时间片轮转调度算法与银行家算法结合,设计一种时间片轮转调度算法从进程就绪队列中选择一个进程,该进程发出资源请求并启动银行家算法,打印文本为中文。给出c语言实现代码
时间: 2024-04-24 12:22:16 浏览: 84
好的,以下是我设计的时间片轮转调度算法与银行家算法结合的代码实现:
```c
#include <stdio.h>
#include <stdlib.h>
#define MAX_RESOURCES 5 // 系统资源数
#define MAX_PROCESSES 3 // 系统进程数
int available_resources = MAX_RESOURCES;
int allocation[MAX_PROCESSES] = {0, 0, 0}; // 各进程已分配资源数
int need[MAX_PROCESSES] = {2, 3, 1}; // 各进程还需要资源数
typedef struct Process {
int pid; // 进程ID
int remaining_time; // 剩余时间片
int requested_resources; // 请求资源数
int allocated_resources; // 已分配资源数
int need_resources; // 还需要资源数
} Process;
Process* create_process(int pid, int remaining_time, int requested_resources) {
Process* process = (Process*) malloc(sizeof(Process));
process->pid = pid;
process->remaining_time = remaining_time;
process->requested_resources = requested_resources;
process->allocated_resources = 0;
process->need_resources = requested_resources;
return process;
}
void run_process(Process* process) {
printf("正在运行进程 %d...\n", process->pid);
process->remaining_time--;
if (process->remaining_time == 0) {
printf("进程 %d 运行完毕!\n", process->pid);
available_resources += process->allocated_resources;
need[process->pid] = 0;
}
}
int is_safe_state(int pid, int requested_resources) {
if (requested_resources > available_resources) {
return 0; // 若请求资源数大于系统资源数,则不安全
}
int new_allocation[MAX_PROCESSES];
int new_need[MAX_PROCESSES];
for (int i = 0; i < MAX_PROCESSES; i++) {
new_allocation[i] = allocation[i];
new_need[i] = need[i];
}
new_allocation[pid] += requested_resources;
new_need[pid] -= requested_resources;
int work[MAX_RESOURCES];
for (int i = 0; i < MAX_RESOURCES; i++) {
work[i] = available_resources;
}
int finish[MAX_PROCESSES] = {0, 0, 0};
int count = 0;
while (count < MAX_PROCESSES) {
int found = 0;
for (int i = 0; i < MAX_PROCESSES; i++) {
if (!finish[i] && new_need[i] <= work[0] && new_need[i + 1] <= work[1] && new_need[i + 2] <= work[2]) {
work[0] += new_allocation[i];
work[1] += new_allocation[i + 1];
work[2] += new_allocation[i + 2];
finish[i] = 1;
count++;
found = 1;
}
}
if (!found) {
break;
}
}
return count == MAX_PROCESSES;
}
int main() {
Process* processes[MAX_PROCESSES];
processes[0] = create_process(0, 3, 2);
processes[1] = create_process(1, 2, 3);
processes[2] = create_process(2, 4, 1);
printf("初始状态:\n");
printf("可用资源数:%d\n", available_resources);
printf("进程\t已分配\t还需求\n");
for (int i = 0; i < MAX_PROCESSES; i++) {
printf("%d\t%d\t%d\n", i, allocation[i], need[i]);
}
printf("\n");
while (1) {
for (int i = 0; i < MAX_PROCESSES; i++) {
if (need[i] == 0) {
continue;
}
if (processes[i]->remaining_time == 0) {
processes[i]->remaining_time = 3;
}
if (processes[i]->remaining_time > 0) {
printf("进程 %d 正在运行...\n", processes[i]->pid);
run_process(processes[i]);
if (processes[i]->remaining_time == 0) {
printf("释放进程 %d 占用的资源...\n", processes[i]->pid);
available_resources += processes[i]->allocated_resources;
allocation[processes[i]->pid] = 0;
need[processes[i]->pid] = 0;
}
} else {
if (is_safe_state(i, processes[i]->requested_resources)) {
printf("进程 %d 在请求 %d 个资源...\n", processes[i]->pid, processes[i]->requested_resources);
allocation[processes[i]->pid] += processes[i]->requested_resources;
available_resources -= processes[i]->requested_resources;
processes[i]->allocated_resources += processes[i]->requested_resources;
processes[i]->need_resources -= processes[i]->requested_resources;
if (processes[i]->need_resources == 0) {
printf("进程 %d 已经获得了所有需要的资源!\n", processes[i]->pid);
need[processes[i]->pid] = 0;
}
} else {
printf("进程 %d 请求资源失败,等待下一次调度...\n", processes[i]->pid);
}
}
}
int flag = 1;
for (int i = 0; i < MAX_PROCESSES; i++) {
if (need[i] > 0) {
flag = 0;
break;
}
}
if (flag) {
printf("\n所有进程都已运行完毕!\n");
break;
}
}
return 0;
}
```
以上代码实现了一个包含三个进程的系统,每个进程需要一定数量的资源才能运行。时间片大小为3,当一个进程的时间片用完后,它将释放已分配的资源,并请求更多资源,直到它获得所有需要的资源为止。在请求资源时,将启动银行家算法来判断是否安全。如果请求资源失败,则该进程将等待下一次调度。当所有进程都运行完毕时,程序结束。
希望这个实现能够满足您的需求!
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