时间片轮状调度算法
时间片轮转调度算法实现:
#include <iostream> #include <string.h> #include <ctime> #include <windows.h> using namespace std; #define BLOCK -1; #define READY 0; #define RUNING 1; int flag; void Runing(); class Node { public: string pid; //进程ID int priority; //进程的优先级 int state; //进程的状态 double time; //进程的运行时间 Node *next; Node() { next=NULL; } Node(string _pid,int _priority,int _state,double _time) { pid=_pid; priority=_priority; state=_state; time=_time; next=NULL; } void display() { cout<<pid<<" "<<priority; if(state==1) cout<<" "<<"Runed"<<" "<<time<<endl; else cout<<" "<<"Ready"<<" "<<time<<endl; } ~Node() {} }; class linklist { public: Node* head; Node* rear; linklist() { head=NULL; rear=NULL; } void InsertNode(string _pid,int _priority,int _state,double _time) { Node* p=new Node(_pid,_priority,_state,_time); if(rear==NULL) head=rear=p; else { rear->next=p; rear=rear->next; } } void DeleteHeadNode() { Node* p=head; cout<<" 运行结束的进程为"<<p->pid<<endl<<endl; if(p->next!=NULL) //如果此时队列中有大于一个进程在排队 head=head->next; else //队列中仅有一个进程在排队 head=rear=NULL; delete p; } void ReInsertNode(Node* p) { p->state=1; rear->next=p; rear->state=0; rear=rear->next; } void Runing() { if(head==NULL||rear==NULL) { cout<<" 进程队列已空,进程全部运行完成!"<<endl; flag=0; return ; } else { Node* p=head; clock_t perruntime=0.1*CLOCKS_PER_SEC; //为每个进程分配的时间片 double time=clock(); if(p->time>0.1) //队首进程的剩余时间大于时间片时 { while((clock()-time)<perruntime) ; p->time=p->time-0.1; if(p->time<0.001) //进程恰好整时间片运行结束,删除队首进程 { DeleteHeadNode(); return; } } //队首进程的剩余时间小于时间片时 else { while((clock()-time)<(p->time*CLOCKS_PER_SEC)) //把队首进程的剩余时间片运行完成后删除队首进程 ; DeleteHeadNode(); return; } if(head->next!=NULL) //如果此时队列中有多于一个进程 { head=head->next; p->next=NULL; ReInsertNode(p); } } } void display() { Node *p=head; cout<<" 当前就绪队列中的进程状态"<<endl; cout<<"********************************************************"<<endl; cout<<"PID "<<"Priority "<<"State "<<"RuningNeedTime"<<endl; while(p!=NULL) { p->display(); p=p->next; } cout<<"********************************************************"<<endl; } }; int main() { flag=1; linklist list; list.InsertNode("process1",4,0,0.5); list.InsertNode("process2",3,0,1.25); list.InsertNode("process3",2,0,0.8); list.InsertNode("process4",1,0,1); while(flag) { list.Runing(); if(list.rear!=NULL) list.display(); cout<<endl; //system("pause"); //system("cls"); } return 0; }
态度决定高度,细节决定成败,