多线程卖票系统

#include <stdio.h>
#include <time.h>
#include <semaphore.h>

int ticket = 100;
sem_t sem;

void *sellticket(void *v)
{
	long num = (long)v;

	srand((unsigned int)time(NULL));
	
	while (1)
	{
		usleep(100000*(rand()%10+1));
		
		sem_wait(&sem);          // p操作
	
		if (0 == ticket)
		{
			printf ("票卖完了\n");
			sem_post(&sem);      // v操作
			break;
		}
		printf ("%ld号窗口卖了一张票，座位号：%d\n",num, ticket);
		ticket -= 1;
	
		sem_post(&sem);          // v操作
	}
}


int main(int argc, char **argv)
{
	
	int i;
	for(i = 0; i < 4; i++)
	{
		pthread_t thread;
		pthread_create(&thread, NULL, sellticket, (void*)(i+1));
		pthread_detach(thread);
	}

	sem_init(&sem, 0, 1);

	pthread_exit(NULL);
	
	return 0;
}