多线程同步方法解决生产者-消费者问题(linux线程实现)

#include <stdlib.h> #include <pthread.h> #include <stdio.h> #include <semaphore.h> #include<time.h> #define NUM 20 int queue[NUM]; int p = 0,c = 0;//记录动态数组下标位置 sem_t blank_number, product_number; pthread_mutex_t counter_mutex = PTHREAD_MUTEX_INITIALIZER; //生产者函数 void *producer(const int i) { int j; time_t t; srand((unsigned) time(&t));//初始化随机数种子 while(1) { sem_wait(&blank_number); pthread_mutex_lock(&counter_mutex); sleep(2); queue[p]=rand()%NUM+1;//1到20随机数 pthread_mutex_unlock(&counter_mutex); sem_post(&product_number); printf("生产者 %d 号的线程标识符: %u ,",i+1,((unsigned int)pthread_self())); printf("生产出 %d\n",queue[p]); printf("缓冲区当前状态：**********************************\n"); printf("编号:"); for(j = 0;j <NUM;j ++) { printf("%4d",j+1); } printf("\n数值:"); for(j = 0;j < NUM;j ++) { printf("%4d",queue[j]); } printf("\n指针:"); for(j = 0;j < NUM;j++) { if(j != p) printf(" "); else printf(" ↑"); } printf("\n"); p=(p + 1)%NUM;//p后移一位 sleep(rand() % 5);//随机阻塞0-4秒 } return NULL; } //生产线程入口函数 void *producer_thread_fun(void *arg) { int realarg = (int)arg;//强制类型转换参数 producer(realarg); return NULL; } //消费者函数 void *consumer(const int i) { int j; time_t t; srand((unsigned) time(&t)); while(1) { sem_wait(&product_number); pthread_mutex_lock(&counter_mutex); sleep(2); printf("消费者 %d 号的线程标识符: %u ,",i+1,((unsigned int)pthread_self())); printf("消费了 %d\n",queue[c]); queue[c] = 0;//空位置 0 填充 pthread_mutex_unlock(&counter_mutex); sem_post(&blank_number); printf("缓冲区当前状态：**********************************\n"); printf("编号:"); for(j = 0;j <NUM;j ++) { printf("%4d",j+1); } printf("\n数值:"); for(j = 0;j < NUM;j ++) { printf("%4d",queue[j]); } printf("\n指针:"); for(j = 0;j < NUM;j++) { if(j != c) printf(" "); else printf(" ▲"); } printf("\n"); c = (c + 1)%NUM; sleep(rand() % 5); } } //消费线程入口函数 void *consumer_thread_fun(void *arg) { int realarg = (int)arg; consumer(realarg); return NULL; } //MAIN int main(int argc, char *argv[]) { int i; pthread_t pid[100],cid[100]; int producer_num,consumer_num; printf("********多进程同步解决生产者--消费者问题********\n"); printf("************************************************\n"); sleep(1); for(i = 0;i < NUM;i ++)//初始化缓冲区 { queue[i] = 0; } printf("请输入生产者数量:"); scanf("%d",&producer_num); while(producer_num > 100 ||producer_num < 1) { printf("生产者数量必须在1--100之间\n"); printf("请重新输入:"); scanf("%d",&producer_num); } printf("请输入消费者数量:"); scanf("%d",&consumer_num); while(consumer_num > 100 ||consumer_num < 1) { printf("消费者数量必须在1--100之间\n"); printf("请重新输入:"); scanf("%d",&consumer_num); } for(i = 0;i < producer_num;i ++) { pthread_t pid[i]; } for(i = 0;i < consumer_num;i ++) { pthread_t cid[i]; } //初始化semaphore ;pshared参数为0表示信号量用于同一进程的线程间同步 sem_init(&blank_number, 0, NUM); sem_init(&product_number, 0, 0); for(i = 0;i < producer_num;i ++)//创建线程 { pthread_create(&pid[0]+i, NULL, producer_thread_fun, (void *)i);//i强制将i转换为void*类型，便于传参 } for(i = 0;i < consumer_num;i ++) { pthread_create(&cid[0]+i, NULL, consumer_thread_fun, (void *)i); } for(i = 0;i < producer_num;i ++)//主线程等待所有线程撤销 { pthread_join(pid[i], NULL); } for(i = 0;i < consumer_num;i ++) { pthread_join(cid[i], NULL); } sem_destroy(&blank_number);//释放semaphore资源 sem_destroy(&product_number); return 0; }