银行家算法_java

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];      }     }

}