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

// 条件变量实例

// 互斥锁和条件变量的初始化
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

void *producer_task(void *data)
{
    int *n = (int *)data;
    while (1)
    {
        pthread_mutex_lock(&mutex);

        while (*n == 10) // 只要资源为 10 ，就等待
        {
            // 条件变量等待后，会自动释放 mutex 锁
            pthread_cond_wait(&cond, &mutex);
        }

        (*n)++;
        printf("生产线程(%ld)生产了 %d 个产品\n", pthread_self(), *n);

        // 发出通知，让等待消费的线程恢复（条件满足）
        pthread_cond_broadcast(&cond);

        pthread_mutex_unlock(&mutex);
        // usleep(200 * 1000);
        sleep(1);
    }

    pthread_exit(NULL);
}

void *consumer_task(void *data)
{
    int *n = (int *)data;
    while (1)
    {
        pthread_mutex_lock(&mutex);
        while (*n == 0) // 只要资源为 0 ，就等待
        {
            // 条件变量等待后，会自动释放 mutex 锁
            pthread_cond_wait(&cond, &mutex);
        }
        printf("消费者(%ld) 消费了 %d 产品\n", pthread_self(), *n);
        (*n)--;
        pthread_mutex_unlock(&mutex);
        // usleep(200 * 1000);
        sleep(1);
    }
    pthread_exit(NULL);
}

int main(int argc, char const *argv[])
{
    int num = 3; // 3 个产品
    pthread_t threads[10];
    // 创建 2 个生产线程
    for (int i = 0; i < 8; i++)
    {
        pthread_create(&threads[i], NULL, producer_task, &num);
    }

    // 创建 3 个消费者线程
    for (int i = 8; i < 10; i++)
    {
        pthread_create(&threads[i], NULL, consumer_task, &num);
    }

    for (int i = 0; i < 10; i++)
    {
        pthread_join(threads[i], NULL);
    }

    pthread_mutex_destroy(&mutex);
    pthread_cond_destroy(&cond);

    return 0;
}