用C语言实现生产者-消费者问题的模拟生产者消费者对缓冲区进行互斥操作。 缓冲区大小为10，缓冲区满则不允许生产者生产数据，缓冲区空则不允许消费者消费数据。 生产者消费者各循环操作10次。

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

#define BUFFER_SIZE 10

int buffer[BUFFER_SIZE];  // 缓冲区
int in = 0;  // 缓冲区中下一个空位的索引
int out = 0;  // 缓冲区中下一个数据的索引
int count = 0;  // 缓冲区中当前存储的数据数量

pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;  // 互斥锁
pthread_cond_t empty = PTHREAD_COND_INITIALIZER;  // 缓冲区空条件变量
pthread_cond_t full = PTHREAD_COND_INITIALIZER;  // 缓冲区满条件变量

void *producer(void *arg) {
    int i;
    for (i = 0; i < 10; i++) {
        pthread_mutex_lock(&mutex);
        while (count == BUFFER_SIZE) {  // 缓冲区满，等待消费者消费
            printf("Buffer is full, producer is waiting...\n");
            pthread_cond_wait(&empty, &mutex);
        }
        buffer[in] = rand() % 100;  // 生产数据
        printf("Producer produces %d, count = %d\n", buffer[in], count + 1);
        in = (in + 1) % BUFFER_SIZE;  // 更新下一个空位的索引
        count++;
        pthread_cond_signal(&full);  // 唤醒等待缓冲区满条件变量的消费者
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

void *consumer(void *arg) {
    int i;
    for (i = 0; i < 10; i++) {
        pthread_mutex_lock(&mutex);
        while (count == 0) {  // 缓冲区空，等待生产者生产
            printf("Buffer is empty, consumer is waiting...\n");
            pthread_cond_wait(&full, &mutex);
        }
        int data = buffer[out];  // 消费数据
        printf("Consumer consumes %d, count = %d\n", data, count - 1);
        out = (out + 1) % BUFFER_SIZE;  // 更新下一个数据的索引
        count--;
        pthread_cond_signal(&empty);  // 唤醒等待缓冲区空条件变量的生产者
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

int main() {
    pthread_t tid1, tid2;
    srand(time(NULL));
    pthread_create(&tid1, NULL, producer, NULL);
    pthread_create(&tid2, NULL, consumer, NULL);
    pthread_join(tid1, NULL);
    pthread_join(tid2, NULL);
    return 0;
}