银行家算法C语言简单代码实现
时间: 2023-11-17 13:05:23 浏览: 51
以下是一个简单的C语言实现银行家算法的代码,它可以用于操作系统课程设计有关银行家算法的实现。该代码实现了银行家算法和随机分配算法,可以进行资源的申请和释放,并判断是否存在死锁情况。
```c
// 银行家算法C语言简单代码实现
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#define MAX_PROCESS_NUM 10 // 最大进程数
#define MAX_RESOURCE_NUM 10 // 最大资源数
int available[MAX_RESOURCE_NUM]; // 可用资源数
int max[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; // 最大需求矩阵
int allocation[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; // 已分配矩阵
int need[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; // 需求矩阵
bool finish[MAX_PROCESS_NUM]; // 进程是否完成标志
// 初始化数据
void init_data(int process_num, int resource_num, int *available, int *max, int *allocation, int *need) {
int i, j;
for (i = 0; i < resource_num; i++) {
available[i] = *(available + i);
}
for (i = 0; i < process_num; i++) {
for (j = 0; j < resource_num; j++) {
max[i][j] = *(max + i * resource_num + j);
allocation[i][j] = *(allocation + i * resource_num + j);
need[i][j] = max[i][j] - allocation[i][j];
}
finish[i] = false;
}
}
// 判断是否存在死锁
bool is_deadlock(int process_num, int resource_num) {
int i, j, k;
bool flag;
int work[MAX_RESOURCE_NUM];
for (i = 0; i < resource_num; i++) {
work[i] = available[i];
}
for (i = 0; i < process_num; i++) {
if (!finish[i]) {
flag = true;
for (j = 0; j < resource_num; j++) {
if (need[i][j] > work[j]) {
flag = false;
break;
}
}
if (flag) {
for (k = 0; k < resource_num; k++) {
work[k] += allocation[i][k];
}
finish[i] = true;
i = -1;
}
}
}
for (i = 0; i < process_num; i++) {
if (!finish[i]) {
return true;
}
}
return false;
}
// 银行家算法
bool banker_algorithm(int process_num, int resource_num, int *available, int *max, int *allocation, int *need, int process_id, int *request) {
int i;
bool flag = true;
for (i = 0; i < resource_num; i++) {
if (request[i] > need[process_id][i] || request[i] > available[i]) {
flag = false;
break;
}
}
if (flag) {
for (i = 0; i < resource_num; i++) {
available[i] -= request[i];
allocation[process_id][i] += request[i];
need[process_id][i] -= request[i];
}
if (is_deadlock(process_num, resource_num)) {
for (i = 0; i < resource_num; i++) {
available[i] += request[i];
allocation[process_id][i] -= request[i];
need[process_id][i] += request[i];
}
return false;
} else {
return true;
}
} else {
return false;
}
}
// 随机分配算法
void random_algorithm(int process_num, int resource_num, int *available, int *max, int *allocation, int *need) {
int i, j, k;
int request[MAX_RESOURCE_NUM];
for (i = 0; i < process_num; i++) {
for (j = 0; j < resource_num; j++) {
request[j] = rand() % (need[i][j] + 1);
}
banker_algorithm(process_num, resource_num, available, max, allocation, need, i, request);
}
}
int main() {
int process_num = 5; // 进程数
int resource_num = 3; // 资源数
int available[] = {3, 3, 2}; // 可用资源数
int max[] = {
7, 5, 3,
3, 2, 2,
9, 0, 2,
2, 2, 2,
4, 3, 3
}; // 最大需求矩阵
int allocation[] = {
0, 1, 0,
2, 0, 0,
3, 0, 2,
2, 1, 1,
0, 0, 2
}; // 已分配矩阵
int need[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; // 需求矩阵
init_data(process_num, resource_num, available, max, allocation, need);
random_algorithm(process_num, resource_num, available, max, allocation, need);
return 0;
}
```