Static memory 的协作图:

结构体
struct	tagMEMBOX_NODE

struct	LOS_MEMBOX_INFO

类型定义
typedef struct tagMEMBOX_NODE	LOS_MEMBOX_NODE

函数
UINT32	LOS_MemboxInit (VOID *pool, UINT32 poolSize, UINT32 blkSize)
	Initialize a memory pool. 更多...

VOID *	LOS_MemboxAlloc (VOID *pool)
	Request a memory block. 更多...

UINT32	LOS_MemboxFree (VOID pool, VOID box)
	Free a memory block. 更多...

VOID	LOS_MemboxClr (VOID pool, VOID box)
	Clear a memory block. 更多...

VOID	LOS_ShowBox (VOID *pool)
	show membox info. 更多...

UINT32	LOS_MemboxStatisticsGet (const VOID boxMem, UINT32 maxBlk, UINT32 blkCnt, UINT32 blkSize)
	calculate membox information. 更多...

详细描述

类型定义说明

◆ LOS_MEMBOX_NODE

typedef struct tagMEMBOX_NODE LOS_MEMBOX_NODE

Structure of a free node in a memory pool

函数说明

◆ LOS_MemboxAlloc()

VOID * LOS_MemboxAlloc ( VOID * pool )

Request a memory block.

Description:

This API is used to request a memory block.

注意

The input pool parameter must be initialized via func LOS_MemboxInit.

参数

pool	[IN] Memory pool address.

返回值

#VOID*	The request is accepted, and return a memory block address.
#NULL	The request fails.

Dependency:

los_membox.h: the header file that contains the API declaration.

参见: LOS_MemboxFree

Request a memory block.

在文件 los_membox.c 第 150 行定义.

{
    LOS_MEMBOX_INFO *boxInfo = (LOS_MEMBOX_INFO *)pool;
    LOS_MEMBOX_NODE *node = NULL;
    LOS_MEMBOX_NODE *nodeTmp = NULL;
    UINT32 intSave;
 
    if (pool == NULL) {
        return NULL;
    }
 
    MEMBOX_LOCK(intSave);
    node = &(boxInfo->stFreeList);//拿到空闲单链表
    if (node->pstNext != NULL) {//不需要遍历链表,因为这是空闲链表
        nodeTmp = node->pstNext;//先记录要使用的节点
        node->pstNext = nodeTmp->pstNext;//不再空闲了,把节点摘出去了.
        OS_MEMBOX_SET_MAGIC(nodeTmp);//为已使用的节块设置魔法数字
        boxInfo->uwBlkCnt++;//已使用块数增加
    }
    MEMBOX_UNLOCK(intSave);
 
    return (nodeTmp == NULL) ? NULL : OS_MEMBOX_USER_ADDR(nodeTmp);//返回可用的虚拟地址
}

这是这个函数的调用关系图:

◆ LOS_MemboxClr()

VOID LOS_MemboxClr	(	VOID *	pool,
		VOID *	box
	)

Clear a memory block.

Description:

This API is used to set the memory block value to be 0.

注意

The input pool parameter must be initialized via func LOS_MemboxInit.
The input box parameter must be allocated by LOS_MemboxAlloc.

参数

pool	[IN] Memory pool address.
box	[IN] Memory block address.

返回值

VOID

Dependency:

los_membox.h: the header file that contains the API declaration.

参见: None.

Clear a memory block.

在文件 los_membox.c 第 201 行定义.

{
    LOS_MEMBOX_INFO *boxInfo = (LOS_MEMBOX_INFO *)pool;
 
    if ((pool == NULL) || (box == NULL)) {
        return;
    }
    //将魔法数字一并清除了.
    (VOID)memset_s(box, (boxInfo->uwBlkSize - OS_MEMBOX_NODE_HEAD_SIZE), 0,
        (boxInfo->uwBlkSize - OS_MEMBOX_NODE_HEAD_SIZE));
}

◆ LOS_MemboxFree()

UINT32 LOS_MemboxFree	(	VOID *	pool,
		VOID *	box
	)

Free a memory block.

Description:

This API is used to free a memory block.

注意

The input pool parameter must be initialized via func LOS_MemboxInit.
The input box parameter must be allocated by LOS_MemboxAlloc.

参数

pool	[IN] Memory pool address.
box	[IN] Memory block address.

返回值

#LOS_NOK	This memory block fails to be freed.
#LOS_OK	This memory block is successfully freed.

Dependency:

los_membox.h: the header file that contains the API declaration.

参见: LOS_MemboxAlloc

Free a memory block.

在文件 los_membox.c 第 174 行定义.

{
    LOS_MEMBOX_INFO *boxInfo = (LOS_MEMBOX_INFO *)pool;
    UINT32 ret = LOS_NOK;
    UINT32 intSave;
 
    if ((pool == NULL) || (box == NULL)) {
        return LOS_NOK;
    }
 
    MEMBOX_LOCK(intSave);
    do {
        LOS_MEMBOX_NODE *node = OS_MEMBOX_NODE_ADDR(box);//通过节体获取节块首地址
        if (OsCheckBoxMem(boxInfo, node) != LOS_OK) {
            break;
        }
 
        node->pstNext = boxInfo->stFreeList.pstNext;//节块指向空闲链表表头
        boxInfo->stFreeList.pstNext = node;//空闲链表表头反指向它,意味节块排到第一,下次申请将首个分配它
        boxInfo->uwBlkCnt--;//已经使用的内存块减一
        ret = LOS_OK;
    } while (0);//将被编译时优化
    MEMBOX_UNLOCK(intSave);
 
    return ret;
}

函数调用图:

这是这个函数的调用关系图:

◆ LOS_MemboxInit()

UINT32 LOS_MemboxInit	(	VOID *	pool,
		UINT32	poolSize,
		UINT32	blkSize
	)

Initialize a memory pool.

Description:

This API is used to initialize a memory pool.

注意

The poolSize parameter value should match the following two conditions : 1) Be less than or equal to the Memory pool size; 2) Be greater than the size of LOS_MEMBOX_INFO.

参数

pool	[IN] Memory pool address.
poolSize	[IN] Memory pool size.
blkSize	[IN] Memory block size.

返回值

#LOS_NOK	The memory pool fails to be initialized.
#LOS_OK	The memory pool is successfully initialized.

Dependency:

los_membox.h: the header file that contains the API declaration.

参见: None.

Initialize a memory pool.

在文件 los_membox.c 第 106 行定义.

{
    LOS_MEMBOX_INFO *boxInfo = (LOS_MEMBOX_INFO *)pool;//在内存起始处安置池头
    LOS_MEMBOX_NODE *node = NULL;
    UINT32 index;
    UINT32 intSave;
 
    if (pool == NULL) {
        return LOS_NOK;
    }
 
    if (blkSize == 0) {
        return LOS_NOK;
    }
 
    if (poolSize < sizeof(LOS_MEMBOX_INFO)) {
        return LOS_NOK;
    }
 
    MEMBOX_LOCK(intSave);
    boxInfo->uwBlkSize = LOS_MEMBOX_ALIGNED(blkSize + OS_MEMBOX_NODE_HEAD_SIZE); //节块总大小(节头+节体)
    boxInfo->uwBlkNum = (poolSize - sizeof(LOS_MEMBOX_INFO)) / boxInfo->uwBlkSize;//总节块数量
    boxInfo->uwBlkCnt = 0;  //已分配的数量
    if (boxInfo->uwBlkNum == 0) {//只有0块的情况
        MEMBOX_UNLOCK(intSave);
        return LOS_NOK;
    }
 
    node = (LOS_MEMBOX_NODE *)(boxInfo + 1);//去除池头,找到第一个节块位置
 
    boxInfo->stFreeList.pstNext = node;//池头空闲链表指向第一个节块
 
    for (index = 0; index < boxInfo->uwBlkNum - 1; ++index) {//切割节块,挂入空闲链表
        node->pstNext = OS_MEMBOX_NEXT(node, boxInfo->uwBlkSize);//按块大小切割好,统一由pstNext指向
        node = node->pstNext;//node存储了下一个节点的地址信息
    }
 
    node->pstNext = NULL;//最后一个为null
 
    MEMBOX_UNLOCK(intSave);
 
    return LOS_OK;
}

这是这个函数的调用关系图:

◆ LOS_MemboxStatisticsGet()

UINT32 LOS_MemboxStatisticsGet	(	const VOID *	boxMem,
		UINT32 *	maxBlk,
		UINT32 *	blkCnt,
		UINT32 *	blkSize
	)

calculate membox information.

Description:

This API is used to calculate membox information.

注意

One parameter of this interface is a pointer, it should be a correct value, otherwise, the system may be abnormal.

参数

boxMem	[IN] Type #VOID* Pointer to the calculate membox.
maxBlk	[OUT] Type UINT32* Record membox max block.
blkCnt	[OUT] Type UINT32* Record membox block count alreay allocated.
blkSize	[OUT] Type UINT32* Record membox block size.

返回值

#LOS_OK	The heap status calculate success.
#LOS_NOK	The membox status calculate with some error.

Dependency:

los_memory.h: the header file that contains the API declaration.

参见: LOS_MemAlloc | LOS_MemRealloc | LOS_MemFree

calculate membox information.

在文件 los_membox.c 第 241 行定义.

{
    if ((boxMem == NULL) || (maxBlk == NULL) || (blkCnt == NULL) || (blkSize == NULL)) {
        return LOS_NOK;
    }
 
    *maxBlk = ((OS_MEMBOX_S *)boxMem)->uwBlkNum;
    *blkCnt = ((OS_MEMBOX_S *)boxMem)->uwBlkCnt;
    *blkSize = ((OS_MEMBOX_S *)boxMem)->uwBlkSize;
 
    return LOS_OK;
}

◆ LOS_ShowBox()

VOID LOS_ShowBox ( VOID * pool )

show membox info.

Description:

This API is used to show the memory pool info.

注意

The input pool parameter must be initialized via func LOS_MemboxInit.

参数

pool	[IN] Memory pool address.

返回值

VOID

Dependency:

los_membox.h: the header file that contains the API declaration.

参见: None.

打印指定静态内存池所有节点信息（打印等级是LOS_INFO_LEVEL），包括内存池起始地址、内存块大小、总内存块数量、每个空闲内存块的起始地址、所有内存块的起始地址

在文件 los_membox.c 第 214 行定义.

{
    UINT32 index;
    UINT32 intSave;
    LOS_MEMBOX_INFO *boxInfo = (LOS_MEMBOX_INFO *)pool;
    LOS_MEMBOX_NODE *node = NULL;
 
    if (pool == NULL) {
        return;
    }
    MEMBOX_LOCK(intSave);
    PRINT_INFO("membox(%p,0x%x,0x%x):\r\n", pool, boxInfo->uwBlkSize, boxInfo->uwBlkNum);
    PRINT_INFO("free node list:\r\n");
 
    for (node = boxInfo->stFreeList.pstNext, index = 0; node != NULL;
         node = node->pstNext, ++index) {
        PRINT_INFO("(%u,%p)\r\n", index, node);
    }
 
    PRINT_INFO("all node list:\r\n");
    node = (LOS_MEMBOX_NODE *)(boxInfo + 1);
    for (index = 0; index < boxInfo->uwBlkNum; ++index, node = OS_MEMBOX_NEXT(node, boxInfo->uwBlkSize)) {
        PRINT_INFO("(%u,%p,%p)\r\n", index, node, node->pstNext);
    }
    MEMBOX_UNLOCK(intSave);
}

结构体

类型定义

函数

详细描述

类型定义说明

◆ LOS_MEMBOX_NODE

函数说明

◆ LOS_MemboxAlloc()

◆ LOS_MemboxClr()

◆ LOS_MemboxFree()

◆ LOS_MemboxInit()

◆ LOS_MemboxStatisticsGet()

◆ LOS_ShowBox()