3_duan_distrib.cpp

实现各种进程调度

#include <malloc.h>
#include <stdio.h>
#include <string.h>
#define NULL 0
typedef struct table
  {int address;        /*存储分区起始地址*/
   int length;         /*存储分区长度*/
   int flag;           /*存储分区标志，0为空闲，1为被作业占据*/
   char name[10];      /*存储分区占用标志作业名*/
   struct table *next;
 }node;
int success=0;/*分配成功与否的标志*/
node *work;
  node *creat()   /*定义函数，建立主存分配表*/
 { node *head;
   node *p1,*p2;
   int n=0;
   printf("address length flag(0..1)\n");
   p1=p2=(node *)malloc(sizeof(node));
   scanf("%d%d%d",&p1->address,&p1->length,&p1->flag);
   if(p1->flag==1&&p1->length>0)
      {printf("\tinput job_name:");scanf("%s",p1->name);}
   else strcpy(p1->name,"nil");
   head=NULL;
   while (p1->length!=0)
   {n=n+1;
    if (n==1) head=p1;
    else p2->next=p1;
    p2=p1;
    p1=(node *) malloc (sizeof(node));
    scanf("%d%d%d",&p1->address,&p1->length,&p1->flag);
    if(p1->flag==1&&p1->length>0)
      {printf("\t input job_name:");scanf("%s",p1->name);}
    else strcpy(p1->name,"nil");
   }
   p2->next=NULL;
   return(head);
 }
 node *found(node *head,int x) /*查找满足分配要求的最小空闲分区*/
  {node *p,*q;
   q=p=head;
   while(p&&p->length<x)
       p=p->next;
   if(!p)
       return(p);
   else
      {q=p;p=p->next;}
   while(p)
    {
      if(q->length>p->length&&p->length>=x)
	 q=p;
     p=p->next;
    }
  return(q);
 }
 node *distribute(node *head,node *work)
 {node *q,*p,*pre;
  q=pre=head;
   p=found(head,work->length);
   if(p)/*完成分配过程*/
    {q=p;
     success=1;work->address=q->address;work->flag=1;
     if(q->length>work->length)/*剩余部分仍修改为空闲分区*/
	 {q->address=q->address+work->length;
	  q->length=q->length-work->length;}
     else/*无剩余部分则删除该节点*/
       if(q==head)
	     head=head->next;
       else
	{while(pre->next!=q)
	   pre=pre->next;
	 pre->next=q->next;
	}
    }
  else
    success=0;
  return(head);
 }
 void print (node *head)  /*输出链表*/
 { node *p;
   p=head;
   if(head !=NULL)
    do{printf("%d,%d,%d,%s\n",p->address,p->length,p->flag,p->name);
       p=p->next;}
    while(p!=NULL);
 }
void main()
 { int count,i,segment[64];
   struct table *q,*q1,*q2,*p,*p1,*work;
   char workname[10];
   printf("The distributed table is:\n");
   p=p1=creat();              /*输入已分配情况表*/
   printf("the free table is:\n");
   q=q1=q2=creat();              /*输入未分配情况表*/
   printf("the work name is:");
   scanf("%s",workname);
   printf("input segment number:\n");   /*输入要分配的作业情况*/
   scanf("%d",&count);
   printf("input each segment length:\n");   /*输入每段的长度*/
   for(i=0;i<count;i++)
    {  scanf("%d",&segment[i]);
       work=(node *)malloc(sizeof(node));
       work->length=segment[i];work->next=NULL;
       strcpy(work->name,workname);
       q2=distribute(q1,work);
       if (success)
	{ while(p1->next)
	      p1=p1->next;
	  p1->next=work;
	  p1=work;
	}
      else
	{ printf("\ndistributing is not successful!\n");
	  printf("\nfree table is !\n");
	  print(q);
	  printf("\ndistribute table is !\n");
	  print(p);
	  success=0;
	  break;
	}
      q1=q2;
    }
   if(success)
    {printf("\ndistributing is successful!\n");
     printf("\nfree table is !\n");
     print(q);
     printf("\ndistribute table is !\n");
     print(p);
    }
}