请用c语言编写linux环境下运行的一个程序，其功能为实现生产者消费者功能。缓冲区大小为10，有3个生产者进程，4个消费者进程。要求生产者任务从文件中读取数据，并将它存放到缓冲区，而消费者任务从缓冲区中取走此数据，并打印输出。

好的，这是一个经典的生产者消费者问题。我给你提供一个基本的代码框架，你可以在此基础上进行修改和完善。

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

#define BUFFER_SIZE 10
#define PRODUCER_NUM 3
#define CONSUMER_NUM 4

int buffer[BUFFER_SIZE];
int in = 0;
int out = 0;
int count = 0;

pthread_mutex_t mutex;
pthread_cond_t full;
pthread_cond_t empty;

void *producer(void *arg)
{
    FILE *fp;
    char line[100];
    fp = fopen("data.txt", "r");
    if (fp == NULL) {
        perror("Error opening file");
        exit(EXIT_FAILURE);
    }
    while (fgets(line, sizeof(line), fp)) {
        int item = atoi(line);
        pthread_mutex_lock(&mutex);
        while (count == BUFFER_SIZE) {
            pthread_cond_wait(&full, &mutex);
        }
        buffer[in] = item;
        in = (in + 1) % BUFFER_SIZE;
        count++;
        printf("Producer %ld produced %d\n", (long)arg, item);
        pthread_cond_signal(&empty);
        pthread_mutex_unlock(&mutex);
    }
    fclose(fp);
    pthread_exit(NULL);
}

void *consumer(void *arg)
{
    while (1) {
        pthread_mutex_lock(&mutex);
        while (count == 0) {
            pthread_cond_wait(&empty, &mutex);
        }
        int item = buffer[out];
        out = (out + 1) % BUFFER_SIZE;
        count--;
        printf("Consumer %ld consumed %d\n", (long)arg, item);
        pthread_cond_signal(&full);
        pthread_mutex_unlock(&mutex);
    }
    pthread_exit(NULL);
}

int main(int argc, char *argv[])
{
    pthread_t producer_thread[PRODUCER_NUM];
    pthread_t consumer_thread[CONSUMER_NUM];
    int i;
    pthread_mutex_init(&mutex, NULL);
    pthread_cond_init(&full, NULL);
    pthread_cond_init(&empty, NULL);
    for (i = 0; i < PRODUCER_NUM; i++) {
        pthread_create(&producer_thread[i], NULL, producer, (void *)(long)i);
    }
    for (i = 0; i < CONSUMER_NUM; i++) {
        pthread_create(&consumer_thread[i], NULL, consumer, (void *)(long)i);
    }
    for (i = 0; i < PRODUCER_NUM; i++) {
        pthread_join(producer_thread[i], NULL);
    }
    for (i = 0; i < CONSUMER_NUM; i++) {
        pthread_join(consumer_thread[i], NULL);
    }
    pthread_mutex_destroy(&mutex);
    pthread_cond_destroy(&full);
    pthread_cond_destroy(&empty);
    return 0;
}

在这个代码中，我们使用了 pthread 库来创建生产者和消费者线程，并使用了互斥锁和条件变量来实现线程之间的同步和互斥。具体来说，我们使用了一个循环缓冲区来存放生产者生产的数据，当缓冲区满时，生产者线程会阻塞等待，直到有消费者线程取走数据并唤醒生产者线程。同样地，当缓冲区为空时，消费者线程会阻塞等待，直到有生产者线程存放数据并唤醒消费者线程。在实际应用中，我们可能需要根据具体情况来调整缓冲区大小和线程数量等参数，以满足实际需求。