基于生产者和消费者问题的总结

代码：

#include<stdio.h> #include<stdlib.h> #include<unistd.h> #include<pthread.h> #include<semaphore.h> #define PRODUCER_NUM 5 //生产者数目 #define CONSUMER_NUM 5 //消费者数目 #define POOL_SIZE 11 //缓冲池大小 int pool[POOL_SIZE]; //缓冲区 int head=0; //缓冲池读取指针 int rear=0; //缓冲池写入指针 sem_t room_sem; //同步信号信号量，表示缓冲区有可用空间 sem_t product_sem; //同步信号量，表示缓冲区有可用产品 pthread_mutex_t mutex; void producer_fun(void *arg) { while (1) { sleep(1); sem_wait(&room_sem); pthread_mutex_lock(&mutex); //生产者往缓冲池中写入数据 pool[rear] = 1; rear = (rear + 1) % POOL_SIZE; printf("producer %d write to pool ", (int)arg); printf("pool size is %d ",(rear-head+POOL_SIZE)%POOL_SIZE); pthread_mutex_unlock(&mutex); sem_post(&product_sem); } } void consumer_fun(void *arg) { while (1) { int data; sleep(10); sem_wait(&product_sem); pthread_mutex_lock(&mutex); //消费者从缓冲池读取数据 data = pool[head]; head = (head + 1) % POOL_SIZE; printf("consumer %d read from pool ", (int)arg); printf("pool size is %d ",(rear-head+POOL_SIZE)%POOL_SIZE); pthread_mutex_unlock(&mutex); sem_post(&room_sem); } } int main() { pthread_t producer_id[PRODUCER_NUM]; pthread_t consumer_id[CONSUMER_NUM]; pthread_mutex_init(&mutex, NULL); //初始化互斥量 int ret = sem_init(&room_sem, 0, POOL_SIZE-1); //初始化信号量room_sem为缓冲池大小 if (ret != 0) { printf("sem_init error"); exit(0); } ret = sem_init(&product_sem, 0, 0); //初始化信号量product_sem为0，开始时缓冲池中没有数据 if (ret != 0) { printf("sem_init error"); exit(0); } for (int i = 0; i < PRODUCER_NUM; i++) { //创建生产者线程 ret =pthread_create(&producer_id[i], NULL, producer_fun, (void*)i); if (ret != 0) { printf("producer_id error"); exit(0); } //创建消费者线程 ret = pthread_create(&consumer_id[i], NULL, consumer_fun, (void*)i); if (ret != 0) { printf("consumer_id error"); exit(0); } } for(int i=0;i<PRODUCER_NUM;i++) { pthread_join(producer_id[i],NULL); pthread_join(consumer_id[i],NULL); } exit(0); }