|
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <string.h>
#include <wait.h>
#include <stdlib.h>
#include <time.h>
int loc_1; //栈底指针
#define frame_num 3 //主存大小
#define Total_instruction 6 //总的额访问页数
int loc_2;//FIFO未满时候的队头指针
//命中和未命中
int is_hit;
#define HIT 1
#define MISS 0
//页面是否在内存的标志
#define IN '1'
#define OUT '0'
//存放页面序列的数组
int Access_Series[Total_instruction]; //(1)
//页表
struct one_frame
{
int page_no; //对应的页号
char flag; //是否在内存的标志
};
struct one_frame M_Frame[frame_num]; //(2)
int disaffect; //缺页的数量
//初始化函数 每个进程开始均调用
void init()
{
loc_1 = 0;
is_hit = MISS; //开始未命中
disaffect = 0;
for (int index = 0; index < frame_num; index++)
M_Frame[index].flag = OUT; //页表初始化 均不在页表中
for(int i=0;i<frame_num;i++)
M_Frame[i].page_no=-1;//初始化-1
}
//输出访问序列
void print_Access_Series()
{
printf("Access Series:\n");
for (int index = 0; index < Total_instruction; index++)
printf("%d ", Access_Series[index]);
printf("\n");
}
//输出在内存的页面
void print_M_Frame()
{
for (int i = 0; i < frame_num; i++)
{
if (M_Frame[i].page_no!=-1)
printf("%d ", M_Frame[i].page_no);
}
printf("\n");
}
//输出缺页次数和缺页率
void print_disaffect(int dis)
{
float disaffect_rate=(float)dis/Total_instruction;
printf("disaffect=%d\ndisafffect_rate=%f",disaffect,disaffect_rate);
}
//LRU命中函数 页表M_Frame0优先级最高 [0]-[index-1]一次向后移动一位
void hit(int index)
{
printf("运行命中函数\n");
int temp; //用于交换
temp = M_Frame[index].page_no;
for (int i = index; i >0; i--)
{
M_Frame[i].page_no = M_Frame[i-1].page_no;
}
M_Frame[0].page_no = temp;
printf("\n");
}
//LRU 未命中函数 调入
void miss_call_in(int page)
{
if (loc_1 < frame_num) //此时的内存未满
{
//全体下移动
for (int i=loc_1; i>0; i--)
{
M_Frame[i].flag=IN;
M_Frame[i].page_no=M_Frame[i-1].page_no;
}
M_Frame[0].flag = IN;
M_Frame[0].page_no = page;//移动完赋值
loc_1++;
}
else
{
//满了就全体后移 栈顶赋值
for (int i = frame_num-1; i>0; i--)
M_Frame[i].page_no= M_Frame[i-1].page_no;
M_Frame[0].page_no = page;
}
}
//FIFO
void FIFO(int page_n)
{
printf("运行FIFO函数\n");
// 全体依次后移
for(int i=frame_num-1 ;i>0 ;i--)
{
M_Frame[i].page_no=M_Frame[i-1].page_no;
}
M_Frame[0].page_no=page_n;
M_Frame[0].flag=IN;
//改变是否在内存的状态位
for(int i=0;i<loc_2;i++)
{
M_Frame[i].flag=IN;//在内存的依次赋值为在内存
}
if(loc_2<=(frame_num-1))
loc_2++;
}
int main()
{
srand(time(NULL));
for (int i = 0; i < Total_instruction; i++) //随机产生访问页面序列
Access_Series[i] = rand() % Total_instruction;
pid_t id1 = fork();
if (id1 == 0) //子进程1 LRU int Access_Series[Total_instruction]
{
printf("\nrun LRU:\n");
init();
print_Access_Series();
for (int cur = 0; cur < Total_instruction; cur++)
{
is_hit=MISS;
int index;
for ( index = 0; index < frame_num; index++) //遍历内存 M_Frame
{
if (M_Frame[index].flag == IN && M_Frame[index].page_no == Access_Series[cur]) //在内存 且 页号命中
{
// printf(" M_Frame[index].page_no == Access_Series[cur]%d %d ",M_Frame[index].page_no,Access_Series[cur]);
is_hit = HIT;
break;
}
}
if (is_hit == HIT)
{
//printf("hit_index=%d " ,index);
hit(index);
printf("hit ");
print_M_Frame();
}
else //未命中
{
miss_call_in(Access_Series[cur]);
printf("miss ");
print_M_Frame();
disaffect++;
}
}
print_disaffect(disaffect);
}
else
{
pid_t id2 = fork(); //子进程2
if (id2 == 0)//FIFO
{
printf("run FIFO:\n");
init();
print_Access_Series();
for (int cur = 0; cur < Total_instruction; cur++)
{
is_hit=MISS;
int index;
for(int index=0;index<frame_num;index++)//遍历页表
{
if (M_Frame[index].page_no!=-1&&M_Frame[index].page_no == Access_Series[cur]) //在内存 且 页号命中
{
is_hit = HIT;
break;
}
}
if(is_hit==MISS)//miss
{
FIFO(Access_Series[cur]);//进队列
disaffect++;
}
print_M_Frame();
}
print_disaffect(disaffect);
}
else
{
wait(0);
wait(0);
printf("\nrun is over\n");
}
}
return (0);
}
| 
转播
