linux多线程--生产者消费者问题_u011412619的专栏

#include<stdio.h>
#include<pthread.h>
#define BUFFER_SIZE 8
struct prodcons {//缓冲区相关数据结构
int buffer[BUFFER_SIZE]; //实际数据存放的数组
pthread_mutex_t lock;//互斥体lock，用于对缓冲区的互斥操作
int readpos , writepos; //读写指针
pthread_cond_t notempty;//缓冲区非空的条件变量
pthread_cond_t notfull; //缓冲区未满的条件变量
};
/*初始化缓冲区结构*/
void init(struct prodcons * b){
pthread_mutex_init(&b->lock,NULL);
pthread_cond_init(&b->notempty,NULL);
pthread_cond_init(&b->notfull,NULL);
b->readpos=0;
b->writepos=0;
}
/*将产品放入缓冲区,这里是存入一个整数*/
void put(struct prodcons* b,int data){
pthread­_mutex_lock(&b->lock);
/*等待缓冲区未满*/
if((b->writepos+1)%BUFFER_SIZE==b->readpos){
pthread_cond_wait(&b->notfull,&b->lock) ;
}
/*写数据,并移动指针*/
b->buffer[b->writepos]=data;
b->writepos++;
if(b->writepos>= BUFFER_SIZE)b->writepos=0;
/*设置缓冲区非空的条件变量*/
pthread_cond_signal(&b->notempty);
pthread_mutex_unlock(&b->lock);
}
/*从缓冲区中取出整数*/
int get(struct prodcons *b){
int data;
pthread_mutex_lock(&b->lock);
/*等待缓冲区非空*/
if(b->writepos==b->readpos){
pthread_cond _wait(&b->notempty,&b->lock);
}
/*读数据,移动读指针*/
data=b->buffer[b->readpos];
b->readpos++;
if(b->readpos>=BUFFER_SIZE)b->readpos=0;
/*设置缓冲区未满的条件变量*/
Pthread_cond_signal(&b->notfull);
Pthread_mutex_unlock(&b->lock);
return data;
}
#define OVER (-1)
struct prodcons buffer;
void * producer(void *data){
int n;
for(n=0;n<10000;n++){
printf(“%d /n”,n) ;
put(&buffer,n);
}
put(&buffer,OVER);
return NULL;
}
void * consumer(void * data){
int d;
while(1){
d =get(&buffer);
if(d==OVER)break;
printf(“%d/n”,d) ;
}
return NULL;
}
int main(void){
pthread_t th_a,th_b;
void * retval;
init(&buffer);
/*创建生产者和消费者线程*/
Pthread_create(&th_a,NULL,producer,0);
Pthread_create(&th_b,NULL,consumer,0);
/*等待两个线程结束*/
Pthread_join(th_a,&retval);
Pthread_join(th_b,&retval);
return 0;
}
#include<stdio.h>
#include<pthread.h>
#define B