实验七 页面置换算法的模拟实现报告_川农.docx
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实验7 页面置换算法的模拟实现
三、实验内容与步骤
1、定义相关数据
#define InitPysiBlocks 4
#define MaxPages 16:
unsigned int PysicalBlocks[InitPysiBlocks] = { 0 };
unsigned int PageSequence[30] = { 1,2,3,6,4,7,3,2,1,4,7,5,6,5,2,1};
2、按照教材中FIFO、LRU算法描述进行算法设计
unsigned FIFO(unsigned *py,unsigned *pg)
unsigned LRU(unsigned *py,unsigned *pg)
3、查看运行结果是否与手工计算一致。
四、实验材料的提交与成绩评定
1.代码:
#includeiostream
using namespace std;
#define InitPysiBlocks 4
#define MaxPages 16
unsigned int PysicalBlocks[InitPysiBlocks] = { 0 };
unsigned int PageSequence[30] = { 1,2,3,6,4,7,3,2,1,4,7,5,6,5,2,1 };
//FIFO算法
unsigned FIFO(unsigned *py, unsigned *pg)
{
//初始化填满数据
for (int i = 0; i InitPysiBlocks; i++)
{
py[i] = pg[i];
}
cout FIFO置换过程如下: endl;
cout py[0] py[1] py[2] py[3] endl;
//判断新获取数据进来的时间
int time[4] = { 3,2,1,0 };
//开始检测
for (int i = 4; i MaxPages; i++)
{
for (int j = 0; j InitPysiBlocks; j++)
{
//如果新获取的已存在,直接输出
if (py[0] == pg[i] || py[1] == pg[i] || py[2] == pg[i] || py[3] == pg[i])
{
cout py[0] py[1] py[2] py[3] endl;
break;
}
else
{
for (int k = 0; k 4; k++)
{
if (time[k] == 3)
{
time[k] = 0;
py[k] = pg[i];
}
else
{
time[k]++;
}
}
cout py[0] py[1] py[2] py[3] endl;
break;
}
}
}
cout 置换结束 endl;
return 0;
}
//LRU算法
//LRU辅助函数:返回除某一排下标后数组中最大元素下标
int Max(unsigned *py, int te)
{
int max = 0;
int index = -1;
for (int i = 0; i InitPysiBlocks; i++)
{
if (i == te)
{
continue;
}
else
{
if (py[i] max)
{
max = py[i];
index = i;
}
else
{
continue;
}
}
}
return index;
}
unsigned LRU(unsigned *py, unsigned *pg)
{
//初始化填满数据
for (int i = 0; i InitPysiBlocks; i++)
{
py[i] = pg[i];
}
cout LRU置换过程如下: endl;
cout py[0] py[1] py[2] py[3] endl;
//判断新获取数据进来的时间
unsigned time[4] = { 3,2,1,0 };
//统计命中次数
int count[4] = { 0 };
//开始检测
for (int i = InitPysiBlocks; i 16; i++)
{
for (int j = 0;
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