避免死锁的银行家算法java
时间: 2023-12-09 09:04:26 浏览: 48
以下是Java实现银行家算法的代码示例:
```java
import java.util.*;
public class BankerAlgorithm {
private int[][] need; // 需求矩阵
private int[][] allocation; // 分配矩阵
private int[][] max; // 最大需求矩阵
private int[] available; // 可用资源向量
private int[] work; // 工作向量
private boolean[] finish; // 完成向量
private int processNum; // 进程数
private int resourceNum; // 资源数
public BankerAlgorithm(int[][] need, int[][] allocation, int[][] max, int[] available) {
this.need = need;
this.allocation = allocation;
this.max = max;
this.available = available;
this.processNum = allocation.length;
this.resourceNum = available.length;
this.work = Arrays.copyOf(available, resourceNum);
this.finish = new boolean[processNum];
}
// 判断是否满足需求
private boolean check(int process) {
for (int i = 0; i < resourceNum; i++) {
if (need[process][i] > work[i]) {
return false;
}
}
return true;
}
// 执行银行家算法
public boolean execute() {
int count = 0;
int[] safeSequence = new int[processNum];
while (count < processNum) {
boolean flag = false;
for (int i = 0; i < processNum; i++) {
if (!finish[i] && check(i)) {
for (int j = 0; j < resourceNum; j++) {
work[j] += allocation[i][j];
}
finish[i] = true;
safeSequence[count] = i;
count++;
flag = true;
}
}
if (!flag) {
return false;
}
}
System.out.println("Safe sequence: " + Arrays.toString(safeSequence));
return true;
}
}
```
使用示例:
```java
public class Main {
public static void main(String[] args) {
int[][] allocation = {{0, 1, 0}, {2, 0, 0}, {3, 0, 2}, {2, 1, 1}, {0, 0, 2}};
int[][] max = {{7, 5, 3}, {3, 2, 2}, {9, 0, 2}, {2, 2, 2}, {4, 3, 3}};
int[] available = {3, 3, 2};
int processNum = allocation.length;
int resourceNum = available.length;
int[][] need = new int[processNum][resourceNum];
for (int i = 0; i < processNum; i++) {
for (int j = 0; j < resourceNum; j++) {
need[i][j] = max[i][j] - allocation[i][j];
}
}
BankerAlgorithm bankerAlgorithm = new BankerAlgorithm(need, allocation, max, available);
bankerAlgorithm.execute();
}
}
```