remove malloc.c

src/c/malloc.c

@@ -1,412 +0,0 @@
-// 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();
-    }
-}