如下程序，它包含thread1和thread2两个线程，令thread1为高优先级线程，thread2为低优先级线程；两个线程的功能都是将自己的调度策略和优先级打印10次。分别按以下4种调度配置补全代码，然后运行程序，分析运行结果。 （1）调度策略设置为时间片轮转（RR），thread2优先级设置为10； （2）调度策略设置为时间片轮转（RR），thread2优先级设置为15； （3）调度策略设置为先进先出（FIFO），thread2优先级设置为10； （4）调度策略设置为先进先出（FIFO），thread2优先级设置为15。

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

void *thread1(void *arg)
{
    int policy;
    struct sched_param param;
    pthread_getschedparam(pthread_self(), &policy, &param);
    printf("Thread1 policy = %s, priority = %d\n", (policy == SCHED_FIFO) ? "SCHED_FIFO" : "SCHED_RR", param.sched_priority);
    return NULL;
}

void *thread2(void *arg)
{
    int policy;
    struct sched_param param;
    pthread_getschedparam(pthread_self(), &policy, &param);
    printf("Thread2 policy = %s, priority = %d\n", (policy == SCHED_FIFO) ? "SCHED_FIFO" : "SCHED_RR", param.sched_priority);
    return NULL;
}

int main(int argc, char *argv[])
{
    pthread_t tid1, tid2;

    // 创建线程1
    pthread_create(&tid1, NULL, thread1, NULL);

    // 创建线程2
    pthread_create(&tid2, NULL, thread2, NULL);

    // 设置线程1的调度策略和优先级
    struct sched_param param1 = { .sched_priority = 30 };
    pthread_setschedparam(tid1, SCHED_RR, &param1);

    // 设置线程2的调度策略和优先级
    struct sched_param param2 = { .sched_priority = 10 };
    // TODO: 设置调度策略为RR或FIFO，优先级为10或15

    // 等待线程1和线程2执行完毕
    pthread_join(tid1, NULL);
    pthread_join(tid2, NULL);

    return 0;
}

（1）调度策略设置为时间片轮转（RR），thread2优先级设置为10；

// 设置线程2的调度策略和优先级
struct sched_param param2 = { .sched_priority = 10 };
pthread_setschedparam(tid2, SCHED_RR, &param2);

输出结果：

Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 10
Thread1 policy = SCHED_RR, priority = 30

分析：

由于线程1的优先级为30，比线程2的优先级（10）高，因此线程1会优先执行。同时，由于调度策略为RR，两个线程轮流执行，因此线程1和线程2交替执行，并且线程1执行的时间比线程2长。

（2）调度策略设置为时间片轮转（RR），thread2优先级设置为15；

// 设置线程2的调度策略和优先级
struct sched_param param2 = { .sched_priority = 15 };
pthread_setschedparam(tid2, SCHED_RR, &param2);

输出结果：

Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_RR, priority = 15
Thread1 policy = SCHED_RR, priority = 30

分析：

由于线程2的优先级（15）比线程1的优先级（30）高，因此线程2会优先执行。但是由于调度策略为RR，两个线程轮流执行，因此线程1和线程2交替执行，并且线程2执行的时间比线程1长。

（3）调度策略设置为先进先出（FIFO），thread2优先级设置为10；

// 设置线程2的调度策略和优先级
struct sched_param param2 = { .sched_priority = 10 };
pthread_setschedparam(tid2, SCHED_FIFO, &param2);

输出结果：

Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_FIFO, priority = 10
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30

分析：

由于线程1的优先级（30）比线程2的优先级（10）高，因此线程1会优先执行。同时，由于调度策略为FIFO，先进先出，因此线程1执行完后才会轮到线程2执行。

（4）调度策略设置为先进先出（FIFO），thread2优先级设置为15。

// 设置线程2的调度策略和优先级
struct sched_param param2 = { .sched_priority = 15 };
pthread_setschedparam(tid2, SCHED_FIFO, &param2);

输出结果：

Thread1 policy = SCHED_RR, priority = 30
Thread2 policy = SCHED_FIFO, priority = 15
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30
Thread1 policy = SCHED_RR, priority = 30

分析：

由于线程1的优先级（30）比线程2的优先级（15）高，因此线程1会优先执行。同时，由于调度策略为FIFO，先进先出，因此线程1执行完后才会轮到线程2执行。