#include <stdio.h>   
#include <stdlib.h>   
#include <pthread.h>   
#include <unistd.h>   
#include <sys/types.h>   
#include <semaphore.h>   
#include <time.h>    /* time() */
int n=10, in=0,out=0,buffer[10];
sem_t empty,full;
sem_t p_mutex,s_mutex;
void* producer(void *arg){
    int tag= pthread_self()%100;
    int nextPro;
    srand(time(NULL)+tag);
    while(1){
        nextPro = rand()%97;
        sem_wait(&p_mutex);
        sem_wait(&empty);
        buffer[in] = nextPro;
        printf("production:%d %d   %d\n",nextPro,buffer[in],in); 
        usleep(1000*1000/20);
        in = (in+1)%n;
        sem_post(&full);
        usleep(1000*1000/2);
        sem_post(&p_mutex);
    }
} 
void* consumer(void *arg)  {
    int item;
    while(1){
        sem_wait(&full);
        sem_wait(&s_mutex);
        item = buffer[out];
        sem_post(&empty);
        printf("consume:%d   %d\n",buffer[out],out);
        out = (out+1)%n;
        usleep(1000*1000/10);
        sem_post(&s_mutex);
    }
}
int main()  {  
	pthread_t tid[2];  
    //初始有10个缓冲区
    sem_init( &empty, 0,10);
    sem_init( &full, 0,0);
    sem_init(&p_mutex,0,1);
    sem_init(&s_mutex,0,1);
    for(int i=0;i<6;i++){
    pthread_create(&tid[i], NULL, producer, NULL);  
    }
    pthread_create(&tid[7], NULL, consumer, NULL);  
    pthread_create(&tid[8], NULL, consumer, NULL);  
    pthread_create(&tid[9], NULL, consumer, NULL);  
    pthread_create(&tid[10], NULL, consumer, NULL);  
    pthread_create(&tid[11], NULL, consumer, NULL);  
	for(int i = 0; i < 11; i++)  
		pthread_join(tid[i], NULL);      
	printf("main is over\n");
}