package BankerDijkstra;
import java.util.Arrays;
import javax.swing.JOptionPane;

public class Banker_Dijkstra {
    static int available[]={3,3,2};         //可利用资源数 
    static int max[][]={{7,5,3},{3,2,2},{9,0,2},{2,2,2},{4,3,3}};;          //每线程最大需求 
    static int allocation[][]={{0,1,0},{2,0,0},{3,0,2},{2,1,1},{0,0,2}};   //已分配资源 
    static int need[][]={{7,4,3},{1,2,2},{6,0,0},{0,1,1},{4,3,1}};        //需求 
    static int request[]=new int[3];           //存放请求资源 
    static int thread;  //线程号 
    static JOptionPane jpane = new JOptionPane();
   // static boolean m;
    public static void main(String[] argv){ 
        int n = 0 ;
        Banker_Dijkstra bd = new Banker_Dijkstra();

        for(int i=0;i<5;i++){
            if(bd.safeState(i)){
                JOptionPane.showMessageDialog(jpane, "系统状态安全");
                n=1;
                break;
            }else{
                n=2;
                continue;           
            }
        }       
        if(n==1){
            bd.getThread();
            }
        else if(n==2){
            JOptionPane.showMessageDialog(jpane, "系统状态不安全");
        }
    }



    protected void getThread(){//输入测试线程号且输出结果
        try{
        String xiancheng = JOptionPane.showInputDialog(jpane,"请输入申请资源的线程:");
        thread = (int) Integer.parseInt(xiancheng);
        }catch(Exception e){
            int response = JOptionPane.showConfirmDialog(jpane, "请输入0～4:",null, JOptionPane.YES_NO_OPTION);  
            // 处理异常
           if(response==0){
               getThread();
           }else if(response ==1){
               System.exit(0);
           }
        }

        if(thread<0||thread>4){  
           JOptionPane.showMessageDialog(jpane, "请输入0～4:");  
            getThread();  
        }else{    
            for(int i=0;i<3;i++){  
                String requestR = JOptionPane.showInputDialog(jpane,"请输入申请的第"+(i+1)+"种资源(若不申请则填0)");
                try{
                request[i]=Integer.parseInt(requestR);}
                catch(Exception e){
                    JOptionPane.showConfirmDialog(jpane, "请输入申请的第"+(i+1)+"种资源(若不申请则填0)",null,JOptionPane.YES_NO_OPTION);
                }
            }  
            if(request[0]>need[thread][0]||request[1]>need[thread][1]||request[2]>need[thread][2]){  
             JOptionPane.showMessageDialog(jpane,thread+"线程申请的资源超出其需要的资源，请重新输入");  
                getThread();  
            }else{  
                if(request[0]> available[0]||request[1]> available[1]||request[2]> available[2]){  
             JOptionPane.showMessageDialog(jpane,thread+"线程申请的资源大于系统资源，请重新输入");  
                    getThread();  
                }  
            }  
            // 分配资源
            allocateData(thread); 
            // 判断 继续模拟选择与处理
            int tag=0;
            if(check(thread)){ 
                try{
                 String str = JOptionPane.showInputDialog(jpane,"是／否 继续模拟？( 1/0 ):");
                  tag = Integer.parseInt(str);
                 }catch(Exception e){
                     JOptionPane.showMessageDialog(jpane, "继续 输入(数值) 1，不继续 输入(数值) 0 ！");
                 }
                 if(tag==1){ 
                     recoverData(thread);  
                     getThread();
                     }
                 else{
                    if( (JOptionPane.YES_NO_OPTION)==JOptionPane.CANCEL_OPTION)System.exit(0);
                    if((JOptionPane.YES_NO_OPTION)==JOptionPane.YES_OPTION) recoverData(thread);
                 }
            }else{  
                recoverData(thread);  
                getThread();  
                }
           }
    }
    // 安全算法
    private boolean check(int thread2) {
        boolean[] finish = new boolean[5];
            Arrays.fill(finish, false);
        int[] work = new int[3];
        int[] queue = new int[5];
        int q=0;//安全序列下标
        for(int i = 0;i<3;i++){
            work[i] = available[i];
        }
        int tT = thread2;
        while(tT<5){
            for(int R=0;R<3;R++){
                if((!(finish[tT]==false))||(!(work[R]>=need[tT][R]))){
                    tT++;
                    break;
                }else{
                    if(R==2){
                        for(int m =0;m<3;m++){
                            work[m] += allocation[tT][m];
                        }
                        for(int s:work){
                            System.out.print(s+" ");
                        }
                        System.out.println("");
                        finish[tT] = true;
                        queue[q] = tT;
                        q++;
                        tT =0;
                    }
                }
            }   
        }

        for(int p =0;p<5;p++){
            if(finish[p]==false){
                JOptionPane.showMessageDialog(jpane, "安全序列生成失败");
                return false;
                }
        }

            JOptionPane.showMessageDialog(jpane, "安全序列："+queue[0]+","+queue[1]+","
        +queue[2]+","+queue[3]+","+queue[4]);
            return true;

    }
    private boolean safeState(int thread3){
        boolean[] finish = new boolean[5];
            Arrays.fill(finish, false);
            int[] work = new int[3];
            int[] queue = new int[5];
            int q=0;//安全序列下标
            for(int i = 0;i<3;i++){
                work[i] = available[i];
            }
            int tT = thread3;
            while(tT<5){
                for(int R=0;R<3;R++){
                    if((!(finish[tT]==false))||(!(work[R]>=need[tT][R]))){
                        tT++;
                        break;
                    }
                    else{
                        if(R==2){
                            for(int m =0;m<3;m++){
                                work[m] += allocation[tT][m];
                            }
                            finish[tT] = true;
                            queue[q] = tT;
                            q++;
                            tT =0;
                        }
                    }
// if((finish[tT]==false)&&(work[R]>=need[tT][R])){
// for(int m =0;m<3;m++){
// work[m] += allocation[tT][m];}
// finish[tT] = true;
// queue[q] = tT;
// q++;
// tT=0;
// }else{ 
// tT++;
// break;
// }
                }   
            }
            for(int p =0;p<5;p++){
                if(finish[p]==false){
                    return false;
                    }
            }
                return true;
    }

    private void recoverData(int thread2) { // 生成失败则重置已分配资源
        for(int i=0;i<3;i++){  
            //重新调整系统资源数 
            available[i]+=request[i];  
            //计算各个线程拥有资源 
            allocation[thread2][i]-=request[i];  
            //重新计算需求 
            need[thread2][i]+=request[i];  
     }   
    }

    private void allocateData(int thread2) { //分配
        for(int i=0;i<3;i++){  
            //重新调整可用系统资源数 
            available[i]-=request[i];  
            //计算各个线程分配后拥有资源 
            allocation[thread2][i]+=request[i];  
            //重新计算需求 
            need[thread2][i]-=request[i];  
        }     
    }
}