围绕FutexNode注解相关逻辑

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kernel/base/include/los_futex_pri.h

@@ -79,7 +79,8 @@ typedef struct {
     UINT32       index;         /* hash bucket index | 哈希桶索引 OsFutexKeyToIndex */
     UINT32       pid;           /* private:process id   shared:OS_INVALID(-1) | 私有锁:进程ID     , 共享锁为 -1 */
     LOS_DL_LIST  pendList;      /* point to pendList in TCB struct | 指向 TCB 结构中的 pendList, 通过它找到任务*/
-    LOS_DL_LIST  queueList;     /* thread list blocked by this lock | 挂等待这把锁的任务,上面挂的是 FutexNode.queueList*/
+    LOS_DL_LIST  queueList;     /* thread list blocked by this lock | 挂等待这把锁的任务，其实这里挂到是FutexNode.queueList , 
+    							通过 queueList 可以找到 pendList ,通过 pendList又可以找到真正的任务*/
     LOS_DL_LIST  futexList;     /* point to the next FutexNode | 下一把Futex锁*/
 } FutexNode;
 

kernel/base/include/los_sched_pri.h

@@ -405,7 +405,7 @@ typedef struct {
     UINTPTR         userArea;			///< 用户空间的堆区开始位置
     UINTPTR         userMapBase;		///< 用户空间的栈顶位置,内存来自用户空间,和topOfStack有本质的区别.
     UINT32          userMapSize;        /**< user thread stack size ,real size : userMapSize + USER_STACK_MIN_SIZE | 用户栈大小 */
-    FutexNode       futex;				///< 实现快锁功能
+    FutexNode       futex;				///< 快锁节点功能 , 一个任务只能等一把快锁
 #endif
     UINT32          processID;          /**< Which belong process */
     LOS_DL_LIST     joinList;           /**< join list | 联结链表,允许任务之间相互释放彼此 */

kernel/base/ipc/los_futex.c

@@ -326,7 +326,7 @@ EXIT:
 
     return;
 }
-
+///< 这块代码谁写的? 这种命名 ... 
 STATIC FutexNode *OsFutexDeleteAlreadyWakeTaskAndGetNext(const FutexNode *node, FutexNode **headNode, BOOL isDeleteHead)
 {
     FutexNode *tempNode = (FutexNode *)node;
@@ -388,7 +388,7 @@ STATIC VOID OsFutexInsertNewFutexKeyToHash(FutexNode *node)
 EXIT:
     return;
 }
-///< 
+///< 从后往前插入快锁 Form写错了 @note_thinking 
 STATIC INT32 OsFutexInsertFindFormBackToFront(LOS_DL_LIST *queueList, const LosTaskCB *runTask, FutexNode *node)
 {
     LOS_DL_LIST *listHead = queueList;
@@ -469,33 +469,33 @@ STATIC INT32 OsFutexRecycleAndFindHeadNode(FutexNode *headNode, FutexNode *node,
 ///< 将快锁挂到任务的阻塞链表上
 STATIC INT32 OsFutexInsertTasktoPendList(FutexNode **firstNode, FutexNode *node, const LosTaskCB *run)
 {
-    LosTaskCB *taskHead = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&((*firstNode)->pendList)));
+    LosTaskCB *taskHead = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&((*firstNode)->pendList)));//获取阻塞链表首个任务
     LOS_DL_LIST *queueList = &((*firstNode)->queueList);
     FutexNode *tailNode = NULL;
     LosTaskCB *taskTail = NULL;
 
-    if (run->priority < taskHead->priority) {
+    if (run->priority < taskHead->priority) {//任务的优先级比较
         /* The one with the highest priority is inserted at the top of the queue */
-        LOS_ListTailInsert(queueList, &(node->queueList));
-        OsFutexReplaceQueueListHeadNode(*firstNode, node);
+        LOS_ListTailInsert(queueList, &(node->queueList));//查到queueList的尾部
+        OsFutexReplaceQueueListHeadNode(*firstNode, node);//同时交换futexList链表上的位置
         *firstNode = node;
         return LOS_OK;
     }
-
+	//如果等锁链表上没有任务或者当前任务大于链表首个任务
     if (LOS_ListEmpty(queueList) && (run->priority >= taskHead->priority)) {
         /* Insert the next position in the queue with equal priority */
-        LOS_ListHeadInsert(queueList, &(node->queueList));
+        LOS_ListHeadInsert(queueList, &(node->queueList));//从头部插入当前任务,当前任务是要被挂起的
         return LOS_OK;
     }
-
-    tailNode = OS_FUTEX_FROM_QUEUELIST(LOS_DL_LIST_LAST(queueList));
-    taskTail = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(tailNode->pendList)));
-    if ((run->priority >= taskTail->priority) ||
-        ((run->priority - taskHead->priority) > (taskTail->priority - run->priority))) {
-        return OsFutexInsertFindFormBackToFront(queueList, run, node);
+	
+    tailNode = OS_FUTEX_FROM_QUEUELIST(LOS_DL_LIST_LAST(queueList));//获取尾部节点
+    taskTail = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(tailNode->pendList)));//获取阻塞任务的最后一个
+    if ((run->priority >= taskTail->priority) ||//当前任务优先级比最后一个更高,或者 ... 没看懂, 为啥要这样 ? @notethinking
+        ((run->priority - taskHead->priority) > (taskTail->priority - run->priority))) {//跟最后一个比较优先级
+        return OsFutexInsertFindFormBackToFront(queueList, run, node);//从后往前插入
     }
 
-    return OsFutexInsertFindFromFrontToBack(queueList, run, node);
+    return OsFutexInsertFindFromFrontToBack(queueList, run, node);//否则从前往后插入
 }
 /// 由指定快锁找到对应哈希桶
 STATIC FutexNode *OsFindFutexNode(const FutexNode *node)

zzz/git/push.sh

 git add -A
-git commit -m  ' 注解 Futex 内核态实现 
+git commit -m  ' 围绕FutexNode注解相关逻辑 
     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)