火车票售票系统

  1 #include<stdio.h>
  2 #include<pthread.h>
  3 #include<string.h>
  4 #include<stdlib.h>
  5 
  6 typedef struct tag {
  7     int ticketcount;
  8     pthread_mutex_t lock;
  9     pthread_cond_t cond1,cond2;    //cond1 putter 补票 cond2 seller 
 10 }NODE,*pNODE;
 11 
 12 
 13 void* sale(void* arg)
 14 {
 15     pNODE p = (pNODE)arg;
 16 
 17     while(1){
 18         pthread_mutex_lock(&p->lock);
 19         while(p->ticketcount <= 0)    //not if  用if卖票会有负值
 20         {
 21             pthread_cond_signal(&p->cond2);
 22 
 23             pthread_cond_wait(&p->cond1,&p->lock);
 24         }
 25         printf("%d sell %d\n",getpid(),p->ticketcount);
 26         p->ticketcount--;
 27         pthread_mutex_unlock(&p->lock);        
 28     }
 29 }
 30 
 31 void* putter(void* arg)
 32 {
 33     pNODE p = (pNODE)arg;
 34     while(1){
 35         pthread_mutex_lock(&p->lock);
 36         while(p->ticketcount > 0){
 37             pthread_cond_wait(&p->cond2,&p->lock);
 38             pthread_cond_signal(&p->cond1);
 39         }
 40         p->ticketcount += 10;
 41         printf("tickets on\n");
 42         sleep(1);
 43         pthread_mutex_unlock(&p->lock);
 44     }
 45 
 46 }
 47 
 48 
 49 int main(int argc,char* argv[])//m seller ,n putter 通过命令行传入m个售票员，n个补票员
 50 {
 51     if(argc!=3)
 52     {
 53         printf("wrong argv!\n");
 54         exit(1);
 55     }
 56     int m = atoi(argv[1]);
 57     int n = atoi(argv[2]);
 58     pthread_t arr[m+n];
 59     memset(arr,0,sizeof(arr));
 60     NODE anode;
 61     memset(&anode,0,sizeof(anode));
　　　　 //初始化锁
 62     if(pthread_mutex_init(&anode.lock, NULL)!=0)
 63     {
 64         printf("mutex_init fail!\n");
 65         exit(1);
 66     }
 67     anode.ticketcount = 0;
 68     //初始化条件变量
 69     if(pthread_cond_init(&anode.cond1,NULL))
 70     {
 71         printf("cond_init fail!\n");
 72         exit(1);
 73     }
 74     
 75     if(pthread_cond_init(&anode.cond2,NULL))
 76     {
 77         printf("cond_init fail!\n");
 78         exit(1);
 79     }
 80 
 81     int index = 0;
 82     //创建m个售票线程
 83     while(m){
 84         if(pthread_create(&arr[index],NULL,sale,(void*)&anode)!=0)
 85         {
 86             printf("pthread_create sale fail!\n");
 87             exit(1);
 88         }
 89             m--;
 90         index++;
 91     }
　　　　//　创建n个补票线程
 92     while(n){
 93         if(pthread_create(&arr[index],NULL,putter,(void*)&anode)!=0){
 94         printf("pthread_create putter fail\n");
 95         exit(1);
 96         }
 97         n--;
 98         index++;
 99     }
100 
101     index--;
102 　　//由于程序是死循环，下面不会执行
103     while(index)
104     {
105         pthread_join(arr[index],NULL);
106         index--;
107     }
108 
109 
110 
111     pthread_cond_destroy(&anode.cond1);
112     pthread_cond_destroy(&anode.cond2);
113     return 0;
114 }