銀行家演算法（Java語言實現）

標籤：

package cn.hncu.mytext;import java.util.Scanner;public class BankerOfAlgorithm {//BankerOfAlgorithm  銀行家演算法int Max[][];int Allocation[][];int Need[][];int Available[];int Work[];String name[];int temp[];int S = 100, P = 100;int safequeue[];int Request[];Scanner sc;public BankerOfAlgorithm() {int text_temp = 100;int Max[][] = new int[text_temp][text_temp];int Allocation[][] = new int[text_temp][text_temp];int Need[][] = new int[text_temp][text_temp];int Available[] = new int[text_temp];int Work[] = new int[text_temp];String name[] = new String[text_temp];int temp[] = new int[text_temp];int S = 100, P = 100;int safequeue[] = new int[text_temp];int Request[] = new int[text_temp];}public void Showdata() {int i, j, k, l;System.out.println("\t資源分派情況\n");System.out.println("\tMax\t已指派\tNeed");System.out.print("\t");for (j = 0; j < 3; j++) {for (i = 0; i < S; i++) {System.out.print(name[i] + " ");}System.out.print("\t");}System.out.println();for (i = 0; i < P; i++) {System.out.print(i+"\t");for (j = 0; j < S; j++) {System.out.print(Max[i][j] + " ");}System.out.print("\t");for (k = 0; k < S; k++) {System.out.print(Allocation[i][k] + " ");}System.out.print("\t");for (l = 0; l < S; l++) {System.out.print(Need[i][l] + " ");}System.out.println();}System.out.println("\nAvailable");for (i = 0; i < S; i++) {System.out.print(name[i] + " ");}System.out.println();for (i = 0; i < S; i++) {System.out.print(Available[i] + " ");}System.out.println();}public int Judgesafe() {int[][] tempwork = new int[100][100];int i, x, k = 0, m, apply;int[] Finish = new int[100];int[] temp = new int[100];int j;int flag = 0;Work = new int[100];for (i = 0; i < S; i++) {Work[i] = Available[i];}for (i = 0; i < P; i++) {apply = 0;for (j = 0; j < S; j++) {if (Finish[i] == 0 && Need[i][j] <= Work[j]) {apply++;if (apply == S) {for (m = 0; m < S; m++) {tempwork[i][m] = Work[m];Work[m] = Work[m] + Allocation[i][m];}Finish[i] = 1;temp[k] = i;i = -1;k++;flag++;}}}}for (i = 0; i < P; i++) {if (Finish[i] == 0) {System.out.println("系統不安全");return -1;}}System.out.println("系統是安全的");System.out.print("分配的序列:");for (i = 0; i < P; i++) {System.out.print(temp[i]);if (i < P - 1) {System.out.print("->");}}System.out.println();return 0;}public void Changedata(int flag) {for (int i = 0; i < S; i++) {Available[i] = Available[i] - Request[i];Allocation[flag][i] = Allocation[flag][i] + Request[i];Need[flag][i] = Need[flag][i] - Request[i];}}public void Share() {sc = new Scanner(System.in);int i, flag;char ch = 'Y';System.out.println("輸入請求資源的進程：");flag = sc.nextInt();Request = new int[100];if (flag >= P) {System.out.println("此進程不存在!");} else {System.out.println("輸入此進程對各個資源的請求數量：");for (i = 0; i < S; i++) {Request[i] = sc.nextInt();}for (i = 0; i < S; i++) {if (Request[i] > Need[flag][i]) {System.out.println("進程" + flag + "申請的資源大於它所需要的資源!");System.out.println("分配不合理不予分配!");ch = 'N';break;} else if (Request[i] > Available[i]) {System.out.println("進程" + flag + "申請的資源大於可利用的資源。");System.out.println("分配不合理，不予分配!");ch = 'N';break;}}if (ch == 'Y') {Changedata(flag);if (Judgesafe() == -1) {System.out.println("進程" + flag + "申請資源後，系統進入死結狀態，分配失敗!");for (int j = 0; j < S; j++) {Available[j] = Available[j] + Request[j];Allocation[flag][j] = Allocation[flag][j] - Request[j];Need[flag][j] = Need[flag][j] + Request[j];}}}}}public static void main(String[] args) {BankerOfAlgorithm mytext = new BankerOfAlgorithm();Scanner sc = new Scanner(System.in);int i, j, p, s, number;String choice, tempstring;System.out.println("\t\t作業系統實驗六");System.out.println("輸入資源種類：");s = sc.nextInt();mytext.S = s;System.out.println("輸入資源的名稱和數量：");mytext.name = new String[100];mytext.Available = new int[100];for (i = 0; i < s; i++) {tempstring = sc.next();number = sc.nextInt();mytext.name[i] = tempstring;mytext.Available[i] = number;}System.out.println("輸入進程的數量：");p = sc.nextInt();mytext.P = p;System.out.println("輸入各進程資源最大需求量：");mytext.Max = new int[100][100];for (i = 0; i < p; i++) {for (j = 0; j < s; j++) {mytext.Max[i][j] = sc.nextInt();}}System.out.println("輸入各進程資源已指派量：");mytext.Allocation = new int[100][100];for (i = 0; i < p; i++) {for (j = 0; j < s; j++) {mytext.Allocation[i][j] = sc.nextInt();mytext.Available[j] = mytext.Available[j]- mytext.Allocation[i][j];}}mytext.Need = new int[100][100];for (i = 0; i < p; i++) {for (j = 0; j < s; j++) {mytext.Need[i][j] = mytext.Max[i][j] - mytext.Allocation[i][j];}}mytext.Showdata();mytext.Judgesafe();while (true) {System.out.println("是否分配資源(n是關閉)：");choice = sc.next();char choice_char = choice.charAt(0);switch (choice_char) {case 'n':System.exit(0);default:mytext.Share();break;}mytext.Showdata();mytext.Judgesafe();}}}

銀行家演算法（Java語言實現）