注解 dmesg模块,环形buf记录内核日志

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注解 dmesg模块,环形buf记录内核日志
ca112dfe · 鸿蒙内核源码分析 · 3e116d6f · ca112dfe · ca112dfe · ca112dfe
6 changed file
--- a/kernel/base/ipc/los_mux.c
+++ b/kernel/base/ipc/los_mux.c
@@ -339,7 +339,7 @@ VOID OsMuxBitmapRestore(const LosMux *mutex, const LosTaskCB *taskCB, LosTaskCB
    }
 }

-//最坏情况就是拿锁失败,让出CPU,变成阻塞任务,等别的任务释放锁后排到自己了接着执行. 
+/// 最坏情况就是拿锁失败,让出CPU,变成阻塞任务,等别的任务释放锁后排到自己了接着执行. 
 STATIC UINT32 OsMuxPendOp(LosTaskCB *runTask, LosMux *mutex, UINT32 timeout)
 {
    UINT32 ret;
@@ -419,7 +419,7 @@ UINT32 OsMuxLockUnsafe(LosMux *mutex, UINT32 timeout)

    return OsMuxPendOp(runTask, mutex, timeout);
 }
-///尝试加锁,
+/// 尝试加锁,
 UINT32 OsMuxTrylockUnsafe(LosMux *mutex, UINT32 timeout)
 {
    LosTaskCB *runTask = OsCurrTaskGet();//获取当前任务
@@ -439,7 +439,7 @@ UINT32 OsMuxTrylockUnsafe(LosMux *mutex, UINT32 timeout)

    return OsMuxPendOp(runTask, mutex, timeout);//当前任务去拿锁,拿不到就等timeout
 }
-///拿互斥锁,
+/// 拿互斥锁,
 LITE_OS_SEC_TEXT UINT32 LOS_MuxLock(LosMux *mutex, UINT32 timeout)
 {
    LosTaskCB *runTask = NULL;
@@ -466,7 +466,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxLock(LosMux *mutex, UINT32 timeout)
    SCHEDULER_UNLOCK(intSave);
    return ret;
 }
-///尝试锁不纠结,没拿到不会等待,返回
+///尝试要锁,没拿到也不等,直接返回,不纠结
 LITE_OS_SEC_TEXT UINT32 LOS_MuxTrylock(LosMux *mutex)
 {
    LosTaskCB *runTask = NULL;

--- a/kernel/common/console.c
+++ b/kernel/common/console.c
@@ -751,8 +751,8 @@ STATIC ssize_t DoWrite(CirBufSendCB *cirBufSendCB, CHAR *buffer, size_t bufLen)
    size_t toWrite = bufLen;
    UINT32 intSave;

-#ifdef LOSCFG_SHELL_DMESG
-    (VOID)OsLogMemcpyRecord(buffer, bufLen);
+#ifdef LOSCFG_SHELL_DMESG 
+    (VOID)OsLogMemcpyRecord(buffer, bufLen); //写到内核缓冲区中
    if (OsCheckConsoleLock()) {
        return 0;
    }

--- a/shell/full/include/dmesg.h
+++ b/shell/full/include/dmesg.h
@@ -44,13 +44,13 @@ extern "C" {
 * @ingroup dmesg
 * Defalut dmesg buffer size.
 */
-#define KERNEL_LOG_BUF_SIZE (8 * 1024)
+#define KERNEL_LOG_BUF_SIZE (8 * 1024) ///< 记录内核日志的 dmesg 缓冲区默认大小 8K

 /**
 * @ingroup dmesg
 * Max dmesg buffer size to set.
 */
-#define MAX_KERNEL_LOG_BUF_SIZE (8 * 1024 * 10)
+#define MAX_KERNEL_LOG_BUF_SIZE (8 * 1024 * 10) ///< dmesg 缓冲区最大尺寸 ,80K

 /**
 * @ingroup dmesg

--- a/shell/full/include/dmesg_pri.h
+++ b/shell/full/include/dmesg_pri.h
@@ -43,12 +43,13 @@ extern "C" {

 /*
 * The dmesg buffer is start with this info structure, then the log.
+ * | dmesg信息管理器,环形buf
 */
-typedef struct {//dmesg信息管理器,环形buf
-    UINT32 logSize; /*! The size of log in buffer */
-    UINT32 logHead; /*! The index of the first log data. Data_out_flag */
-    UINT32 logTail; /*! The index where to write, write in and plus one. Data_it_flag */
-    CHAR   *logBuf; /*! The log buffer addr */
+typedef struct {
+    UINT32 logSize; /*! The size of log in buffer | 已写入的日志大小 */
+    UINT32 logHead; /*! The index of the first log data. Data_out_flag | 首条日志位置 */
+    UINT32 logTail; /*! The index where to write, write in and plus one. Data_it_flag | 写入日志的位置 */
+    CHAR   *logBuf; /*! The log buffer addr | 缓冲区地址 */
 } DmesgInfo;

 extern UINT32 OsDmesgInit(VOID);

--- a/shell/full/src/cmds/dmesg.c
+++ b/shell/full/src/cmds/dmesg.c
+/*!
+ * @file    dmesg.c
+ * @brief dmesg命令用于控制内核dmesg缓存区。
+ * @link dmesg http://weharmonyos.com/openharmony/zh-cn/device-dev/kernel/kernel-small-debug-shell-cmd-dmesg.html 
+ 				https://man7.org/linux/man-pages/man1/dmesg.1.html
+ * @endlink
+   @verbatim
+	  +-------------------------------------------------------+
+	  | Info |			log_space							  |
+	  +-------------------------------------------------------+
+	  |
+	  |__buffer_space
+   
+   Case A:
+	  +-------------------------------------------------------+
+	  | 		  |#############################|			  |
+	  +-------------------------------------------------------+
+				  | 							|
+				 Head							Tail
+   Case B:
+	  +-------------------------------------------------------+
+	  |##########|									  |#######|
+	  +-------------------------------------------------------+
+				 |									  |
+				 Tail								  Head
+
+   @endverbatim
+ * @version 
+ * @author  weharmonyos.com | 鸿蒙研究站 | 每天死磕一点点
+ * @date    2021-11-25
+ */
 /*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
@@ -29,27 +60,6 @@
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

-/*
-   +-------------------------------------------------------+
-   | Info |          log_space                             |
-   +-------------------------------------------------------+
-   |
-   |__buffer_space
-
-Case A:
-   +-------------------------------------------------------+
-   |           |#############################|             |
-   +-------------------------------------------------------+
-               |                             |
-              Head                           Tail
-Case B:
-   +-------------------------------------------------------+
-   |##########|                                    |#######|
-   +-------------------------------------------------------+
-              |                                    |
-              Tail                                 Head
-*/
-
 #ifdef LOSCFG_SHELL_DMESG
 #include "dmesg_pri.h"
 #include "show.h"
@@ -61,17 +71,17 @@ Case B:
 #include "los_task.h"


-#define BUF_MAX_INDEX (g_logBufSize - 1)
+#define BUF_MAX_INDEX (g_logBufSize - 1) ///< 缓存区最大索引,可按单个字符保存

 LITE_OS_SEC_BSS STATIC SPIN_LOCK_INIT(g_dmesgSpin);

-STATIC DmesgInfo *g_dmesgInfo = NULL;
-STATIC UINT32 g_logBufSize = 0;
-STATIC VOID *g_mallocAddr = NULL;
-STATIC UINT32 g_dmesgLogLevel = 3;//日志等级
-STATIC UINT32 g_consoleLock = 0;//用于关闭和打开控制台
-STATIC UINT32 g_uartLock = 0;//用于关闭和打开串口
-STATIC const CHAR *g_levelString[] = {
+STATIC DmesgInfo *g_dmesgInfo = NULL;///< 保存在 g_mallocAddr 的开始位置,即头信息
+STATIC UINT32 g_logBufSize = 0;	///< 缓冲区内容体大小
+STATIC VOID *g_mallocAddr = NULL;///< 缓存区开始位置,即头位置
+STATIC UINT32 g_dmesgLogLevel = 3;	///< 日志等级
+STATIC UINT32 g_consoleLock = 0;	///< 用于关闭和打开控制台
+STATIC UINT32 g_uartLock = 0;		///< 用于关闭和打开串口
+STATIC const CHAR *g_levelString[] = {///< 日志等级
    "EMG",
    "COMMON",
    "ERR",
@@ -79,22 +89,22 @@ STATIC const CHAR *g_levelString[] = {
    "INFO",
    "DEBUG"
 };
-//关闭控制台
+/// 关闭控制台
 STATIC VOID OsLockConsole(VOID)
 {
    g_consoleLock = 1;
 }
-///打开控制台
+/// 打开控制台
 STATIC VOID OsUnlockConsole(VOID)
 {
    g_consoleLock = 0;
 }
-///关闭串口
+/// 关闭串口
 STATIC VOID OsLockUart(VOID)
 {
    g_uartLock = 1;
 }
-///打开串口
+/// 打开串口
 STATIC VOID OsUnlockUart(VOID)
 {
    g_uartLock = 0;
@@ -117,7 +127,7 @@ STATIC UINT32 OsCheckError(VOID)

    return LOS_OK;
 }
-
+///< 读取dmesg日志
 STATIC INT32 OsDmesgRead(CHAR *buf, UINT32 len)
 {
    UINT32 readLen;
@@ -168,7 +178,7 @@ STATIC INT32 OsDmesgRead(CHAR *buf, UINT32 len)
    }
    return (INT32)readLen;
 }
-
+/// 把旧人账目移交给新人
 STATIC INT32 OsCopyToNew(const VOID *addr, UINT32 size)
 {
    UINT32 copyStart = 0;
@@ -211,7 +221,7 @@ STATIC INT32 OsCopyToNew(const VOID *addr, UINT32 size)

    return (INT32)copyLen;
 }
-
+/// 重置内存
 STATIC UINT32 OsDmesgResetMem(const VOID *addr, UINT32 size)
 {
    VOID *temp = NULL;
@@ -246,7 +256,7 @@ STATIC UINT32 OsDmesgResetMem(const VOID *addr, UINT32 size)

    return LOS_OK;
 }
-
+///调整缓冲区大小,如下五个步骤
 STATIC UINT32 OsDmesgChangeSize(UINT32 size)
 {
    VOID *temp = NULL;
@@ -257,34 +267,34 @@ STATIC UINT32 OsDmesgChangeSize(UINT32 size)
    if (size == 0) {
        return LOS_NOK;
    }
-
+	//1. 重新整一块新地方
    newString = (CHAR *)malloc(size + sizeof(DmesgInfo));
-    if (newString == NULL) {
+    if (newString == NULL) {//新人未找到,旧人得接着用
        return LOS_NOK;
    }

    LOS_SpinLockSave(&g_dmesgSpin, &intSave);
    temp = g_dmesgInfo;
-
+	//2.把旧人账目移交给新人
    copyLen = OsCopyToNew(newString, size + sizeof(DmesgInfo));
    if (copyLen < 0) {
        LOS_SpinUnlockRestore(&g_dmesgSpin, intSave);
        free(newString);
        return LOS_NOK;
    }
-
+	//3.以新换旧
    g_logBufSize = size;
    g_dmesgInfo = (DmesgInfo *)newString;
    g_dmesgInfo->logBuf = (CHAR *)newString + sizeof(DmesgInfo);
    g_dmesgInfo->logSize = copyLen;
    g_dmesgInfo->logTail = ((copyLen == g_logBufSize) ? 0 : copyLen);
    g_dmesgInfo->logHead = 0;
-
+	//4. 有新欢了,释放旧人去找寻真爱
    if (temp == g_mallocAddr) {
        g_mallocAddr = NULL;
        free(temp);
    }
-    g_mallocAddr = newString;
+    g_mallocAddr = newString;//5. 正式和新人媾和
    LOS_SpinUnlockRestore(&g_dmesgSpin, intSave);

    return LOS_OK;
@@ -299,26 +309,26 @@ UINT32 OsCheckUartLock(VOID)
 {
    return g_uartLock;
 }
-///初始化 dmesg
+/// 初始化 dmesg
 UINT32 OsDmesgInit(VOID)
 {
    CHAR* buffer = NULL;

-    buffer = (CHAR *)malloc(KERNEL_LOG_BUF_SIZE + sizeof(DmesgInfo));
+    buffer = (CHAR *)malloc(KERNEL_LOG_BUF_SIZE + sizeof(DmesgInfo));//总内存分 头 + 体两部分
    if (buffer == NULL) {
        return LOS_NOK;
    }
    g_mallocAddr = buffer;
-    g_dmesgInfo = (DmesgInfo *)buffer;
-    g_dmesgInfo->logHead = 0;
-    g_dmesgInfo->logTail = 0;
-    g_dmesgInfo->logSize = 0;
-    g_dmesgInfo->logBuf = buffer + sizeof(DmesgInfo);
-    g_logBufSize = KERNEL_LOG_BUF_SIZE;
+    g_dmesgInfo = (DmesgInfo *)buffer;//全局变量
+    g_dmesgInfo->logHead = 0;//读取开始位置 记录在头部
+    g_dmesgInfo->logTail = 0;//写入开始位置 记录在头部
+    g_dmesgInfo->logSize = 0;//日志已占用数量 记录在头部
+    g_dmesgInfo->logBuf = buffer + sizeof(DmesgInfo);//身体部分开始位置
+    g_logBufSize = KERNEL_LOG_BUF_SIZE;//身体部分总大小位置

    return LOS_OK;
 }
-
+/// 只记录一个字符
 STATIC CHAR OsLogRecordChar(CHAR c)
 {
    *(g_dmesgInfo->logBuf + g_dmesgInfo->logTail++) = c;
@@ -334,7 +344,7 @@ STATIC CHAR OsLogRecordChar(CHAR c)
    }
    return c;
 }
-
+/// 记录一个字符串
 UINT32 OsLogRecordStr(const CHAR *str, UINT32 len)
 {
    UINT32 i = 0;
@@ -401,7 +411,7 @@ STATIC VOID OsBufFullWrite(const CHAR *dst, UINT32 logLen)
        }
    }
 }
-
+/// 从头写入 
 STATIC VOID OsWriteTailToHead(const CHAR *dst, UINT32 logLen)
 {
    UINT32 writeLen = 0;
@@ -436,7 +446,7 @@ STATIC VOID OsWriteTailToHead(const CHAR *dst, UINT32 logLen)
        g_dmesgInfo->logSize += logLen;
    }
 }
-
+/// 从尾写入 
 STATIC VOID OsWriteTailToEnd(const CHAR *dst, UINT32 logLen)
 {
    UINT32 writeLen;
@@ -474,7 +484,7 @@ STATIC VOID OsWriteTailToEnd(const CHAR *dst, UINT32 logLen)
        g_dmesgInfo->logSize += logLen;
    }
 }
-
+/// 内存拷贝日志
 INT32 OsLogMemcpyRecord(const CHAR *buf, UINT32 logLen)
 {
    UINT32 intSave;
@@ -497,7 +507,7 @@ INT32 OsLogMemcpyRecord(const CHAR *buf, UINT32 logLen)

    return LOS_OK;
 }
-
+/// 使用串口打印日志
 VOID OsLogShow(VOID)
 {
    UINT32 intSave;
@@ -515,21 +525,21 @@ VOID OsLogShow(VOID)
    }
    (VOID)memset_s(p, g_dmesgInfo->logSize + 1, 0, g_dmesgInfo->logSize + 1);

-    while (i < g_dmesgInfo->logSize) {
+    while (i < g_dmesgInfo->logSize) {//一个一个字符拷贝
        *(p + i) = *(g_dmesgInfo->logBuf + index++);
-        if (index > BUF_MAX_INDEX) {
+        if (index > BUF_MAX_INDEX) {//循环buf,读到尾了得从头开始读
            index = 0;
        }
        i++;
-        if (index == g_dmesgInfo->logTail) {
+        if (index == g_dmesgInfo->logTail) {//一直读到写入位置,才退出
            break;
        }
    }
    LOS_SpinUnlockRestore(&g_dmesgSpin, intSave);
-    UartPuts(p, i, UART_WITH_LOCK);
-    free(p);
+    UartPuts(p, i, UART_WITH_LOCK);//串口输出
+    free(p);//释放内存
 }
-
+/// 设置日志层级
 STATIC INT32 OsDmesgLvSet(const CHAR *level)
 {
    UINT32 levelNum, ret;
@@ -599,7 +609,7 @@ VOID LOS_DmesgClear(VOID)
    g_dmesgInfo->logSize = 0;
    LOS_SpinUnlockRestore(&g_dmesgSpin, intSave);
 }
-
+/// 设置dmesg缓存大小
 UINT32 LOS_DmesgMemSet(const VOID *addr, UINT32 size)
 {
    UINT32 ret = 0;
@@ -611,7 +621,7 @@ UINT32 LOS_DmesgMemSet(const VOID *addr, UINT32 size)
    }
    return ret;
 }
-
+/// 读取 dmesg 消息
 INT32 LOS_DmesgRead(CHAR *buf, UINT32 len)
 {
    INT32 ret;
@@ -644,12 +654,13 @@ INT32 OsDmesgWrite2File(const CHAR *fullpath, const CHAR *buf, UINT32 logSize)
 }

 #ifdef LOSCFG_FS_VFS
+/// 将dmesg 保存到文件中
 INT32 LOS_DmesgToFile(const CHAR *filename)
 {
    CHAR *fullpath = NULL;
    CHAR *buf = NULL;
    INT32 ret;
-    CHAR *shellWorkingDirectory = OsShellGetWorkingDirectory();
+    CHAR *shellWorkingDirectory = OsShellGetWorkingDirectory();//获取工作路径
    UINT32 logSize, bufSize, head, tail, intSave;
    CHAR *logBuf = NULL;

@@ -665,7 +676,7 @@ INT32 LOS_DmesgToFile(const CHAR *filename)
    logBuf = g_dmesgInfo->logBuf;
    LOS_SpinUnlockRestore(&g_dmesgSpin, intSave);

-    ret = vfs_normalize_path(shellWorkingDirectory, filename, &fullpath);
+    ret = vfs_normalize_path(shellWorkingDirectory, filename, &fullpath);//获取绝对路径
    if (ret != 0) {
        return -1;
    }
@@ -691,7 +702,7 @@ INT32 LOS_DmesgToFile(const CHAR *filename)
        }
    }

-    ret = OsDmesgWrite2File(fullpath, buf, logSize);
+    ret = OsDmesgWrite2File(fullpath, buf, logSize);//写文件
 ERR_OUT3:
    free(buf);
 ERR_OUT2:

--- a/zzz/git/push.sh
+++ b/zzz/git/push.sh
 git add -A
-git commit -m  ' 开始注解 VDSO（Virtual Dynamic Shared Object，虚拟动态共享库）
+git commit -m  ' 注解 dmesg模块,环形buf记录内核日志
    百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码
    鸿蒙研究站 | http://weharmonyos.com (国内) 
              | https://weharmony.github.io (国外)