（1）设计进程同步算法，使用P/V（wait/signal）操作模拟解决进程中经典同步问题。假设有一个生产者和一个消费者，缓冲区可以存放产品，生产者不断生产产品并存入缓冲区，消费者不断从缓冲区中取出产品并消费，设计代码并运行实现结果。 （2）编制时间片轮转调度算法，可自定义时间片的大小。 编制静态优先级调度算法，优先级高低可自定义。

1. 进程同步算法实现

生产者和消费者问题是经典的同步问题，可以使用信号量来实现进程之间的同步，其中P操作相当于获取资源，V操作相当于释放资源。具体实现如下：

#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <queue>

using namespace std;

const int buffer_size = 10;
queue<int> buffer;
mutex mtx;
condition_variable cv_producer, cv_consumer;

void producer() {
    for (int i = 0; i < 20; i++) {
        unique_lock<mutex> lock(mtx);
        while (buffer.size() == buffer_size) {
            cout << "buffer is full, waiting for consumer..." << endl;
            cv_producer.wait(lock);
        }
        buffer.push(i);
        cout << "producer produced item " << i << endl;
        cv_consumer.notify_one();
    }
}

void consumer() {
    for (int i = 0; i < 20; i++) {
        unique_lock<mutex> lock(mtx);
        while (buffer.empty()) {
            cout << "buffer is empty, waiting for producer..." << endl;
            cv_consumer.wait(lock);
        }
        int item = buffer.front();
        buffer.pop();
        cout << "consumer consumed item " << item << endl;
        cv_producer.notify_one();
    }
}

int main() {
    thread producer_thread(producer);
    thread consumer_thread(consumer);
    producer_thread.join();
    consumer_thread.join();
    return 0;
}

2. 时间片轮转调度算法实现

时间片轮转调度算法是一种基于时间片的调度算法，每个进程在CPU上运行的时间片是固定的，当一个进程的时间片用完后，它就被暂停，等待下一个时间片。具体实现如下：

#include <iostream>
#include <queue>

using namespace std;

struct Process {
    string name;
    int burst_time;
    int remaining_time;
};

void round_robin_scheduling(queue<Process>& process_queue, int time_slice) {
    while (!process_queue.empty()) {
        Process& current_process = process_queue.front();
        if (current_process.remaining_time <= time_slice) {
            cout << "Process " << current_process.name << " finished in " << current_process.burst_time << "ms" << endl;
            process_queue.pop();
        } else {
            current_process.remaining_time -= time_slice;
            process_queue.push(current_process);
            process_queue.pop();
        }
    }
}

int main() {
    queue<Process> process_queue;
    process_queue.push({"P1", 10, 10});
    process_queue.push({"P2", 5, 5});
    process_queue.push({"P3", 8, 8});
    round_robin_scheduling(process_queue, 5);
    return 0;
}

3. 静态优先级调度算法实现

静态优先级调度算法是一种基于优先级的调度算法，每个进程在进入系统时就被分配一个优先级，当CPU空闲时，选择具有最高优先级的进程运行。具体实现如下：

#include <iostream>
#include <queue>

using namespace std;

struct Process {
    string name;
    int burst_time;
    int priority;
};

bool operator<(const Process& p1, const Process& p2) {
    return p1.priority < p2.priority;
}

void priority_scheduling(priority_queue<Process>& process_queue) {
    while (!process_queue.empty()) {
        Process current_process = process_queue.top();
        cout << "Process " << current_process.name << " finished in " << current_process.burst_time << "ms" << endl;
        process_queue.pop();
    }
}

int main() {
    priority_queue<Process> process_queue;
    process_queue.push({"P1", 10, 2});
    process_queue.push({"P2", 5, 1});
    process_queue.push({"P3", 8, 3});
    priority_scheduling(process_queue);
    return 0;
}