|  |  | + * @brief 释放一块堆内存
 | 
	
		
			
				|  |  | + *
 | 
	
		
			
				|  |  | + * @param ptr 堆内存的指针
 | 
	
		
			
				|  |  | + */
 | 
	
		
			
				|  |  | +void _dragonos_free(void *ptr)
 | 
	
		
			
				|  |  | +{
 | 
	
		
			
				|  |  | +    // 找到结点(此时prev和next都处于未初始化的状态)
 | 
	
		
			
				|  |  | +    malloc_mem_chunk_t *ck = (malloc_mem_chunk_t *)((uint64_t)ptr - sizeof(uint64_t));
 | 
	
		
			
				|  |  | +    // printf("free(): addr = %#018lx\t len=%#018lx\n", (uint64_t)ck, ck->length);
 | 
	
		
			
				|  |  | +    count_last_free_size += ck->length;
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    malloc_insert_free_list(ck);
 | 
	
		
			
				|  |  | +
 | 
	
		
			
				|  |  | +    if (count_last_free_size > PAGE_2M_SIZE)
 | 
	
		
			
				|  |  | +    {
 | 
	
		
			
				|  |  | +        count_last_free_size = 0;
 | 
	
		
			
				|  |  | +        malloc_merge_free_chunk();
 | 
	
		
			
				|  |  | +        release_brk();
 | 
	
		
			
				|  |  | +    }
 | 
	
		
			
				|  |  | +}
 |