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kernel/base/core/los_tick.c

-/*
- * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
- * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this list of
- *    conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice, this list
- *    of conditions and the following disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its contributors may be used
- *    to endorse or promote products derived from this software without specific prior written
- *    permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "los_tick_pri.h"
-#include "los_swtmr_pri.h"
-#include "los_task_pri.h"
-#include "los_timeslice_pri.h"
-#ifdef LOSCFG_KERNEL_TICKLESS
-#include "los_tickless_pri.h"
-#endif
-#ifdef LOSCFG_KERNEL_VDSO
-#include "los_vdso.h"
-#endif
-
-#ifdef __cplusplus
-#if __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-#endif /* __cplusplus */
-
-LITE_OS_SEC_BSS volatile UINT64 g_tickCount[LOSCFG_KERNEL_CORE_NUM] = {0};//tick计数器,系统一旦启动,一直在++, 为防止溢出,这是一个 UINT64 的变量
-LITE_OS_SEC_DATA_INIT UINT32 g_sysClock;//系统时钟
-LITE_OS_SEC_DATA_INIT UINT32 g_tickPerSecond;//每秒Tick数,鸿蒙默认是每秒100次,即:10ms
-LITE_OS_SEC_BSS DOUBLE g_cycle2NsScale;
-
-/* spinlock for task module */
-LITE_OS_SEC_BSS SPIN_LOCK_INIT(g_tickSpin);
-
-/*
- * Description : Tick interruption handler
- *///系统时钟中断处理函数 ,鸿蒙是 10ms触发一次
-LITE_OS_SEC_TEXT VOID OsTickHandler(VOID)
-{
-    UINT32 intSave;
-
-    TICK_LOCK(intSave);
-    g_tickCount[ArchCurrCpuid()]++;//当前CPU核 计数器
-    TICK_UNLOCK(intSave);
-
-#ifdef LOSCFG_KERNEL_VDSO
-    OsUpdateVdsoTimeval();
-#endif
-
-#ifdef LOSCFG_KERNEL_TICKLESS
-    OsTickIrqFlagSet(OsTicklessFlagGet());
-#endif
-
-#if (LOSCFG_BASE_CORE_TICK_HW_TIME == YES)
-    HalClockIrqClear(); /* diff from every platform */
-#endif
-
-    OsTimesliceCheck();//时间片检查
-
-    OsTaskScan(); /* task timeout scan *///任务扫描
-
-#if (LOSCFG_BASE_CORE_SWTMR == YES)
-    OsSwtmrScan();//定时器扫描,看是否有超时的定时器
-#endif
-}
-
-#ifdef __cplusplus
-#if __cplusplus
-}
-#endif /* __cplusplus */
-#endif /* __cplusplus */
+/*
+ * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
+ * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *    of conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used
+ *    to endorse or promote products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "los_tick_pri.h"
+#include "los_swtmr_pri.h"
+#include "los_task_pri.h"
+#include "los_timeslice_pri.h"
+#ifdef LOSCFG_KERNEL_TICKLESS
+#include "los_tickless_pri.h"
+#endif
+#ifdef LOSCFG_KERNEL_VDSO
+#include "los_vdso.h"
+#endif
+
+#ifdef __cplusplus
+#if __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+#endif /* __cplusplus */
+
+LITE_OS_SEC_BSS volatile UINT64 g_tickCount[LOSCFG_KERNEL_CORE_NUM] = {0};//tick计数器,系统一旦启动,一直在++, 为防止溢出,这是一个 UINT64 的变量
+LITE_OS_SEC_DATA_INIT UINT32 g_sysClock;//系统时钟
+LITE_OS_SEC_DATA_INIT UINT32 g_tickPerSecond;//每秒Tick数,鸿蒙默认是每秒100次,即:10ms
+LITE_OS_SEC_BSS DOUBLE g_cycle2NsScale;
+
+/* spinlock for task module */
+LITE_OS_SEC_BSS SPIN_LOCK_INIT(g_tickSpin); //节拍器自旋锁
+
+/*
+ * Description : Tick interruption handler
+ *///系统时钟中断处理函数 ,鸿蒙是 10ms触发一次
+LITE_OS_SEC_TEXT VOID OsTickHandler(VOID)
+{
+    UINT32 intSave;
+
+    TICK_LOCK(intSave);
+    g_tickCount[ArchCurrCpuid()]++;//当前CPU核 计数器
+    TICK_UNLOCK(intSave);
+
+#ifdef LOSCFG_KERNEL_VDSO
+    OsUpdateVdsoTimeval();
+#endif
+
+#ifdef LOSCFG_KERNEL_TICKLESS
+    OsTickIrqFlagSet(OsTicklessFlagGet());
+#endif
+
+#if (LOSCFG_BASE_CORE_TICK_HW_TIME == YES)
+    HalClockIrqClear(); /* diff from every platform */
+#endif
+
+    OsTimesliceCheck();//时间片检查
+
+    OsTaskScan(); /* task timeout scan *///任务扫描
+
+#if (LOSCFG_BASE_CORE_SWTMR == YES)
+    OsSwtmrScan();//定时器扫描,看是否有超时的定时器
+#endif
+}
+
+#ifdef __cplusplus
+#if __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* __cplusplus */

kernel/base/include/los_vm_map.h

@@ -109,7 +109,7 @@ struct VmMapRegion {//线性区描述符,内核通过线性区管理虚拟地址
     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
-    UINT32              shmid;          /**< shmid about shared region */	//shmid为共享线性区id
+    UINT32              shmid;          /**< shmid about shared region */	//shmid为共享线性区id,id背后就是共享线性区
     UINT8               protectFlags;   /**< vm region protect flags: PROT_READ, PROT_WRITE, *///线性区中页框的访问许可权
     UINT8               forkFlags;      /**< vm space fork flags: COPY, ZERO, */	//fork的方式
     UINT8               regionType;     /**< vm region type: ANON, FILE, DEV */	//映射类型是匿名,文件,还是设备,所谓匿名可理解为内存映射

kernel/base/include/los_vm_syscall.h

-/*
- * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
- * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this list of
- *    conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice, this list
- *    of conditions and the following disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its contributors may be used
- *    to endorse or promote products derived from this software without specific prior written
- *    permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-/**
- * @defgroup los_vm_syscall vm syscall definition
- * @ingroup kernel
- */
-
-#ifndef __LOS_VM_SYSCALL_H__
-#define __LOS_VM_SYSCALL_H__
-
-#include "sys/shm.h"
-#include "sys/mman.h"
-
-#ifdef __cplusplus
-#if __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-#endif /* __cplusplus */
-
-STATIC INLINE BOOL LOS_IsNamedMapping(unsigned long flags)//是否非匿名映射
-{
-    return ((flags & MAP_ANONYMOUS) == 0);
-}
-
-STATIC INLINE BOOL LOS_IsAnonymousMapping(unsigned long flags)
-{
-    return ((flags & MAP_ANONYMOUS) == MAP_ANONYMOUS);
-}
-
-VADDR_T LOS_MMap(VADDR_T vaddr, size_t len, unsigned prot, unsigned long flags, int fd, unsigned long pgoff);
-STATUS_T LOS_UnMMap(VADDR_T addr, size_t size);
-VOID *LOS_DoBrk(VOID *addr);
-int LOS_DoMprotect(VADDR_T vaddr, size_t len, unsigned long prot);
-VADDR_T LOS_DoMremap(VADDR_T oldAddress, size_t oldSize, size_t newSize, int flags, VADDR_T newAddr);
-VOID LOS_DumpMemRegion(VADDR_T vaddr);
-INT32 ShmInit(VOID);
-INT32 ShmDeinit(VOID);
-INT32 ShmGet(key_t key, size_t size, INT32 shmflg);
-VOID *ShmAt(INT32 shmid, const VOID *shmaddr, INT32 shmflg);
-INT32 ShmCtl(INT32 shmid, INT32 cmd, struct shmid_ds *buf);
-INT32 ShmDt(const VOID *shmaddr);
-
-#ifdef __cplusplus
-#if __cplusplus
-}
-#endif /* __cplusplus */
-#endif /* __cplusplus */
-
-#endif /* __LOS_VM_SYSCALL_H__ */
+/*
+ * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
+ * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *    of conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used
+ *    to endorse or promote products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @defgroup los_vm_syscall vm syscall definition
+ * @ingroup kernel
+ */
+
+#ifndef __LOS_VM_SYSCALL_H__
+#define __LOS_VM_SYSCALL_H__
+
+#include "sys/shm.h"
+#include "sys/mman.h"
+
+#ifdef __cplusplus
+#if __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+#endif /* __cplusplus */
+//是否非匿名映射
+STATIC INLINE BOOL LOS_IsNamedMapping(unsigned long flags)
+{
+    return ((flags & MAP_ANONYMOUS) == 0);
+}
+//是否匿名映射
+STATIC INLINE BOOL LOS_IsAnonymousMapping(unsigned long flags)
+{
+    return ((flags & MAP_ANONYMOUS) == MAP_ANONYMOUS);
+}
+
+VADDR_T LOS_MMap(VADDR_T vaddr, size_t len, unsigned prot, unsigned long flags, int fd, unsigned long pgoff);
+STATUS_T LOS_UnMMap(VADDR_T addr, size_t size);
+VOID *LOS_DoBrk(VOID *addr);
+int LOS_DoMprotect(VADDR_T vaddr, size_t len, unsigned long prot);
+VADDR_T LOS_DoMremap(VADDR_T oldAddress, size_t oldSize, size_t newSize, int flags, VADDR_T newAddr);
+VOID LOS_DumpMemRegion(VADDR_T vaddr);
+INT32 ShmInit(VOID);
+INT32 ShmDeinit(VOID);
+INT32 ShmGet(key_t key, size_t size, INT32 shmflg);
+VOID *ShmAt(INT32 shmid, const VOID *shmaddr, INT32 shmflg);
+INT32 ShmCtl(INT32 shmid, INT32 cmd, struct shmid_ds *buf);
+INT32 ShmDt(const VOID *shmaddr);
+
+#ifdef __cplusplus
+#if __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* __cplusplus */
+
+#endif /* __LOS_VM_SYSCALL_H__ */

kernel/base/vm/shm.c

@@ -52,15 +52,23 @@ extern "C" {
 #endif /* __cplusplus */
 #endif /* __cplusplus */
 
+/******************************************************************************
+共享内存是进程间通信中最简单的方式之一。共享内存允许两个或更多进程访问同一块内存
+不同进程返回了指向同一个物理内存区域的指针。当一个进程改变了这块地址中的内容的时候，
+其它进程都会察觉到这个更改。
+
+共享线性区可以由任意的进程创建,每个使用共享线性区都必须经过映射.
+******************************************************************************/
+
 STATIC LosMux g_sysvShmMux;
 
 /* private macro */
-#define SYSV_SHM_LOCK()     (VOID)LOS_MuxLock(&g_sysvShmMux, LOS_WAIT_FOREVER)	//拿永久等待锁
+#define SYSV_SHM_LOCK()     (VOID)LOS_MuxLock(&g_sysvShmMux, LOS_WAIT_FOREVER)	//申请永久等待锁
 #define SYSV_SHM_UNLOCK()   (VOID)LOS_MuxUnlock(&g_sysvShmMux)	//释放锁
 
 #define SHM_MAX_PAGES 12800	//共享最大页
-#define SHM_MAX (SHM_MAX_PAGES * PAGE_SIZE) // 12800*4K = 50M
-#define SHM_MIN 1
+#define SHM_MAX (SHM_MAX_PAGES * PAGE_SIZE) // 最大共享空间,12800*4K = 50M
+#define SHM_MIN 1	
 #define SHM_MNI 192
 #define SHM_SEG 128
 #define SHM_ALL (SHM_MAX_PAGES)
@@ -86,7 +94,7 @@ struct shmSegMap {
     INT32 shmID;	//可看出共享内存使用了ID管理机制
 };
 
-struct shmIDSource {//共享存储结构体
+struct shmIDSource {//共享内存描述符
     struct shmid_ds ds; //是内核为每一个共享内存段维护的数据结构,包含权限,各进程最后操作的时间,进程ID等信息
     UINT32 status;	//状态 SHM_SEG_FREE ...
     LOS_DL_LIST node; //节点,挂vmPage
@@ -98,7 +106,7 @@ STATIC struct shminfo g_shmInfo = {
     .shmmin = SHM_MIN,//最小的内存segment的大小 1M
     .shmmni = SHM_MNI,//整个系统的内存segment的总个数  :默认192     			ShmAllocSeg 
     .shmseg = SHM_SEG,//每个进程可以使用的内存segment的最大个数 128
-    .shmall = SHM_ALL,
+    .shmall = SHM_ALL,//系统范围内共享内存的最大页数
 };
 
 STATIC struct shmIDSource *g_shmSegs = NULL;
@@ -129,7 +137,7 @@ INT32 ShmInit(VOID)
 
     return 0;
 }
-//共享内存释放初始化
+//共享内存反初始化
 INT32 ShmDeinit(VOID)
 {
     UINT32 ret;
@@ -296,7 +304,7 @@ STATIC VOID ShmVmmMapping(LosVmSpace *space, LOS_DL_LIST *pageList, VADDR_T vadd
     PADDR_T pa;
     STATUS_T ret;
 
-    LOS_DL_LIST_FOR_EACH_ENTRY(vmPage, pageList, LosVmPage, node) {
+    LOS_DL_LIST_FOR_EACH_ENTRY(vmPage, pageList, LosVmPage, node) {//遍历一页一页映射
         pa = VM_PAGE_TO_PHYS(vmPage);//拿到物理地址
         LOS_AtomicInc(&vmPage->refCounts);//自增
         ret = LOS_ArchMmuMap(&space->archMmu, va, pa, 1, regionFlags);//虚实映射
@@ -321,7 +329,7 @@ VOID OsShmFork(LosVmSpace *space, LosVmMapRegion *oldRegion, LosVmMapRegion *new
 
     newRegion->shmid = oldRegion->shmid;//一样的共享区ID
     newRegion->forkFlags = oldRegion->forkFlags;//forkFlags也一样了
-    ShmVmmMapping(space, &seg->node, newRegion->range.base, newRegion->regionFlags);//共享内存映射
+    ShmVmmMapping(space, &seg->node, newRegion->range.base, newRegion->regionFlags);//新线性区与共享内存进行映射
     seg->ds.shm_nattch++;//附在共享线性区上的进程数++
     SYSV_SHM_UNLOCK();
 }
@@ -331,7 +339,7 @@ VOID OsShmRegionFree(LosVmSpace *space, LosVmMapRegion *region)
     struct shmIDSource *seg = NULL;
 
     SYSV_SHM_LOCK();
-    seg = ShmFindSeg(region->shmid);////通过线性区ID获取对应的共享资源ID结构体
+    seg = ShmFindSeg(region->shmid);//通过线性区ID获取对应的共享资源ID结构体
     if (seg == NULL) {
         SYSV_SHM_UNLOCK();
         return;
@@ -344,7 +352,7 @@ VOID OsShmRegionFree(LosVmSpace *space, LosVmMapRegion *region)
     }
     SYSV_SHM_UNLOCK();
 }
-//是否为共享线性区,看他有没有标签
+//是否为共享线性区,是否有标签?
 BOOL OsIsShmRegion(LosVmMapRegion *region)
 {
     return (region->regionFlags & VM_MAP_REGION_FLAG_SHM) ? TRUE : FALSE;
@@ -478,7 +486,7 @@ INT32 ShmatParamCheck(const void *shmaddr, int shmflg)
 
     return 0;
 }
-//共享
+//分配一个共享线性区
 LosVmMapRegion *ShmatVmmAlloc(struct shmIDSource *seg, const VOID *shmaddr,
                               INT32 shmflg, UINT32 prot)
 {

zzz/git/push.sh

 git add -A
-git commit -m  '注解让你彻底明白什么是圆整函数(ROUNDUP,ROUNDDOWN).
+git commit -m  '关于内核这些问题你知道多少? .
 搜索 @note_pic 方便理解画的字符图
 搜索 @note_why 尚未看明白的地方，如果您看明白了，请告知完善
 搜索 @note_thinking 一点思考和吐槽的地方