Question

我正在使用1 Producer和N Consumers，其中消费者的数量来自提示参数。

我面临的问题是：我的生产者线程在消费者结束之前就结束了。因此，制作人不会给消费者提供标志，而且它会永远陷入困境......

我的代码：

void* producerFunc(void* arg)
{
    while(n_insertions < N_PRODUCTS)
    {       
        sem_wait(&sem_postAvaliable);
        sem_wait(&mutex);
        x = produce_item();
        insert_buffer(x);
        sem_post(&mutex);
        sem_post(&sem_posTaken);
    }
    pthread_exit(NULL);
}

void* consumerFunc(void* arg)
{
    struct sConsumer* cons = (struct sConsumer*) arg;

    while(n_consumed < N_PRODUCTS)
    {   
        sem_wait(&sem_posTaken);//Here is where thread consumer get stuck.
//Because producer thread is finished and cant give a post in this semaphore.   
        sem_wait(&mutex);   
        remove_buffer();
        sem_post(&mutex);   
        sem_post(&sem_postAvaliable);
    }
    pthread_exit(NULL);
}

int main(int argc, char const *argv[])
{
    if(argc > 1)
    {
        int i, numConsumers = atoi(argv[1]);
        pthread_t tConsumers[numConsumers], producer;
        sem_init(&sem_posTaken, 0, 0);
        sem_init(&sem_postAvaliable, 0, Buffer_Size);
        sem_init(&mutex, 0, 1);

        for(i=0; i<numConsumers; i++)
        {
            struct sConsumer* cons = (struct sConsumer*) malloc(sizeof(*cons));
            cons->id = i;
            pthread_create(&tConsumers[i], NULL, consumerFunc, (void*) cons);
        }

        pthread_create(&producer, NULL, producerFunc, NULL);

        for(i=0; i<numConsumers; i++)
        {
            pthread_join(tConsumers[i], NULL);
        }
        pthread_join(producer, NULL);       

    }
    else
        printf("Por favor. Informe o número de consumidores\n");
    return 0;
}

我只测试了2个消费者并且已经发现了这个问题。我想要一些想法/提示如何解决它。也许是while循环？

消费者和制片人陷入困境

0 个答案: