0131作业

请使用互斥锁 和 信号量分别实现5个线程之间的同步

#define THREAD_COUNT 5

pthread_mutex_t mutex;
int shared_resource = 0;

void *thread_function(void *arg) {
    int thread_id = *(int *)arg;

    pthread_mutex_lock(&mutex); // 加锁
    printf("Thread %d is accessing the shared resource.\n", thread_id);
    shared_resource++;
    printf("Thread %d updated the shared resource to %d.\n", thread_id, shared_resource);
    pthread_mutex_unlock(&mutex); // 解锁

    pthread_exit(NULL);
}

int main() {
    pthread_t threads[THREAD_COUNT];
    int thread_ids[THREAD_COUNT];

    pthread_mutex_init(&mutex, NULL); // 初始化互斥锁

    for (int i = 0; i < THREAD_COUNT; i++) {
        thread_ids[i] = i + 1;
        pthread_create(&threads[i], NULL, thread_function, &thread_ids[i]);
    }

    for (int i = 0; i < THREAD_COUNT; i++) {
        pthread_join(threads[i], NULL);
    }

    pthread_mutex_destroy(&mutex); // 销毁互斥锁
    printf("Final value of shared resource: %d\n", shared_resource);

    return 0;
}

#define THREAD_COUNT 5

sem_t semaphore;
int shared_resource = 0;

void *thread_function(void *arg) {
    int thread_id = *(int *)arg;

    sem_wait(&semaphore); // 等待信号量
    printf("Thread %d is accessing the shared resource.\n", thread_id);
    shared_resource++;
    printf("Thread %d updated the shared resource to %d.\n", thread_id, shared_resource);
    sem_post(&semaphore); // 释放信号量

    pthread_exit(NULL);
}

int main() {
    pthread_t threads[THREAD_COUNT];
    int thread_ids[THREAD_COUNT];

    sem_init(&semaphore, 0, 1); // 初始化信号量，初始值为 1

    for (int i = 0; i < THREAD_COUNT; i++) {
        thread_ids[i] = i + 1;
        pthread_create(&threads[i], NULL, thread_function, &thread_ids[i]);
    }

    for (int i = 0; i < THREAD_COUNT; i++) {
        pthread_join(threads[i], NULL);
    }

    sem_destroy(&semaphore); // 销毁信号量
    printf("Final value of shared resource: %d\n", shared_resource);

    return 0;
}