操作系统之银行家算法源代码

package bankeralgorithm; public class BankerAlgorithmPresenter { private boolean isError = false;// 是否出错 private boolean isWait = false;// 是否处于等待状态 private boolean isSafeState = true;// 是否安全状态 private int threadId;// 进程序号 private boolean isNeedLargerThanWork = false;//资源需求量是否大于work数量 private Data data; private int [][]REQUEST; private int []AVAILABLE; private int [][]NEED; private int [][]MAX; private int[][]ALLOCATION; boolean[] isFinished = { false, false, false, false };// 为4个进程初始化完成情况为false public BankerAlgorithmPresenter() { super(); // TODO Auto-generated constructor stub data=new Data(); REQUEST=data.getREQUEST(); AVAILABLE=data.getAVAILABLE(); NEED=data.getNEED(); MAX=data.getMAX(); ALLOCATION=data.getALLOCATION(); } public void setThreadId(int threadId) { this.threadId=threadId; } //检查是否出错 private void checkIsError() { for (int i = 0; i < 3; i++) { if (REQUEST[threadId][i] > NEED[threadId][i]) { isError = true; break; } } } //检查是否出错 private void checkIsWait() { for (int i = 0; i < 3; i++) { if (REQUEST[threadId][i] > AVAILABLE[i]) { isWait = true; break; } } } //安全性算法中更新数据结构 private void update(int i,int WORK[]) { if (!isNeedLargerThanWork) { isFinished[i] = true; for (int k = 0; k < 3; k++) { WORK[k] += ALLOCATION[i][k]; } } else { isNeedLargerThanWork = false; } } //安全性算法中查找满足条件的值 private void serach(int i,int []WORK) { if (!isFinished[i]) { for (int j = 0; j < 3; j++) {// 资源数 if (NEED[i][j] > WORK[j]) { isNeedLargerThanWork = true; break; } } } } //查找是否有isFinished=falsed的情况发生 private void checkIsFinished() { for (int i = 0; i < 4; i++) { if (!isFinished[i]) { isSafeState = false; break; } } } //安全性算法 private void safe() { // 系统执行安全性算法 int[] WORK = AVAILABLE; // 开始查找满足条件的进程资源分配情况 // 并改变数据结构中的值 for (int i = 0; i < 4; i++) {// 进程数 serach(i, WORK); update(i, WORK); } } //执行安全性算法 private void excuteSafeAlgorithm() { safe(); checkIsFinished(); } //更改数据结构 private void allocate() { for (int i = 0; i < 3; i++) { AVAILABLE[i] -= REQUEST[threadId][i]; ALLOCATION[threadId][i] += REQUEST[threadId][i]; NEED[threadId][i] -= REQUEST[threadId][i]; } } //执行 public void execute(OnExcuteListener listener) { threadId=listener.onStartInputData(); checkIsError(); if (!isError) { checkIsWait(); if (!isWait) { allocate(); excuteSafeAlgorithm(); listener.onSuccess(isSafeState); } else { listener.onWait(threadId); } } else { listener.onError(); } } }