mem_admin.c

一个ARM内核通用的内存管理程序。通过使用三个链表进行管理

	}
	
	return NULL;	//没有找到相应的空表项

}


/*******************************************************************************************************
**函	数：Fun_JointItem
**功	能：判断是否合并相邻的控制块为一个IDLE控制块
**输	入：*DestCB要进行操作的控制块 
**输	出：1 已经被合并入相邻的控制块内了
**			-1	没有被合并进相邻的块内
**受影响的全局变量： 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
int32	Fun_JointItem(PMEMCB DestCB)
{
	PMEMCB	temp_sp1, temp_sp2, temp_sp0;

	temp_sp0 = DestCB;
	temp_sp1 = (PMEMCB)DestCB->Mem_LB;
	temp_sp2 = (PMEMCB)DestCB->Mem_RB;

	if((temp_sp1 != NULL) && (temp_sp2 != NULL))
	{
		if((temp_sp1->Busy_Flag == IDLE_FLAG) && (temp_sp2->Busy_Flag == IDLE_FLAG))
		{
			//要把三个控制合Joint为一个Control Block
			temp_sp1->spacesize += (temp_sp2->spacesize + temp_sp0->spacesize);

			temp_sp1->Mem_RB = temp_sp2->Mem_RB;						 
			if(temp_sp2->Mem_RB != NULL)
			{
				((PMEMCB)(temp_sp2->Mem_RB))->Mem_LB = (void *)temp_sp1;
			}

			if(IDLE_LIST->FirstItem == (void *)temp_sp2)
			{
				((PMEMCB)temp_sp2->Next)->Prev = NULL;
				IDLE_LIST->FirstItem = temp_sp2->Next;
			}
			else if(IDLE_LIST->LastItem == (void *)temp_sp2)
			{
				((PMEMCB)temp_sp2->Prev)->Next = NULL;
				IDLE_LIST->LastItem = temp_sp2->Prev;
			}
			else
			{
				((PMEMCB)(temp_sp2->Next))->Prev = temp_sp2->Prev;
				((PMEMCB)(temp_sp2->Prev))->Next = temp_sp2->Next;
			}

			return 1;
		}
	}

	if(temp_sp1 != NULL)
	{
		if(temp_sp1->Busy_Flag == IDLE_FLAG)
		{
			temp_sp1->spacesize += temp_sp0->spacesize;
			temp_sp1->Mem_RB = temp_sp0->Mem_RB;
			//if(temp_sp0->Mem_RB != NULL)
			//{
				if(temp_sp2 != NULL)
				{
					temp_sp2->Mem_LB = (void *)temp_sp1;
				}				 
			//}
			return 1;
		}
	}

	if(temp_sp2 != NULL)
	{
		if(temp_sp2->Busy_Flag == IDLE_FLAG)
		{
			temp_sp0->spacesize += temp_sp2->spacesize;
			temp_sp0->Busy_Flag = IDLE_FLAG;

			temp_sp0->Mem_RB = temp_sp2->Mem_RB;
			if(temp_sp0->Mem_RB != NULL)
			{
				((PMEMCB)(temp_sp0->Mem_RB))->Mem_LB = (void *)temp_sp0;
			}

			temp_sp0->Next = temp_sp2->Next;
			temp_sp0->Prev = temp_sp2->Prev;
						
			if(IDLE_LIST->LastItem == (void *)temp_sp2)
			{
				IDLE_LIST->LastItem = (void *)temp_sp0;				 
			}
			else
			{
				((PMEMCB)(temp_sp2->Next))->Prev = temp_sp0;
			}

			if(IDLE_LIST->FirstItem == (void *)temp_sp2)
			{
				IDLE_LIST->FirstItem = (void *)temp_sp0;
			}
			else
			{
				((PMEMCB)(temp_sp2->Prev))->Next = temp_sp0;
			}
			return 1;
		}
	}

	return -1;
}


/*******************************************************************************************************
**函	数：Fun_Free
**功	能：释放一块已经分配出去的内存块，并与相邻的空闲块合并
**输	入：free_sp 要释放的内存地址
**输	出：NULL 不管失败还是成功
**受影响的全局变量：
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
void	*Fun_Free(void *free_sp)
{
	PMEMCB	temp_sp;
	int		xu_ret;

	if(free_sp == NULL)
	{
		return NULL;
	}
	temp_sp = Fun_FindItemInList(BUSY_LIST, free_sp);
	if(temp_sp == NULL)
	{
		//没有找到相应的表项
		return NULL;
	}

	/* 从原先的链表中清除这个表项 */
	if(BUSY_LIST->FirstItem == BUSY_LIST->LastItem)
	{
		if(BUSY_LIST->FirstItem == (void *)temp_sp)
		{
			//链表中就这个表项
			BUSY_LIST->FirstItem = NULL;
			BUSY_LIST->LastItem = NULL;
		}		 
	}
	else
	{
		if(BUSY_LIST->FirstItem == (void *)temp_sp)
		{
			//链表中第一个表项
			BUSY_LIST->FirstItem = temp_sp->Next;
			((PMEMCB)(temp_sp->Next))->Prev = NULL;
		}
		else if(BUSY_LIST->LastItem == (void *)temp_sp)
		{
			BUSY_LIST->LastItem = temp_sp->Prev;
			((PMEMCB)(temp_sp->Prev))->Next = NULL;
		}
		else
		{
			((PMEMCB)(temp_sp->Prev))->Next = temp_sp->Next;
			((PMEMCB)(temp_sp->Next))->Prev = temp_sp->Prev;
		}
	}

	/* 找到相应的表项 要判断是否合并相邻的控制块到IDLE LIST中 */
	xu_ret = Fun_JointItem(temp_sp);
	if(xu_ret == 1)
	{
		//发生了合并
		return NULL;
	}
	else 
	{
		//没有发生合并
		temp_sp->Busy_Flag = IDLE_FLAG;		//设为空闲状态
		Sub_ListAdd(IDLE_LIST, temp_sp);
		return NULL;
	}
}






#ifdef XU_SIM
int	Fun_RetBusyList(void)	//返回忙链表中表项的个数
{
	return Fun_RetList(BUSY_LIST);
}

int	Fun_RetIdleList(void)	//返回闲链表中表项的个数
{
	return Fun_RetList(IDLE_LIST);
}

int	Fun_RetList(PLISTHEADER DestListHeader)	//返回指定链表的个数
{
	PMEMCB	temp_sp;
	int		ret;

	ret = 0;
	temp_sp = DestListHeader->FirstItem;
	if(temp_sp == NULL)
	{
		return 0;
	}
	if(DestListHeader->FirstItem == DestListHeader->LastItem)
	{
		return 1;
	}
	do
	{
		ret += 1;
		temp_sp = (PMEMCB)temp_sp->Next;
	}while((void *)temp_sp != DestListHeader->LastItem);
	ret += 1;

	return ret;
}

int Fun_RetListItemInfo(PLISTHEADER DestListHeader, int i, int *Next, int *Prev, int *Addr, int *Space, int *LB, int *RB, int *SelfAddr, int *BusyFlag)
{
	PMEMCB	temp_sp;
	int		j;

	j = 0;
	temp_sp = (PMEMCB)DestListHeader->FirstItem;
	do
	{
		if(j == (i - 1))
		{
			*Next = (int)temp_sp->Next;
			*Prev = (int)temp_sp->Prev;
			*Addr = (int)temp_sp->Addr;
			*Space = (int)temp_sp->spacesize;
			*LB	= (int)temp_sp->Mem_LB;
			*RB = (int)temp_sp->Mem_RB;
			*SelfAddr = (int)temp_sp;
			*BusyFlag = (int)temp_sp->Busy_Flag;
			return 1;
		}
		else
		{
			temp_sp = (PMEMCB)temp_sp->Next;
			j += 1;
		}
	}while(temp_sp != NULL);
	return 0;
}

int Fun_RetBusyListItemInfo(int i, int *Next, int *Prev, int *Addr, int *Space, int *LB, int *RB, int *SelfAddr, int *BusyFlag) 
{
	return Fun_RetListItemInfo(BUSY_LIST, i, Next, Prev, Addr, Space, LB, RB, SelfAddr, BusyFlag);
}

int Fun_RetIDLEListItemInfo(int i, int *Next, int *Prev, int *Addr, int *Space, int *LB, int *RB, int *SelfAddr, int *BusyFlag)
{
	return Fun_RetListItemInfo(IDLE_LIST, i, Next, Prev, Addr, Space, LB, RB, SelfAddr, BusyFlag);
}

int Fun_RetPhyList(void)	//返回物理链表中表项的个数
{
	PMEMCB	temp_sp;
	int		count;

	temp_sp = ROOT_CB;
	count = 0;
	while(temp_sp != NULL)
	{
		count += 1;
		temp_sp = (PMEMCB)temp_sp->Mem_RB;
	}

	return count;
}

int Fun_RetPhyItemInfo(int i, int *Next, int *Prev, int *Addr, int *Space, int *LB, int *RB, int *SelfAddr, int *BusyFlag)
{
	PMEMCB	temp_sp;
	int		j;

	j = 0;
	temp_sp = ROOT_CB;
	do
	{
		if(j == (i - 1))
		{
			*Next = (int)temp_sp->Next;
			*Prev = (int)temp_sp->Prev;
			*Addr = (int)temp_sp->Addr;
			*Space = (int)temp_sp->spacesize;
			*LB	= (int)temp_sp->Mem_LB;
			*RB = (int)temp_sp->Mem_RB;
			*SelfAddr = (int)temp_sp;
			*BusyFlag = (int)temp_sp->Busy_Flag;
			return 1;
		}
		else
		{
			temp_sp = (PMEMCB)temp_sp->Mem_RB;
			j += 1;
		}
	}while(temp_sp != NULL);
	return 0;
}
#endif