#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/types.h>
#include <semaphore.h>
int n = 10, in = 0, out = 0, buffer[10];
sem_t empty, full,mutex_in,mutex_out,mutex_buf;
void *producer(void *arg)
{
    int tag = pthread_self() % 100;
    int nextPro;
    srand(time(NULL) + tag);
    while (1)
    {
        nextPro = rand() % 97;
        sem_wait(&empty);
        sem_wait(&mutex_in);
        buffer[in] = nextPro;
        printf("production:%d %d\n", nextPro, buffer[in]);
        in = (in + 1) % n;
        sem_post(&mutex_in);
        sem_post(&full);
        usleep(1000 * 1000 / 2);
    }
}
void *consumer(void *arg)
{
    int item;
    while (1)
    {
        sem_wait(&full);
        sem_wait(&mutex_out);
        item = buffer[out];
        sem_post(&empty);
        printf("consume:%d\n", buffer[out]);
        out = (out + 1) % n;
        sem_post(&mutex_out);
        usleep(1000 * 1000 / 10);
    }
}
int main()
{
    // 6个生产者和6个消费者
    pthread_t tid[12];
    //初始有10个缓冲区
    sem_init(&empty, 0, 10);
    sem_init(&full, 0, 0);
    sem_init(&mutex_in, 0, 1);
    sem_init(&mutex_out, 0, 1);
    for (size_t i = 0; i < 6; i++)
    {
        pthread_create(&tid[0], NULL, producer, NULL);
    }
    for (size_t i = 6; i < 12; i++)
    {
        pthread_create(&tid[i], NULL, consumer, NULL);
    }
    
    for (int i = 0; i < 7; i++)
        pthread_join(tid[i], NULL);
    printf("main is over\n");
}