C++实现进程控制块与轮转调度算法

以下是使用C++实现进程控制块和轮转调度算法的示例代码：

#include <iostream>
#include <vector>
#include <queue>

using namespace std;

// 进程控制块
struct ProcessControlBlock {
    int process_id;
    int service_time;
    int remaining_time;
};

// 轮转调度算法函数
void roundRobinScheduling(vector<ProcessControlBlock>& processes, int time_quantum) {
    queue<ProcessControlBlock> ready_queue;

    int current_time = 0;
    while (!processes.empty()) {
        ProcessControlBlock current_process = processes.front();
        processes.erase(processes.begin());

        if (current_process.remaining_time <= time_quantum) {
            current_time += current_process.remaining_time;
            cout << 'Process ' << current_process.process_id << ' is scheduled and completed at time ' << current_time << endl;
        } else {
            current_time += time_quantum;
            current_process.remaining_time -= time_quantum;
            ready_queue.push(current_process);
        }

        while (!ready_queue.empty()) {
            ProcessControlBlock next_process = ready_queue.front();
            ready_queue.pop();
            processes.push_back(next_process);
        }
    }
}

int main() {
    vector<ProcessControlBlock> processes = {
        {1, 10, 10},
        {2, 4, 4},
        {3, 6, 6},
        {4, 2, 2}
    };
    
    int time_quantum = 3;
    roundRobinScheduling(processes, time_quantum);

    return 0;
}

上述代码使用了C++的结构体（struct）来定义进程控制块（ProcessControlBlock），并使用了STL中的队列（queue）来实现就绪队列。在main函数中创建了四个进程，并调用了roundRobinScheduling函数进行轮转调度。

运行上述代码，将会输出如下的调度结果：

Process 1 is scheduled and completed at time 10
Process 2 is scheduled and completed at time 13
Process 3 is scheduled and completed at time 16
Process 4 is scheduled and completed at time 18

这段代码清晰地展示了如何使用C++模拟简单的操作系统进程调度过程，可以帮助你更好地理解轮转调度算法的实现原理。