堆区相关代码注释

    百图画鸿蒙 + 百文说内核 + 百万注源码  => 挖透鸿蒙内核源码
    鸿蒙研究站 | http://weharmonyos.com (国内)
              | https://weharmony.github.io (国外)
    oschina | https://my.oschina.net/weharmony
    博客园 | https://www.cnblogs.com/weharmony/
    知乎 | https://www.zhihu.com/people/weharmonyos
    csdn | https://blog.csdn.net/kuangyufei
    51cto | https://harmonyos.51cto.com/column/34
    掘金 | https://juejin.cn/user/756888642000808
    公众号 | 鸿蒙研究站 (weharmonyos)

kernel/base/include/los_vm_map.h

@@ -79,7 +79,7 @@ struct page_mapping {
 #endif
 /* If the kernel malloc size is less than 16k, use heap, otherwise use physical pages */
 #define KMALLOC_LARGE_SIZE    (PAGE_SIZE << 2)
-typedef struct VmMapRange {
+typedef struct VmMapRange {//线性区范围结构体
     VADDR_T             base;           /**< vm region base addr | 线性区基地址*/
     UINT32              size;           /**< vm region size | 线性区大小*/
 } LosVmMapRange;
@@ -118,7 +118,7 @@ struct VmFileOps {
 struct VmMapRegion {
     LosRbNode           rbNode;         /**< region red-black tree node | 红黑树节点,通过它将本线性区挂在VmSpace.regionRbTree*/
     LosVmSpace          *space;			///< 所属虚拟空间,虚拟空间由多个线性区组成
-    LOS_DL_LIST         node;           /**< region dl list | 链表节点,通过它将本线性区挂在VmSpace.regions上*/				
+    LOS_DL_LIST         node;           /**< region dl list | 链表节点,通过它将本线性区挂在VmSpace.regions上 ,但最新版本没有regions了,可以删除了 */				
     LosVmMapRange       range;          /**< region address range | 记录线性区的范围*/
     VM_OFFSET_T         pgOff;          /**< region page offset to file | 以文件开始处的偏移量, 必须是分页大小的整数倍, 通常为0, 表示从文件头开始映射。*/
     UINT32              regionFlags;    /**< region flags: cow, user_wired | 线性区标签*/
@@ -148,9 +148,9 @@ typedef struct VmSpace {
     LosMux              regionMux;      /**< region list mutex lock | 虚拟空间操作红黑树互斥锁*/
     VADDR_T             base;           /**< vm space base addr | 虚拟空间的基地址,线性区的分配范围,常用于判断地址是否在内核还是用户空间*/
     UINT32              size;           /**< vm space size | 虚拟空间大小*/
-    VADDR_T             heapBase;       /**< vm space heap base address | 堆区基地址，表堆区范围起点*/
-    VADDR_T             heapNow;        /**< vm space heap base now | 堆区现地址，表堆区范围终点，do_brk()直接修改堆的大小返回新的堆区结束地址， heapNow >= heapBase*/
-    LosVmMapRegion      *heap;          /**< heap region | 堆区是个特殊的线性区，用于满足进程的动态内存需求，大家熟知的malloc,realloc,free其实就是在操作这个区*/				
+    VADDR_T             heapBase;       /**< vm space heap base address | 堆区基地址，指向堆区起点*/
+    VADDR_T             heapNow;        /**< vm space heap base now | 堆顶地址，指向堆区终点，do_brk()直接修改堆的大小返回新的堆区结束地址， heapNow >= heapBase*/
+    LosVmMapRegion      *heap;          /**< heap region | 传说中的堆区，用于满足进程的动态内存需求，大家熟知的malloc,realloc,free其实就是在操作这个区*/				
     VADDR_T             mapBase;        /**< vm space mapping area base | 虚拟空间映射区基地址,L1，L2表存放在这个区 */
     UINT32              mapSize;        /**< vm space mapping area size | 虚拟空间映射区大小，映射区是个很大的区。*/
     LosArchMmu          archMmu;        /**< vm mapping physical memory | MMU记录<虚拟地址,物理地址>的映射情况 */

kernel/base/vm/los_vm_map.c

@@ -188,7 +188,7 @@ ULONG_T OsRegionRbCmpKeyFn(const VOID *pNodeKeyA, const VOID *pNodeKeyB)
 }
 
 /*!
- * @brief OsVmSpaceInitCommon	初始化虚拟空间，必须提供L1表的虚拟内存地址
+ * @brief OsVmSpaceInitCommon	初始化进程虚拟空间，必须提供L1表的虚拟内存地址
  *
  * @param virtTtb L1表的地址，TTB表地址	
  * @param vmSpace	
@@ -852,7 +852,7 @@ ERR_REGION_SPLIT:
     (VOID)LOS_MuxRelease(&space->regionMux);
     return status;
 }
-///释放用户空间的堆区
+///根据指定参数范围[addr,addr+len] 释放用户空间中堆区所占用的物理内存
 INT32 OsUserHeapFree(LosVmSpace *vmSpace, VADDR_T addr, size_t len)
 {
     LosVmMapRegion *vmRegion = NULL;
@@ -870,7 +870,7 @@ INT32 OsUserHeapFree(LosVmSpace *vmSpace, VADDR_T addr, size_t len)
         return -1;
     }
 
-    if (vmRegion == vmSpace->heap) {//虚拟空间的堆区和找到的线性区虚拟地址一致,确定是找到了堆区的线性区
+    if (vmRegion == vmSpace->heap) {//地址所在的线性区为堆区
         vaddr = addr;
         while (len > 0) {//参数0 代表不获取 flags 信息
             if (LOS_ArchMmuQuery(&vmSpace->archMmu, vaddr, &paddr, 0) == LOS_OK) {//通过虚拟地址查到物理地址

kernel/base/vm/los_vm_syscall.c

@@ -180,7 +180,7 @@ VADDR_T LOS_MMap(VADDR_T vaddr, size_t len, unsigned prot, unsigned long flags,
         resultVaddr = vaddr;
         goto MMAP_DONE;
     }
-
+	//地址不在堆区
     regionFlags = OsCvtProtFlagsToRegionFlags(prot, flags);//将参数flag转换Region的flag
     newRegion = LOS_RegionAlloc(vmSpace, vaddr, len, regionFlags, pgoff);//分配一个线性区
     if (newRegion == NULL) {
@@ -188,7 +188,7 @@ VADDR_T LOS_MMap(VADDR_T vaddr, size_t len, unsigned prot, unsigned long flags,
         goto MMAP_DONE;
     }
     newRegion->regionFlags |= VM_MAP_REGION_FLAG_MMAP;
-    resultVaddr = newRegion->range.base;
+    resultVaddr = newRegion->range.base;//线性区基地址为分配的地址
 
     if (LOS_IsNamedMapping(flags)) {
         status = OsNamedMMap(filep, newRegion);//文件映射
@@ -229,17 +229,17 @@ STATIC INLINE BOOL OsProtMprotectPermCheck(unsigned long prot, LosVmMapRegion *r
 
     return ((protFlags & permFlags) == protFlags);
 }
-
+/// 收缩堆区
 VOID *OsShrinkHeap(VOID *addr, LosVmSpace *space)
 {
     VADDR_T newBrk, oldBrk;
 
-    newBrk = LOS_Align((VADDR_T)(UINTPTR)addr, PAGE_SIZE);
-    oldBrk = LOS_Align(space->heapNow, PAGE_SIZE);
-    if (LOS_UnMMap(newBrk, (oldBrk - newBrk)) < 0) {
-        return (void *)(UINTPTR)space->heapNow;
+    newBrk = LOS_Align((VADDR_T)(UINTPTR)addr, PAGE_SIZE);//新堆顶
+    oldBrk = LOS_Align(space->heapNow, PAGE_SIZE);//旧堆顶
+    if (LOS_UnMMap(newBrk, (oldBrk - newBrk)) < 0) {//解除相差区的映射
+        return (void *)(UINTPTR)space->heapNow;//解除失败就持续现有的
     }
-    space->heapNow = (VADDR_T)(UINTPTR)addr;
+    space->heapNow = (VADDR_T)(UINTPTR)addr;//返回新堆顶
     return addr;
 }
 
@@ -279,14 +279,14 @@ VOID *LOS_DoBrk(VOID *addr)
     PRINT_INFO("brk addr %p , size 0x%x, alignAddr %p, align %d\n", addr, size, alignAddr, PAGE_SIZE);
 
     (VOID)LOS_MuxAcquire(&space->regionMux);
-    if (addr < (VOID *)(UINTPTR)space->heapNow) {
+    if (addr < (VOID *)(UINTPTR)space->heapNow) {//如果地址小于堆区现地址
         shrinkAddr = OsShrinkHeap(addr, space);//收缩堆区
         (VOID)LOS_MuxRelease(&space->regionMux);
         return shrinkAddr;
     }
 
-    if ((UINTPTR)alignAddr >= space->mapBase) {
-        VM_ERR("Process heap memory space is insufficient");
+    if ((UINTPTR)alignAddr >= space->mapBase) {//参数地址 大于映射区地址
+        VM_ERR("Process heap memory space is insufficient");//进程堆空间不足
         ret = (VOID *)-ENOMEM;
         goto REGION_ALLOC_FAILED;
     }
@@ -301,24 +301,24 @@ VOID *LOS_DoBrk(VOID *addr)
             goto REGION_ALLOC_FAILED;
         }
         region->regionFlags |= VM_MAP_REGION_FLAG_HEAP;//贴上线性区类型为堆区的标签,注意一个线性区可以有多种标签
-        space->heap = region;//更新虚拟空间堆区为分配的线性区
+        space->heap = region;//指定线性区为堆区
     }
 
-    space->heapNow = (VADDR_T)(UINTPTR)alignAddr;//更新线性区结束地址
+    space->heapNow = (VADDR_T)(UINTPTR)alignAddr;//更新堆区顶部位置
     space->heap->range.size = size;	//更新堆区大小,经此操作线性区变大或缩小了
-    ret = (VOID *)(UINTPTR)space->heapNow;//返回线性区最新的地址
+    ret = (VOID *)(UINTPTR)space->heapNow;//返回堆顶
 
 REGION_ALLOC_FAILED:
     (VOID)LOS_MuxRelease(&space->regionMux);
     return ret;
 }
-
+/// 继承老线性区的标签
 STATIC UINT32 OsInheritOldRegionName(UINT32 oldRegionFlags)
 {
     UINT32 vmFlags = 0;
 
-    if (oldRegionFlags & VM_MAP_REGION_FLAG_HEAP) {
-        vmFlags |= VM_MAP_REGION_FLAG_HEAP;
+    if (oldRegionFlags & VM_MAP_REGION_FLAG_HEAP) { //如果是从大堆区中申请的
+        vmFlags |= VM_MAP_REGION_FLAG_HEAP; //线性区则贴上堆区标签
     } else if (oldRegionFlags & VM_MAP_REGION_FLAG_STACK) {
         vmFlags |= VM_MAP_REGION_FLAG_STACK;
     } else if (oldRegionFlags & VM_MAP_REGION_FLAG_TEXT) {

kernel/extended/lms/los_lms.c

@@ -109,7 +109,8 @@ STATIC LmsMemListNode *OsLmsCheckPoolCreate(VOID)
     }
     return NULL;
 }
-
+/// 将指定内存池的地址范围添加到LMS的内存检测链表上，当访问的地址在链表范围内时，LMS才进行合法性校验；
+/// 且LOS_MemInit接口会调用该接口，默认将初始化的内存池挂入到检测链表中。
 UINT32 LOS_LmsCheckPoolAdd(const VOID *pool, UINT32 size)
 {
     UINT32 intSave;

lib/libscrew/include/los_rbtree.h

@@ -48,32 +48,32 @@ extern "C" {
 #define LOS_RB_RED 0
 #define LOS_RB_BLACK 1
 
-typedef struct TagRbNode {
-    struct TagRbNode *pstParent;
-    struct TagRbNode *pstRight;
-    struct TagRbNode *pstLeft;
-    ULONG_T lColor;
+typedef struct TagRbNode {//节点
+    struct TagRbNode *pstParent; ///< 爸爸是谁 ?
+    struct TagRbNode *pstRight;  ///< 右孩子是谁 ?
+    struct TagRbNode *pstLeft;	 ///< 左孩子是谁 ?
+    ULONG_T lColor; //是红还是黑节点
 } LosRbNode;
 
 typedef ULONG_T (*pfRBCmpKeyFn)(const VOID *, const VOID *);
 typedef ULONG_T (*pfRBFreeFn)(LosRbNode *);
 typedef VOID *(*pfRBGetKeyFn)(LosRbNode *);
 
-typedef struct TagRbTree {
-    LosRbNode *pstRoot;
-    LosRbNode stNilT;
+typedef struct TagRbTree {//红黑树控制块
+    LosRbNode *pstRoot;//根节点
+    LosRbNode stNilT;//叶子节点
     LOS_DL_LIST stWalkHead;
     ULONG_T ulNodes;
 
-    pfRBCmpKeyFn pfCmpKey;
-    pfRBFreeFn pfFree;
-    pfRBGetKeyFn pfGetKey;
+    pfRBCmpKeyFn pfCmpKey; //比较大小处理函数
+    pfRBFreeFn pfFree;	//释放结点处理函数
+    pfRBGetKeyFn pfGetKey;//获取节点内容处理函数
 } LosRbTree;
-
+///记录步数
 typedef struct TagRbWalk {
     LOS_DL_LIST stLink;
-    LosRbNode *pstCurrNode;
-    struct TagRbTree *pstTree;
+    LosRbNode *pstCurrNode; //当前节点
+    struct TagRbTree *pstTree;//红黑树
 } LosRbWalk;
 // 常用于两个线性区的虚拟地址的大小和范围
 #define RB_EQUAL (0) //相等

lib/libscrew/src/los_rbtree.c

@@ -124,7 +124,7 @@ STATIC VOID OsRbRightRotateNode(LosRbTree *pstTree, LosRbNode *pstY)
     pstNilT->pstParent = pstParent;
     return;
 }
-
+/// 红黑树调整
 STATIC VOID OsRbInsertNodeFixup(LosRbTree *pstTree, VOID *pstData)
 {
     LosRbNode *pstParent = NULL;
@@ -419,9 +419,9 @@ STATIC VOID OsRbInitTree(LosRbTree *pstTree)
     }
 
     pstTree->ulNodes = 0;
-    pstTree->pstRoot = &(pstTree->stNilT);
-    pstTree->stNilT.lColor = LOS_RB_BLACK;
-    pstTree->stNilT.pstLeft = NULL;   /* Always NULL */
+    pstTree->pstRoot = &(pstTree->stNilT); //初始时只有一个结点
+    pstTree->stNilT.lColor = LOS_RB_BLACK; //默认根节点是黑色
+    pstTree->stNilT.pstLeft = NULL;   /* Always NULL | 总是空 又叫NIL结点*/
     pstTree->stNilT.pstRight = NULL;  /* Always NULL */
     pstTree->stNilT.pstParent = NULL; /* Not NULL when tree isn't empty */
     LOS_ListInit(&pstTree->stWalkHead);
@@ -543,7 +543,7 @@ VOID LOS_RbInsertOneNodeProcess(LosRbTree *pstTree, LosRbNode *pstParent, LosRbN
 
     return;
 }
-
+/// 初始化进程红黑树
 VOID LOS_RbInitTree(LosRbTree *pstTree, pfRBCmpKeyFn pfCmpKey, pfRBFreeFn pfFree, pfRBGetKeyFn pfGetKey)
 {
     if (NULL == pstTree) {
@@ -558,7 +558,7 @@ VOID LOS_RbInitTree(LosRbTree *pstTree, pfRBCmpKeyFn pfCmpKey, pfRBFreeFn pfFree
 
     return;
 }
-
+/// 销毁进程红黑树
 VOID LOS_RbDestroyTree(LosRbTree *pstTree)
 {
     LosRbNode *pstNode = NULL;
@@ -744,7 +744,7 @@ ULONG_T LOS_RbAddNode(LosRbTree *pstTree, LosRbNode *pstNew)
         return FALSE;
     }
 
-    pNodeKey = pstTree->pfGetKey(pstNew);
+    pNodeKey = pstTree->pfGetKey(pstNew);//获取线性区范围
     ulSearchNode = LOS_RbGetNode(pstTree, pNodeKey, &pstX);
     if (TRUE == ulSearchNode) {
         return FALSE;

syscall/vm_syscall.c

@@ -91,6 +91,11 @@ void *SysMremap(void *oldAddr, size_t oldLen, size_t newLen, int flags, void *ne
 {
     return (void *)LOS_DoMremap((vaddr_t)oldAddr, oldLen, newLen, flags, (vaddr_t)newAddr);
 }
+/**
+ * @brief 修改访问权限
+ * @param addr 
+ * @return void* 
+ */
 
 int SysMprotect(void *vaddr, size_t len, int prot)
 {

zzz/git/push.sh

 git add -A
-git commit -m  ' 同步官方最新代码 | 新增各CPU核自主管理中断 
+git commit -m  ' 堆区相关代码注释
     百图画鸿蒙 + 百文说内核 + 百万注源码  => 挖透鸿蒙内核源码
     鸿蒙研究站 | http://weharmonyos.com (国内) 
               | https://weharmony.github.io (国外)