生产者消费者问题C语言

#include<stdio.h>
#include<pthread.h>
#include<stdlib.h>
#include<malloc.h> 
#include<time.h>
#include<semaphore.h>
#include<unistd.h>
 
#define N 4
int buf[N]={0};
int putin=0;
int takeout=0;
 
//时延函数 
void delay(int len){
    int i=rand()%len;
    int x;
    while(i>0){
        x=rand()%len;
        while(x>0){
            x--;
        }
        i--;
    }
}
//生产者 
void producer(){
    while(1){
        delay(50000);//模拟正在生产 
        int d=1+rand()%100;
        buf[putin]=d; //入库 
        printf("Put %d the buffer at %d.\n",d,putin);
        putin++;
        if(putin==N){   // 超出范围 
            putin=0;
        }
    }
}
//消费者 
void consumer(){
    while(1){
        delay(50000);//模拟活动 
        printf("Take out %d from the buffer at %d.\n",buf[takeout],takeout);
        buf[takeout]=-1; // 此处产品已取出 
        takeout++;
        if(takeout==N){ // 超出范围 
            takeout=0;
        }
    }
}
 
int main(){
    pthread_t manufacturer;
    pthread_t customer;
    //创建线程 
    pthread_create(&manufacturer,NULL,(void*)producer,NULL);
    pthread_create(&customer,NULL,(void*)consumer,NULL);
    //阻塞当前线程直至t1，t2执行结束 
    pthread_join(manufacturer,NULL);
    pthread_join(customer,NULL);
    

　　信号量

#include<stdio.h>
#include<pthread.h>
#include<stdlib.h>
#include<malloc.h> 
#include<time.h>
#include<semaphore.h>
#include<unistd.h>
 
/*semaphore 函数库 
设置 sem_t sign；
初始化 sem_init int sem_init(sem_t*sem,int pshared,int value) 类型，初值;
操作 sem_post：释放时+1，唤醒线程 
 sem_wait ：使用时-1为0调用 ，则线程停止 —原子操作，不能被中断
释放 sem_destory 
*/
#define N 4
int buf[N]={0};
int putin=0;
int takeout=0;
//设置信号量
sem_t unoccupied; //空位个数，满缓冲区时 ，其值0，阻止生产者存入商品
sem_t occupied; //产品个数 ，空 0，消费者取 
 
//时延函数 
void delay(int len){
    int i=rand()%len;
    int x;
    while(i>0){
        x=rand()%len;
        while(x>0){
            x--;
        }
        i--;
    }
}
//生产者 
void producer(){
    while(1){
        int d=1+rand()%100;
        delay(50000);//模拟正在生产 
         
        sem_wait(&unoccupied) ; //可用空位的信号量-1 
         
        buf[putin]=d; //入库 
        printf("Put %d the buffer at %d.\n",d,putin);
        putin++;
         
        if(putin==N){   // 超出范围 
            putin=0;
        }
        sem_post(&occupied) ; //可取数据的信号量+1 
    }
}
//消费者 
void consumer(){
    while(1){
        delay(50000);//模拟活动 
        sem_wait(&occupied) ; //可取空位的信号量-1 
         
        printf("Take out %d from the buffer at %d.\n",buf[takeout],takeout);
        buf[takeout]=-1; // 此处产品已取出 
        takeout++;
        if(takeout==N){ // 超出范围 
            takeout=0;
        }
        sem_post(&unoccupied) ; //可用空位的信号量+1 
    }
}
 
int main(){
     
    srand(time(NULL)) ; //初始化随机函数
      
    pthread_t manufacturer;
    pthread_t customer;
     
    //初始化信号量
    sem_init(&unoccupied,0,N) ;
    sem_init(&occupied,0,0) ;
     
    //创建线程 
    pthread_create(&manufacturer,NULL,(void*)producer,NULL);
    pthread_create(&customer,NULL,(void*)consumer,NULL);
    //阻塞当前线程直至t1，t2执行结束 
    pthread_join(manufacturer,NULL);
    pthread_join(customer,NULL);
     
    //撤销信号量 
    sem_destroy(&unoccupied) ;
    sem_destroy(&occupied) ;
     
     
}