OS作业的第一步骤

进程用链表表示，资源也是用链表表示。类似一个十字链表。能在进程里面去查看资源。

 

#include<iostream>
#include<time.h>

using namespace std;

#define Sort 5
#define Number 20

struct Resource{
 int r_No;
 int max;
 int allocation;
 int need;
 Resource *next;
};
struct Process{
 int p_No;
 Process * next;
 Resource * Rhead;
};

 

Process *Creat_Process(int n){
 Process *pP;
 Process *pEnd;
 Process *pHead;

 pHead = NULL;
   pP = new Process;
   pEnd = pP;

 for(int i = 0 ; i < n ; i++){
  
   
   Resource *rR;
   Resource *rEnd;
   Resource *rHead;

  if(pHead == NULL){
   pHead = pP;

   pP->p_No =i+1;
   
   

  
   rHead = NULL;
   rR = new Resource;
      rEnd =rR;

   for(int j = 0; j < Sort; j++)
   {  
   
    if(rHead == NULL){
     
     pP->Rhead=rHead = rR;
     rR->r_No = j+1;
     rR->max = rand()%Number + 1;
     rR->allocation = rand()%rR->max;
     rR->need = rR->max - rR->allocation;
    }//if

    else {
     rEnd->next = rR;
     rR->r_No = j+1;
     rR->max = rand()%Number + 1;
     rR->allocation = rand()%rR->max;
     rR->need = rR->max - rR->allocation;

     rEnd = rR;

    }
    rR = new Resource;
   }//for
   rEnd->next =NULL;
   delete rR;

   
  }//if

  else{
   pEnd->next=pP;
   pEnd = pP;
   pP->p_No = i+1;
            rHead = NULL;
   rR = new Resource;
   rEnd =rR;
   for(int f=0;f<Sort;f++){

  
   if(rHead ==NULL){
    pP->Rhead=rHead = rR;
    rR->r_No = f+1;
    rR->max = rand()%Number + 1;
    rR->allocation = rand()%rR->max;
    rR->need = rR->max - rR->allocation;
   
   }//if

   else{
    rEnd->next=rR;
    rEnd=rR;
    rR->r_No =f+1;
    rR->max = rand()%Number + 1 ;
    rR->allocation = rand()%rR ->max;
    rR->need = rR ->max - rR->allocation;
   
   }//else
    rR = new Resource;

   }//for

   rEnd->next =NULL;
   delete rR;

 

  }//else
   pP = new Process;
 
 }//for
  pEnd->next=NULL;
  delete pP;
cout<<"1"<<endl;
return (pHead);
}

int main(void)
{
 srand(time(NULL));
 Process *show;
 show = Creat_Process(5);
 cout<<"2"<<endl;
 while(show)
 {
  cout<<"P_NO: "<<show->p_No<<"Re: "<<show->Rhead->r_No<<endl;
  for(int i=0;i<5;i++){
   cout<<"R_NO:"<<show->Rhead->r_No<<" alloc: "<<show->Rhead->allocation<<endl;
      show->Rhead=show->Rhead->next;
  }
  show=show->next;
 }
 return 0;
}