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


#define N_CONSUMER 3 //消費者數量
#define N_PRODUCER 2 //生產者數量
#define C_SLEEP 1 //控制 consumer 消費的節奏
#define P_SLEEP 1 //控制 producer 生產的節奏

pthread_t ctid[N_CONSUMER];//消費者執行緒陣列
pthread_t ptid[N_PRODUCER];//生產者執行緒陣列

pthread_cond_t notFull,notEmpty;//定義條件變數，notFull緩衝區不滿;notEmpty緩衝區不空
pthread_mutex_t buf = PTHREAD_MUTEX_INITIALIZER;//靜態分配互斥量，用於鎖住緩衝區
 


int begin = 0,end = 0, cnt = 0, max = 4;//從 begin 到 end(不含end) 代表產品，cnt 代表產品數量，max 代
                                          表庫房的容量，即最多生產多少產品

void * consumer(void * pidx)//consumer thread idx
{
        printf("consumer thread id %d\n",*((int *)pidx));
        while(1)
        {
 pthread_mutex_lock(&buf);
                while(cnt == 0){//當緩衝區空時
                        pthread_cond_wait(¬Empty,&buf);//阻塞並等待不空的訊號
                }
                printf("consume %d\n",begin);
                begin = (begin+1)%max;
                cnt--;
                pthread_mutex_unlock(&buf);
                sleep(C_SLEEP);
                pthread_cond_signal(¬Full);
        }
        pthread_exit((void *)0);
}

void * producer(void * pidx)//producer thread idx
{
        printf("producer thread id %d\n",*((int *)pidx));
        while(1)
        {
                pthread_mutex_lock(&buf);
                while(cnt == max){//當緩衝區滿時
                        pthread_cond_wait(¬Full,&buf);
                }
 pthread_mutex_lock(&buf);
                while(cnt == 0){//當緩衝區空時
                        pthread_cond_wait(¬Empty,&buf);//阻塞並等待不空的訊號
                }
                printf("consume %d\n",begin);
                begin = (begin+1)%max;
                cnt--;
                pthread_mutex_unlock(&buf);
                sleep(C_SLEEP);
                pthread_cond_signal(¬Full);
        }
        pthread_exit((void *)0);
}

void * producer(void * pidx)//producer thread idx
{
        printf("producer thread id %d\n",*((int *)pidx));
        while(1)
        {
                pthread_mutex_lock(&buf);
                while(cnt == max){//當緩衝區滿時
                        pthread_cond_wait(¬Full,&buf);
                }
int main()
{
        int i  = 0;
        for(i = 0; i < N_CONSUMER; i++)
        {
                int * j = (int *) malloc(sizeof(int));
                *j = i;
                if(pthread_create(&ctid[i],NULL,consumer,j) != 0)
                {
                        perror("create consumer failed\n");
                        exit(1);
                }
        }
        for(i = 0; i < N_PRODUCER; i++)
        {
                int * j = (int *) malloc(sizeof(int));
                *j = i;
                if(pthread_create(&ptid[i],NULL,producer,j) != 0)
                {
                        perror("create producer failed\n");
                        exit(1);
                }
        }
 while(1)
        {
                sleep(10);
        }
        return 0;
}