生产者消费者

实验课程：操作系统实验实验编号：实验名称：生产者消费者算法实验人员：年级专业学号姓名实验日期：上交日期：实 验 室：实验评价：实验成绩：评定日期：指导教师：一、目的和要求生产者消费者算法是操作系统中很重要的同步算法，通过本实验加深对互斥信号量和同步信号量的理解，掌握如何用信号量机制实现生产者消费者之间的同步算法。二、实验内容运用高级语言模拟实现生产者消费者算法，要求实现对缓冲池的互斥访问和生产者进程与消费者进程之间的同步，观察程序的运行情况并分析执行结果。三、实验环境1PC微机。2Windows 操作系统。3C/C+/VB开发集成环境。四、实验结果1. 程序源代码：生产者&消费者如下图：# include # include # include # include # include # include # include # include #define BUFFER_SIZE 5typedef int buffer_item;/semaphoressem_t empty, full, mutex;/bufferbuffer_item bufferBUFFER_SIZE;int in, out;/存储数据的结构体struct data int id; int opTime; int lastTime; int productId;/有限缓存插入-生产int insert_item(buffer_item item) /* insert item into buffer */ bufferout = item; out = (out + 1) % BUFFER_SIZE; return 0;/有限缓存删除-消费int remove_item(buffer_item *item) /* remove an object from buffer and then place it in item */ *item = bufferin; in = (in + 1) % BUFFER_SIZE; return 0; /生产者void *producer(void* param) int productId = (struct data*)param)-productId; int lastTime = (struct data*)param)-lastTime; int opTime = (struct data*)param)-opTime; int id = (struct data*)param)-id; free(param); sleep(opTime); sem_wait(&empty); sem_wait(&mutex); /* critical section */ /add a item insert_item(productId); sleep(lastTime); printf(Thread %d: Producer produce %dn, id, productId); sem_post(&mutex); sem_post(&full); pthread_exit(0);/消费者void *consumer(void* param) int lastTime = (struct data*)param)-lastTime; int opTime = (struct data*)param)-opTime; int id = (struct data*)param)-id; free(param); sleep(opTime); sem_wait(&full); sem_wait(&mutex); /* critical section */ /remove a item buffer_item item; remove_item(&item); sleep(lastTime); printf(Thread %d: Consumer consume %dn, id, item); sem_post(&mutex); sem_post(&empty); pthread_exit(0);int main() /pthread pthread_t tid; / the thread identifier pthread_attr_t attr; /set of thread attributes /* get the default attributes */ pthread_attr_init(&attr); /initial the semaphores sem_init(&mutex, 0, 1); sem_init(&empty, 0, BUFFER_SIZE); sem_init(&full, 0, 0); in = out = 0; int id = 0; while(scanf(%d, &id) != EOF) char role; /producer or consumer int opTime; /operating time int lastTime; /run time int productId; /product id scanf(%c%d%d, &role, &opTime, &lastTime); struct data* d = (struct data*)malloc(sizeof(struct data); d-id = id; d-opTime = opTime; d-lastTime = lastTime; if(role = P) scanf(%d, &productId); d-productId = productId; pthread_create(&tid, &attr, producer, d); else if(role = C) pthread_create(&tid, &attr, consumer, d); /释放信号量 sem_destroy(&mutex); sem_destroy(&empty); sem_destroy(&full); return 0;- 2实验报告。1（设计思路）&2（使用了几个信号量，每个信号量的作用）设置三个信号量：empty (以记录有多少空位)、full (以记录有多少满位)以及mutex (二进制信号量或互斥信号量，以保护对缓冲插入与删除的操作)当信号量empty为0的时候，此时有限缓存已满，生产者必须等待，当信号量full为0的时候，此时有限缓存为空，消费者无法进行消费，必须等待信号量mutex使得各个线程之间互斥，每次只允许一个线程进入临界区，一旦有线程进入自己的临界区，其余线程必须等待有限缓存区为循环队列，尾部插入新的产品，头部产品先被消耗（3）解决方法的整体流程：有多个进程：多个生产者进程和多个消费者进程共享一个初始为空、固定大小为n的缓存（缓冲区）。生产者的工作是制造