linux生产者消费者代码

生产者消费者问题是一个经典的多线程问题，可以使用 Linux 中的 pthread 库来实现。下面是一个简单的生产者消费者代码示例:

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

#define BUFFER_SIZE 16
#define OVER (-1)

int buffer[BUFFER_SIZE];
int add = 0;
int rem = 0;
int num = 0;

pthread_mutex_t mutex;
pthread_cond_t wait_empty;
pthread_cond_t wait_full;

void *producer(void *data) {
    int i;
    for (i = 1; i <= 50; i++) {
        pthread_mutex_lock(&mutex);
        while (num == BUFFER_SIZE) {
            pthread_cond_wait(&wait_empty, &mutex);
        }
        buffer[add] = i;
        add = (add + 1) % BUFFER_SIZE;
        num++;
        pthread_cond_signal(&wait_full);
        pthread_mutex_unlock(&mutex);
    }
    pthread_mutex_lock(&mutex);
    while (num == BUFFER_SIZE) {
        pthread_cond_wait(&wait_empty, &mutex);
    }
    buffer[add] = OVER;
    add = (add + 1) % BUFFER_SIZE;
    num++;
    pthread_cond_signal(&wait_full);
    pthread_mutex_unlock(&mutex);
    return NULL;
}

void *consumer(void *data) {
    int i;
    while (1) {
        pthread_mutex_lock(&mutex);
        while (num == 0) {
            pthread_cond_wait(&wait_full, &mutex);
        }
        i = buffer[rem];
        rem = (rem + 1) % BUFFER_SIZE;
        num--;
        pthread_cond_signal(&wait_empty);
        pthread_mutex_unlock(&mutex);
        if (i == OVER) {
            break;
        }
        printf("%d\n", i);
    }
    return NULL;
}

int main() {
    pthread_t th_a, th_b;
    pthread_mutex_init(&mutex, NULL);
    pthread_cond_init(&wait_empty, NULL);
    pthread_cond_init(&wait_full, NULL);
    pthread_create(&th_a, NULL, producer, 0);
    pthread_create(&th_b, NULL, consumer, 0);
    pthread_join(th_a, NULL);
    pthread_join(th_b, NULL);
    pthread_cond_destroy(&wait_empty);
    pthread_cond_destroy(&wait_full);
    pthread这是一个简单的生产者消费者问题的 C 程序示例，使用了 Linux 中的 pthread 库来实现多线程。代码中定义了一个缓冲区 buffer，生产者线程将数据放入缓冲区，消费者线程从缓冲区中取出数据。使用了互斥锁和条件变量来保证线程间的同步和通信。