C语言实现的进程调度
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct node
{
char name[20];
int prio;
int round;
int cputime;
int needtime;
char state;
int count;
struct node *next;
}PCB;
PCB *ready=NULL,*run=NULL,*finish=NULL;
int num;
void GetFirst();
void Output();
void InsertPrio(PCB *in);
void InsertTime(PCB *in);
void InsertFinish(PCB *in);
void PrioCreate();
void TimeCreate();
void Priority();
void RoundRun();
int main(void)
{
char chose;
printf("请输入要创建的进程数目:\n");
scanf("%d",&num);
getchar();
printf("输入进程的调度方法：(P/R)\n");
scanf("%c",&chose);
switch(chose)
{
case 'P':
case 'p':
PrioCreate();
Priority();
break;
case 'R':
case 'r':
TimeCreate();
RoundRun();
break;
default:break;
}
Output();
return 0;
}
void GetFirst()
{
run = ready;
if(ready!=NULL)
{
run ->state = 'R';
ready = ready ->next;
run ->next = NULL;
}
}
void Output()
{
PCB *p;
p = ready;
printf("进程名\t优先级\t轮数\tcpu时间\t需要时间\t进程状态\t计数器\n");
while(p!=NULL)
{
printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
p = p->next;
}
p = finish;
while(p!=NULL)
{
printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
p = p->next;
}
p = run;
while(p!=NULL)
{
printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
p = p->next;
}
}
void InsertPrio(PCB *in)
{
PCB *fst,*nxt;
fst = nxt = ready;
if(ready == NULL)
{
in->next = ready;
ready = in;
}
else
{
if(in ->prio >= fst ->prio)
{
in->next = ready;
ready = in;
}
else
{
while(fst->next != NULL)
{
nxt = fst;
fst = fst->next;
}
if(fst ->next == NULL)
{
in ->next = fst ->next;
fst ->next = in;
}
else
{
nxt = in;
in ->next = fst;
}
}
}
}
void InsertTime(PCB *in)
{
PCB *fst;
fst = ready;
if(ready == NULL)
{
in->next = ready;
ready = in;
}
else
{
while(fst->next != NULL)
{
fst = fst->next;
}
in ->next = fst ->next;
fst ->next = in;
}
}
void InsertFinish(PCB *in)
{
PCB *fst;
fst = finish;
if(finish == NULL)
{
in->next = finish;
finish = in;
}
else
{
while(fst->next != NULL)
{
fst = fst->next;
}
in ->next = fst ->next;
fst ->next = in;
}
}
void PrioCreate()
{
PCB *tmp;
int i;
printf("输入进程名字和进程所需时间：\n");
for(i = 0;i < num; i++)
{
if((tmp = (PCB *)malloc(sizeof(PCB)))==NULL)
{
perror("malloc");
exit(1);
}
scanf("%s",tmp->name);
getchar();
scanf("%d",&(tmp->needtime));
tmp ->cputime = 0;
tmp ->state ='W';
tmp ->prio = 50 - tmp->needtime;
tmp ->round = 0;
tmp ->count = 0;
InsertPrio(tmp);
}
}
void TimeCreate()
{
PCB *tmp;
int i;
printf("输入进程名字和进程时间片所需时间：\n");
for(i = 0;i < num; i++)
{
if((tmp = (PCB *)malloc(sizeof(PCB)))==NULL)
{
perror("malloc");
exit(1);
}
scanf("%s",tmp->name);
getchar();
scanf("%d",&(tmp->needtime));
tmp ->cputime = 0;
tmp ->state ='W';
tmp ->prio = 0;
tmp ->round = 2;
tmp ->count = 0;
InsertTime(tmp);
}
}
void Priority()
{
int flag = 1;
GetFirst();
while(run != NULL)
{
Output();
while(flag)
{
run->prio -= 3;
run->cputime++;
run->needtime--;
if(run->needtime == 0)
{
run ->state = 'F';
run->count++;
InsertFinish(run);
flag = 0;
}
else
{
run->state = 'W';
run->count++;
InsertTime(run);
flag = 0;
}
}
flag = 1;
GetFirst();
}
}
void RoundRun()
{
int flag = 1;
GetFirst();
while(run != NULL)
{
Output();
while(flag)
{
run->count++;
run->cputime++;
run->needtime--;
if(run->needtime == 0)
{
run ->state = 'F';
InsertFinish(run);
flag = 0;
}
else if(run->count == run->round)
{
run->state = 'W';
}
}
}
}
希望各位大侠给我讲解一些 写一下注释
[解决办法]
