los_hilog.c 文件参考

浏览源代码.

结构体
struct	HiLogEntry
struct	HiLogCharDevice

函数
ssize_t	HilogRead (struct file *filep, char __user *buf, size_t count)
ssize_t	HilogWrite (struct file *filep, const char __user *buf, size_t count)
int	HiLogOpen (struct file *filep)
	为支持VFS,作打开状 更多...
int	HiLogClose (struct file *filep)
	为支持VFS,作关闭状 更多...
static ssize_t	HiLogWrite (struct file *filep, const char *buffer, size_t bufLen)
	写hilog,外部以VFS方式写入 更多...
static ssize_t	HiLogRead (struct file *filep, char *buffer, size_t bufLen)
static unsigned char *	HiLogBufferHead (void)
static void	HiLogBufferInc (size_t sz)
	读写对冲,对hilog的写操作,更新相关变量内容 更多...
static void	HiLogBufferDec (size_t sz)
	读写对冲,对hilog的读操作,更新相关变量内容 更多...
static int	HiLogBufferCopy (unsigned char *dst, unsigned dstLen, const unsigned char *src, size_t srcLen)
static int	HiLogReadRingBuffer (unsigned char *buffer, size_t bufLen)
	读取ring buffer 更多...
static int	HiLogWriteRingBuffer (unsigned char *buffer, size_t bufLen)
	写入 RingBuffer环形缓冲，也叫 circleBuffer 更多...
static void	HiLogHeadInit (struct HiLogEntry *header, size_t len)
	hilog实体初始化 更多...
static void	HiLogCoverOldLog (size_t bufLen)
int	HiLogWriteInternal (const char *buffer, size_t bufLen)
	将外部buf写入hilog设备分两步完成 更多...
static void	HiLogDeviceInit (void)
	初始化全局变量g_hiLogDev 更多...
int	OsHiLogDriverInit (VOID)
	初始化hilog驱动 更多...
	LOS_MODULE_INIT (OsHiLogDriverInit, LOS_INIT_LEVEL_KMOD_EXTENDED)

变量
STATIC struct file_operations_vfs	g_hilogFops
struct HiLogCharDevice	g_hiLogDev

函数说明

HiLogBufferCopy()

static int HiLogBufferCopy ( unsigned char *  dst, unsigned  dstLen, const unsigned char *  src, size_t  srcLen  )

static

在文件 los_hilog.c 第 129 行定义.

{
    int retval = -1;
    size_t minLen = (dstLen > srcLen) ? srcLen : dstLen;
 
    if (LOS_IsUserAddressRange((VADDR_T)(UINTPTR)dst, minLen) &&
        LOS_IsUserAddressRange((VADDR_T)(UINTPTR)src, minLen)) {
        return retval;
    }
 
    if (LOS_IsUserAddressRange((VADDR_T)(UINTPTR)dst, minLen)) {
        retval = LOS_ArchCopyToUser(dst, src, minLen);
    } else if (LOS_IsUserAddressRange((VADDR_T)(UINTPTR)src, minLen)) {
        retval = LOS_ArchCopyFromUser(dst, src, minLen);
    } else {
        retval = memcpy_s(dst, dstLen, src, srcLen);
    }
    return retval;
}

函数调用图:

这是这个函数的调用关系图:

HiLogBufferDec()

static void HiLogBufferDec ( size_t  sz )

static

读写对冲,对hilog的读操作,更新相关变量内容

在文件 los_hilog.c 第 119 行定义.

{
    if (g_hiLogDev.size >= sz) {
        g_hiLogDev.size -= sz;//维持可使用buf size
        g_hiLogDev.headOffset += sz;
        g_hiLogDev.headOffset %= HILOG_BUFFER;
        g_hiLogDev.count--;//读写对冲
    }
}

这是这个函数的调用关系图:

HiLogBufferHead()

static unsigned char * HiLogBufferHead ( void  )

inlinestatic

在文件 los_hilog.c 第 92 行定义.

{
    return g_hiLogDev.buffer + g_hiLogDev.headOffset;
}

这是这个函数的调用关系图:

HiLogBufferInc()

static void HiLogBufferInc ( size_t  sz )

static

读写对冲,对hilog的写操作,更新相关变量内容

在文件 los_hilog.c 第 109 行定义.

{
    if (g_hiLogDev.size + sz <= HILOG_BUFFER) {
        g_hiLogDev.size += sz;  //已使用buf的size 
        g_hiLogDev.writeOffset += sz;//大小是不断累加
        g_hiLogDev.writeOffset %= HILOG_BUFFER;//ring buf
        g_hiLogDev.count++;//读写对冲
    }
}

这是这个函数的调用关系图:

HiLogClose()

int HiLogClose

(

struct file *

filep

)

为支持VFS,作关闭状

在文件 los_hilog.c 第 103 行定义.

{
    (void)filep;
    return 0;
}

HiLogCoverOldLog()

static void HiLogCoverOldLog ( size_t  bufLen )

static

在文件 los_hilog.c 第 254 行定义.

{
    int retval;
    struct HiLogEntry header;
    size_t totalSize = bufLen + sizeof(struct HiLogEntry);
    static int dropLogLines = 0;
    static int isLastTimeFull = 0;
    int isThisTimeFull = 0;
 
    while (totalSize + g_hiLogDev.size > HILOG_BUFFER) {
        retval = HiLogReadRingBuffer((unsigned char *)&header, sizeof(header));
        if (retval < 0) {
            break;
        }
 
        dropLogLines++;
        isThisTimeFull = 1;
        isLastTimeFull = 1;
        HiLogBufferDec(sizeof(header));
        HiLogBufferDec(header.len);
    }
    if (isLastTimeFull == 1 && isThisTimeFull == 0) {
        /* so we can only print one log if hilog ring buffer is full in a short time */
        if (dropLogLines > 0) {
            PRINTK("hilog ringbuffer full, drop %d line(s) log\n", dropLogLines);
        }
        isLastTimeFull = 0;
        dropLogLines = 0;
    }
}

函数调用图:

这是这个函数的调用关系图:

HiLogDeviceInit()

static void HiLogDeviceInit ( void  )

static

初始化全局变量g_hiLogDev

在文件 los_hilog.c 第 339 行定义.

{
    g_hiLogDev.buffer = LOS_MemAlloc((VOID *)OS_SYS_MEM_ADDR, HILOG_BUFFER);//分配内核空间
    if (g_hiLogDev.buffer == NULL) {
        PRINTK("In %s line %d,LOS_MemAlloc fail\n", __FUNCTION__, __LINE__);
    }
    //初始化waitqueue头,请确保输入参数wait有效，否则系统将崩溃。
    init_waitqueue_head(&g_hiLogDev.wq);//见于..\third_party\FreeBSD\sys\compat\linuxkpi\common\src\linux_semaphore.c
    LOS_MuxInit(&g_hiLogDev.mtx, NULL);//初始化hilog互斥量
 
    g_hiLogDev.writeOffset = 0;//写g_hiLogDev.buffer偏移地址
    g_hiLogDev.headOffset = 0;
    g_hiLogDev.size = 0;    //
    g_hiLogDev.count = 0;
}

函数调用图:

这是这个函数的调用关系图:

HiLogHeadInit()

static void HiLogHeadInit ( struct HiLogEntry *  header, size_t  len  )

static

hilog实体初始化

在文件 los_hilog.c 第 235 行定义.

{
    struct timespec now;//标准C库函数,时间格式,包含秒数和纳秒数
    int ret;
 
    ret = clock_gettime(CLOCK_REALTIME, &now);//获取系统实时时间
    if (ret != 0) {
        PRINTK("In %s line %d,clock_gettime fail\n", __FUNCTION__, __LINE__);
        return;
    }
 
    header->len = len;//写入buffer的内容长度
    header->pid = LOS_GetCurrProcessID();//当前进程ID
    header->taskId = LOS_CurTaskIDGet();    //当前任务ID
    header->sec = now.tv_sec;   //秒级记录
    header->nsec = now.tv_nsec; //纳秒级记录
    header->hdrSize = sizeof(struct HiLogEntry);
}

函数调用图:

这是这个函数的调用关系图:

HiLogOpen()

int HiLogOpen

(

struct file *

filep

)

为支持VFS,作打开状

在文件 los_hilog.c 第 97 行定义.

{
    (void)filep;
    return 0;
}

HiLogRead()

static ssize_t HiLogRead ( struct file *  filep, char *  buffer, size_t  bufLen  )

static

在文件 los_hilog.c 第 166 行定义.

{
    int retval;
    struct HiLogEntry header;
 
    (void)filep;
 
    wait_event_interruptible(g_hiLogDev.wq, (g_hiLogDev.size > 0));
 
    (VOID)LOS_MuxAcquire(&g_hiLogDev.mtx);//临界区操作开始
    retval = HiLogReadRingBuffer((unsigned char *)&header, sizeof(header));
    if (retval < 0) {
        retval = -EINVAL;
        goto out;
    }
 
    if (bufLen < header.len + sizeof(header)) {
        PRINTK("buffer too small,bufLen=%d, header.len=%d,%d\n", bufLen, header.len, header.hdrSize);
        retval = -ENOMEM;
        goto out;
    }
 
    HiLogBufferDec(sizeof(header));
 
    retval = HiLogBufferCopy((unsigned char *)buffer, bufLen, (unsigned char *)&header, sizeof(header));
    if (retval < 0) {
        retval = -EINVAL;
        goto out;
    }
 
    retval = HiLogReadRingBuffer((unsigned char *)(buffer + sizeof(header)), header.len);
    if (retval < 0) {
        retval = -EINVAL;
        goto out;
    }
 
    HiLogBufferDec(header.len);
    retval = header.len + sizeof(header);
out:
    if (retval == -ENOMEM) {
        // clean ring buffer
        g_hiLogDev.writeOffset = 0;
        g_hiLogDev.headOffset = 0;
        g_hiLogDev.size = 0;
        g_hiLogDev.count = 0;
    }
    (VOID)LOS_MuxRelease(&g_hiLogDev.mtx);//临界区操作结束
    return (ssize_t)retval;
}

函数调用图:

HilogRead()

ssize_t HilogRead	(	struct file *	filep,
		char __user *	buf,
		size_t	count
	)

HiLogReadRingBuffer()

static int HiLogReadRingBuffer ( unsigned char *  buffer, size_t  bufLen  )

static

读取ring buffer

在文件 los_hilog.c 第 149 行定义.

{
    int retval;
    size_t bufLeft = HILOG_BUFFER - g_hiLogDev.headOffset;
    if (bufLeft > bufLen) {//计算出读取方向
        retval = HiLogBufferCopy(buffer, bufLen, HiLogBufferHead(), bufLen);
    } else {
        retval = HiLogBufferCopy(buffer, bufLen, HiLogBufferHead(), bufLeft);
        if (retval < 0) {
            return retval;
        }
 
        retval = HiLogBufferCopy(buffer + bufLeft, bufLen - bufLeft, g_hiLogDev.buffer, bufLen - bufLeft);
    }
    return retval;
}

函数调用图:

这是这个函数的调用关系图:

HiLogWrite()

static ssize_t HiLogWrite ( struct file *  filep, const char *  buffer, size_t  bufLen  )

static

写hilog,外部以VFS方式写入

在文件 los_hilog.c 第 328 行定义.

{
    (void)filep;
    if (bufLen + sizeof(struct HiLogEntry) > HILOG_BUFFER) {
        PRINTK("input too large\n");
        return -ENOMEM;
    }
 
    return HiLogWriteInternal(buffer, bufLen);
}

函数调用图:

HilogWrite()

ssize_t HilogWrite	(	struct file *	filep,
		const char __user *	buf,
		size_t	count
	)

HiLogWriteInternal()

int HiLogWriteInternal	(	const char *	buffer,
		size_t	bufLen
	)

将外部buf写入hilog设备分两步完成

在文件 los_hilog.c 第 285 行定义.

{
    struct HiLogEntry header;
    int retval;
    LosTaskCB *runTask =  (LosTaskCB *)OsCurrTaskGet();
 
    if ((g_hiLogDev.buffer == NULL) || (OS_INT_ACTIVE) || (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK)) {
        PRINTK("%s\n", buffer);
        return -EAGAIN;
    }
 
    (VOID)LOS_MuxAcquire(&g_hiLogDev.mtx);
    HiLogCoverOldLog(bufLen);
    HiLogHeadInit(&header, bufLen);
 
    retval = HiLogWriteRingBuffer((unsigned char *)&header, sizeof(header));//1.先写入头部内容
    if (retval) {
        retval = -ENODATA;
        goto out;
    }
    HiLogBufferInc(sizeof(header));//
 
    retval = HiLogWriteRingBuffer((unsigned char *)(buffer), header.len);//2.再写入实际buf内容
    if (retval) {
        retval = -ENODATA;
        goto out;
    }
 
    HiLogBufferInc(header.len);
 
    retval = header.len;
 
out:
    (VOID)LOS_MuxRelease(&g_hiLogDev.mtx);
    if (retval > 0) {
        wake_up_interruptible(&g_hiLogDev.wq);
    }
    if (retval < 0) {
        PRINTK("write fail retval=%d\n", retval);
    }
    return retval;
}

函数调用图:

这是这个函数的调用关系图:

HiLogWriteRingBuffer()

static int HiLogWriteRingBuffer ( unsigned char *  buffer, size_t  bufLen  )

static

写入 RingBuffer环形缓冲，也叫 circleBuffer

在文件 los_hilog.c 第 216 行定义.

{
    int retval;
    size_t bufLeft = HILOG_BUFFER - g_hiLogDev.writeOffset;
    if (bufLen > bufLeft) {
        retval = HiLogBufferCopy(g_hiLogDev.buffer + g_hiLogDev.writeOffset, bufLeft, buffer, bufLeft);
        if (retval) {
            return -1;
        }
        retval = HiLogBufferCopy(g_hiLogDev.buffer, HILOG_BUFFER, buffer + bufLeft, bufLen - bufLeft);
    } else {
        retval = HiLogBufferCopy(g_hiLogDev.buffer + g_hiLogDev.writeOffset, bufLeft, buffer, bufLen);
    }
    if (retval < 0) {
        return -1;
    }
    return 0;
}

函数调用图:

这是这个函数的调用关系图:

LOS_MODULE_INIT()

LOS_MODULE_INIT	(	OsHiLogDriverInit	,
		LOS_INIT_LEVEL_KMOD_EXTENDED
	)

OsHiLogDriverInit()

int OsHiLogDriverInit

(

VOID

)

初始化hilog驱动

在文件 los_hilog.c 第 355 行定义.

{
    HiLogDeviceInit();//初始化全局变量g_hiLogDev
    return register_driver(HILOG_DRIVER, &g_hilogFops, DRIVER_MODE, NULL);//注册字符设备驱动程序,生成inode节点
}

函数调用图:

变量说明

g_hiLogDev

struct HiLogCharDevice g_hiLogDev

g_hilogFops

STATIC struct file_operations_vfs g_hilogFops

初始值:

= {
    HiLogOpen,  
    HiLogClose, 
    HiLogRead,  
    HiLogWrite, 
    NULL,       
    NULL,       
    NULL,       
#ifndef CONFIG_DISABLE_POLL
    NULL, 
#endif
    NULL, 
}

在文件 los_hilog.c 第 67 行定义.